Search

Interleukin-6 (IL-6) is a major pro-inflammatory cytokine that demonstrates a robust correlation with age and body mass index (BMI) as part of the senescence-associated secretory phenotype. IL-6 cytokines also play a crucial role in metabolic homeostasis and regenerative processes primarily via the canonical STAT3 pathway. Thus, selective modulation of IL-6 signaling may offer a unique opportunity for therapeutic interventions. Our recent studies identified a novel non-canonical signaling pathway that involves prolonged activation of SRC family of kinases (SFKs) by IL-6/gp130, where genetic or pharmacological inhibition of this pathway was protective in several acute injury models. This study was designed to assess the effect of a small molecule (R159) that inhibits the non-canonical signaling in a mouse model of multimorbidity induced by chronic inflammation. Aged mice were fed a high-fat diet (HFD) to exacerbate chronic inflammation and inflammaging-related conditions, and R159 significantly decreased systemic inflammatory responses in adipose tissue and liver. R159 was protective against trabecular bone and articular cartilage loss and markedly prevented neurogenesis decline. Moreover, R159 reduced weight gain induced by HFD and increased physical activity levels. These findings suggest that selective pharmacological inhibition of SFK signaling downstream of IL6/gp130 offers a promising strategy to alleviate systemic chronic inflammation and relevant multimorbidity. [ABSTRACT FROM AUTHOR]

Breast cancer stem cells (CSCs) are resistant to most cancer therapeutics and contribute to tumor recurrence and metastasis. Two breast CSC-promoting transcription factors, truncated glioma-associated oncogene homolog 1 (tGLI1) and signal transducer and activator of transcription 3 (STAT3), have been reported to be frequently co-expressed in HER2-enriched breast cancer and triple-negative breast cancer (TNBC), undergo protein-protein interactions for gene regulation and activation, and functionally cooperate to promote breast CSCs. STAT3 can be activated by activated interleukin-6 receptor/glycoprotein-130 (IL-6R/GP130). Co-targeting of tGLI1 and IL-6R/GP130 has not been investigated in breast cancer or any tumor type. Here, we report that tGLI1 and GP130 are co-overexpressed in the majority of HER2-enriched breast cancers and TNBCs at 53.8% and 44.4%, respectively. tGLI1+IL-6/IL-6R/GP130 signaling is frequently co-enriched and co-activated in HER2-enriched breast cancer and TNBC when compared to luminal subtypes. tGLI1+GP130 co-overexpression strongly promotes CSCs of HER2-enriched breast cancer and TNBC. FDA-approved tGLI1 inhibitor Ketoconazole and GP130 inhibitor Bazedoxifene synergize against breast cancer proliferation and CSC phenotypes in vitro and reduce TNBC tumor growth and metastatic burden in vivo. Our study demonstrates, for the first time, that co-targeting tGLI1 and IL-6R/GP130/STAT3 signaling pathways is synergistic against HER2-enriched breast cancer and TNBC, warranting future clinical investigations. [ABSTRACT FROM AUTHOR]

Historically, cytokines belonging to the gp130 family bind to specific ligand‐binding receptors that stimulate cell signaling through a receptor complex comprising gp130 or gp130 together with another structurally related signaling receptor. However, recent findings increasingly dispel these stereotypes and suggest that the receptor specificity of gp130‐activating cytokines is less strict than originally assumed. Weitz et al. now provide the latest example of this pleiotropy and report that human interleukin‐6 can bind and stimulate signaling via the interleukin‐11 receptor. Possible biological and therapeutic consequences of these findings are discussed. [ABSTRACT FROM AUTHOR]

Debilitating abdominal pain is a common symptom affecting patients with chronic pancreatitis (CP). CP pain is dynamic due to multiple underlying mechanisms. The objective of this study was to 1) evaluate changes in pain phenotype at one year follow-up and 2) validate putative pain biomarkers in a prospective cohort study. The Neuropathic and Nociceptive PROMIS-PQ questionnaires were used to classify pain for participants with in the PROCEED study. Putative serum biomarkers were measured via immunoassay. At enrollment, 17.6 % (120/681) subjects with CP reported no pain in the previous year. Of those, 29 % experienced pain during the 1 yr follow-up whereas 18 % of those with pain prior to enrollment reported no pain during the 1 yr follow-up period. Of the 393 subjects with PROMIS-PQ data at enrollment, 212 also had follow-up data at 1 yr. Approximately half (53.3 %) of those individuals changed pain phenotype between baseline and follow-up. At 1 yr, serum TGFβ1 level was negatively correlated with nociceptive T-scores (p = 0.006). GP130 was significantly correlated with both nociceptive (p = 0.012) and neuropathic T-scores (p = 0.043) at 1 yr, which is consistent with the previously published findings. The positive association between TGFβ1 and pain is not maintained over time, suggesting it is a poor pain biomarker. However, serum GP130 is a consistent biomarker for mixed-type pain in CP. Preclinical studies show that targeting TGFβ1 or IL-6 (ligand for GP130) is sufficient to inhibit CP pain supporting further investigation of this as a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Targeting the interleukin-6 (IL-6)/glycoprotein 130 (GP130) signaling pathway holds significant promise for cancer therapy given its essential role in the survival and progression of various cancer types. We have identified that bazedoxifene (BZA), a Food and Drug Administration (FDA)-approved drug used for the prevention of postmenopausal osteoporosis, when combined with conjugated estrogens in Duavee, also has a novel function as an inhibitor of IL-6/GP130 interaction. BZA is currently under investigation for its potential anticancer therapeutic function through the inhibition of the IL-6/GP130 pathway. Numerous studies have highlighted the efficacy of BZA (monotherapy or combined with other chemotherapy drugs) in impeding progression across multiple cancers. In this review, we mainly focus on the anticancer activity of BZA and the underlying anticancer mechanism through inhibition of the IL-6/GP130 pathway, aiming to provide valuable insights for the design and execution of further research and the potential repositioning of BZA in oncological clinical trials.

Abstract Background Leukemia inhibitory factor (LIF) is a multifunctional member of the IL-6 cytokine family that activates downstream signaling pathways by binding to the heterodimer consisting of LIFR and gp130 on the cell surface. Previous research has shown that LIF is highly expressed in various tumor tissues (e.g. pancreatic cancer, breast cancer, prostate cancer, and colorectal cancer) and promotes cancer cell proliferation, migration, invasion, and differentiation. Moreover, the overexpression of LIF correlates with poor clinicopathological characteristics. Therefore, we hypothesized that LIF could be a promising target for the treatment of cancer. In this work, we developed the antagonist antibody 1G11 against LIF and investigated its anti-tumor mechanism and its therapeutic efficacy in mouse models. Results A series of single-chain variable fragments (scFvs) targeting LIF were screened from a naive human scFv phage library. These scFvs were reconstructed in complete IgG form and produced by the mammalian transient expression system. Among the antibodies, 1G11 exhibited the excellent binding activity to human, cynomolgus monkey and mouse LIF. Functional analysis demonstrated 1G11 could block LIF binding to LIFR and inhibit the intracellular STAT3 phosphorylation signal. Interestingly, 1G11 did not block LIF binding to gp130, another LIF receptor that is involved in forming the receptor complex together with LIFR. In vivo, intraperitoneal administration of 1G11 inhibited tumor growth in CT26 and MC38 models of colorectal cancer. IHC analysis demonstrated that p-STAT3 and Ki67 were decreased in tumor tissue, while c-caspase 3 was increased. Furthermore, 1G11 treatment improves CD3+, CD4 + and CD8 + T cell infiltration in tumor tissue. Conclusions We developed antagonist antibodies targeting LIF/LIFR signaling pathway from a naive human scFv phage library. Antagonist anti-LIF antibody exerts antitumor effects by specifically reducing p-STAT3. Further studies revealed that anti-LIF antibody 1G11 increased immune cell infiltration in tumor tissues.

