Sphingosine 1-Phosphate Modulation in Inflammatory Bowel Diseases: Keeping Lymphocytes Out of the Intestine

The potential capacities of FTY720: Novel therapeutic functions, targets, and mechanisms against diseases

Fingolimod (FTY720), an antagonist of sphingosine-1-phosphate (S1P), functions by binding to S1P receptors (S1PRs), excluding S1PR2. It received approval from the Food and Drug Administration (FDA) for the treatment of multiple sclerosis (MS) in 2010. As the first non-selective oral agonist for S1PRs, FTY720's diverse and systemic receptor expression often leads to alterations in various signaling pathways and multiple systems, making it a subject of intense research. Recent studies have identified a wide range of novel or potential functions for FTY720 beyond its application in MS. These include effects on the blood-brain barrier (BBB), vascular system, organelles, and cell death, as well as potential applications in organ transplantation, immune disorders, oncological conditions, neurological and psychiatric disorders, viral infections, and hypersensitivity diseases. This paper reviews the novel roles, targets, and mechanisms of FTY720 that hold promise for clinical utility. Additionally, it summarizes FTY720's derivation and development process, the characterization and mechanism of the structure of FTY720-P bound to S1PRs, the clinical safety profile, future challenges, and potential strategies to address them. These insights aim to guide future research and applications of FTY720, maximizing its therapeutic potential.

Pan-Cancer Insights: A Study of Microbial Metabolite Receptors in Malignancy Dynamics

BACKGROUND/OBJECTIVES

The role of the gut microbiome in cancer biology has become an increasingly prominent area of research, particularly regarding the role of microbial metabolites and their receptors (MMRs). These metabolites, through the various gut-organ axes, have been proven to influence several pathogenetic mechanisms. This study conducted a comprehensive pan-cancer analysis of MMR transcriptomic profiles across twenty-three cancer types, exploring the mechanisms through which they can influence cancer development and progression.

METHODS

Utilizing both cancer cell lines from CCLE (Cancer Cell Line Encyclopedia) and human tumor samples from TCGA (The Cancer Gene Atlas), we analyzed 107 MMRs interacting with microbial metabolites such as short-chain fatty acids, bile acids, indole derivatives, and others while studying their interactions with key known cancer genes.

RESULTS

Our results revealed that certain MMRs, such as GPR84 and serotonin receptors, are consistently upregulated in various malignancies, while others, like ADRA1A, are frequently downregulated, suggesting diverse roles in cancer pathophysiology. Furthermore, we identified significant correlations between MMR expression and cancer hallmark genes and pathways, including immune evasion, proliferation, and metastasis.

CONCLUSIONS

These findings suggest that the interactions between microbial metabolites and MMRs may serve as potential biomarkers for cancer diagnosis, prognosis, and therapy, highlighting their therapeutic potential. This study underscores the significance of the microbiota-cancer axis and provides novel insights into microbiome-based strategies for cancer treatment.

Evaluation of proximod, a selective agonist of sphingosine-1-phosphate receptor-1, in healthy volunteers and patients with rheumatoid arthritis: a phase 1, double-blind, randomised, placebo-controlled, ascending dose trial

BACKGROUND

Proximod is a selective agonist of sphingosine-1-phosphate receptor-1 (S1PR1). It acts by redirecting lymphocytes from the circulation to secondary lymph nodes, and is under development as an immunomodulator for rheumatoid arthritis. We aimed to evaluate the safety, pharmacokinetics, and preliminary efficacy of proximod in healthy volunteers and patients with rheumatoid arthritis.

METHODS

We did a two part, phase 1, double-blind, randomised, placebo-controlled, ascending dose trial at a single centre in China. Eligible participants were adults aged 18-50 years with a BMI of 18-28 kg/m2 for healthy volunteers and aged 18-70 years with a BMI of 18-30 kg/m2 for patients with rheumatoid arthritis. In part 1, healthy volunteers were randomly assigned within ten cohorts to receive a single oral dose of proximod (0·125 mg, 0·25 mg, 0·5 mg, 1 mg, 1·5 mg, 2 mg, 3 mg, 5 mg, 10 mg, or 15 mg in cohorts 1-10) or placebo. In part 2, healthy volunteers were randomly assigned to receive once-daily doses of proximod 5 mg or placebo, and patients with rheumatoid arthritis were randomly assigned to receive once-daily doses of proximod 5 mg, proximod 10 mg, or placebo, for 28 days. Patients and investigators were masked to treatment assignment. The primary outcomes were safety, tolerability, and pharmacokinetic profile of proximod for 72 days in healthy volunteers and for 48 days in patients with rhematoid arthritis, assessed in all treated participants. This trial is registered with ClinicalTrials.gov (NCT06361199, NCT06361186), and is complete.

