Janus Kinase Antagonists and Other Novel Small Molecules for the Treatment of Crohn's Disease

Tofacitinib for Refractory Uveitis and Scleritis in Children: A Case Series

PURPOSE

This study analyzes the efficacy and safety of tofacitinib in pediatric patients presenting with treatment-resistant uveitis and scleritis.

METHOD

Retrospective Chart Review.

RESULT

Nine children diagnosed with uveitis and one with scleritis received oral tofacitinib treatment. The median age of these patients was 9 years, with bilateral involvement observed in nine of them. Juvenile idiopathic arthritis was the most identifiable cause of uveitis, with anterior uveitis (50%) being the most frequent subtype of inflammation among these children. The median duration of immunosuppressive treatment before switching to tofacitinib was 18 (16-49) months. Remission of uveitis was achieved in all but two children, who experienced recurrence - manifesting as anterior uveitis. The median duration of follow-up in these children after tofacitinib treatment was 277.5 (183-549) days. At the end of follow-up, topical steroids could be withdrawn in six children, and two children were on topical steroids once a day. None of the children developed any systemic side-effect during the follow-up period. The mean BCVA at presentation was 0.62 ± 0.55, which improved to a mean of 0.27 ± 0.325 at the final follow-up (p = 0.0014).

CONCLUSION

Treatment of pediatric uveitis with tofacitinib can be a valuable second-line treatment option and useful alternative in low- and middle-income countries.

Hematopoietic stem cell transplantation therapy for refractory' Crohn disease: A systematic review and meta-analysis

BACKGROUND

Despite the availability of numerous treatments for Crohn disease, there are patients who do not respond to any therapy, thereby diminishing their quality of life. The aim of this review is to analyze the efficacy and safety of autologous hematopoietic stem cell transplantation therapy for refractory Crohn disease.

METHODS

This work is a systematic review with meta-analysis conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analyses. Electronic databases such as PubMed, Scopus, Web of Science, and ClinicalTrials were consulted. The searches were carried out in August 2024. To evaluate the efficacy of autologous hematopoietic stem cell transplantation in inducing remission, the mean and standard deviation of the Crohn's Disease Activity Index pre- and post- treatment were used, and a fixed-effects meta-analysis was conducted. Additionally, to assess the efficacy in perianal fistulas, a random-effects meta-analysis was performed, collecting data on the number of subjects with fistulas at the beginning and end of the intervention. All 95% confidence intervals were calculated, and the I2 statistic was used to assess the heterogeneity of the outcome variables.

RESULTS

A total of 609 records were identified from databases, with 12 studies selected for inclusion in the review. Immediate intervention proved effective in inducing a decrease in the Crohn Disease Activity Index compared to late intervention with conventional therapies. Moreover, the meta-analysis demonstrated efficacy for Crohn disease and associated fistulas with a mean decrease in the CDAI of -217.53 ± 14.3. When evaluating the efficacy of the procedure in perianal fistulas, a risk ratio of 0.47 with a 95% CI of [0.26, 0.86] was obtained. However, the procedure showed adverse effects, such as infections, acute renal failure or deaths.

CONCLUSION

Systemic autologous hematopoietic stem cell transplantation has shown efficacy in patients who fail to achieve remission of their Crohn disease with conventional therapies. This procedure has also demonstrated efficacy in treating perianal fistulas. However, it is essential to carefully evaluate de implementation of this procedure due to the associated risks.

Tofacitinib and peficitinib inhibitors of Janus kinase for autoimmune disease treatment: a quantum biochemistry approach

Autoimmune inflammatory diseases, such as rheumatoid arthritis (RA) and ulcerative colitis, are associated with an uncontrolled production of cytokines leading to the pronounced inflammatory response of these disorders. Their therapy is currently focused on the inhibition of cytokine receptors, such as the Janus kinase (JAK) protein family. Tofacitinib and peficitinib are JAK inhibitors that have been recently approved to treat rheumatoid arthritis. In this study, an in-depth analysis was carried out through quantum biochemistry to understand the interactions involved in the complexes formed by JAK1 and tofacitinib or peficitinib. Computational analyses provided new insights into the binding mechanisms between tofacitinib or peficitinib and JAK1. The essential amino acid residues that support the complex are also identified and reported. Additionally, we report new interactions, such as van der Waals; hydrogen bonds; and alkyl, pi-alkyl, and pi-sulfur forces, that stabilize the complexes. The computational results revealed that peficitinib presents a similar affinity to JAK1 compared to tofacitinib based on their interaction energies.