The cytokine interleukin 6 (IL‐6) signals via the IL‐6 α‐receptor (IL‐6Rα or IL‐6R) in complex with the gp130 β‐receptor. Cell type restricted expression of the IL‐6R limits the action of IL‐6 mainly to hepatocytes and some immune cells. Here, we show that IL‐6 also binds to the IL‐11 α receptor (IL‐11Rα or IL‐11R) and induces signaling via IL‐11R:gp130 complexes, albeit with a lower affinity compared to IL‐11. Antagonistic antibodies directed against IL‐11R, but not IL‐6R, inhibit IL‐6 signaling via IL‐11R:gp130 receptor complexes. Notably, IL‐11 did not cross‐react with IL‐6R. IL‐11R has also been identified as an alternative α receptor for the CNTF/IL‐6‐derived chimeric cytokine IC7, which has recently been shown to induce weight loss in mice. Accordingly, the effects of therapeutic monoclonal antibodies against IL‐6 or IL‐6R, which both block IL‐6 signaling, may be slightly different. These findings provide new insights into IL‐6 signaling and therefore offer new potential therapeutic intervention options in the future. [ABSTRACT FROM AUTHOR]

Targeting the interleukin-6 (IL-6)/glycoprotein 130 (GP130) signaling pathway holds significant promise for cancer therapy given its essential role in the survival and progression of various cancer types. We have identified that bazedoxifene (BZA), a Food and Drug Administration (FDA)-approved drug used for the prevention of postmenopausal osteoporosis, when combined with conjugated estrogens in Duavee, also has a novel function as an inhibitor of IL-6/GP130 interaction. BZA is currently under investigation for its potential anticancer therapeutic function through the inhibition of the IL-6/GP130 pathway. Numerous studies have highlighted the efficacy of BZA (monotherapy or combined with other chemotherapy drugs) in impeding progression across multiple cancers. In this review, we mainly focus on the anticancer activity of BZA and the underlying anticancer mechanism through inhibition of the IL-6/GP130 pathway, aiming to provide valuable insights for the design and execution of further research and the potential repositioning of BZA in oncological clinical trials. [ABSTRACT FROM AUTHOR]

• A novel case of ALG11-CDG, a very rare disease, is reported. • Novel compound heterozygous variants: c.1307G> T (p.G436V) and c.1403G> A (p.R468H) are identified in ALG11 gene. • These two variants decreased stability of the mutant protein and concurrent hypoglycosylation of GP130, a hyperglycosylated protein. Congenital disorders of glycosylation (CDG) represent a heterogeneous group of rare inherited metabolic disorders due to abnormalities in protein or lipid glycosylation pathways, affecting multiple systems, and frequently being accompanied by neurological symptoms. ALG11-CDG, also known as CDG-1p, arises from a deficiency in a specific mannosyltransferase encoded by the ALG11 gene. To date, only 17 cases have been documented, and these patients have prominent clinical phenotypes, including seizures, developmental delay, and microcephaly. We describe a novel case of a four-month-old boy from a Chinese family exhibiting developmental delay, seizures, and microcephaly. Trio whole-exome sequencing (WES) and subsequent Sanger sequencing were employed to identify the potential genetic cause, and functional study was performed to evaluate the pathogenicity of genetic variant identified. Trio WES unveiled novel compound heterozygous variants: c.1307G> T (p.G436V) and c.1403G> A (p.R468H) within exon 4 of the ALG11 gene, inherited from the father and mother, respectively. Subsequent in vitro functional analysis revealed decreased stability of the mutant protein and concurrent hypoglycosylation of GP130, a hyperglycosylated protein. Our findings not only expand the clinical and variant spectrum of ALG11-CDG, but also emphasize the importance of WES as a first-tier genetic test in determining the molecular diagnosis. [ABSTRACT FROM AUTHOR]

An upregulation of the gp130-signalling cascade has been reported in multiple cancers, making gp130 an attractive target for the development of anticancer drugs. An inverted-funnel-like approach was utilised along with various structure-based drug designing strategies to discover and optimise novel potential inhibitors of gp130. The study resulted in the discovery of 2 ligands- 435 and 510, both of which exhibit a very high-binding affinity towards the gp130 D1 domain which controls cytokine recognition and interaction thus being involved in complexation. The two resulting complexes remained stable over time with the ligands maintaining a steady interaction with the target. This inference is drawn from their RMSD, Rg, SASA and RMSF analysis. We also tested the protein folding patterns based on their principal component analysis, energy of surface and landscape. The leads also displayed a more favourable ADMET profile than their parent compounds. The two lead candidates show a better therapeutic profile in comparison to the two existing drugs- bazedoxifene and raloxifene. Both these potential leads can be addressed for their activity in-vitro and can be used as a potential anti-cancer treatment as well as to combat Covid-19 related cytokine storm. [ABSTRACT FROM AUTHOR]

Inflammation with expression of interleukin 6 (IL-6) in the central nervous system (CNS) occurs in several neurodegenerative/neuroinflammatory conditions and may cause neurochemical changes to endogenous neuroprotective systems. Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are two neuropeptides with well-established protective and anti-inflammatory properties. Yet, whether PACAP and VIP levels are altered in mice with CNS-restricted, astrocyte-targeted production of IL-6 (GFAP-IL6) remains unknown. In this study, PACAP/VIP levels were assessed in the brain of GFAP-IL6 mice. In addition, we utilised bi-genic GFAP-IL6 mice carrying the human sgp130-Fc transgene (termed GFAP-IL6/sgp130Fc mice) to determine whether trans-signalling inhibition rescued PACAP/VIP changes in the CNS. Transcripts and protein levels of PACAP and VIP, as well as their receptors PAC1, VPAC1 and VPAC2, were significantly increased in the cerebrum and cerebellum of GFAP-IL6 mice vs. wild type (WT) littermates. These results were paralleled by a robust activation of the JAK/STAT3, NF-κB and ERK1/2MAPK pathways in GFAP-IL6 mice. In contrast, co-expression of sgp130Fc in GFAP-IL6/sgp130Fc mice reduced VIP expression and activation of STAT3 and NF-κB pathways, but it failed to rescue PACAP, PACAP/VIP receptors and Erk1/2MAPK phosphorylation. We conclude that forced expression of IL-6 in astrocytes induces the activation of the PACAP/VIP neuropeptide system in the brain, which is only partly modulated upon IL-6 trans-signalling inhibition. Increased expression of PACAP/VIP neuropeptides and receptors may represent a homeostatic response of the CNS to an uncontrolled IL-6 synthesis and its neuroinflammatory consequences. [ABSTRACT FROM AUTHOR]

Summary: Purpose: Multiple Myeloma (MM) is considered an incurable, biologically heterogeneous disease of the plasma cells. The clinical data on the association between stress and the molecular mechanism of stress hormone receptor expression and its relationship with IL‑6 signaling pathway have not yet proposed a clear answer in MM. This study aims to explore the effect of isoproterenol and propranolol, which are beta-adrenergic agonists and antagonists, respectively on suppressor of cytokine signaling (SOCS) and IL-6/gp130 signaling in MM cell lines. Material and methods: Four different MM cell lines (KMM‑1, RPMI 8226, LP‑1, and L363) were treated with isoproterenol and propranolol. Optimal dosages of isoproterenol and propranolol were determined, and the mRNA expression levels of IL‑6, gp130, and SOCS‑1 were examined using qRT-PCR. Results: The analysis of our results indicated that propranolol, as a β-adrenoreceptor antagonist, could increase MM cell death and ameliorate IL‑6 and its receptor gp130 in addition to up-regulate SOCS‑1 gene expression. On the other hand, isoproterenol, as a β-adrenoreceptor agonist, could provoke MM cell viability and IL‑6 expression. Conclusions: β‑adrenergic signaling seems to affect cell viability through targeting IL-6/gp130 and SOCS‑1 signaling in MM, underscoring the importance of further studies on stress hormones and IL‑6 suppressors as potent candidates for MM therapy. [ABSTRACT FROM AUTHOR]