FINDINGS

Between Nov 1, 2017, and June 22, 2021, 124 healthy volunteers were randomly assigned in part 1 of the study and 124 were included in the analyses (mean age 34·3 years [SD 6·9], 62 [50%] of 124 participants were women and 62 [50%] were men, and 116 [94%] were Han Chinese ethnicity). Between Feb 16, 2022, and Oct 8, 2023, 113 participants were screened for inclusion in part 2 (80 healthy volunteers and 33 patients with rheumatoid arthritis). 79 participants were excluded and 34 were randomly assigned (10 healthy participants and 24 patients with rheumatoid arthritis), 34 of whom were included in the analyses. Ten (100%) of ten healthy participants were Han Chinese ethnicity, with a mean age of 39·9 years (SD 7·3). Five (50%) of ten healthy volunteers were women and five (50%) were men). 22 (92%) of 24 participants with rheumatoid arthritis were Han Chinese ethnicity, with a mean age of 52·7 years (SD 6·8). 22 (92%) of 24 patients with rheumatoid arthritis were women and two (8%) were men. In part 1, all doses of proximod were well tolerated, with no dose-related adverse reactions or serious adverse events observed. In part 2, 74 adverse reactions were reported in eight (80%) of ten healthy volunteers and 22 (92%) of 24 patients with rheumatoid arthritis. Adverse events associated with proximod were predominantly mild or moderate. In part 2, the concentration of proximod and its active metabolite, proximod-phosphate, gradually increased in all three groups receiving proximod and the EC50 of the S1PR1 agonist for proximod-phosphate (6·1 ng/mL) was reached on day 14 for both 5 mg groups, and on day 7 for the 10 mg group. The mean Ctrough values for proximod-phosphate on day 28 were 7·7 ng/mL and 10·2 ng/mL for 5 mg in healthy volunteers and patients with rheumatoid arthritis, respectively, and 15·3 ng/mL for 10 mg in patients with rheumatoid arthritis. In patients with rheumatoid arthritis, lymphocyte count decreased after treatment in all proximod groups reaching nadir at approximately day 28, with a corresponding percentage decline from baseline of 65·25% in the 5 mg group, 71·64% in the 10 mg group, and 20·57% in the placebo group.

INTERPRETATION

Proximod exhibited good tolerability over the 28-day treatment period, demonstrating its potential in reducing blood lymphocyte count. These results highlight the promise of the S1PR1 agonist proximod as a potential candidate for rheumatoid arthritis treatment, warranting further investigation in subsequent clinical studies.

FUNDING

Beijing Union Pharmaceutical Factory and Jian Kuan (Suzhou) Biotechnology.

Targeting mucosal healing in Crohn's disease: efficacy of novel pathways and therapeutic targets

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory bowel disease affecting the entire gastrointestinal tract with a progressive and relapsing course. Achieving mucosal healing has emerged as a critical therapeutic goal, as it is associated with sustained clinical remission, reduced hospitalizations, and fewer surgery rates. Therefore, targeting mucosal healing is essential for long-term control in CD.

AREAS COVERED

This review evaluates the efficacy of novel biologic therapies and small molecules in inducing mucosal healing, specifically targeting pathways like IL-12/23, IL-23, α4β7 integrins, Janus kinase 1 (JAK1), and sphingosine-1-phosphate receptor (S1PR) in adults (≥18 years) with moderate-to-severe CD. The rationale for selecting these specific pathways is their central role in modulating key inflammatory processes implicated in CD pathogenesis. We compare these therapies with placebo for both induction and maintenance of remission, based on a PubMed literature review for published articles and ClinicalTrials.gov for ongoing trials.

EXPERT OPINION

Upadacitinib and anti-IL23p19 agents (risankizumab, guselkumab and mirikizumab) are promising advanced non-TNF-targeting therapies for inducing endoscopic remission and mucosal healing but further studies are needed to integrate mucosal healing into a broader definition of endoscopic response, with a unified and precise definition.

Advancements in the Management of Pediatric and Adult Inflammatory Bowel Disease: A Systematic Review of Treatment Strategies and Long-Term Outcomes

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis (UC), remains a clinically complex condition in children and adults. This study is a systematic analysis of key developments in the treatment of inflammatory bowel diseases, as well as their efficacy and safety over time. Early diagnosis of pediatric IBD is very important since it affects growth and development in children. New therapeutic approaches like biological agents, small molecules, and gene or targeted drugs have given the medical fraternity new treatment protocols. There is a trend towards more selective therapies for adult IBD, especially for anti-tumor necrosis factor (anti-TNF) biologics, integrin antagonists, and interleukin-12/23 (IL-12/23) inhibitors. This review emphasizes the need for patient management where early intervention leading to mucosal healing has been identified to predict durable outcomes. Systematic analysis of existing literature comparing childhood and adult populations shows that morbidity, pathophysiology, therapeutic outcome, as well as the potential for adverse outcomes are dissimilar, which supports the need for differentiated therapy. This work also looks at long-term consequences of the intervention course, the avoidance of surgery, and an improvement in the quality and stability of life as well as reduction in further development of malignant transformation. The new developing strategy of gut microbiome modification and nutrition support for maintaining remission is also argued. Despite these progresses, issues still persist concerning the effectiveness of treatments, side effects, and patients' compliance. These recommendations give this review a prospective outlook of treatment regimens likely to define the future of IBD management for all age groups.

