S100A8 and S100A9 Positive Cells in Colorectal Carcinoma: Clinicopathological Analysis

Galactomannan-graft-poly(methyl methacrylate) nanoparticles induce an anti-inflammatory phenotype in human macrophages

Macrophages are immune cells that can be activated into either pro-inflammatory M1 or anti-inflammatory M2 phenotypes. Attempts to modulate macrophage phenotype using drugs have been limited by targeting issues and systemic toxicity. This study investigates the effect of drug-free self-assembled hydrolyzed galactomannan-poly(methyl methacrylate) (hGM-g-PMMA) nanoparticles on the activation of the human monocyte-derived macrophage THP-1 cell line. Nanoparticles are cell compatible and are taken up by macrophages. RNA-sequencing analysis of cells exposed to NPs reveal the upregulation of seven metallothionein genes. Additionally, the secretion of pro-inflammatory and anti-inflammatory cytokines upon exposure of unpolarized macrophages and M1-like cells obtained by activation with lipopolysaccharide + interferon-γ to the NPs is reduced and increased, respectively. Finally, nanoparticle-treated macrophages promote fibroblast migration in vitro. Overall, results demonstrate that hGM-g-PMMA nanoparticles induce the release of anti-inflammatory cytokines by THP-1 macrophages, which could pave the way for their application in the therapy of different inflammatory conditions, especially by local delivery.

Protective effects of S100A8 on sepsis mortality: Links to sepsis risk in obesity and diabetes

Obesity and diabetes are independent risk factors for death during sepsis. S100A8, an alarmin, is related to inflammation, obesity, and diabetes. Here, we examine the role of S100A8 in sepsis of obesity and diabetes models. Injection of S100A8 prolongs the survival of septic mice induced by lethal endotoxemia, Escherichia coli injection, or cecal ligation and puncture. S100A8 decrease the LPS-induced expression of proinflammatory cytokines in peritoneal macrophages by inhibiting TLR4-mediated signals in an autocrine manner. db/db, ob/ob, and western diet-fed mice demonstrate reduced upregulation of S100A8 induced by LPS treatment in both serum and peritoneal cells. These mice also show shorter survival after LPS injection, and S100A8 supplementation prolonged the survival. While myelomonocytic cells-specific S100A8-deficient mice (Lyz2 ^cre :S100A8 ^{floxed/floxed} ) exhibit shorter survival after LPS treatment, S100A8 supplementation prolonged the survival. Thus, myelomonocytic cell-derived S100A8 is crucial for protection from sepsis, and S100A8 supplementation improves sepsis, particularly in mice with obesity and diabetes.

Fusobacterium nucleatum Facilitates M2 Macrophage Polarization and Colorectal Carcinoma Progression by Activating TLR4/NF-κB/S100A9 Cascade

Fusobacterium nucleatum (Fn) has been considered as a significant contributor in promoting colorectal carcinoma (CRC) development by suppressing host anti-tumor immunity. Recent studies demonstrated that the aggregation of M2 macrophage (Mφ) was involved in CRC progress driven by Fn infection. However, the underlying molecular mechanisms are poorly characterized. Here, we investigated the role of Fn in Mφ polarization as well as its effect on CRC malignancy. Fn infection facilitated differentiation of Mφ into the M2-like Mφ phenotype by in vitro study. Histological observation from Fn-positive CRC tissues confirmed the abundance of tumor-infiltrating M2-like Mφ. Fn-induced M2-like Mφ polarization was weakened once inhibiting a highly expressed damage-associated molecular pattern (DAMP) molecule S100A9 mainly derived from Fn-challenged Mφ and CRC cells. In addition, Fn-challenged M2-like Mφ conferred CRC cells a more malignant phenotype, showing stronger proliferation and migration characteristics in vitro and significantly enhanced tumor growth in vivo, all of which were partially inhibited when S100A9 was lost. Mechanistic studies further demonstrated that activation of TLR4/NF-κB signaling pathway mediated Fn-induced S100A9 expression and subsequent M2-like Mφ activation. Collectively, these findings indicate that elevated S100A9 in Fn-infected CRC microenvironment participates in M2-like Mφ polarization, thereby facilitating CRC malignancy. Furthermore, targeting TLR4/NF-κB/S100A9 cascade may serve as promising immunotherapeutic strategy for Fn-associated CRC.