Background: Leukemia inhibitory factor (LIF) is a multifunctional member of the IL-6 cytokine family that activates downstream signaling pathways by binding to the heterodimer consisting of LIFR and gp130 on the cell surface. Previous research has shown that LIF is highly expressed in various tumor tissues (e.g. pancreatic cancer, breast cancer, prostate cancer, and colorectal cancer) and promotes cancer cell proliferation, migration, invasion, and differentiation. Moreover, the overexpression of LIF correlates with poor clinicopathological characteristics. Therefore, we hypothesized that LIF could be a promising target for the treatment of cancer. In this work, we developed the antagonist antibody 1G11 against LIF and investigated its anti-tumor mechanism and its therapeutic efficacy in mouse models. Results: A series of single-chain variable fragments (scFvs) targeting LIF were screened from a naive human scFv phage library. These scFvs were reconstructed in complete IgG form and produced by the mammalian transient expression system. Among the antibodies, 1G11 exhibited the excellent binding activity to human, cynomolgus monkey and mouse LIF. Functional analysis demonstrated 1G11 could block LIF binding to LIFR and inhibit the intracellular STAT3 phosphorylation signal. Interestingly, 1G11 did not block LIF binding to gp130, another LIF receptor that is involved in forming the receptor complex together with LIFR. In vivo, intraperitoneal administration of 1G11 inhibited tumor growth in CT26 and MC38 models of colorectal cancer. IHC analysis demonstrated that p-STAT3 and Ki67 were decreased in tumor tissue, while c-caspase 3 was increased. Furthermore, 1G11 treatment improves CD3+, CD4 + and CD8 + T cell infiltration in tumor tissue. Conclusions: We developed antagonist antibodies targeting LIF/LIFR signaling pathway from a naive human scFv phage library. Antagonist anti-LIF antibody exerts antitumor effects by specifically reducing p-STAT3. Further studies revealed that anti-LIF antibody 1G11 increased immune cell infiltration in tumor tissues. [ABSTRACT FROM AUTHOR]

Simple Summary: Microsatellite instability (MSI) is crucial in colorectal cancer (CRC) due to deficient mismatch repair (MMR), often caused by MLH1 and MSH2 loss of function. This defect affects microsatellite loci globally. Recently, MSI at tetranucleotide loci has been identified as a distinct entity, potentially arising from isolated MSH3 loss of function due to its translocation to the cytoplasm under interleukin-6 (IL-6) influence. This study examined the impact of MSH3 and IL-6 signaling pathway polymorphisms (MSH3 exon 1, MSH3+3133A/G, IL-6-174G/C, IL-6R+48892A/C, and gp130+148G/C) on MSI types in sporadic CRC. A significant difference in gp130+148G/C genotypes (p = 0.037) and alleles (p = 0.031) was found, with the C allele being less common in tumors with di- and tetranucleotide instability (related to isolated MSH3 loss of function) compared to tumors without microsatellite instability. A functional polymorphism in gp130 may influence the IL-6 pathway, leading to MSI linked to MSH3 loss of function. Microsatellite instability (MSI) has been recognized as an important factor in colorectal cancer (CRC). It arises due to deficient mismatch repair (MMR), mostly attributed to MLH1 and MSH2 loss of function leading to a global MMR defect affecting mononucleotide and longer microsatellite loci. Recently, microsatellite instability at tetranucleotide loci, independent of the global MMR defect context, has been suggested to represent a distinct entity with possibly different consequences for tumorigenesis. It arises as a result of an isolated MSH3 loss of function due to its translocation from the nucleus to the cytoplasm under the influence of interleukin-6 (IL-6). In this study the influence of MSH3 and IL-6 signaling pathway polymorphisms (MSH3 exon 1, MSH3+3133A/G, IL-6-174G/C, IL-6R+48892A/C, and gp130+148G/C) on the occurrence of different types of microsatellite instability in sporadic CRC was examined by PCR–RFLP and real-time PCR SNP analyses. A significant difference in distribution of gp130+148G/C genotypes (p = 0.037) and alleles (p = 0.031) was observed in CRC patients with the C allele being less common in tumors with di- and tetranucleotide instability (isolated MSH3 loss of function) compared to tumors without microsatellite instability. A functional polymorphism in gp130 might modulate the IL-6 signaling pathway, directing it toward the occurrence of microsatellite instability corresponding to the IL-6-mediated MSH3 loss of function. [ABSTRACT FROM AUTHOR]

Interleukin‐6 (IL‐6)‐type cytokines not only have key immunomodulatory functions that affect the pathogenesis of diseases such as autoimmune diseases, chronic inflammatory conditions, and cancer, but also fulfill important homeostatic tasks. Even though the pro‐inflammatory arm has hindered the development of therapeutics based on natural‐like IL‐6‐type cytokines to date, current synthetic trends might pave the way to overcome these limitations and eventually lead to immune‐inert designer cytokines to aid type 2 diabetes and brain injuries. Those synthetic biology approaches include mutations, fusion proteins, and inter‐cytokine swapping, and resulted in IL‐6‐type cytokines with altered receptor affinities, extended target cell profiles, and targeting of non‐natural cytokine receptor complexes. Here, we survey synthetic cytokine developments within the IL‐6‐type cytokine family and discuss potential clinical applications. [ABSTRACT FROM AUTHOR]

Abstract Colorectal cancer (CRC) is a worldwide health concern. Chronic inflammation is a risk factor for CRC, and interleukin-6 (IL-6) plays a pivotal role in this process. Arginine-specific mono-ADP-ribosyltransferase-1 (ART1) positively regulates inflammatory cytokines. ART1 knockdown reduces the level of glycoprotein 130 (gp130), a key transducer in the IL-6 signalling pathway. However, the relationship between ART1 and IL-6 and the resulting effects on IL-6-induced proliferation in CRC cells remain unclear. The aims of this study were to investigate the effects of ART1 knockdown on IL-6-induced cell proliferation in vitro and use an in vivo murine model to observe the growth of transplanted tumours. The results showed that compared with the control, ART1-sh cancer cells induced by IL-6 exhibited reduced viability, a lower rate of colony formation, less DNA synthesis, decreased protein levels of gp130, c-Myc, cyclin D1, Bcl-xL, and a reduced p-STAT3/STAT3 ratio (P

Skull growth involves the expansion of both the flat calvarial bones of the skull and the fibrous marginal zones, termed sutures, between them. This process depends on co‐ordinated proliferation of mesenchymal‐derived progenitor cells within the sutures, and their differentiation to osteoblasts which produce the bone matrix required to expand the size of the bony plates. Defects lead to premature closure of these sutures, termed craniosynostosis, resulting in heterogeneous head shape differences due to restricted growth of one or more sutures. The impact on the individual depends on how many and which sutures are affected and the severity of the effect. Several genetic loci are responsible, including a wide range of variants in the gene for the interleukin 11 receptor (IL11RA, OMIM#600939). Recent work from Kespohl and colleagues provides new insights into how some of these variants influence IL‐11R function; we discuss their influences on IL‐11R structure and IL‐11 function as a stimulus of osteoblast differentiation. [ABSTRACT FROM AUTHOR]

