IL-1 inhibitors: novel agents in the treatment of rheumatoid arthritis

Correlation of the Pro-Inflammatory Cytokines IL-1β, IL-6, and TNF-α, Inflammatory Markers, and Tumor Markers with the Diagnosis and Prognosis of Colorectal Cancer

Colorectal cancer (CRC) remains one of the most important global health problems, being in the top 3 neoplasms in terms of the number of cases worldwide. Although CRC develops predominantly from the adenoma-adenocarcinoma sequence through APC gene mutations, in recent years, studies have demonstrated the role of chronic inflammation in this neoplasia pathogenesis. Cytokines are important components of chronic inflammation, being some of the host regulators in response to inflammation. The pro-inflammatory cytokines IL-1β, IL-6, and TNF-α are involved in tumor cell proliferation, angiogenesis, and metastasis and seem to strengthen each other's mode of action, these being stimulated by the same mediators. In our study, we collected data on 68 patients with CRC and 20 healthy patients from the Gastroenterology Department of Craiova County Emergency Clinical Hospital, who were assessed between January 2022 and February 2023. The main purpose of this study was to investigate the correlation between increased plasma levels of the cytokines and the extent of the tumor, lymph nodes, and metastasis-(TNM stage), as well as the patients' prognoses. We also compared the plasma levels of cytokines and acute inflammatory markers, namely, the erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and fibrinogen, along with the tumor markers, carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA 19.9), in CRC patients. We showed that all the pro-inflammatory cytokines studied had higher levels in patients with CRC in comparison with the control group. We also showed that the acute inflammatory markers of erythrocyte sedimentation rate, C-reactive protein, and fibrinogen, and the tumor markers of CEA and CA 19.9 can be useful in diagnosis and prognosis in patients with CRC. Considering the association between pro-inflammatory cytokines and CRC, the development of new targeted therapies against IL-1β, IL-6, and TNF-α can improve patient care and the CRC survival rate.

Non-Transcriptional and Translational Function of Canonical NF-κB Signaling in Activating ERK1/2 in IL-1β-Induced COX-2 Expression in Synovial Fibroblasts

The pro-inflammatory cytokine interleukin 1β (IL-1β) induces the synthesis of prostaglandin E₂ by upregulating cyclooxygenase-2 (COX-2) in the synovial tissue of individuals with autoimmune diseases, such as rheumatoid arthritis (RA). IL-1β-mediated stimulation of NF-κB and MAPK signaling is important for the pathogenesis of RA; however, crosstalk(s) between NF-κB and MAPK signaling remains to be understood. In this study, we established a model for IL-1β-induced synovitis and investigated the role of NF-κB and MAPK signaling in synovitis. We observed an increase in the mRNA and protein levels of COX-2 and prostaglandin E₂ release in cells treated with IL-1β. NF-κB and ERK1/2 inhibitors significantly reduced IL-1β-induced COX-2 expression. IL-1β induced the phosphorylation of canonical NF-κB complex (p65 and p105) and degradation of IκBα. IL-1β also induced ERK1/2 phosphorylation but did not affect the phosphorylation levels of p38 MAPK and JNK. IL-1β failed to induce COX-2 expression in cells transfected with siRNA for p65, p105, ERK1, or ERK2. Notably, NF-κB inhibitors reduced IL-1β-induced ERK1/2 phosphorylation; however, the ERK1/2 inhibitor had no effect on the phosphorylation of the canonical NF-κB complex. Although transcription and translation inhibitors had no effect on IL-1β-induced ERK1/2 phosphorylation, the silencing of canonical NF-κB complex in siRNA-transfected fibroblasts prevented IL-1β-induced phosphorylation of ERK1/2. Taken together, our data indicate the importance of the non-transcriptional/translational activity of canonical NF-κB in the activation of ERK1/2 signaling involved in the IL-1β-induced development of autoimmune diseases affecting the synovial tissue, such as RA.

Microenvironmental considerations in the application of human mesenchymal stem cells in regenerative therapies

The therapeutic utilization of stem cells has been ongoing for several decades, principally in the form of bone marrow (BM) transplants to treat various hematological disorders and other immune-related diseases. More recently, stem cells have been examined as a potential therapy for a multitude of other diseases and disorders, many of which are currently untreatable. One consideration that poses a formidable task for the successful clinical application of stem cells in new disease models is the impact of the host tissue microenvironment on the desired therapeutic outcome. In vitro, stem cells exist in surroundings directly controllable by the researcher to produce the desired cellular behavior. In vivo, the transplanted cells are exposed to a dynamic host microenvironment laden with soluble mediators and immunoreactive cells. In this review, we focus on the possible contribution by microenvironmental factors, and how these influences can be overcome in therapies utilizing mesenchymal stem cells (MSCs), such as for graft versus host disease, multiple sclerosis and ischemia among others. Specifically, we examine three ubiquitous microenvironmental factors, IL-1alpha/beta(,) TNFalpha, and SDF-1alpha, and consider how inhibitors and receptor antagonists to these molecules could be applied to increase the efficacy of MSC therapies while minimizing unforeseen harm to the patient.

