Inflammatory Cytokine Profile in Crohn's Disease Nonresponders to Optimal Antitumor Necrosis Factor Therapy

An in vitro study elucidating the synergistic effects of aqueous cinnamon extract and an anti-TNF-α biotherapeutic: implications for a complementary and alternative therapy for non-responders

BACKGROUND

Tumor necrosis factor-alpha (TNF-α) is a critical pro-inflammatory cytokine, and its abnormal production is associated with several immune mediated inflammatory diseases (IMID). Biological anti-TNF-α therapy includes treatment with monoclonal antibodies such as infliximab which have proven successful and are well-tolerated in most patients. Unfortunately, some patients may not respond to therapy (primary non-responders) or may lose sensitivity to the biological agent over time (early and late secondary non-responders). Natural products can reduce inflammation and act synergistically with small molecules or biologics, although evidence remains limited. This study aimed to investigate whether complementary and alternative medicine (CAM) could play a role in infliximab non-responders. Reportedly, cinnamon can help manage chronic inflammatory conditions owing to its anti-inflammatory properties.

METHODS

We studied the synergistic effects of cinnamon and infliximab in vitro using a two-step approach. First, we investigated whether cinnamon and infliximab act synergistically. Second, we selected conditions that supported statistically significant synergy with infliximab and studied the mRNA expression of several genes involved in non-response to infliximab. We used aqueous cinnamon extract (aCE) from Cinnamomum cassia, Cinnamomum zeylanicum, and Cinnamomum loureiroi and bioactive trans-cinnamaldehyde (TCA), cinnamic acid (CA), and eugenol to study the synergy between infliximab and aCE/bioactive compounds using bioassays in fibroblast (L929) and monocytic (U937) cell lines, followed by qPCR for molecular-level insights. TCA, C. cassia aCE, and C. zeylanicum aCE demonstrated a dose-dependent synergistic effect with infliximab. Moreover, we saw differential gene expression for adhesion molecules, apoptotic factors, signaling molecules, and matrix remodelers in presence and absence of aCE/bioactives.

RESULTS

CAM supplementation was most effective with C. cassia aCE, where a synergistic effect was observed for all the tested genes specifically for MMP-1, BcL-xL, Bax and JAK2, followed by TCA, which affected most of the tested genes except TLR-2, MMP1, MMP3, TIMP-1, and BAX, and C. zeylanicum aCE, which did not affect ICAM-1, VCAM-1, TLR-2, TLR-4, MMP1, MMP3, TIMP-1, and STAT3.

CONCLUSION

In conclusion, cinnamon acted synergistically with infliximab to mitigate inflammation when used as an extract. Purified bioactive TCA also showed synergistic activity. Thus, aCE, or cinnamon bioactive may be used as a CAM to improve patients' quality of life.

Serum Interleukin (IL)-23 and IL-17 Profile in Inflammatory Bowel Disease (IBD) Patients Could Differentiate between Severe and Non-Severe Disease

Interleukin (IL)-17 and IL-23 are crucial for mediating gut mucosal inflammation in inflammatory bowel disease (IBD), which has led to new therapeutic strategies. We assessed the relevancy of IL-17 and IL-23 serum levels as potential biomarkers towards severe IBD discrimination and disease-related complications. Sixty-two patients diagnosed with Crohn's disease (CD) and ulcerative colitis (UC) were included. Serum IL-17 and IL-23 were measured by sandwich enzyme-linked immunosorbent assays (ELISA). IL-23 and fecal calprotectin (FCal) were significantly higher in severe CD (p < 0.001) and UC (p < 0.001 and p = 0.001, respectively), compared to mild or moderate. Elevated C-reactive protein (CRP) was correlated with severe disease only in CD (p = 0.008), whereas for UC, disease severity was associated with increased IL-17 values (p < 0.001). Diagnostic role of IL-23 was superior to FCal in discriminating between severe and mild to moderate CD (p < 0.001). IL-23 levels were also significantly higher in CD patients with intestinal complications (p = 0.04). Both IL-17 and IL-23 correlate with IBD severity, and IL-23 might be a promising novel biomarker for severe CD. Identifying the dominant IL pathway involved in IBD severity could serve as guidance for clinical decision-making on biologic therapy.