Interleukin‐11 (IL‐11) is a member of the IL‐6 family of cytokines and is an important factor for bone homeostasis. IL‐11 binds to and signals via the membrane‐bound IL‐11 receptor (IL‐11R, classic signaling) or soluble forms of the IL‐11R (sIL‐11R, trans‐signaling). Mutations in the IL11RA gene, which encodes the IL‐11R, are associated with craniosynostosis, a human condition in which one or several of the sutures close prematurely, resulting in malformation of the skull. The biological mechanisms of how mutations within the IL‐11R are linked to craniosynostosis are mostly unexplored. In this study, we analyze two variants of the IL‐11R described in craniosynostosis patients: p.T306_S308dup, which results in a duplication of three amino‐acid residues within the membrane‐proximal fibronectin type III domain, and p.E364_V368del, which results in a deletion of five amino‐acid residues in the so‐called stalk region adjacent to the plasma membrane. The stalk region connects the three extracellular domains to the transmembrane and intracellular region of the IL‐11R and contains cleavage sites for different proteases that generate sIL‐11R variants. Using a combination of bioinformatics and different biochemical, molecular, and cell biology methods, we show that the IL‐11R‐T306_S308dup variant does not mature correctly, is intracellularly retained, and does not reach the cell surface. In contrast, the IL‐11R‐E364_V368del variant is fully biologically active and processed normally by proteases, thus allowing classic and trans‐signaling of IL‐11. Our results provide evidence that mutations within the IL11RA gene may not be causative for craniosynostosis and suggest that other regulatory mechanism(s) are involved but remain to be identified. [ABSTRACT FROM AUTHOR]

Simple Summary: In cancer, including head and neck cancer (HNC), certain key players in the body's inflammatory process, such as the interleukin (IL)-6 and IL-1 systems, are associated with outcomes. We studied some of these key players in a subgroup of HNC patients. From one blood sample measured at diagnosis, we determined high levels of molecules from members of the IL-6 and IL-1 families with their associated soluble cytokine receptors. High values indicated a lower survival rate. This prediction was to some extent better than the standard clinical predictors used. The results highlight potential new targets for immune treatment development. Additionally, these findings could contribute to the refinement of cancer treatment strategies, particularly in the context of emerging immune therapies. Activation of the acute-phase cascade (APC) has been correlated with outcomes in various cancers, including head and neck squamous cell carcinoma (HNSCC). Primary drivers of the APC are the cytokines within the interleukin-6 (IL-6) and IL-1 families. Plasma levels of IL-6 family cytokines/soluble receptors (IL-6, IL-27, IL-31, OSM, CNTF, soluble (s-)gp130, s-IL-6Rα) and IL-1 family members (IL-1RA, s-IL-33Rα) were determined at diagnosis for 87 human papillomavirus (HPV)-negative (−) HNSCC patients. We then studied the 5-year Disease-Specific Survival (DSS) and Overall Survival (OS). Increased plasma levels of IL-6 (p < 0.001/p < 0.001) (DSS/OS), IL-31 (p = 0.044/p = 0.07), IL-1RA (p = 0.004/p = 0.035), soluble (s)-IL-6Rα p = 0.022/p = 0.035), and s-gp130 (p = 0.007/p = 0.003) at diagnosis were predictors of both OS and DSS from HPV(−) HNSCC patients. The cytokine DSS/OS predictions were associated with TNM stage and smoking history, whereas the soluble receptors IL-6Rα, gp130, and IL33Rα more uniquely predicted DSS/OS. Clinically, IL-6 levels above 2.5 pg/mL yielded 75% specificity and 70% sensitivity for DSS. In conclusion, high plasma levels of IL-6, IL-31, and IL-1RA, as well as the soluble receptors IL-6Rα, gp130, and IL33Rα, predicted clinical outcome. This shows their potential as candidates for both general therapy and immune therapy stratification, as well as being future platforms for the development of new immunotherapy. [ABSTRACT FROM AUTHOR]

Introduction: The cytokine interleukin-11 (IL-11) binds on its target cells to a membrane-bound IL-11R, which results in homodimerization of the signal-transducing ß-receptor gp130. Recent studies have uncovered a proinflammatory role in several diseases, including different tumor entities, and mouse models have revealed a crucial role of the IL-11/IL-11R axis in gastric cancer. However, studies regarding human gastric cancer are sparse, and whether the results obtained in mouse models also hold true in the human situation is little investigated. Material and methods: We analyzed gene expression of IL11RA, IL11, IL6R, IL6 and IL6ST in different gastric tumor and immune cell lines. Furthermore, we stimulated these cell lines with exogenous cytokines and determined intracellular signaling. Finally, we analyzed gene expression data of gastric tumor patients and correlated them with overall patient survival. Results: This study showed that different gastric tumor cell lines respond to IL-6 classic and trans-signaling, but only slightly to stimulation with IL-11. We observed that monocyte-like cell lines expressed high levels of IL-6R and responded to IL-6, but not to stimulation with IL-11. Using gene expression data, we found that IL11RA and IL11 are not overexpressed in human gastric cancer tissue and do not correlate with patient survival. However, low IL6 expression is associated with higher overall survival. Conclusions: We provided evidence for IL-6 but not IL-11 signaling in gastric tumor cells and demonstrated that IL6 expression in gastric tumors is associated with overall survival of patients. [ABSTRACT FROM AUTHOR]

The tick‐borne encephalitis virus (TBEV) serocomplex includes several medically important flavivirus members endemic to Europe, Asia, and North America, which can induce severe neuroinvasive or viscerotropic diseases with unclear mechanisms of pathogenesis. Langat virus (LGTV) shares a high sequence identity with TBEV but exhibits lower pathogenic potential in humans and serves as a model for virus‐host interactions. In this study, we demonstrated that LGTV infection inhibits the activation of gp130/JAK/STAT (Janus kinases (JAK) and signal transducer and activator of transcription (STAT)) signaling, which plays a pivotal role in numerous biological processes. Our data show that the LGTV‐infected cells had significantly lower phosphorylated STAT3 (pSTAT3) protein upon oncostatin M (OSM) stimulation than the mock‐infected control. LGTV infection blocked the nuclear translocation of STAT3 without a significant effect on total STAT3 protein level. LGTV inhibited JAK1 activation and reduced gp130 protein expression in infected cells, with the viral NS5 protein mediating this effect. TBEV infection also reduces gp130 level. On the other hand, pretreatment of Vero cells with OSM significantly reduces LGTV replication, and STAT1/STAT2 knockdown had little effect on OSM‐mediated antiviral effect, which suggests it is independent of STAT1/STAT2 and, instead, it is potentially mediated by STAT3 signlaing. These findings shed light on the LGTV and TBEV‐cell interactions, offering insights for the future development of antiviral therapeutics and improved vaccines. [ABSTRACT FROM AUTHOR]

IL6 is a proinflammatory cytokine that binds to membrane-bound IL6 receptor (IL6R) or soluble IL6R to signal via gp130 in cis or trans, respectively. We tested the hypothesis that sgp130Fc, which is believed to be a selective IL6 trans-signalling inhibitor, is in fact a non-specific inhibitor of gp130 signalling. In human cancer and primary cells, sgp130Fc inhibited IL6, IL11, OSM and CT1 cis-signalling. The IC50 values of sgp130Fc for IL6 and OSM cis-signalling were markedly (20- to 200-fold) lower than the concentrations of sgp130Fc used in mouse studies and clinical trials. sgp130 inhibited IL6 and OSM signalling in the presence of an ADAM10/17 inhibitor and the absence of soluble IL6R or OSMR, with effects that were indistinguishable from those of a gp130 neutralising antibody. These data show that sgp130Fc does not exclusively block IL6 trans-signalling and reveal instead that broad inhibition of gp130 signalling likely underlies its therapeutic effects. This proposes global or modular inhibition of gp130 as a therapeutic approach for treating human disease. [ABSTRACT FROM AUTHOR]

