Blockade of translationally controlled tumor protein attenuated the aggressiveness of fibroblast-like synoviocytes and ameliorated collagen-induced arthritis

Peptoniphilus gorbachii alleviates collagen-induced arthritis in mice by improving intestinal homeostasis and immune regulation

Introduction

The intricate connection between gut microbiota and rheumatoid arthritis (RA) pathogenesis has gained prominence, although the specific microbial species contributing to RA development remain largely unknown. Recent studies have sought to comprehensively explore alterations in the human microbiome, focusing on identifying disease-related microbial species through blood analysis. Consequently, this study aimed to identify RA-associated microbial species using a serum microbial array system and to investigate the efficacy and underlying mechanisms of potential microbial species for RA treatment.

Methods

Serum immunoglobulin M levels against 384 intestinal microbial species were assessed using a microbial microarray in patients with RA and healthy individuals. We investigated the therapeutic potential of the identified microbial candidate regarding arthritis development, immune responses, gut barrier function, and gut microbiome using a collagen-induced arthritis (CIA) mouse model.

Results

Our findings revealed significant alterations in antibody levels against 36 microbial species in patients with RA compared to healthy individuals. Notably, the antibody levels against Peptoniphilus gorbachii (PG) were decreased in patients with RA and exhibited an inverse correlation with RA disease activity. In vitro experiments demonstrated that PG produced acetate and butyrate, while exhibiting anti-inflammatory properties. In CIA mice, PG administration suppressed arthritis symptoms, reduced the accumulation of inflammatory monocytes in the mesenteric lymph nodes, and downregulated gene expression of pro-inflammatory cytokines in the ileum. Additionally, PG supplementation restored intestinal barrier integrity and partially resolved gut microbial dysbiosis in CIA mice. The fecal microbiota in PG-treated mice corresponded to improved intestinal barrier integrity and reduced inflammatory responses.

Conclusion

This study highlights the potential of serum-based detection of anti-microbial antibodies to identify microbial targets at the species level for RA treatment. Moreover, our findings suggest that PG, identified through the microbial microarray analysis, holds therapeutic potential for RA by restoring intestinal barrier integrity and suppressing the immunologic response associated with RA.

Targeting the translationally controlled tumor protein by a monoclonal antibody improves allergic airway inflammation in mice

Secretion of translationally controlled tumor protein (TCTP) was found in body fluids during the late phase of allergic reactions, implicating TCTP in allergic diseases. Furthermore, blocking TCTP has been shown to be helpful in treating asthma and allergies in animal models. The objectives of this study were to produce anti-TCTP monoclonal antibodies (mAbs), test their ability to inhibit the cytokine-like function of dimeric TCTP (dTCTP) in vitro and to assess their therapeutic effects in a murine model of ovalbumin (OVA)-induced airway inflammation. We first verified the inhibitory effects of 4 anti-TCTP mAbs on dTCTP-induced secretion of IL-8 in BEAS-2B cells. To investigate the anti-inflammatory effect of anti-TCTP mAbs on allergic airway inflammation, we treated OVA-sensitized mice with anti-TCTP mAbs before OVA challenge. The changes in bronchoalveolar lavage fluid (BALF) cells, IL-4, IL-5, and IL-13 levels in both BALF and lung homogenates, plasma levels of OVA-specific IgE, and lung tissues were analyzed. We found that JEW-M449 anti-TCTP mAb bound to the flexible loop of TCTP and significantly inhibited dTCTP-induced IL-8 release, making it the most effective inhibitor in our study. We also found that treatment with JEW-M449 significantly reduced the infiltration of inflammatory cells and suppressed the OVA-induced upregulation of type 2 cytokines in both BALF and lung homogenates in a dose-dependent manner. In addition, JEW-M449 significantly attenuated the degree of goblet cell hyperplasia and mucus secretion. Our results demonstrate that specific targeting of the flexible loop of TCTP is a potent strategy for treating airway inflammatory diseases.

Harnessing the value of TCTP in breast cancer treatment resistance: an opportunity for personalized therapy

Early identification of breast cancer (BC) patients at a high risk of progression may aid in therapeutic and prognostic aims. This is especially true for metastatic disease, which is responsible for most cancer-related deaths. Growing evidence indicates that the translationally controlled tumor protein (TCTP) may be a clinically relevant marker for identifying poorly differentiated aggressive BC tumors. TCTP is an intriguing protein with pleiotropic functions, which is involved in multiple signaling pathways. TCTP may also be involved in stress response, cell growth and proliferation-related processes, underlying its potential role in the initiation of metastatic growth. Thus, TCTP marks specific cancer cell sub-populations with pronounced stress adaptation, stem-like and immune-evasive properties. Therefore, we have shown that in vivo phospho-TCTP levels correlate with the response of BC cells to anti-HER2 agents. In this review, we discuss the clinical relevance of TCTP for personalized therapy, specific TCTP-targeting strategies, and currently available therapeutic agents. We propose TCTP as an actionable clinically relevant target that could potentially improve patient outcomes.