The Complex Relationship between Mechanisms Underlying Inflammatory Bowel Disease, Its Treatment, and the Risk of Lymphomas: A Comprehensive Review

Patients with inflammatory bowel disease may be at higher risk of developing lymphomas and other cancers of the gastrointestinal tract. In addition, there may be a link between the use of thiopurines or anti-tumor necrosis factor drugs (anti-TNF) and these pathologies. The treatment of patients with Crohn's disease who have previously been diagnosed with lymphoma is a challenge for gastroenterologists. In this report, we examine important clinical issues related to the treatment of patients with inflammatory bowel disease with active lymphoma, as well as of patients with hematological cancer history. In this discussion, we take into account most of the available treatments for inflammatory bowel disease, as well as the impact of chronic inflammation and viral infections. In addition, we try to find common ground for the development of lymphoproliferative disorders and autoimmune diseases. Patients with inflammatory bowel disease may be at higher risk of developing lymphomas and other cancers of the gastrointestinal tract. Chronic inflammatory processes and viral infections play an important role in carcinogenesis. In addition, there may be a link between the use of thiopurines or anti-TNF drugs and these pathologies. A significant risk of the development of lymphoma in people undergoing each therapy should be considered, and it should be estimated how much greater this risk will be in patients with a history of lymphoproliferative disorders. The following review is an attempt to answer which therapy would be the most appropriate for patients with Crohn's disease and a history of lymphoma treatment. A lack of clear guidelines creates great challenges for doctors.

Breaking through the therapeutic ceiling of inflammatory bowel disease: Dual-targeted therapies

Emerging biologics and small-molecule drugs have changed the clinical status quo of inflammatory bowel disease (IBD). However, current treatments remain at a standstill in terms of response and remission in many cases. Accumulating evidence indicates that dual-targeted therapy (DTT) could be promising in overcoming the existing ceiling of IBD treatment. However, data on the efficacy and safety of DTT on Crohn's disease and ulcerative colitis are still limited or insufficient. Moreover, there is a lack of studies delineating the mechanisms of DTT. Given that various targeted drugs have different targets among the extensive redundant inflammatory networks, DTT could result in various outcomes. In this review, we have summarized the current data on the safety, effectiveness, and clinical development status of novel targeted drugs related to refractory IBD, and have explored the mechanism of action of therapy. We have categorized therapeutic agents into "Therapeutic Agents Targeting Cellular Signaling Pathways" and "Therapeutic Agents Targeting Leukocyte Trafficking" based on the different therapeutic targets, and also by classifying therapeutic agents targeting the cellular signaling pathways into "JAK-dependent" and "JAK-independent," and placed the existing drug combinations into 3 categories based on their mechanisms, namely, overlapping, synergistic, and complementary effects. Lastly, we have proposed the possible mechanisms of DTT to conceive a theoretical framework for clinical decision-making and further drug development and research from an IBD standpoint.

The Role of Tissue-Resident Macrophages in the Development and Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), comprising Crohn’s disease and ulcerative colitis, is a refractory disease with many immune abnormalities and pathologies in the gastrointestinal tract. Because macrophages can distinguish innocuous antigens from potential pathogens to maintain mucosa barrier functions, they are essential cells in the intestinal immune system. With numerous numbers in the intestinal tract, tissue-resident macrophages have a significant effect on the constant regeneration of intestinal epithelial cells and maintaining the immune homeostasis of the intestinal mucosa. They also have a significant influence on IBD through regulating pro-(M1) or anti-inflammatory (M2) phenotype polarization according to different environmental cues. The disequilibrium of the phenotypes and functions of macrophages, disturbed by intracellular or extracellular stimuli, influences the progression of disease. Further investigation of macrophages’ role in the progression of IBD will facilitate deciphering the pathogenesis of disease and exploring novel targets to develop novel medications. In this review, we shed light on the origin and maintenance of intestinal macrophages, as well as the role of macrophages in the occurrence and development of IBD. In addition, we summarize the interaction between gut microbiota and intestinal macrophages, and the role of the macrophage-derived exosome. Furthermore, we discuss the molecular and cellular mechanisms participating in the polarization and functions of gut macrophages, the potential targeted strategies, and current clinical trials for IBD.