Biochemical Biomarkers of Mucosal Healing for Inflammatory Bowel Disease in Adults

Mucosal healing (MH) is the key therapeutic target of inflammatory bowel disease (IBD). The evaluation of MH remains challenging, with endoscopy being the golden standard. We performed a comprehensive overview of the performance of fecal-, serum-, and urine-based biochemical markers in colonic IBD to find out whether we are ready to replace endoscopy with a non-invasive but equally accurate instrument. A Pubmed, Web of Knowledge, and Scopus search of original articles as potential MH markers in adults, published between January 2009 and March 2020, was conducted. Finally, 84 eligible studies were identified. The most frequently studied fecal marker was calprotectin (44 studies), with areas under the curves (AUCs) ranging from 0.70 to 0.99 in ulcerative colitis (UC) and from 0.70 to 0.94 in Crohn`s disease (CD), followed by lactoferrin (4 studies), matrix metalloproteinase-9 (3 studies), and lipocalin-2 (3 studies). The most frequently studied serum marker was C-reactive protein (30 studies), with AUCs ranging from 0.60 to 0.96 in UC and from 0.64 to 0.93 in CD. Fecal calprotectin is an accurate MH marker in IBD in adults; however, it cannot replace endoscopy and the application of calprotectin is hampered by the lack of standardization concerning the cut-off value. Other markers are either not sufficiently accurate or have not been studied extensively enough.

Serum Interleukin-6 and -8 as Predictors of Response to Vedolizumab in Inflammatory Bowel Diseases

Vedolizumab, a monoclonal antibody directed against integrin α4β7, is an effective treatment for inflammatory bowel diseases. However, a significant number of patients do not achieve steroid-free clinical remission in the first year of treatment. An early identification of these patients is one of the most important challenges for clinicians and offers the possibility of therapeutic optimization in order to personalize biological therapy. The aim of our study was to test the prediction ability of interleukin (IL)-6 and -8 of clinical response after 12 months of therapy with vedolizumab (T2). We performed a prospective, multicentre study in patients affected by inflammatory bowel disease by analysing cytokines level before starting vedolizumab (T0) and after 10 weeks of therapy (T1). In the overall cohort (n = 54), IL-8 decrease > 2.6 pg/mL in the first 10 weeks of therapy was able to predict clinical response (area under the curve (AUC) = 0.70, sensitivity = 66%, specificity = 75%, p = 0.010), negative C-reactive protein (CRP) (AUC = 0.71, sensitivity = 64%, specificity = 80%, p = 0.009) and calprotectin < 250 mg/kg (AUC = 0.69, sensitivity = 64%, specificity = 78%, p = 0.030) after 44 weeks of therapy. In patients with ulcerative colitis (n = 40), baseline IL-8 values > 8.6 pg/mL and a decrease of IL-6 values > 0.4 pg/mL from T0 to T1 were significant and independent predictors of clinical response after 12 months of vedolizumab therapy (odds ratio (OR) = 6.96, 95% CI 1.27–38.22, p = 0.026 and OR = 7.29, 95% CI 1.42–37.50, p = 0.017, respectively). In patients with Crohn’s disease (n = 14), baseline IL-8 values > 8.6 pg/mL and baseline IL-6 values > 1.6 pg/mL allowed the identification of patients achieving negative CRP at T2 (AUC = 0.75, sensitivity = 74%, specificity = 76%, p < 0.001) and patients with faecal calprotectin values < 250 mg/kg at T2 (AUC = 0.71, sensitivity = 78%, specificity = 63%, p = 0.004). In conclusion, our study highlights a potential clinical role of serum cytokine levels for the prediction of clinical and biochemical steroid-free response in patients treated with vedolizumab.