Genetic variants in IL6ST encoding the shared cytokine receptor for the IL-6 cytokine family GP130 have been associated with a diverse number of clinical phenotypes and disorders. We provide a molecular classification for 59 reported rare IL6ST pathogenic or likely pathogenic variants and additional polymorphisms. Based on loss- or gain-of-function, cytokine selectivity, mono- and biallelic associations, and variable cellular mosaicism, we grade six classes of IL6ST variants and explore the potential for additional variants. We classify variants according to the American College of Medical Genetics and Genomics criteria. Loss-of-function variants with (i) biallelic complete loss of GP130 function that presents with extended Stüve-Wiedemann Syndrome; (ii) autosomal recessive hyper-IgE syndrome (HIES) caused by biallelic; and (iii) autosomal dominant HIES caused by monoallelic IL6ST variants both causing selective IL-6 and IL-11 cytokine loss-of-function defects; (iv) a biallelic cytokine-specific variant that exclusively impairs IL-11 signaling, associated with craniosynostosis and tooth abnormalities; (v) somatic monoallelic mosaic constitutively active gain-of-function variants in hepatocytes that present with inflammatory hepatocellular adenoma; and (vi) mosaic constitutively active gain-of-function variants in hematopoietic and non-hematopoietic cells that are associated with an immune dysregulation syndrome. In addition to Mendelian IL6ST coding variants, there are common non-coding cis-acting variants that modify gene expression, which are associated with an increased risk of complex immune-mediated disorders and trans-acting variants that affect GP130 protein function. Our taxonomy highlights IL6ST as a gene with particularly strong functional and phenotypic diversity due to the combinatorial biology of the IL-6 cytokine family and predicts additional genotype-phenotype associations. [ABSTRACT FROM AUTHOR]

The article discusses the Langat virus (LGTV), a tick-borne flavivirus that shares genetic similarities with tick-borne encephalitis virus (TBEV). The study focuses on the impact of LGTV on the cellular interleukin (IL)-6 pathway, which plays a role in inflammation and immune cell activation. The authors found that LGTV inhibits the gp130/JAK/STAT signaling pathway by downregulating gp130 protein expression. This finding provides a potential target for therapeutic development against TBEV infection and its associated complications. Further research is needed to fully understand the correlation between TBEV and LGTV infections and the contribution of IL-6 inhibition to immune responses. [Extracted from the article]

Patients with autosomal dominant (AD) hyper-IgE syndrome (HIES) suffer from a constellation of manifestations including recurrent bacterial and fungal infections, severe atopy, and skeletal abnormalities. This condition is typically caused by monoallelic dominant-negative (DN) STAT3 variants. In 2020, we described 12 patients from eight kindreds with DN IL6ST variants resulting in a new form of AD HIES. These variants encoded truncated GP130 receptors, with intact extracellular and transmembrane domains, but lacking the intracellular recycling motif and the four STAT3-binding residues, resulting in an inability to recycle and activate STAT3. We report here two new DN variants of IL6ST in three unrelated families with HIES-AD. The biochemical and clinical impacts of these variants are different from those of the previously reported variants. The p.(Ser731Valfs*8) variant, identified in seven patients from two families, lacks the recycling motif and all the STAT3-binding residues, but its levels on the cell surface are only slightly increased and it underlies mild biological phenotypes with variable clinical expressivity. The p.(Arg768*) variant, identified in a single patient, lacks the recycling motif and the three most distal STAT3-binding residues. This variant accumulates at the cell surface and underlies severe biological and clinical phenotypes. The p.(Ser731Valfs*8) variant shows that a DN GP130 expressed at near normal levels on the cell surface can underlie heterogeneous clinical presentations, ranging from mild to severe. The p.(Arg768*) variant demonstrates that a truncated GP130 protein retaining one STAT3-binding residue can underlie severe HIES. [ABSTRACT FROM AUTHOR]

Context: Interleukin-6 (IL-6), a pro-inflammatory cytokine, plays an important role in the pathogenesis of myocardial hypertrophy. By integrating its membrane receptor complex (gp80), IL-6 activates the signal guidance components (gp130) and activates the hypertrophic signaling pathways. There is some evidence that 1,25 dihydroxyvitamin D exerts antihypertrophic effects, but the cellular and molecular mechanisms are not fully understood. The aim of this study was to evaluate the effect of calcitriol on the level of IL-6 and its receptor components in hypertrophied rat heart. Subjects and Methods: Male rats were divided into control, hypertrophy, Vitamin D + hypertrophy, and propylene glycol + hypertrophy groups. The groups receiving Vitamin D and propylene glycol were treated 2 weeks before induction of hypertrophy and 2 weeks after hypertrophy. Myocardial hypertrophy was induced by abdominal aortic stenosis. Mean arterial blood pressure was measured by cannulation of the left carotid artery, and expression of genes was determined by reverse transcription-polymerase chain reaction. Results: Blood pressure and heart-to-body weight ratio increased in hypertrophic groups compared to the control group (P < 0.01), but Vitamin D administration decreased these parameters (P < 0.05). Abdominal aortic stenosis increased IL-6 expression levels (P < 0.001) and Vitamin-D decreased IL-6 mRNA levels (P < 0.01). The expression of gp80 in the hypertrophic group increased compared to the control group (P < 0.05), but Vitamin D did not affect the expression of receptor subunits genes. Conclusions: The data from this study suggest a possible mechanism for the antihypertrophic effects of Vitamin D through the regulation of inflammatory responses during hypertrophy. Thus, Vitamin D can reduce IL-6 expression levels, thereby reducing hypertrophy.

ALG11-Congenital Disorder of Glycosylation (ALG11-CDG, also known as congenital disorder of glycosylation type Ip) is an inherited inborn error of metabolism due to abnormal protein and lipid glycosylation. We describe two unrelated patients with ALG11-CDG due to novel mutations, review the literature of previously described affected individuals, and further expand the clinical phenotype. Both affected individuals reported here had severe psychomotor disabilities and epilepsy. Their fibroblasts synthesized truncated precursor glycan structures, consistent with ALG11-CDG, while also showing hypoglycosylation of a novel biomarker, GP130. Surprisingly, one patient presented with normal transferrin glycosylation profile, a feature that has not been reported previously in patients with ALG11-CDG. Together, our data expand the clinical and mutational spectrum of ALG11-CDG.

Background and objective: Acute lung injury or acute respiratory distress syndrome (ALI/ARDS) is a life-threatening respiratory disease. Gp130 is a signal transduction receptor that participates in a variety of essential biological processes. The biological function of gp130 in ALI/ARDS is unclear. This study aims to investigate the roles and potential mechanisms of gp130 in lung injury induced by lipopolysaccharide (LPS). Methods: The ALI/ARDS mouse model was established using intratracheal LPS administration. Hematoxylin and eosin staining and bronchoalveolar lavage fluid analysis were used to evaluate the degree of lung injury. Cell apoptosis was assessed by TUNEL staining, flow cytometry, and western blot. Then the expression of gp130, IL-6, IL-10, TNF-α, and the JAK1/STAT3 signaling pathway-related proteins was assessed by RT-PCR, western blot, and immunohistochemistry. Results: The expression of gp130 increased after 24 h of LPS treatment. Inhibiting gp130 improved inflammatory infiltration and alveolar collapsed, decreased IL-6 and TNF-α levels, raised IL-10 levels, and decreased cell apoptosis in LPS-induced mice. Meanwhile, suppressing gp130 reduced the inflammatory response and cell apoptosis in LPS-induced Beas-2B cells. Furthermore, p-JAK1 and p-STAT3 expressions were elevated after LPS stimulation and decreased following gp130 inhibition, suggesting that gp130 may regulate the JAK1/STAT3 signaling pathway in LPS-induced mice and Beas-2B cells. Conclusion: The findings suggest that gp130 regulates the inflammatory response and cell apoptosis through the JAK1/STAT3 signaling pathway, thereby mitigating LPS-induced lung injury. Gp130 may be a potential therapeutic target for ALI/ARDS. [ABSTRACT FROM AUTHOR]