Selective tyrosine kinase 2 inhibitors in inflammatory bowel disease

Recent significant advances have been made in the treatment of chronic inflammatory diseases with initiation of the era of biologics. However, an unmet medical need still exists for novel targeted therapies. Compared with biologics, Janus kinase inhibitors (JAKis) are a new drug class of orally administered small molecules that have been shown to efficiently modulate complex cytokine-driven inflammation in preclinical models and human studies. Unfortunately, serious adverse effects have been reported with the first introduced pan-JAKi, tofacitinib. Here, we review tyrosine kinase 2 (TYK2) signaling in the pathophysiology of inflammatory bowel disease (IBD), examine mechanisms of action of selective TYK2 inhibitors (TYK2is), and discuss the potential for these inhibitors in efforts to balance benefits and harms.

Clinical and Mechanistic Characteristics of Current JAK Inhibitors in IBD

Crohn's disease (CD) and ulcerative colitis (UC) are chronic, immune-mediated diseases of the gastrointestinal (GI) tract. Their etiology is complex and involves immune (eg, cytokines) and nonimmune (eg, environment) mediated contributions, causing inflammatory damage to the GI tract. Though cytokines contribute a major role in the inflammatory process of both CD and UC, there are some key differences in which cytokines are involved in the pathobiology of CD and UC. Over the past several years, new biologic-directed therapies have focused on controlling specific aspects of inflammation associated with both conditions. Although these treatments have benefited patients overall, approximately 30% of patients still do not respond to induction (initial) therapy, and up to 50% of patients lose response to treatment over a year. Many of these therapies are administered parenterally and have been associated with adverse events such as serious infections or malignancy. Therefore, there is a significant unmet medical need for these patients to minimize symptoms and promote GI healing. There are several therapeutic agents in the pipeline, including oral, small molecules, which hold much promise. One group of small molecules known as Janus kinase (JAK) inhibitors offers an additional option for treatment of chronic inflammatory conditions, based on currently available data. The article will focus on the potential benefits of JAK inhibitors as oral, small molecules, such as the potential role of selectivity, and potential risks.

Implications of lymphatic alterations in the pathogenesis and treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by intense immune dysregulation, gut microbiota imbalance, and intestinal epithelium destruction. Among the factors that contribute to the pathogenesis of IBD, lymphatics have received less attention, hence less studied, characterized, and explored. However, in recent years, the role of the lymphatic system in gastrointestinal pathophysiology continues to be highlighted. This paper examines the implications of lymphatic changes in IBD pathogenesis related to immune cells, gut microbiota, intestinal and mesenteric epithelial barrier integrity, and progression to colorectal cancer (CRC). Therapeutic targets of lymphatics in IBD studies are also presented. Available studies indicate that lymph nodes and other secondary lymphatic tissues, provide highly specialized microenvironments for mounting effective immune responses and that lymphatic integrity plays a significant role in small intestine homeostasis, where the lymphatic vasculature effectively controls tissue edema, leukocyte exit, bacterial antigen, and inflammatory chemokine clearance. In IBD, there are functional and morphological alterations in intestinal and mesenteric lymphatic vessels (more profoundly in Crohn's disease [CD] compared to ulcerative colitis [UC]), including lymphangiogenesis, lymphangiectasia, lymphadenopathy, and lymphatic vasculature blockade, affecting not only immunity but gut microbiota and epithelial barrier integrity. While increased lymphangiogenesis is primarily associated with a good prognosis of IBD, increased lymphangiectasia, lymphadenopathy, and lymphatic vessel occlusion correlate with poor prognosis. IBD therapies that target the lymphatic system seek to increase lymphangiogenesis via induction of lymphangiogenic factors and inhibition of its antagonists. The resultant increased lymphatic flow coupled with other anti-inflammatory activities restores gut homeostasis.

JAK selectivity: more precision less troubles

INTRODUCTION

Janus kinases inhibitors (JAKi) are new small molecules recently introduced in the armamentarium of treatments for Inflammatory Bowel Disease (IBD). Janus Kinases (JAK) are tyrosine kinases that act by linkage with different intracellular receptors, regulating cytokines gene transcription implicated in the inflammatory burden seen in IBD patients.