Safety and efficacy of S1P receptor modulators for the induction and maintenance phases in inflammatory bowel disease: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that significantly affects quality of life. Conventional treatments have had limited success. this study evaluates the safety and efficacy of Sphingosine 1-phosphate receptor modulators (S1PrMs) as a potential treatment for IBD.

METHODS

We conducted a thorough search of published literature on PubMed, EMBASE, and Google Scholar from 2000 to 2023. The inclusion criteria were randomized controlled trials (RCTs) with a target population comprising of IBD patients receiving either S1PrMs or placebo and a comparison of the 2. The statistical analysis was conducted using RevMan (version 5.4). Forest plots presented the results as risk ratios (RR) with a 95% confidence interval.

RESULTS

A total of 7 RCTs involving 2471 patients were included. The results were reported for both the induction and maintenance phases of treatment. in the induction phase, the intervention group proved to have a significantly higher incidence of histological remission (RR = 2.67; 95% CI [1.97, 3.60]; P < .00001), endoscopic improvement (RR = 2.06; 95% CI [1.66, 2.56]; P < .00001), clinical remission (RR = 2.23; 95% CI [1.43, 3.46]; P < .0004) and clinical response (RR = 1.37; 95% CI [1.01, 1.84]; P = .04) compared to the placebo group. Outcomes assessed in maintenance phase significantly favored the intervention group over placebo as well, histologic remission (RR = 2.39; 95% CI [1.83, 3.11]; P < .00001), endoscopic improvement (RR = 2.20; 95% CI [1.28, 3.77]; P = .004), clinical remission (RR = 3.03; 95% CI [1.84, 4.99]; P < .0001), and clinical response (RR = 1.74; 95% CI [1.25, 2.42]; P = .001).

CONCLUSION

S1PrMs show promising potential for establishing histologic remission, endoscopic improvement, clinical remission, and corticosteroid-free clinical remission. With more studies and clinical trials, these modulators may become a reliable therapeutic choice for UC patients everywhere.

Immunity in digestive diseases: new drugs for inflammatory bowel disease treatment-insights from Phase II and III trials

BACKGROUND

Inflammatory bowel disease (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), continues to challenge treatment paradigms. Advancements in therapeutic options have been have been driven by Phase 2 and 3 clinical trials of new drug classes, particularly sphingosine-1-phosphate (S1P) modulators and interleukin-23 (IL-23) inhibitors.

METHODS

This review synthesizes findings from Phase 2 and 3 clinical trials conducted up to early 2024, focusing on the impact of S1P modulators and IL-23 inhibitors on IBD management. Drugs such as ozanimod, etrasimod, risankizumab, mirikizumab, guselkumab, and brasikumab were evaluated for their efficacy and safety profiles.

RESULTS

S1P modulators, such as ozanimod and etrasimod, effectively regulate immune cell trafficking to reduce inflammation and several trials highlight their clinical effectiveness in both inducing and maintaining remission in IBD, highlighting its long-term safety and sustained therapeutic effects. Additionally, IL-23 inhibitors including risankizumab, mirikizumab, and guselkumab, which disrupt key inflammatory cytokine pathways, have already shown significant effectiveness in inducing and maintaining remission in both CD and UC, with favorable safety profiles across multiple studies, suggesting their potential as critical components in managing IBD.

CONCLUSIONS

The clinical trials indicate that both S1P modulators and IL-23 inhibitors offer promising therapeutic benefits and maintain strong safety profiles, positioning them as potential cornerstone treatments for IBD. Despite these advancements, further exploration into long-term safety and the development of personalized treatment strategies is essential for maximizing clinical outcomes.

Antibodies Targeting the Tumor Necrosis Factor-Like Ligand 1A in Inflammatory Bowel Disease: A New Kid on the (Biologics) Block?

BACKGROUND

The treatment options for inflammatory bowel disease (IBD) have grown over the last years. However, a significant fraction of patients either do not respond to their treatment or lose response over time.

SUMMARY

Future treatment options could include antibodies that target the tumor necrosis factor-like ligand 1A (TL1A). TL1A is a key cytokine involved in the pathogenesis of a variety of autoimmune diseases including IBD. Studies have shown that IBD disease severity correlates well with serum levels of TL1A. Phase 2 data from two agents currently in clinical testing have been released. In line with requirements for modern therapeutics, companion diagnostic was part of these trials. This aims to identify those patients that are more likely to respond to the agents tested.

KEY MESSAGES

With regard to the available data the risk/benefit profile of TL1A inhibitors seems to be promising. This article gives a short update and overview, where we are at this point in time with antibodies targeting the TL1A protein in IBD.