The study of the role of cytokines in various pathological conditions of the body is a topical area in modern biomedicine. Understanding the physiological roles played by cytokines will aid in finding applications for them as pharmacological agents in clinical practice. Interleukin 11 (IL-11) was discovered in 1990 in fibrocyte-like bone marrow stromal cells, but there has been increased interest in this cytokine in recent years. IL-11 has been shown to correct inflammatory pathways in the epithelial tissues of the respiratory system, where the main events occur during SARS-CoV-2 infection. Further research in this direction will probably support the use of this cytokine in clinical practice. The cytokine plays a significant role in the central nervous system; local expression by nerve cells has been shown. Studies show the involvement of IL-11 in the mechanisms of development of a number of pathologies of the nervous system, and therefore it seems relevant to generalize and analyze the experimental data obtained in this direction. This review summarizes information that shows the involvement of IL-11 in the mechanisms of development of brain pathologies. In the near future this cytokine will likely find clinical application for the correction of mechanisms that are involved in the formation of pathological conditions of the nervous system. [ABSTRACT FROM AUTHOR]

Obesity is the main cause of metabolic complications. Fatty liver infiltration is a companion of obesity. NAFLD is associated with impaired energy metabolism with an excess of nutrients. Mitochondrial dynamics are important for the regulation of energy balance, which regulates mitochondrial function, apoptosis, and mitophagy. The aim of this study was to investigate the effect of gp130 on the components of mitochondrial dynamics in a cellular model of steatohepatitis. Addition of IL-6/gp130 contributed to an increase in the percentage of live cells and a decrease in the percentage of dead and apoptotic cells. Addition of IL-6/gp130 increased the expression of NF-kB1 gene and mitochondrial dynamics markers (MFN2 and TFAM) in HepG2 with tBHP/Oleic. Addition of IL-6 or gp130 reduced the expression of cytoprotector genes (HSF1 and HSP70) in HepG2 cell cultures with tBHP/Oleic. Increased mitochondrial dynamics gene activity protected against HepG2 cell death in the steatohepatitis model. Trans-signaling resulted in increased TFAM and MAPLC3B, and decreased DNM1L gene expression in HepG2 with tBHP/Oleic. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is an immunosuppressive hematologic malignancy with a poor prognosis. An immunosuppressive microenvironment blunts AML therapy. However, the prognostic and therapeutic roles of the factors that mediate immunosuppression in AML remain elusive. S100 calcium-binding protein A4 (S100A4) was identified as an immunosuppression-mediating factor by analyzing The Cancer Genome Atlas AML project (TCGA-LAML) transcriptome data and data from AML-bearing mice and AML patients. The S100A4-mediated signaling pathway in myeloid-derived suppressor cells (MDSCs) was evaluated. Elevated S100A4 expression was positively associated with worse survival of AML patients, MDSCs, macrophages and immune checkpoints. S100A4 silencing downregulated the expression levels of MDSC-associated CD14, CCR2 and CCL2, reduced MDSC expansion and impaired MDSC-mediated inhibition of T cell activation and proliferation. S100A4-based prognostic signature (SPS) was an independent risk factor for AML patients. The high-risk group based on SPS was not only associated with adverse survival, MDSCs and macrophages and immune checkpoints but also insensitive to 25 chemotherapy drugs. It was also found that CCAAT enhancer binding protein beta (CEBPB) mediated S100A4 transcription. CEBPB silencing downregulated the expression levels of MDSC-associated CD14, CCR2 and CCL2. Mechanistically, S100A4 activated GP130/JAK2/STAT3 signaling in MDSCs by interacting with the cytokine-binding domain of GP130. Moreover, S100A4 mediated MDSC expansion through JAK2/STAT3 signaling. This study uncovers the critical role of S100A4 in MDSC accumulation, and S100A4-based prognostic signature may guide chemotherapy sensitivity in patients with AML. [Display omitted] • S100A4 is elevated in AML blasts and positively associated with poor survival of AML patients and immunosuppression. • Eleavted S100A4 positively correlates myeloid derived suppressor cells (MDSCs) and several immune checkpoints. • S100A4-based prognostic signature predicts immunosuppression and the insensitivity to chemodrugs. • S100A4 activates GP130/JAK2/STAT3 pathway to promote MDSC accumulation and functions in AML via interacting GP130. • CEBPB positively regulates S100A4 expression as a transcription factor and mediates several MDSC-related markers. [ABSTRACT FROM AUTHOR]

In previous study, lower levels of serum GP130 were reported in children with MPP. GP130 is an important signal transducer, the down regulation of which may influence host immune responses. In this study, we aimed to analyze the regulatory mechanism of GP130 during MP infection. Firstly, the mRNA and protein levels of GP130 both decrease and then increase with increasing multiplicity of infection (MOI: 1 to 40) of MP. The lowest levels of GP130 were detected at MOI of 5. Then, heat treated MP but not trypsin treated MP or MP extracted proteins show regulatory effect to the expression of GP130. These indicate that the down regulation of GP130 is related to protein mediate adhesion process of MP. Gene expression analysis revealed that MP affected apoptosis and the TLR4 pathway in infected cells, and the mRNA level of IL-6 was correlated with that of GP130. Further, Z-VAD-FMK (pan-caspase inhibitor) can suppress the apoptosis induced by MP infection and restore GP130 at protein level. Further studies revealed that MP infection promoted TLR4 internalization but did not activate the NF-κB pathway. The levels of surface TLR4 showed correlation with the transcription of IL-6 and GP130. TAK242 (TLR4 inhibitor) and PS341 (proteasome inhibitor) can restore the decreased transcription of GP130, both of which were able to promote NF-κB pathway activation in MP-infected cells. These suggested that the regulation of TLR4/NF-κB pathway and induced apoptosis post MP infection are involved in the down-regulation of GP130 at transcription and protein levels, respectively. The infection of Mycoplasma pneumoniae promotes the internalization of TLR4, which reduces the transcription of GP130. Meanwhile, apoptosis induced by Mycoplasma pneumoniae infection may degrade GP130 protein through Caspases. [Display omitted] • Mycoplasma pneumoniae (MP) infection promotes internalization of TLR4. • Mycoplasma pneumoniae affects GP130 transcription by TLR4 pathway. • MP infection decreases the protein levels of GP130 at multiplicity of infection of 5–20. [ABSTRACT FROM AUTHOR]

• Gp130 regulates immune function, tissue homeostasis, regeneration, and metabolism in mammals. • Dysregulation of this receptor contributes to diseases like cancer and chronic inflammation. • New chimeric receptors IL-6R ECD -gp130 TMD/ICD and gp130 ΔD1 induce STAT3 dominant signalling profiles. • These new receptors can help to customize synthetic IL-6 signaling and to understand cascade specific effects. In Interleukin (IL)-6 signalling, IL-6 site I binds to the IL-6 receptor (IL-6R) first, following by IL-6 site II interaction to domain 2/3 of gp130 to form premature trimeric IL-6:IL–6R:gp130 receptor complexes. Formation of the mature hexameric receptor complex is then facilitated by the inter-trimeric interaction of IL-6 site III with domain 1 of the opposing gp130. The two gp130-associated Janus kinases (JAKs) trans -phosphorylate when their spatiotemporal pairing is correct, which causes the activation of STAT, ERK, and AKT pathways in a balanced manner. Since the intracellular domain (ICD) of IL-6R is not needed for STAT/ERK/AKT phosphorylation, we investigated the conditions under which a chimeric IL-6R ECD -gp130 TMD/ICD receptor protein confers biological activity. For IL–6R ECD –gp130 TMD/ICD , the extracellular domain (ECD) of IL-6R was fused to the transmembrane domain (TMD) and ICD of gp130. Co-expression of IL–6R ECD –gp130 TMD/ICD with signalling-deficient gp130 variants did not induce IL-6 signalling, suggesting that the assembly of hexameric complexes failed to dimerize the IL-6R-associated JAKs correctly. By mimicking the premature trimeric receptor complex, IL-6-mediated dimerization of IL-6R ECD -gp130 TMD/ICD with the single-cytokine-binding variant gp130 ΔD1 induced signalling. Of note, IL-6 signalling via these synthetic gp130 ΔD1 :IL-6R ECD -gp130 TMD/ICD complexes resulted predominantly in STAT3 phosphorylation. A STAT3-dominated profile was also observed after IL-6-induced signalling mediated by a JAK-deficient IL–6R ECD –gp130 TMD/ICDΔJAK variant in complex with the JAK-proficient but STAT/ERK/AKT-deficient gp130 JAKΔICD variant. Our data showed that effective ERK/AKT signalling could not be executed after intracellular domain swapping from gp130 to the IL-6R. Taken together, the chimeric IL-6R/gp130 receptor may be helpful in the creation of customized synthetic IL-6 signalling. [ABSTRACT FROM AUTHOR]