AREAS COVERED

A comprehensive literature search was performed to retrieve studies on JAKi and IBD to discuss the latest developments and how the selectivity of these drugs is changing the natural course of IBD.

EXPERT OPINION

Available data on efficacy and safety of JAKi in IBD are highly encouraging and because of their selectivity, these drugs might become among the foremost options in the treatment algorithm.

Clinical Pharmacology of Janus Kinase Inhibitors in Inflammatory Bowel Disease

Inflammatory bowel disease, including ulcerative colitis and Crohn's disease, are chronic inflammatory disorders of the gastrointestinal tract which are characterised, in part, by an imbalance in the production of several pro- and anti-inflammatory cytokines. Although various agents are effective for inducing and maintaining remission, approximately 20% of patients are treatment-refractory and require surgery. Parenterally administered monoclonal antibody-based biologics are associated with adverse effects resulting in treatment discontinuation and/or immunogenicity, leading to loss of response to therapy. Approximately 50% of patients who initially respond to treatment with tumour necrosis factor antagonists lose response to therapy within the 1st year of treatment. Incidence of immunogenicity tends to decrease over time, but once present can persist for years, even after treatment discontinuation. Nonimmunogenic oral small molecule therapies, including Janus kinase inhibitors, are currently being developed and have demonstrated efficacy in early phase clinical trials, which has already led to regulatory approval of tofacitinib for the treatment of patients with moderate-to-severe ulcerative colitis. Differentiation of T cells into T helper cells, which are mediators of the inflammatory response in inflammatory bowel disease, is mediated by the Janus kinase signal transducer and activator of the transcription signalling pathway. Absorption and distribution of Janus kinase inhibitors occurs at the site of action in the gastrointestinal tract, and newer compounds are being developed with limited systemic absorption, potentially reducing the risk of adverse effects. The current review describes the clinical pharmacology of approved Janus kinase inhibitors, as well as those in clinical development for the treatment of inflammatory bowel disease.

JAK-inhibitors. New players in the field of immune-mediated diseases, beyond rheumatoid arthritis

Janus kinase (JAK)/signal transducers and activators of transcription (STATs) are a group of molecules associated with one of the major pathways through which many cytokines exert and integrate their function, and as such they are increasingly recognized as playing critical role in the pathogenesis subserving various immune-mediated diseases, including RA, PsA, SpAs, IBD, skin disorders (e.g. alopecia areata, atopic dermatitis), single-gene disorders like interferonopathies, and others. JAKs are the key initiating players of the JAK/STAT pathway. Upon binding of their respective effector molecules (cytokines, IFNs, growth factors and others) to type I and type II receptors, JAKs are activated, and through phosphorylation of themselves and of other molecules (including STATs), they mediate signal transduction to the nucleus. A class of drugs—called JAK inhibitors or JAKinibs—that block one or more JAKs has been developed in the last decade, and now numbers >20 members. Although, so far, JAK inhibitors have been marketed only for RA and PsA, these drugs have been tested in phase 2 and phase 3 clinical trials for other inflammatory conditions and beyond. In this review, we summarize the clinical data, including efficacy and safety, available for JAK inhibitors used in some immune-mediated conditions other than RA.

Thalidomide Prevented and Ameliorated Pathogenesis of Crohn's Disease in Mice via Regulation of Inflammatory Response and Fibrosis

Crohn's disease (CD) is a chronic, relapsing form of inflammatory bowel disease, seriously threatening human health. Thalidomide has been used for the treatment of CD. However, the effects and the possible mechanisms of thalidomide on CD are still unclear. Herein, our study demonstrated that thalidomide protected colon mucosa against trinitro-benzene-sulfonic acid (TNBS)-induced injury, diminished inflammatory infiltration and levels of IFN-γ, IGF-1, IL-6, IL-17, TNF-α, while increased the levels of IL-10 and TGF-γ. Moreover, it reversed the intestinal fibrosis and inhibited the accumulated infiltration, down-regulated the expression of col1a2, col3a2, MMP-3, MMP-9, MMP-1, TGF-γ, α-SMA, but up-regulated the expression of TIMP-1 and Vimentin. Although it could be observed that the effect of thalidomide administration in modeling was better than after modeling, there was no statistical difference between the two groups. The present study provided evidence that the therapeutic effect of thalidomide alleviated the inflammatory response and damage of colon tissue, mainly by restoring the imbalance of TH17/Treg cells and inhibiting intestinal fibrosis in TNBS-induced mice colitis.