Development and validation of stability-indicating method of etrasimod by HPLC/DAD/MS/MS technique with greenness profiling

Etrasimod, a novel selective sphingosine-1-phosphate receptor modulator, was recently approved by the U.S. Food and Drug Administration and the European Medicinal Agency for the treatment of moderately to severely active ulcerative colitis in adults. In this research, the forced degradation study as an integral part of drug product and packaging development, which generates data on degradation mechanisms, is published. The development and validation of the stability-indicating method using a superior high-performance liquid chromatography technique coupled with a diode array detector and tandem mass spectrometer was performed to support the forced degradation study and monitor the formation of degradation products. Etrasimod demonstrated good stability under elevated temperature and basic stress conditions, while acidic hydrolysis, oxidative, and photolytic degradation produced eight degradation products. The knowledge of degradation products will be useful in the long-term stability study for establishing the acceptance criteria of etrasimod as a drug substance and dosage form during quality control and stability assessment. The eco-friendliness of the developed forced degradation procedure was evaluated using various greenness appraisal tools. The green metric tools showed that the forced degradation procedure obeys eco-friendly conditions.

Acute interstitial nephritis in patients with inflammatory bowel disease treated with vedolizumab: a systematic review

BACKGROUND

Acute interstitial nephritis (AIN) is a complication of drugs that may cause permanent kidney injury. AIN has been reported in patients with inflammatory bowel disease (IBD) treated with the integrin inhibitor vedolizumab. Through systematic review of existing literature, we aimed to identify and describe cases of AIN in patients with IBD treated with vedolizumab.

METHODS

We searched Medline, Embase, Cochrane, and Web of Science Core Collection between 1 January 2009 and 25 April 2023. The search yielded 1473 publications. Titles and abstracts were screened by two independent reviewers. Seventy publications were reviewed in full-text. Eight met the inclusion criteria. Clinical characteristics of AIN cases were extracted. Case causality assessment was performed according to two international adverse drug reaction probability assessment scales. Results were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Nine biopsy-confirmed cases of AIN were reported in six patients with ulcerative colitis and three with Crohn's disease. Mean age at AIN onset was 36 years (range = 19-58) and the majority of patients were females (n = 6/9). Time from vedolizumab treatment initiation to AIN onset spanned from hours to 12 months. Common symptoms were fever and malaise. Creatinine levels were elevated in all patients. Five patients sustained permanent kidney injury.

CONCLUSION

Our findings suggest that vedolizumab, although rarely, could cause AIN in patients with IBD. Awareness of laboratory findings and symptoms consistent with AIN, along with monitoring of the kidney function, could be warranted in patients with IBD treated with vedolizumab.

Expression of sphingosine-1-phosphate receptor 1 in neuroinflammation of canine brains

Sphingosine-1-phosphate (S1P) is a signaling lipid mediator that is involved in multiple biological processes. The S1P/S1P receptor (S1PR) signaling pathway has an important role in the central nervous system. It contributes to physiologic cellular homeostasis and is also associated with neuroinflammation. Therefore, this study was performed to evaluate the expression of S1PR in dogs with meningoencephalitis of unknown etiology (MUE) and experimental autoimmune encephalomyelitis (EAE). The analysis used 12 brain samples from three neurologically normal dogs, seven dogs with MUE, and two canine EAE models. Anti-S1PR1 antibody was used for immunohistochemistry. In normal brain tissues, S1PR1s were expressed on neurons, astrocytes, oligodendrocytes, and endothelial cells. In MUE and EAE lesions, there was positive staining of S1PR1 on leukocytes. Furthermore, the expression of S1PR1 on neurons, astrocytes, oligodendrocytes, and endothelial cells was upregulated compared to normal brains. This study shows that S1PR1s are expressed in normal brain tissues and leukocytes in inflammatory lesions, and demonstrates the upregulation of S1PR1 expression on nervous system cells in inflammatory lesions of MUE and EAE. These findings indicate that S1P/S1PR signaling pathway might involve physiologic homeostasis and neuroinflammation and represent potential targets for S1PR modulators to treat MUE.

Exploring Microbial Metabolite Receptors in Inflammatory Bowel Disease: An In Silico Analysis of Their Potential Role in Inflammation and Fibrosis