Abstract Background Sepsis and inflammation can cause intensive care unit‐acquired weakness (ICUAW). Increased interleukin‐6 (IL‐6) plasma levels are a risk factor for ICUAW. IL‐6 signalling involves the glycoprotein 130 (gp130) receptor and the JAK/STAT‐pathway, but its role in sepsis‐induced muscle wasting is uncertain. In a clinical observational study, we found that the IL‐6 target gene, SOCS3, was increased in skeletal muscle of ICUAW patients indicative for JAK/STAT‐pathway activation. We tested the hypothesis that the IL‐6/gp130‐pathway mediates ICUAW muscle atrophy. Methods We sequenced RNA (RNAseq) from tibialis anterior (TA) muscle of cecal ligation and puncture‐operated (CLP) and sham‐operated wildtype (WT) mice. The effects of the IL‐6/gp130/JAK2/STAT3‐pathway were investigated by analysing the atrophy phenotype, gene expression, and protein contents of C2C12 myotubes. Mice lacking Il6st, encoding gp130, in myocytes (cKO) and WT controls, as well as mice treated with the JAK2 inhibitor AG490 or vehicle were exposed to CLP or sham surgery for 24 or 96 h. Results Analyses of differentially expressed genes in RNAseq (≥2‐log2‐fold change, P

Simple Summary: Pancreatic cancer is presently the fourth most common cause of cancer-related death. Treatment options and prognosis are poor. Therefore, new therapeutic approaches are urgently needed. Molecular targeting of the interleukin-6/glycoprotein-130/signal transducer and activator of transcription 3 signaling cascade is a promising approach in pancreatic cancer therapy. The present study investigates the combined effect of the first-line chemotherapeutic paclitaxel with the small-molecule gp130 inhibitor SC144 and the non-steroidal selective estrogen receptor modulator raloxifene that both interfere with interleukin-6/glycoprotein-130 signaling. Experiments performed on a mouse model of pancreatic cancer and cell lines proved both molecules to enhance low-dose paclitaxel effects by increasing apoptosis in tumor cells or reducing interleukin-6 levels, respectively. These findings might be promising to improve treatment efforts in pancreatic cancer, while the paclitaxel side-effect profile could be improved by lowering paclitaxel doses. Interleukine-6 plays a key role in the progression and poor survival in pancreatic ductal adenocarcinoma (PDAC). The present study aimed to clarify if targeting the interleukin-6/glycoprotein-130 signaling cascade using the small-molecule gp130 inhibitor SC144 or raloxifene, a non-steroidal selective estrogen receptor modulator, enhances paclitaxel efficacy. MTT/BrdU assays or TUNEL staining were performed to investigate cell viability, proliferation and apoptosis induction in L3.6pl and AsPC-1 human pancreatic cell lines. In vivo, effects were studied in an orthotopic PDAC mouse model. Tumor specimens were analyzed by qPCR, immunohistochemistry and ELISA. Combination of paclitaxel/raloxifene, but not paclitaxel/SC144, enhanced proliferation and viability inhibition and increased apoptosis compared to single treatment in vitro. Synergy score calculations confirmed an additive influence of raloxifene on paclitaxel. In the PDAC mouse model, both combinations of raloxifene/paclitaxel and SC144/paclitaxel reduced tumor weight and volume compared to single-agent therapy or control. Raloxifene/paclitaxel treatment decreased survivin mRNA expression and showed tendencies of increased caspase-3 staining in primary tumors. SC144/paclitaxel reduced interleukin-6 levels in mice's tumors and plasma. In conclusion, raloxifene or SC144 can enhance the anti-tumorigenic effects of paclitaxel, suggesting that paclitaxel doses might also be reduced in combined chemotherapy to lessen paclitaxel side effects. [ABSTRACT FROM AUTHOR]

Purpose: Interleukin 6 (IL-6), Oncostatin M (OSM), and downstream effector STAT3 are pro-tumorigenic agents in pancreatic ductal adenocarcinoma (PDAC). Glycoprotein 130 (gp130) is a compound of the IL-6 and OSM receptor complex that triggers STAT3 signaling. SC144 is a small molecule gp130 inhibitor with anticancer activity. This study examines the gp130 expression in human PDAC specimens and the in vitro effects of SC144 in PDAC cell lines. Methods: Tissue micro-arrays were constructed from 175 resected human PDAC. The gp130 expression in tumor epithelium and stroma was determined by immunohistochemistry, and survival analysis was performed. Growth inhibition by SC144 was assessed in vitro using BrdU and MTT assays. Western blotting was performed to evaluate the SC144 effect on IL-6 and OSM signaling. Results: Gp130 was expressed in the epithelium of 78.8% and the stroma of 9.4% of the tumor samples. The median overall survival for patients with or without epithelial gp130 expression was 16.7 months and 15.9 months, respectively (p = 0.830). Patients with no stromal gp130 expression showed poorer survival than patients with stromal gp130 expression (median 16.2 and 22.9 months, respectively), but this difference did not reach significance (p = 0.144). SC144 inhibited cell proliferation and viability and suppressed IL-6- and OSM-stimulated STAT3Y705 phosphorylation in PDAC cells. Conclusion: Gp130 is expressed in the epithelium of most human PDAC, but stromal expression is rare. The small molecule gp130 inhibitor SC144 potently inhibits PDAC progression in vitro and may abrogate IL-6 or OSM/gp130/STAT3 signaling. These results suggest gp130 as a novel drug target for pancreatic cancer therapy. [ABSTRACT FROM AUTHOR]

Oral squamous cell carcinoma (OSCC) is an extremely common head and neck cancer with a poor 5‐year survival rate, especially in cases of metastatic disease. Interleukin (IL)‐11 reportedly promotes cell growth and the epithelial–mesenchymal transition process in metastasis. However, the molecular mechanisms of IL‐11 in OSCC metastasis are unclear. This study found that IL‐11 upregulates matrix metalloproteinase 13 (MMP‐13) expression in OSCC via the IL‐11 receptor alpha subunit/glycoprotein 130 receptors that activate phosphatidyl‐inositol 3‐kinase, Ak strain transforming, and activator protein 1 signaling, which subsequently enhance MMP‐13‐induced tumor metastasis. TIMER2.0 analysis revealed a positive correlation between MMP‐13 and IL‐11 levels (r = 0.454). Moreover, a strong positive association was observed between higher levels of IL‐11 expression in OSCC tissue (p < 0.01), lymph node metastasis (p = 0.0154), and clinical disease stage (p = 0.0337). IL‐11 knockdown suppressed the migration of OSCC cells (p < 0.05). The evidence indicates that IL‐11 can serve as a new molecular therapeutic target in OSCC metastasis. [ABSTRACT FROM AUTHOR]