Interleukin-1beta and tumor necrosis factor alpha inhibit chondrogenesis by human mesenchymal stem cells through NF-kappaB-dependent pathways

OBJECTIVE

The differentiation of mesenchymal stem cells (MSCs) into chondrocytes provides an attractive basis for the repair and regeneration of articular cartilage. Under clinical conditions, chondrogenesis will often need to occur in the presence of mediators of inflammation produced in response to injury or disease. The purpose of this study was to examine the effects of 2 important inflammatory cytokines, interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha), on the chondrogenic behavior of human MSCs.

METHODS

Aggregate cultures of MSCs recovered from the femoral intermedullary canal were used. Chondrogenesis was assessed by the expression of relevant transcripts by quantitative reverse transcription-polymerase chain reaction analysis and examination of aggregates by histologic and immunohistochemical analyses. The possible involvement of NF-kappaB in mediating the effects of IL-1beta was examined by delivering a luciferase reporter construct and a dominant-negative inhibitor of NF-kappaB (suppressor-repressor form of IkappaB [srIkappaB]) with adenovirus vectors.

RESULTS

Both IL-1beta and TNFalpha inhibited chondrogenesis in a dose-dependent manner. This was associated with a marked activation of NF-kappaB. Delivery of srIkappaB abrogated the activation of NF-kappaB and rescued the chondrogenic response. Although expression of type X collagen followed this pattern, other markers of hypertrophic differentiation responded differently. Matrix metalloproteinase 13 was induced by IL-1beta in a NF-kappaB-dependent manner. Alkaline phosphatase activity, in contrast, was inhibited by IL-1beta regardless of srIkappaB delivery.

CONCLUSION

Cell-based repair of lesions in articular cartilage will be compromised in inflamed joints. Strategies for enabling repair under these conditions include the use of specific antagonists of individual pyrogens, such as IL-1beta and TNFalpha, or the targeting of important intracellular mediators, such as NF-kappaB.

Cytokine inhibitors in the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an immune-mediated disease characterised by articular inflammation and subsequent tissue damage leading to severe disability and increased mortality. A variety of cytokines are produced locally in the rheumatoid joints. Numerous studies have demonstrated that IL-1 and TNF-alpha, two prototypic pro-inflammatory cytokines, play an important role in the mechanisms involved in synovial inflammation and in progressive joint destruction. Indeed, the administration of TNF-alpha and IL-1 inhibitors in patients with RA led to a dramatic improvement of clinical and biological signs of inflammation and a reduction of radiological signs of bone erosion and cartilage destruction. However, despite these encouraging results, a significant percentage of patients do not respond to these agents, suggesting that other mediators are also involved in the pathophysiology of arthritis. This review describes the results of clinical trials with TNF-alpha inhibitors and a specific IL-1 inhibitor (IL-1 receptor antagonist [IL-1Ra]). In addition, other therapeutic strategies are also discussed.

Production of interleukin-1 receptor antagonist by human articular chondrocytes

Interleukin-1 receptor antagonist (IL-1Ra) is a natural IL-1 inhibitor possessing anti-inflammatory properties. IL-1Ra is produced as different isoforms, one secreted (sIL-1Ra) and three intracellular (icIL-1Ra1, icIL-1Ra2 and icIL-1Ra3), derived from the same gene. We examined the production of IL-1Ra species by cultured human articular chondrocytes in response to various cytokines. The levels of IL-1Ra were undetectable in culture supernatants of untreated cells, but were significantly increased by IL-1beta. Cell lysates contained very low levels of IL-1Ra, even in response to IL-1beta, suggesting that chondrocytes produce predominantly sIL-1Ra. IL-6, which had no effect on its own, enhanced the effect of IL-1beta, while dexamethasone prevented the response. We observed by RT-PCR that IL-1beta and IL-6 induced primarily the production of sIL-1Ra mRNA. Furthermore, IL-1beta alone or combined with IL-6 increased the levels of nascent unspliced sIL-1Ra mRNA, suggesting that sIL-1Ra expression is regulated at the transcriptional level. Reporter gene assays in immortalized chondrocytes, C-20/A4, consistently showed increased sIL-1Ra promoter activity in response to IL-1beta and IL-6. In conclusion, human articular chondrocytes produce sIL-1Ra in response to IL-1beta and IL-6. The production of sIL-1Ra by chondrocytes may have a protective effect against articular inflammatory and catabolic responses.