Mechanism-Based Treatment Strategies for IBD: Cytokines, Cell Adhesion Molecules, JAK Inhibitors, Gut Flora, and More

BACKGROUND

Although TNF inhibitors revolutionized the therapy of inflammatory bowel disease (IBD), we have been reaching a point where other therapies with different mechanisms of action are necessary. A rising number of elderly IBD patients with contraindications to established therapies and a growing group of patients losing response to anti-TNF therapy compel us to find safer, better-tolerated, and, ideally, personalized treatment options. However, in order to choose the right drug to fit a patient, it is indispensable to understand the pathomechanism involved in IBD.

SUMMARY

The aim of this review is to explain the inflammatory signaling pathways in IBD and how to inhibit them with current and future therapeutic approaches. Next to biologic agents targeting inflammatory cytokines (anti-TNF agents, anti-IL-12/-23 agents, and specific inhibitors of IL-23), biologics blocking leukocyte trafficking to the gut (anti-integrin antibodies) are available nowadays. More recently, small molecules inhibiting the JAK-STAT pathway (JAK inhibitors) or preventing lymphocyte trafficking (sphingosine-1-phosphate modulators) have been approved or are under investigation. Furthermore, modifying the microbiota has potential therapeutic effects on IBD, and autologous hematopoietic or mesenchymal stem cell transplantation may be considered for a highly selected group of IBD patients.

KEY MESSAGE

Physicians should understand the different mechanisms of action of the potential therapies for IBD to select the right drug for the right patient.

The use of Tofacitinib in the treatment of inflammatory bowel disease

Major advances in pharmacology of the 21st century include the development of a new class of drugs, which are low-molecular, chemically synthesized molecules (the so-called "small molecules"), the point of application of which is Janus kinase (Janus kinase, JAK) involved in intracellular cytokine signaling. The review examines the molecular aspects of the JAK-STAT signaling pathway, justifying the use of the JAK-kinase inhibitor (tofacitinib) in the treatment of inflammatory bowel disease.

New biologics and small molecules in inflammatory bowel disease: an update

Inflammatory bowel disease (IBD) is a spectrum of immune-mediated inflammatory disorders with a complex multifactorial pathogenesis, where different pathways may predominate in different individuals. This complexity will most likely require a panoply of drugs targeting different pathways if one wants to treat to steroid-free sustained remission and mucosal healing. Presently, the mainstay of medical management of IBD is based on 5-aminosalicylates, corticosteroids, thiopurines, methotrexate, antitumor necrosis factor, anti-alpha4 beta7 (α4β7) integrin and anti-interleukin (IL)-12/IL-23 therapies. The discovery of new pathways involved in the pathogenesis of IBD resulted in new drugs targeting Janus kinase/signal transducers and activators of transcription, IL-6, spingosine-1-phosphate, and phosphodiesterase 4, among others. These new therapies might result in more advantageous safety profiles. Several of these new drugs have already been successfully tested in other inflammatory disorders, such as psoriasis or rheumatoid arthritis. In this review, evidence from phase II and phase III randomized controlled clinical trials in patients with IBD involving new biologicals and small molecules are summarized.

Targeting Cytokine Signaling and Lymphocyte Traffic via Small Molecules in Inflammatory Bowel Disease: JAK Inhibitors and S1PR Agonists

The inflammatory Bowel diseases (IBDs) are a chronic, relapsing inflammatory diseases of the gastrointestinal tract with heterogeneous behavior and prognosis. The introduction of biological therapies including anti-TNF, anti-IL-12/23, and anti-integrins, has revolutionized the treatment of IBD, but these drugs are not universally effective. Due to the complex molecular structures of biologics, they are uniformly immunogenic. New discoveries concerning the underlying mechanisms involved in the pathogenesis of IBD have allowed for progress in the development of new treatment options. The advantage of small molecules (SMs) over biological therapies includes their lack of immunogenicity, short half-life, oral administration, and low manufacturing cost. Among these, the Janus Kinases (JAKs) inhibition has emerged as a novel strategy to modulate downstream cytokine signaling during immune-mediated diseases. These drugs target various cytokine signaling pathways that participate in the pathogenesis of IBD. Tofacitinib, a JAK inhibitor targeting predominantly JAK1 and JAK3, has been approved for the treatment of ulcerative colitis (UC), and there are other specific JAK inhibitors under development that may be effective in Crohn's. Similarly, the traffic of lymphocytes can now be targeted by another SM. Sphingosine-1-phosphate receptor (S1PR) agonism is a novel strategy that acts, in part, by interfering with lymphocyte recirculation, through blockade of lymphocyte egress from lymph nodes. S1PR agonists are being studied in IBD and other immune-mediated disorders. This review will focus on SM drugs approved and under development, including JAK inhibitors (tofacitinib, filgotinib, upadacitinib, peficitinib) and S1PR agonists (KRP-203, fingolimod, ozanimod, etrasimod, amiselimod), and their mechanism of action.