S100A8/A9 in Inflammation

S100A8 and S100A9 (also known as MRP8 and MRP14, respectively) are Ca²⁺ binding proteins belonging to the S100 family. They often exist in the form of heterodimer, while homodimer exists very little because of the stability. S100A8/A9 is constitutively expressed in neutrophils and monocytes as a Ca²⁺ sensor, participating in cytoskeleton rearrangement and arachidonic acid metabolism. During inflammation, S100A8/A9 is released actively and exerts a critical role in modulating the inflammatory response by stimulating leukocyte recruitment and inducing cytokine secretion. S100A8/A9 serves as a candidate biomarker for diagnosis and follow-up as well as a predictive indicator of therapeutic responses to inflammation-associated diseases. As blockade of S100A8/A9 activity using small-molecule inhibitors or antibodies improves pathological conditions in murine models, the heterodimer has potential as a therapeutic target. In this review, we provide a comprehensive and detailed overview of the distribution and biological functions of S100A8/A9 and highlight its application as a diagnostic and therapeutic target in inflammation-associated diseases.

Proteomic analysis of stromal proteins in different stages of colorectal cancer establishes Tenascin-C as a stromal biomarker for colorectal cancer metastasis

Tumor microenvironment is crucial to tumor development and metastasis. Little is known about the roles of stromal proteins in colorectal carcinogenesis. In this study, we used a combination of laser capture microdissection (LCM), iTRAQ labeling and two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) to compare stromal proteomes in different stages of colorectal cancer. A total of 1966 proteins were identified, and 222 proteins presenting a significant fold change were quantified in different stages. Differentially expressed proteins (DEPs) were subjected to cluster and pathway analyses. We confirmed the differential expression of Tenascin-C and S100A9 using immunohistochemical analysis, and found that the expression levels of S100A9 and Tenascin-C were correlated with TNM stages and metastasis. In addition, our results showed that Tenascin-C was abundantly secreted by the colon cancer cells with high metastatic potential, and highly expressed in lymph nodes with metastasis. Our studies not only shed light on the mechanism by which stromal proteins contributed to colorectal carcinogenesis, but also identified Tenascin-C as a potential stromal biomarker for colorectal cancer metastasis.

Chitinase 3-like 1 induces survival and proliferation of intestinal epithelial cells during chronic inflammation and colitis-associated cancer by regulating S100A9

Many host-factors are inducibly expressed during the development of inflammatory bowel disease (IBD), each having their unique properties, such as immune activation, bacterial clearance, and tissue repair/remodeling. Dysregulation/imbalance of these factors may have pathogenic effects that can contribute to colitis-associated cancer (CAC). Previous reports showed that IBD patients inducibly express colonic chitinase 3-like 1 (CHI3L1) that is further upregulated during CAC development. However, little is known about the direct pathogenic involvement of CHI3L1 in vivo. Here we demonstrate that CHI3L1 (aka Brp39) knockout (KO) mice treated with azoxymethane (AOM)/dextran sulphate sodium (DSS) developed severe colitis but lesser incidence of CAC as compared to that in wild-type (WT) mice. Highest CHI3L1 expression was found during the chronic phase of colitis, rather than the acute phase, and is essential to promote intestinal epithelial cell (IEC) proliferation in vivo. This CHI3L1-mediated cell proliferation/survival involves partial downregulation of the pro-apoptotic S100A9 protein that is highly expressed during the acute phase of colitis, by binding to the S100A9 receptor, RAGE (Receptor for Advanced Glycation End products). This interaction disrupts the S100A9-associated expression positive feedback loop during early immune activation, creating a CHI3L1^hi S100A9^low colonic environment, especially in the later phase of colitis, which promotes cell proliferation/survival of both normal IECs and tumor cells.

[Expression of S100A8 and A100A9 in giant cell tumor of bone and its relation with CT and MR imaging findings]

OBJECTIVE

To investigate the mRNA and protein expression levels of S100A8 and S100A9 in giant cell tumor (GCT) of bone, and its relation with radiological findings and biological behavior.

METHODS

Forty three patient with GCT of bone admitted in Ruijin Hospital Shanghai Jiaotong University School of Medicine from January 2009 to June 2012 were enrolled in the study. The expression levels of S100A8 and S100A9 mRNA and protein were detected by using semiquantitative RT-PCR and Western blotting in 43 specimens of GCT and 6 specimens of normal bone marrow. The CT and MRI findings of patients were retrospectively reviewed, its relation with tissue expression of S100A8 and S100A9 was analyzed.

RESULTS

Among 43 GCT cases 40 showed positive expression of S100A8 and S100A9 mRNA and protein, and the expression levels were significantly higher than those in normal bone marrow P<0.05). The expression level of S100A8 protein was significantly different in bone GCT with different composition ratio on MRI (P<0.05).The expression level of S100A9 protein was significantly different in GCT with different degree of bone destruction on CT scan (P<0.05).

CONCLUSION

The expression of S100A8 and S100A9 mRNA and protein is up-regulated in GCT of bone. The expression of S100A8 and S100A9 is associated with the real composition ratio and the degree of bone destruction, respectively, indicating that S100A8 and S100A9 may be involved in the biological behavior of bone GCT.