Metabolites produced by dysbiotic intestinal microbiota can influence disease pathophysiology by participating in ligand-receptor interactions. Our aim was to investigate the differential expression of metabolite receptor (MR) genes between inflammatory bowel disease (IBD), healthy individuals (HIs), and disease controls in order to identify possible interactions with inflammatory and fibrotic pathways in the intestine. RNA-sequencing datasets containing 643 Crohn's disease (CD) patients, 467 ulcerative colitis (UC) patients and 295 HIs, and 4 Campylobacter jejuni-infected individuals were retrieved from the Sequence Read Archive, and differential expression was performed using the RaNA-seq online platform. The identified differentially expressed MR genes were used for correlation analysis with up- and downregulated genes in IBD, as well as functional enrichment analysis using a R based pipeline. Overall, 15 MR genes exhibited dysregulated expression in IBD. In inflamed CD, the hydroxycarboxylic acid receptors 2 and 3 (HCAR2, HCAR3) were upregulated and were associated with the recruitment of innate immune cells, while, in the non-inflamed CD ileum, the cannabinoid receptor 1 (CNR1) and the sphingosine-1-phospate receptor 4 (S1PR4) were downregulated and were involved in the regulation of B-cell activation. In inflamed UC, the upregulated receptors HCAR2 and HCAR3 were more closely associated with the process of TH-17 cell differentiation, while the pregnane X receptor (NR1I2) and the transient receptor potential vanilloid 1 (TRPV1) were downregulated and were involved in epithelial barrier maintenance. Our results elucidate the landscape of metabolite receptor expression in IBD, highlighting associations with disease-related functions that could guide the development of new targeted therapies.

Novel and emerging drugs for the treatment of Crohn's disease: a review of phase II and III trials

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory bowel disease characterized by unpredictable flare-ups and periods of remission. While several therapeutic options, such as anti-tumor necrosis factor (TNF), anti-integrin, and interleukin (IL) 12/23 inhibitors, as well as IL-23 and Janus kinase (JAK) inhibitors, have been approved for CD treatment, a substantial number of patients fail to respond adequately or experience a loss of response over time. In recent years, the scientific community has been actively investigating novel agents to address these challenges and improve the management of CD.

AREAS COVERED

This comprehensive narrative review provides an overview of recent developments in CD treatment, summarizing phase 2 and phase 3 clinical trial data. We delve into the clinical efficacy and safety profiles of emerging therapies, encompassing JAK inhibitors, IL-23 inhibitors, anti-adhesion molecules, S1P1 receptor modulators, and combined targeted treatments.

EXPERT OPINION

The armamentarium of CD therapeutic agents is constantly expanding. We analyze pivotal findings from phase 2 and phase 3 CD treatment trials. We also underscore the existing gaps in therapy and the paramount role of ongoing research and innovation in CD management.

Predictive, preventive and personalised approach as a conceptual and technological innovation in primary and secondary care of inflammatory bowel disease benefiting affected individuals and populations

Inflammatory bowel disease (IBD) is a global health burden which carries lifelong morbidity affecting all age groups in populations with the disease-specific peak of the age groups ranging between 15 and 35 years, which are of great economic importance for the society. An accelerating incidence of IBD is reported for newly industrialised countries, whereas stabilising incidence but increasing prevalence is typical for countries with a Westernised lifestyle, such as the European area and the USA. Although the aetiology of IBD is largely unknown, the interplay between the genetic, environmental, immunological, and microbial components is decisive for the disease manifestation, course, severity and individual outcomes. Contextually, the creation of an individualised patient profile is crucial for the cost-effective disease management in primary and secondary care of IBD. The proposed pathomechanisms include intestinal pathoflora and dysbiosis, chronic inflammation and mitochondrial impairments, amongst others, which collectively may reveal individual molecular signatures defining IBD subtypes and leading to clinical phenotypes, patient stratification and cost-effective protection against health-to-disease transition and treatments tailored to individualised patient profiles-all the pillars of an advanced 3PM approach. The paradigm change from reactive medical services to predictive diagnostics, cost-effective targeted prevention and treatments tailored to individualised patient profiles in overall IBD management holds a promise to meet patient needs in primary and secondary care, to increase the life-quality of affected individuals and to improve health economy in the area of IBD management. This article analyses current achievements and provides the roadmap for future developments in the area in the context of 3P medicine benefiting society at large.

Efficacy and Safety of Approximately 3 Years of Continuous Ozanimod in Moderately to Severely Active Ulcerative Colitis: Interim Analysis of the True North Open-label Extension

BACKGROUNDS AND AIMS

This interim analysis from the True North open-label extension [OLE] study examines efficacy and safety of approximately 3 years of continuous ozanimod treatment in patients with moderately to severely active ulcerative colitis.

METHODS

Clinical responders after 52 weeks of ozanimod during the phase 3 True North study, who continued treatment in the OLE, were evaluated. Efficacy, including endoscopic and histological endpoints, was assessed during the OLE for approximately 2 additional years through OLE Week 94, using observed case [OC] and nonresponder imputation [NRI] analyses. Adverse events were monitored from True North baseline through OLE data cutoff and expressed as exposure-adjusted incidence rates.

RESULTS

This analysis included 131 patients; 54% had achieved corticosteroid-free remission at True North Week 52. In OC analyses, clinical response, clinical remission, and corticosteroid-free remission were achieved by 91.4%, 69.1%, and 67.9% of patients, respectively, at OLE Week 94 [146 weeks of total treatment]. Similarly, endoscopic improvement, histological remission, and mucosal healing were achieved by 73.3%, 67.3%, and 56.3% of patients, respectively, at OLE Week 94. Efficacy rates were lower using NRI analyses, but maintenance of efficacy was demonstrated through OLE Week 94. No new safety signals emerged from this analysis. Serious infections, malignancy, cardiovascular events, and hepatic events occurred infrequently.