Interleukin-6 (IL-6) is a multifaceted cytokine essential in many immune system processes and their regulation. It also plays a key role in hematopoiesis, and in triggering the acute phase reaction. IL-6 overproduction is critical in chronic inflammation associated with autoimmune diseases like rheumatoid arthritis and contributes to cytokine storms in COVID-19 patients. Over 20 years ago, researchers proposed that IL-6, which is typically monomeric, can also form dimers via a domain-swap mechanism, with indirect evidence supporting their existence. The physiological significance of IL-6 dimers was shown in B-cell chronic lymphocytic leukemia. However, no structures have been reported so far. Here, we present the crystal structure of an IL-6 domain-swapped dimer that computational approaches could not predict. The structure explains why the IL-6 dimer is antagonistic to the IL-6 monomer in signaling complex formation and provides insights for IL-6 targeted therapies., Competing Interests: Declaration of interests N.P., S.R., A.I., and A.P. are inventors of the patent “Monoclonal antibody against human interleukin-6 and hybridoma producing this monoclonal antibody.” RU Patent 2 550 262 C1. (2015)., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background/objectives: Debilitating abdominal pain is a common symptom affecting patients with chronic pancreatitis (CP). CP pain is dynamic due to multiple underlying mechanisms. The objective of this study was to 1) evaluate changes in pain phenotype at one year follow-up and 2) validate putative pain biomarkers in a prospective cohort study., Methods: The Neuropathic and Nociceptive PROMIS-PQ questionnaires were used to classify pain for participants with in the PROCEED study. Putative serum biomarkers were measured via immunoassay., Results: At enrollment, 17.6 % (120/681) subjects with CP reported no pain in the previous year. Of those, 29 % experienced pain during the 1 yr follow-up whereas 18 % of those with pain prior to enrollment reported no pain during the 1 yr follow-up period. Of the 393 subjects with PROMIS-PQ data at enrollment, 212 also had follow-up data at 1 yr. Approximately half (53.3 %) of those individuals changed pain phenotype between baseline and follow-up. At 1 yr, serum TGFβ1 level was negatively correlated with nociceptive T-scores (p = 0.006). GP130 was significantly correlated with both nociceptive (p = 0.012) and neuropathic T-scores (p = 0.043) at 1 yr, which is consistent with the previously published findings., Conclusions: The positive association between TGFβ1 and pain is not maintained over time, suggesting it is a poor pain biomarker. However, serum GP130 is a consistent biomarker for mixed-type pain in CP. Preclinical studies show that targeting TGFβ1 or IL-6 (ligand for GP130) is sufficient to inhibit CP pain supporting further investigation of this as a potential therapeutic target., Competing Interests: Declaration of competing interest The co-authors have no conflicts of interest to disclose., (Copyright © 2024 IAP and EPC. All rights reserved.)

IL-6 signaling plays a crucial role in the survival and metastasis of skin cancer. NEDD4L acts as a suppressor of IL-6 signaling by targeting GP130 degradation. However, the effects of the NEDD4L-regulated IL-6/GP130 signaling pathway on skin cancer remain unclear. In this study, protein expression levels of NEDD4L and GP130 were measured in tumor tissues from patients with cutaneous squamous cell carcinoma. Skin tumors were induced in wild-type and Nedd4l-knockout mice, and activation of the IL-6/GP130/signal transducer and activator of transcription 3 signaling pathway was detected. The results indicated a negative correlation between the protein expression levels of NEDD4L and GP130 in cutaneous squamous cell carcinoma tissues from patients. Nedd4l deficiency significantly promoted 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate-induced skin tumorigenesis and benign-to-malignant conversion by activating the IL-6/GP130/signal transducer and activator of transcription 3 signaling pathway, which was abrogated by supplementation with the GP130 inhibitor SC144. Furthermore, our findings suggested that NEDD4L can interact with GP130 and promote its ubiquitination in skin tumors. In conclusion, our results indicate that NEDD4L could act as a tumor suppressor in skin cancer, and inhibition of GP130 could be a potential therapeutic method for treating this disease., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The functional interleukin 6 (IL-6) signaling complex is a hexameric structure composed of IL-6, IL-6Rα, and the signaling receptor gp130. There are three different modes of IL-6 signaling, classic signaling, trans-signaling, and trans-presentation, which are not functionally redundant and mediate pleiotropic effects on both physiological and pathophysiological states. Monoclonal antibodies against IL-6 or IL-6Rα have been successfully developed for clinical application. However, designing therapeutic interventions that block specific modes of IL-6 signaling in a pathologically relevant manner remains a great challenge. Here, we constructed a fusion protein Hyper-IL-6 (HyIL-6) composed of human IL-6 and IL-6Rα to develop specific blocking antibodies against the IL-6/IL-6Rα complex. We successfully screened the monoclonal antibody C14mab, which can bind to HyIL-6 with the binding constant 2.86 × 10−10 and significantly inhibit IL-6/IL-6Rα/gp130 complex formation. In vitro, C14mab effectively inhibited HyIL-6-stimulated signal transducer and activator of transcription 3 (STAT3) activation and related vascular endothelial growth factor (VEGF) induction. Moreover, C14mab efficaciously suppressed HyIL-6-induced acute phase response in vivo. Our data from hydrogen-deuterium exchange mass spectrometry demonstrate that C14mab mainly binds to site IIIa of IL-6 and blocks the final step in the interaction between gp130 and IL-6/IL-6Rα complex. Additionally, data from enzyme-linked immunosorbent assays and kinetics assays indicate that C14mab interacts simultaneously with IL-6 and IL-6Rα, while it does not interact with IL-6Rα alone. The unique features of C14mab may offer a novel alternative for IL-6 blockade and illuminate a better therapeutic intervention targeting IL-6.

Interleukin 27 (IL‐27) is a heterodimeric cytokine that elicits potent immunosuppressive responses. Comprised of EBI3 and p28 subunits, IL‐27 binds GP130 and IL‐27Rα receptor chains to activate the JAK/STAT signaling cascade. However, how these receptors recognize IL‐27 and form a complex capable of phosphorylating JAK proteins remains unclear. Here, we used cryo electron microscopy (cryoEM) and AlphaFold modeling to solve the structure of the IL‐27 receptor recognition complex. Our data show how IL‐27 serves as a bridge connecting IL‐27Rα (domains 1–2) with GP130 (domains 1–3) to initiate signaling. While both receptors contact the p28 component of the heterodimeric cytokine, EBI3 stabilizes the complex by binding a positively charged surface of IL‐27Rα and Domain 1 of GP130. We find that assembly of the IL‐27 receptor recognition complex is distinct from both IL‐12 and IL‐6 cytokine families and provides a mechanistic blueprint for tuning IL‐27 pleiotropic actions. Synopsis: Interleukin 27 is a heterodimeric cytokine that elicits potent immuno‐suppressive responses. The structure of the IL‐27 signalling complex provides a mechanistic blueprint to fine‐tune IL‐27 immuno‐modulatory activities.IL‐27 is a heterodimeric cytokine in which EBI3 engages p28 at site 1.IL‐27Rα binds site 2 of p28 and is stabilized by electrostatic interactions with EBI3.Domain 1 of GP130 binds site 3 of p28 in a low affinity interaction. [ABSTRACT FROM AUTHOR]

Interleukin 11 (IL-11) was discovered in 1990 in fibrocyte-like stromal cells of the bone marrow, but there has recently been an increased interest in the cytokine. Understanding the physiological roles of cytokines will allow their use as pharmacological agents in clinical practice. Studies have indicated that IL-11 affects the mechanism for the development of a number of pathologies of the nervous system. IL-11 plays a significant role in the central nervous system. The local expression of this cytokine by nerve cells has been observed. The current work summarizes the results of studies which found that the cytokine affects the mechanism of development of pathologies of the central nervous system. In the near future, this cytokine may be used clinically to fix the mechanisms that are involved in the development of pathological conditions of the nervous system. [ABSTRACT FROM AUTHOR]