Potent Inhibitory Effect of BJ-3105, a 6-Alkoxypyridin-3-ol Derivative, on Murine Colitis Is Mediated by Activating AMPK and Inhibiting NOX

Inflammatory bowel disease (IBD) is a chronic relapsing inflammation in the gastrointestinal tract. Biological therapeutics and orally available small molecules like tofacitinib (a JAK inhibitor) have been developed to treat IBD, but half of the patients treated with these drugs fail to achieve sustained remission. In the present study, we compared the therapeutic effects of BJ-3105 (a 6-alkoxypyridin-3-ol derivative) and tofacitinib in IBD. BJ-3105 induced activation of AMP-activated protein kinase (AMPK) in the kinase activity measurement and recovery from cytokine-induced AMPK deactivation in HT-29 human colonic epithelial cells. Similar to tofacitinib and D942 (an AMPK activator), BJ-3105 inhibited IL-6-induced JAK2/STAT3 phosphorylation and TNF-α-stimulated activation of IKK/NF-κB, and consequently, stimulus-induced upregulations of inflammatory cytokines and inflammasome components. In addition, unlike tofacitinib or D942, BJ-3105 inhibited NADPH oxidase (NOX) activation and consequent superoxide production induced by activators (mevalonate and geranylgeranyl pyrophosphate) of the NOX cytosolic component Rac. In mice, oral administration with BJ-3105 ameliorated dextran sulfate sodium (DSS)-induced colitis and azoxymethane/DSS-induced colitis-associated tumor formation (CAT) much more potently than that with tofacitinib. Moreover, BJ-3105 suppressed the more severe form of colitis and CAT formation in mice with AMPK knocked-out in macrophages (AMPKα^fl/fl-Lyz2-Cre mice) with much greater efficacy than tofacitinib. Taken together, our findings suggest BJ-3105, which exerted a much better anti-colitis effect than tofacitinib through AMPK activation and NOX inhibition, is a promising candidate for the treatment of IBD.

Exploring inflammatory and apoptotic signatures in distinct Crohn's disease phenotypes: Way towards molecular stratification of patients and targeted therapy

BACKGROUND

Crohn's disease (CD) is chronic inflammatory bowel disease with different phenotypic characteristics influencing disease prognosis and therapeutic strategies. The aim of this pilot study was to analyze selected inflammatory and apoptotic markers in non-inflamed and inflamed samples of ileal mucosa of non-stricturing/non-penetrating (NS/NP) and stricturing (S) CD mucosal phenotypes in order to characterize their distinct profiles.

METHODS

From twenty CD patients (9 NS/NP, 11 S) paired non-inflamed and inflamed ileal biopsies were collected and used for analysis of cytokine (TNF and IL6) and apoptotic (Bcl2, Bax, Fas and FasL) genes' expression levels by real-time PCR, while NFκB transcriptional potency was assessed by electromobility gel shift assay.

RESULTS

Our results demonstrated significant upregulation of TNF and IL6 in inflamed area of both NS/NP (p = 0.03, p = 0.01) and S phenotypes (p = 0.04, p = 0.04), respectively. However, TNF increase was more prominent in NS/NP compared to S inflamed mucosa (p = 0.02). Also, level of proapoptotic Bax was significantly higher in NS/NP compared to S inflamed mucosa (p = 0.01). Opposing transcription potency of NFκB has been detected between two phenotypes: being decreased in NS/NP (p = 0.07) and increased in S (p = 0.1) inflamed compared to non-inflamed mucosa, demonstrating trend towards statistical significance.

CONCLUSIONS

We found that two distinct CD phenotypes have specific molecular signatures. Obtained results could direct improvement of current and development of new therapeutic strategies based on more specific molecular stratification of CD patients.