CONCLUSIONS

Among patients who achieved clinical response after 1 year of ozanimod treatment during True North, a high percentage sustained clinical and mucosal efficacy over 2 additional years in the OLE. No new safety signals were observed with long-term ozanimod use.

Therapeutic Potential for Sphingolipids in Inflammatory Bowel Disease and Colorectal Cancer

Inflammatory bowel disease (IBD), characterized by chronic inflammation in the intestinal tract, increases the risk for the development of colorectal cancer (CRC). Sphingolipids, which have been implicated in IBD and CRC, are a class of bioactive lipids that regulate cell signaling, differentiation, apoptosis, inflammation, and survival. The balance between ceramide (Cer), the central sphingolipid involved in apoptosis and differentiation, and sphingosine-1-phosphate (S1P), a potent signaling molecule involved in proliferation and inflammation, is vital for the maintenance of normal cellular function. Altered sphingolipid metabolism has been implicated in IBD and CRC, with many studies highlighting the importance of S1P in inflammatory signaling and pro-survival pathways. A myriad of sphingolipid analogues, inhibitors, and modulators have been developed to target the sphingolipid metabolic pathway. In this review, the efficacy and therapeutic potential for modulation of sphingolipid metabolism in IBD and CRC will be discussed.

Clinician's Guide to Using Ozanimod for the Treatment of Ulcerative Colitis

The emergence of advanced therapies [eg, biologics, Janus kinase inhibitors] over the past few decades has revolutionised the treatment of ulcerative colitis. However, the limitations of these therapies leave an unmet need for safer and more effective or convenient treatment options. There is growing interest in the development of novel oral small molecule therapies for the treatment of ulcerative colitis. Ozanimod is an oral small molecule therapy that is approved in the USA, the European Union, and other countries as the first sphingosine 1-phosphate receptor modulator for the treatment of moderately to severely active ulcerative colitis in adults. This review provides guidance for ozanimod use for the treatment of ulcerative colitis, based on the prescribing information, clinical trial and real-world data, and the authors' clinical experiences. This guidance outlines patient characteristics to consider when deciding if ozanimod treatment is suitable and describes how to educate patients on risks and best practices. It also details the nature and frequency of monitoring during treatment, which should be adapted to the individual patient based on pre-existing risk factors and events that possibly occur during treatment. This review also provides insights into the patient characteristics and clinical scenarios best suited for ozanimod treatment, based on its efficacy, safety profile, and risks compared with other therapies.

Efficacy and Safety of Advanced Oral Small Molecules for Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

Oral small-molecule drugs [SMDs] are expanding the therapeutic landscape for inflammatory bowel disease [IBD]. This systematic review and meta-analysis summarizes the efficacy and safety of JAK inhibitor [JAKi] and sphingosine-1-phosphate [S1P] receptor modulator treatments for ulcerative colitis [UC] and Crohn's disease [CD].

METHODS

MEDLINE, Embase, and CENTRAL were searched from inception to May 30, 2022. Randomized controlled trials [RCTs] of JAKi and S1P receptor modulators in adults with UC or CD were eligible. Clinical, endoscopic, histological, and safety data were pooled and analysed using a random-effects model.

RESULTS

Thirty-five RCTs [26 UC, nine CD] were included. In UC, JAKi therapy was associated with induction of clinical (risk ratio [RR] 3.16, 95% confidence interval [CI] 2.03-4.92; I2 = 65%) and endoscopic [RR 3.99, 95% CI 2.36-6.75; I2 = 36%] remission compared to placebo. Upadacitinib was associated with histological response [RR 2.63, 95% CI 1.97-3.53]. S1P modulator therapy was associated with induction of clinical [RR 2.52, 95% CI 1.88-3.39; I2 = 1%] and endoscopic [RR 2.39, 95% CI 1.07-5.33; I2 = 0%] remission relative to placebo. Ozanimod was superior to placebo for inducing histological remission in UC [RR 2.20, 95% CI 1.43-3.37; I2 = 0%], while etrasimod was not [RR 2.36, 95% CI 0.71-7.88; I2 = 0%]. In CD, JAKi therapy was superior to placebo for induction of clinical remission [RR 1.53, 95% CI 1.19-1.98; I2 = 31%], and endoscopic remission [RR 4.78, 95% CI 1.63-14.06; I2 = 43%] compared to placebo. The risk of serious infections was similar for oral SMDs and placebo.

CONCLUSION

JAKi and S1P receptor modulator therapies are effective in IBD for inducing clinical and endoscopic remission and, in some circumstances, histological response.

Treatment Strategies in Inflammatory Bowel Diseases

BACKGROUND

The prevalence of inflammatory bowel disease (IBD) is rising globally. In Germany, these conditions affect 0.7% of the population, or approximately 600 000 patients. Treatment strategies have become more diversified as a result of an improved understanding of disease pathogenesis. It remains unclear how the currently available drugs should best be used in each individual patient.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed, with special attention to phase III and IV trials and to the German and European guidelines on the treatment of IBD.