Clinical Pharmacology in Adult and Pediatric Inflammatory Bowel Disease

This review describes the clinical pharmacology of the major drugs used for the treatment of patients with inflammatory bowel disease (IBD). Pharmacokinetics, drug metabolism, mechanism of action, efficacy, and safety profile are discussed. Some small molecules were developed to act systemically (eg, ozanimod) or locally (eg, aminosalicylates) and thus have disparate pharmacokinetic properties. In addition, locally acting compounds have been optimized to mitigate systemic exposure-eg, budesonide, which undergoes extensive first-pass metabolism-thereby reducing systemic bioavailability and side effects. Other small molecules such as thiopurines are precursors of their active metabolites and differences in genotype or phenotype of metabolizing enzymes may affect efficacy and safety, requiring therapeutic drug monitoring (TDM). Monoclonal antibodies (MAs) are large molecules administered parenterally, and their pharmacokinetics may be influenced not only by the general immunoglobulin (Ig) G metabolism and recycling pathways but also by antigen properties such as antigen distribution and antigen concentration. In addition, antibody structure, host factors, concurrent medications, and immunogenicity may contribute to the substantial inter- and intrapatient variability in drug exposure and response observed for MAs. Current guidelines recommend reactive TDM of tumor necrosis factor antagonists at the time of loss of response. Evidence for proactive TDM and for the role of TDM for biologics with a different mechanism of action is emerging. Although small molecules offer potential benefits over biologics with oral administration and lack of immunogenicity, there may be risk for more systemic side effects due to off-target binding. Understanding drug metabolism, pharmacokinetic characteristics, and mechanism of action are important in selecting the right drug at the right time at the right dose for patients with IBD.10.1093/ibd/izy189_video1izy189.video15786062223001.

Total flavone of Abelmoschus manihot suppresses epithelial-mesenchymal transition via interfering transforming growth factor-β1 signaling in Crohn's disease intestinal fibrosis

AIM

To explore the role and mechanism of total flavone of Abelmoschus manihot (TFA) on epithelial-mesenchymal transition (EMT) progress of Crohn's disease (CD) intestinal fibrosis.

METHODS

First, CCK-8 assay was performed to assess TFA on the viability of intestinal epithelial (IEC-6) cells and select the optimal concentrations of TFA for our further studies. Then cell morphology, wound healing and transwell assays were performed to examine the effect of TFA on morphology, migration and invasion of IEC-6 cells treated with TGF-β1. In addition, immunofluorescence, real-time PCR analysis (qRT-PCR) and western blotting assays were carried out to detect the impact of TFA on EMT progress. Moreover, western blotting assay was performed to evaluate the function of TFA on the Smad and MAPK signaling pathways. Further, the role of co-treatment of TFA and si-Smad or MAPK inhibitors has been examined by qRT-PCR, western blotting, morphology, wound healing and transwell assays.

RESULTS

In this study, TFA promoted transforming growth factor-β1 (TGF-β1)-induced (IEC-6) morphological change, migration and invasion, and increased the expression of epithelial markers and reduced the levels of mesenchymal markers, along with the inactivation of Smad and MAPK signaling pathways. Moreover, we revealed that si-Smad and MAPK inhibitors effectively attenuated TGF-β1-induced EMT in IEC-6 cells. Importantly, co-treatment of TFA and si-Smad or MAPK inhibitors had better inhibitory effects on TGF-β1-induced EMT in IEC-6 cells than either one of them.

CONCLUSION

These findings could provide new insight into the molecular mechanisms of TFA on TGF-β1-induced EMT in IEC-6 cells and TFA is expected to advance as a new therapy to treat CD intestinal fibrosis.