Inhibitors of dimerized translationally controlled tumor protein, a histamine releasing factor, may serve as anti-allergic drug candidates

It has been established that translationally controlled tumor protein (TCTP), also called histamine releasing factor (HRF), exhibits cytokine-like activities associated with initiation of allergic responses only after forming dimers (dTCTP). Agents that inhibit dTCTP by preventing its dimerization or otherwise block its function, also block development of allergic reactions, thereby serving as potential drugs to treat allergic diseases. Several lines of evidence have proven that peptides and antibodies that specifically inhibit the interactions between dTCTP and either its putative receptor or immunoglobulins exhibit significant in vivo efficacy as potential anti-inflammatory agents in murine models of allergic inflammatory diseases. This review highlights the development of several inhibitors targeting dTCTP and discusses how they affect the pathophysiologic processes of allergic and inflammatory diseases in several animal models and offers new perspectives on anti-allergic drug discovery.

Meclizine, a piperazine-derivative antihistamine, binds to dimerized translationally controlled tumor protein and attenuates allergic reactions in a mouse model

Translationally controlled tumor protein (TCTP), a highly conserved protein present in most eukaryotes, is involved in numerous biological processes. Only the dimeric form of TCTP (dTCTP) formed during inflammatory conditions exhibits cytokine-like activity. Therefore, dTCTP is considered as a therapeutic target for allergic diseases. Because monomeric TCTP (mTCTP) and dTCTP share a high topological similarity, we hypothesized that small molecules interacting with mTCTP would also bind to dTCTP and interfere with dTCTP-based cellular processes. In this study, nine compounds listed in the literature as interacting with mTCTP were investigated for their ability to suppress the activity of extracellular dTCTP in bronchial epithelial cells. It was found that one of the nine, meclizine, a piperazine-derivative antihistamine, significantly reduced IL-8 release and suppressed the NF-κB pathway. The direct interaction of meclizine with dTCTP was confirmed by surface plasmon resonance (SPR). Also, we found that meclizine can attenuate ovalbumin (OVA)-induced airway inflammation in mice. Therefore, meclizine might be a potential anti-allergic drug as an inhibitor for dTCTP.

Role of Translationally Controlled Tumor Protein (TCTP) in the Development of Hypertension and Related Diseases in Mouse Models

Translationally controlled tumor protein (TCTP) is a multifunctional protein that plays a wide variety of physiological and pathological roles, including as a cytoplasmic repressor of Na,K-ATPase, an enzyme pivotal in maintaining Na+ and K+ ion gradients across the plasma membrane, by binding to and inhibiting Na,K-ATPase. Studies with transgenic mice overexpressing TCTP (TCTP-TG) revealed the pathophysiological significance of TCTP in the development of systemic arterial hypertension. Overexpression of TCTP and inhibition of Na,K-ATPase result in the elevation of cytoplasmic Ca2+ levels, which increases the vascular contractility in the mice, leading to hypertension. Furthermore, studies using an animal model constructed by multiple mating of TCTP-TG with apolipoprotein E knockout mice (ApoE KO) indicated that TCTP-induced hypertension facilitates the severity of atherosclerotic lesions in vivo. This review attempts to discuss the mechanisms underlying TCTP-induced hypertension and related diseases gleaned from studies using genetically altered animal models and the potential of TCTP as a target in the therapy of hypertension-related pathological conditions.

Dimeric translationally controlled tumor protein-binding peptide 2 attenuates imiquimod-induced psoriatic inflammation through induction of regulatory T cells

Psoriasis is a chronic skin inflammation caused by a dysfunctional immune system, which causes systemic inflammation in various organs and tissues. Due to the risk of systemic inflammation and recurrence of psoriasis, it is important to identify the critical targets in the pathogenesis of psoriasis and develop targeted therapeutics. Dimerized translationally controlled tumor protein (dTCTP) promotes immune cell activation as a pro-inflammatory cytokine and plays a role in developing allergic diseases such as asthma and rhinitis. Here, we sought to explore whether dTCTP and its inhibition contributed to the development and control of imiquimod (IMQ)-induced psoriasis. Topical application of IMQ inflamed the skin of the back and ear, increased inflammatory cytokines, and decreased regulatory T cell markers. Interestingly, TCTP was significantly increased in inflamed skin and immune cells such as T cells, B cells, and macrophages after IMQ treatment and was secreted into the serum to undergo dimerization. Extracellular dTCTP treatment selectively suppressed regulatory T (Treg) cells, not other effector T helper (Th) cells, and increased M1 macrophages. Moreover, dTCTP-binding peptide 2 (dTBP2), a dTCTP inhibitor peptide, effectively attenuated the systemic inflammatory responses, including Th17 cell response, and alleviated psoriatic skin inflammation. dTBP2 blocked dTCTP-mediated Treg suppression and stimulated the expression of Treg cell markers in the spleen and inflammatory skin lesions. These results suggest that dTCTP dysregulated immune balance through Treg suppression in psoriatic inflammation and that functional inhibition of dTCTP by dTBP2 maintained immune homeostasis and attenuated inflammatory skin diseases by expanding Treg cells.