Actinobacillus actinomycetemcomitans-induced expression of IL-1alpha and IL-1beta in human gingival epithelial cells: role in IL-8 expression

Gingival epithelial cells (GEC) are the first cells of the host that encounter the periodontal pathogens. and therefore their role in the initiation of the inflammatory response is critical. We aimed to: 1) characterize the expression of interleukin (IL)- Ialpha and IL-Ibeta in human gingiva and cultured GEC: 2) demonstrate the ability of A. actinomycetemcomitans extracts to upregulate IL-1alpha, IL-1beta and IL-8 expression in GEC in vitro: and 3) characterize the role of IL-1alpha and IL-1beta in the induction of IL-8 expression in GEC in vitro. Ten gingival biopsies (5 inflamed and 5 controls) and cultured GEC were examined for IL-1alpha and IL-Ibeta using immunohistochemical techniques. GEC were also challenged with A. actinomycetemcomitans extracts or IL-1alpha, and secretion of IL-1 and IL-8 was determined by ELISA. In vivo, IL-lalpha and IL-1beta were localized in the gingival epithelium and the infiltrating leukocytes. In vitro, A. actinomycetemcomitans extracts induced a time-dependent expression of IL-1alpha, IL-1beta and IL-8 in GEC. IL-1 inhibitors did not affect A. actinomycetemcomitans-induced IL-8. although they inhibited IL-8 induced by IL-1alpha or IL-1beta. In conclusion, GEC are a major source of IL-1alpha and IL-1beta in the periodontium, which in turn induce additional inflammatory mediators such as IL-8. Therefore GEC can be a potential target for therapeutic intervention in the future.

Synthesis and bioactivities of novel 5,6-bis(4-methoxyphenyl)-2H-pyridazin-3-one derivatives: inhibitors of interleukin-1 beta (IL-1beta) production

New 5,6-bis(4-methoxyphenyl)-2H-pyridazin-3-one derivatives were prepared, and their abilities to inhibit IL-1beta production were evaluated. Some compounds showed potent inhibitory activity against IL-1beta production in HL-60 cells stimulated with lipopolysaccharide (LPS). The synthesis and structure-activity relationships of these compounds are described.

Synthesis and bioactivities of novel pyridazine derivatives: inhibitors of interleukin-1 beta (IL-1beta) production

New pyridazine derivatives were prepared, and their abilities to inhibit IL-1beta production were evaluated. Some compounds showed potent inhibitory activity against IL-1beta production in HL-60 cells stimulated with lipopolysaccharide (LPS). The synthesis and structure-activity relationships of these compounds are described.

New approaches to treatment in systemic vasculitis: biological therapies

Although the effectiveness of biological agents in systemic vasculitis is unproven, their introduction heralds a new era of vasculitis treatment. These agents offer the promise of targeted immunotherapies; the possibility of greater efficacy (and fewer side-effects) than conventional vasculitis treatments; and the potential to provide novel insights into the pathophysiology of these diseases-insights that may be gained only by using these agents in humans. Challenges to the investigation of these therapies in the systemic vasculitides exist, but important basic and clinical investigations are already in progress. We review the major issues facing the investigation of biological agents in vasculitis; examine the rationale for believing that biological strategies in vasculitis will be efficacious; identify several candidate targets for biological approaches; and discuss the results to date of early studies. The potential biological targets discussed include cytokines such as tumour necrosis factor; interleukins-1, -6, and -12; interferon-gamma; the co-stimulatory molecules B7-1 and B7-2; and others.

Have the new drugs relieved the burden of the orthopedic surgeon?

Rheumatoid arthritis (RA) represents a chronic joint inflammation that leads to destructive lesions of joint cartilage and periarticular bone. Increased understanding of the molecular and cellular mechanisms of RA and recent advantages in molecular technology have resulted in new antirheumatic drugs such as tumor necrosis factor-alpha blockers, inhibitors of interleukin-1, and novel disease-modifying antirheumatic drugs such as leflunomide. This review summarizes the important effects of the novel antirheumatic drugs and their potential impact on the work of orthopedic surgeons. The ability of these agents not only to improve the clinical signs and symptoms of RA but also to prevent progressive joint damage promises support to the work of orthopedic surgeons and to the interdisciplinary treatment of RA patients. The challenge, however, will be to conduct studies that show the concrete way in which the single drugs may best relieve the burden of the orthopedic surgeon.