RESULTS

An improved understanding of the immunological mechanisms of disease underlies the current treatment strategies in patients with IBD. For those with a complex clinical course, monoclonal antibodies against pro-inflammatory cytokines (TNF, IL-12/IL-23, IL-23) and cell adhesion molecules (α4β7) are of established therapeutic value, along with "small molecules" such as JAK inhibitors and sphingosine-1-phosphate receptor modulators. The numerous studies that have been performed, only a few of which have been head-to-head comparison trials, and the (network) meta-analyses that have been published to date do not imply that any single one of these drugs can be considered the universal, primary treatment for all patients with IBD. In this review, we discuss the available substances and certain important differential-therapeutic aspects of the treatment of IBD.

CONCLUSION

The treatment of a patient with IBD must take his or her prior treatment(s) and comorbidities into account, along with individual patient characteristics and treatment goals. Rational decision-making is required on the basis of the mechanism of action and the side-effect profile of the various drugs that are now available for use.

The role of sphingosine-1-phosphate in autophagy and related disorders

S1P, also referred to as sphingosine-1-phosphate, is a lipid molecule with bioactive properties involved in numerous cellular processes such as cell growth, movement, programmed cell death, self-degradation, cell specialization, aging, and immune system reactions. Autophagy is a meticulously controlled mechanism in which cells repurpose their elements to maintain cellular balance. There are five stages in autophagy: initiation, nucleation, elongation and maturation, fusion, and degradation. New research has provided insight into the complex connection between S1P and autophagy, uncovering their interaction in both normal and abnormal circumstances. Gaining knowledge about the regulatory mechanism of S1P signaling on autophagy can offer a valuable understanding of its function in well-being and illness, potentially leading to innovative therapeutic concepts for diverse ailments. Hence, this review analyzes the essential stages in mammalian autophagy, with a specific emphasis on recent research exploring the control of each stage by S1P. Additionally, it sheds light on the roles of S1P-induced autophagy in various disorders.

Editorial: Novel Therapeutic Approaches in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBDs) encompass ulcerative colitis (UC) and Crohn's disease (CD), both of which are inflammatory ailments affecting the gastrointestinal tract [...].

Oral small molecule agents in management of ulcerative colitis: fact or fancy?

Ulcerative colitis is a chronic, immune-mediated disease characterized by recurring episodes of mucosal inflammation in the colon and rectum. The primary pathogenic mechanism of ulcerative colitis is the dysregulation of the mucosal immune response. The disease follows a relapsing-remitting course, and the goal of management is to successfully induce and then maintain remission. Effectively managing this chronic disease requires addressing all aspects of it. Currently, we have various antitumor necrosis factor agents and novel biologics available for treating ulcerative colitis patients with moderate-to-severe disease. However, none of the existing treatments are considered entirely satisfactory or ideal in these cases. After extensive progressive research, oral small molecule therapies targeting mediators of ongoing inflammation represent an exciting and revolutionary change in the treatment of ulcerative colitis, especially for patients with moderate-to-severe disease. In this review, we aimed to summarize the available experience and ongoing research on oral small molecule agents in the management of ulcerative colitis. The available experience and ongoing research with promising outcomes provide convincing evidence that the value of oral small molecule agents is fact not fancy.

Transmembrane protein CD69 acts as an S1PR1 agonist

The activation of Sphingosine-1-phosphate receptor 1 (S1PR1) by S1P promotes lymphocyte egress from lymphoid organs, a process critical for immune surveillance and T cell effector activity. Multiple drugs that inhibit S1PR1 function are in use clinically for the treatment of autoimmune diseases. Cluster of Differentiation 69 (CD69) is an endogenous negative regulator of lymphocyte egress that interacts with S1PR1 in cis to facilitate internalization and degradation of the receptor. The mechanism by which CD69 causes S1PR1 internalization has been unclear. Moreover, although there are numerous class A GPCR structures determined with different small molecule agonists bound, it remains unknown whether a transmembrane protein per se can act as a class A GPCR agonist. Here, we present the cryo-EM structure of CD69-bound S1PR1 coupled to the heterotrimeric Gi complex. The transmembrane helix (TM) of one protomer of CD69 homodimer contacts the S1PR1-TM4. This interaction allosterically induces the movement of S1PR1-TMs 5-6, directly activating the receptor to engage the heterotrimeric Gi. Mutations in key residues at the interface affect the interactions between CD69 and S1PR1, as well as reduce the receptor internalization. Thus, our structural findings along with functional analyses demonstrate that CD69 acts in cis as a protein agonist of S1PR1, thereby promoting Gi-dependent S1PR1 internalization, loss of S1P gradient sensing, and inhibition of lymphocyte egress.