Low-Dose Interleukin-2 Altered Gut Microbiota and Ameliorated Collagen-Induced Arthritis

Purpose

Low-dose interleukin-2 (ld-IL-2) has been shown to regulate the balance between effector T and regulatory T (Treg) cells and has been used in several clinical trials to treat autoimmune diseases including rheumatoid arthritis (RA). In this study, we investigated the effects of ld-IL-2 on collagen-induced arthritis (CIA) in mice.

Methods

Arthritis severity in CIA mice was measured using the arthritis index (AI), radiographs, and hematoxylin and eosin staining. Cytokines were detected using enzyme-linked immunosorbent assay. Gut microbiota alterations and short-chain fatty acid production were analyzed through 16S rRNA sequencing and gas chromatography.

Results

The AI scores of CIA mice treated with ld-IL-2 were significantly lower compared to the model group, which significantly reduced the severity of arthritis. Ld-IL-2 also altered the gut microbiota in CIA mice. The diversity, composition, and dominant species of gut microbiota were altered by ld-IL-2 treatment. Ld-IL-2 also increased short-chain fatty acid levels. There was a strong correlation between ld-IL-2 treatment and improved gut microbiota.

Conclusion

Ld-IL-2 significantly ameliorated joint inflammation and bone damage and improved gut microbial dysbiosis in CIA, indicating that it may be a promising therapy for RA patients.

dTBP2 attenuates severe airway inflammation by blocking inflammatory cellular network mediated by dTCTP

Dimeric translationally controlled tumor protein (dTCTP), also known as histamine-releasing factor, amplifies allergic responses and its production has been shown to increase in inflammatory diseases such as allergic asthma. Despite the critical role of dTCTP in allergic inflammation, little is known about its production pathways, associated cellular networks, and underlying molecular mechanisms. In this study, we explored the dTCTP-mediated inflammatory networks and molecular mechanisms of dTCTP associated with lipopolysaccharides (LPS)-induced severe asthma. LPS stimulation increased dTCTP production by mast cells and dTCTP secretion during degranulation, and extracellular dTCTP subsequently increased the production of pro-inflammatory molecules, including IL-8, by airway epithelial cells without affecting mast cell activation. Furthermore, dimeric TCTP-binding peptide 2 (dTBP2), a dTCTP inhibitor peptide, selectively blocked the dTCTP-mediated signaling network from mast cells to epithelial cells and decreased IL-8 production through IkB induction and nuclear p65 export in airway epithelial cells. More importantly, dTBP2 efficiently attenuated LPS-induced severe airway inflammation in vivo, resulting in decreased immune cell infiltration and IL-17 production and attenuated dTCTP secretion. These results suggest that dTCTP produced by mast cells exacerbates airway inflammation through activation of airway epithelial cells in a paracrine signaling manner, and that dTBP2 is beneficial in the treatment of severe airway inflammation by blocking the dTCTP-mediated inflammatory cellular network.

Dimerized Translationally Controlled Tumor Protein-Binding Peptide 2 Attenuates Systemic Anaphylactic Reactions Through Direct Suppression of Mast Cell Degranulation

Dimerized translationally controlled tumor protein (dTCTP) amplifies allergic responses through activation of several types of immune cells and release of inflammatory mediators. In particular, dTCTP plays an important role in histamine release by triggering mast cells and has been proposed as a target in the treatment of allergic diseases. dTCTP-binding peptide 2 (dTBP2) is known to attenuate severe allergic rhinitis and asthma through inhibition of dTCTP activity on airway epithelial cells and T cells; however, it is unclear whether dTBP2 affects mast cell function and mast cell disease. In this study, we explored the effects of dTBP2 on mast cell degranulation and allergen-induced anaphylactic reactions. We found that bacterial product lipopolysaccharide increased the expression of dTCTP in mast cells and rapidly released dTCTP by the mast cell stimulator compound 48/80. Interestingly, the released dTCTP further promoted mast cell degranulation in an autocrine activation manner and increased calcium mobilization in mast cells, which is essential for degranulation. Furthermore, dTBP2 directly and dose-dependently inhibited in vitro mast cell degranulation enhanced by compound 48/80, suggesting a direct and potent anti-anaphylactic activity of dTBP2. dTBP2 also significantly suppressed the dTCTP-induced degranulation and histamine release through inhibition of the p38 MAPK signaling pathway and suppression of lysosomal expansion and calcium mobilization in mast cells. More importantly, in vivo administration of dTBP2 decreased mortality and significantly attenuated histamine release and inflammatory cytokine production in compound 48/80-induced systemic anaphylactic reactions. These results suggest that dTBP2 is beneficial for the control of anaphylaxis with increased dTCTP.

Role of TCTP in Cell Biological and Disease Processes

Translationally controlled tumor protein (TCTP), also referred to as histamine-releasing factor (HRF) or fortilin, is a multifunctional protein, expressed in essentially all eukaryotic organisms [...].