Guidelines for the management of ulcerative colitis. Recommendations of the Polish Society of Gastroenterology and the Polish National Consultant in Gastroenterology

This paper is an update of the diagnostic and therapeutic recommendations of the National Consultant for Gastroenterology and the Polish Society of Gastroenterology from 2013. It contains 49 recommendations for the diagnosis and treatment, both pharmacological and surgical, of ulcerative colitis in adults. The guidelines were developed by a group of experts appointed by the Polish Society of Gastroenterology and the National Consultant in the field of Gastroenterology. The methodology related to the GRADE methodology was used to assess the quality of available evidence and the strength of therapeutic recommendations. The degree of expert support for the proposed statements was assessed on a 6-point Likert scale. Voting results, together with comments, are included with each statement.

Selective JAK1 inhibitors for the treatment of inflammatory bowel disease

Janus kinase (JAK) inhibitors, also known as jakinibs, are third-generation oral small molecules that have expanded the therapeutic options for the management of chronic inflammatory diseases, including inflammatory bowel disease (IBD). Tofacitinib, a pan-JAK inhibitor, has spearheaded the new JAK class for IBD treatment. Unfortunately, serious adverse effects, including cardiovascular complications such as pulmonary embolism and venous thromboembolism or even death from any cause, have been reported for tofacitinib. However, it is anticipated that next-generation selective JAK inhibitors may limit the development of serious adverse events, leading to a safer treatment course with these novel targeted therapies. Nevertheless, although this drug class was recently introduced, following the launch of second-generation biologics in the late 1990s, it is breaking new ground and has been shown to efficiently modulate complex cytokine-driven inflammation in both preclinical models and human studies. Herein, we review the clinical opportunities for targeting JAK1 signaling in the pathophysiology of IBD, the biology and chemistry underpinning these target-selective compounds, and their mechanisms of actions. We also discuss the potential for these inhibitors in efforts to balance their benefits and harms.

Transmembrane protein CD69 acts as an S1PR1 agonist

The activation of Sphingosine-1-phosphate receptor 1 (S1PR1) by S1P promotes lymphocyte egress from lymphoid organs, a process critical for immune surveillance and T cell effector activity 1-4 . Multiple drugs that inhibit S1PR1 function are in use clinically for the treatment of autoimmune diseases. Cluster of Differentiation 69 (CD69) is an endogenous negative regulator of lymphocyte egress that interacts with S1PR1 in cis to facilitate internalization and degradation of the receptor 5,6 . The mechanism by which CD69 causes S1PR1 internalization has been unclear. Moreover, although there are numerous class A GPCR structures determined with different small molecule agonists bound, it remains unknown whether a transmembrane protein per se can act as a class A GPCR agonist. Here, we present the cryo-EM structure of CD69-bound S1PR1 coupled to the heterotrimeric G i complex. The transmembrane helix (TM) of one protomer of CD69 homodimer contacts the S1PR1-TM4. This interaction allosterically induces the movement of S1PR1-TMs 5-6, directly activating the receptor to engage the heterotrimeric G i . Mutations in key residues at the interface affect the interactions between CD69 and S1PR1, as well as reduce the receptor internalization. Thus, our structural findings along with functional analyses demonstrate that CD69 acts in cis as a protein agonist of S1PR1, thereby promoting G i -dependent S1PR1 internalization, loss of S1P gradient sensing, and inhibition of lymphocyte egress.

The role of Th17 cells in inflammatory bowel disease and the research progress

Th17 cells play an important role in the abnormal immune response in inflammatory bowel disease (IBD) and are involved in the development and progression of inflammation and fibrosis. An increasing amount of data has shown that gut microbes are important parts of intestinal immunity and regulators of Th17 cellular immunity. Th17 cell differentiation is regulated by intestinal bacteria and cytokines, and Th17 cells regulate the intestinal mucosal immune microenvironment by secreting cytokines, such as IL-17, IL-21, and IL-26. Solid evidence showed that, regarding the treatment of IBD by targeting Th17 cells, the therapeutic effect of different biological agents varies greatly. Fecal bacteria transplantation (FMT) in the treatment of IBD has been a popular research topic in recent years and is safe and effective with few side effects. To further understand the role of Th17 cells in the progression of IBD and associated therapeutic prospects, this review will discuss the progress of related research on Th17 cells in IBD by focusing on the interaction and immune regulation between Th17 cells and gut microbiota.

Remyelination in Multiple Sclerosis: Findings in the Cuprizone Model

Remyelination therapies, which are currently under development, have a great potential to delay, prevent or even reverse disability in multiple sclerosis patients. Several models are available to study the effectiveness of novel compounds in vivo, among which is the cuprizone model. This model is characterized by toxin-induced demyelination, followed by endogenous remyelination after cessation of the intoxication. Due to its high reproducibility and ease of use, this model enjoys high popularity among various research and industrial groups. In this review article, we will summarize recent findings using this model and discuss the potential of some of the identified compounds to promote remyelination in multiple sclerosis patients.