Differences in p38-STAT3-S100A11 signaling after the administration of aristolochic acid I and IVa may account for the disparity in their nephrotoxicity.

BACKGROUND: The safety of herbs containing aristolochic acids (AAs) has become a widespread concern. Previous reports indicate that AAs are highly nephrotoxic and carcinogenic, although there are more than 170 analogues of aristolochic acid. Not all AAs have the same degree of nephrotoxicity or carcinogenicity. Previous studies have found that aristolochic acid IVa (AA-IVa), the principal component of AAs within members of the Aristolochiaceae family, especially Asarum, a commonly used herb in China, has essentially no significant nephrotoxicity. However, several studies, including ours, have shown that aristolochic acid I (AA-I) is clearly nephrotoxic. PURPOSE: The focus of the study was to elucidate the molecular mechanism responsible for the difference in nephrotoxicity between the AA-I and AA-IVa. STUDY DESIGN/METHOD: Mice were administered with AA-I or AA-IVa for 22 weeks through the oral route, followed by a 50-week recovery time. The kidney tissues of mice were extracted at the end of 22 weeks. Pathological examination and proteomic detection (tandem mass tagging (TMT) and phosphorylated proteomics) were performed on the kidney tissue to investigate the key signaling pathways and targets of AAs-induced renal interstitial fibrosis (RIF). The key signaling pathways and targets were verified by Western blot (WB), siRNA transfection, and luciferase assays. RESULTS: AA-I caused severe nephrotoxicity, high mortality, and extensive RIF. However, the same AA-IVa dosage exhibited almost no nephrotoxicity and does not trigger RIF. The activation of the p38-STAT3-S100A11 signaling pathway and upregulated expression of α smooth muscle actin (α-SMA) and Bcl2-associated agonist of cell death (Bad) proteins could be the molecular mechanism underlying AA-I-induced nephrotoxicity. On the other hand, AA-IVa did not regulate the activation of the p38-STAT3-S100A11 signaling pathway and had relatively little effect on the expression of α-SMA and Bad. Consequently, the difference in the regulation of p38-STAT3-S100A11 pathway, α-SMA, and Bad proteins between AA-I and AA-IVa may be responsible for the divergence in their level of nephrotoxicity. CONCLUSION: This is the first study to reveal the molecular mechanism underlying the difference in nephrotoxicity between AA-I and AA-IVa. Whether STAT3 is activated or not may be the key factor leading to the difference in nephrotoxicity between AA-I and AA-IVa.

NFIC1 inhibits the migration and invasion of MDA-MB-231 cells through S100A2-mediated inactivation of MEK/ERK pathway.

NFIC is a potent transcriptional factor involved in many physiological and pathological processes, including tumorigenesis. However, the role of NFIC1, the longest isoform of NFIC, in the progression of triple negative breast cancer (TNBC) remains elusive. Our study demonstrates that overexpression of NFIC1 inhibits the migration and invasion of TNBC MDA-MB-231 cells. NFIC1 regulates the expression of S100A2, and knockdown of S100A2 reverses the inhibitive effects of NFIC1 on the migration and invasion of MDA-MB-231 cells. Furthermore, knockdown of S100A2 activates the MEK/ERK signaling transduction pathway that is inhibited by NFIC1 overexperssion. Treatment with MEK/ERK pathway inhibitor, U0126, abolishes the effects of S100A2 knockdown. In addition, overexpression of NFIC1 in MDA-MB-231 cells increases the expression of epithelial markers and decreases the expression of mesenchymal markers, and these effects could also be reversed by knockdown of S100A2. Collectively, these results demonstrate that NFIC1 inhibits the Epithelial-mesenchymal transition (EMT) of MDA-MB-231 cells by regulating S100A2 expression, which suppress the activation of MEK/ERK pathway. Therefore, our study confirms the role of NFIC1 as a tumor repressor in TNBC, and reveals the molecular mechanism through which NFIC1 inhibits the migration and invasion of MDA-MB-231 cells.

An inhibitor of BRD4, GNE987, inhibits the growth of glioblastoma cells by targeting C-Myc and S100A16.

PURPOSE: Among children, glioblastomas (GBMs) are a relatively common type of brain tumor. BRD4 expression was elevated in GBM and negatively correlated with the prognosis of glioma. We investigated the anti-GBM effects of a novel BRD4 inhibitor GNE987. METHODS: We evaluated the anti-tumor effect of GNE987 in vitro and in vivo by Western blot, CCK8, flow cytometry detection, clone formation, the size of xenografts, and Ki67 immunohistochemical staining, and combined ChIP-seq with RNA-seq techniques to find its anti-tumor mechanism. RESULTS: In vitro experiments showed that GNE987 significantly degraded BRD4, inhibited the proliferation of GBM cells, blocked the cell cycle, and induced apoptosis. Similarly, in vivo experiments, GNE987 also inhibited GBM growth as seen from the size of xenografts and Ki67 immunohistochemical staining. Based on Western blotting, GNE987 can significantly reduce the protein level of C-Myc; meanwhile, we combined ChIP-seq with RNA-seq techniques to confirm that GNE987 downregulated the transcription of S100A16 by disturbing H3K27Ac. Furthermore, we validated that S100A16 is indispensable in GBM growth. CONCLUSION: GNE987 may be effective against GBM that targets C-Myc expression and influences S100A16 transcription through downregulation of BRD4.

Inhibitory Effect of S100A11 on Airway Smooth Muscle Contraction and Airway Hyperresponsiveness.

OBJECTIVE: S100A11 is a member of the S100 calcium-binding protein family and has intracellular and extracellular regulatory activities. We previously reported that S100A11 was differentially expressed in the respiratory tracts of asthmatic rats as compared with normal controls. Here, we aimed to analyze the potential of S100A11 to regulate both allergen-induced airway hyperresponsiveness (AHR) as well as acetylcholine (ACh)-induced hypercontractility of airway smooth muscle (ASM) and contraction of ASM cells (ASMCs). METHODS: Purified recombinant rat S100A11 protein (rS100A11) was administered to OVA-sensitized and challenged rats and then the AHR of animals was measured. The relaxation effects of rS100A11 on ASM were detected using isolated tracheal rings and primary ASMCs. The expression levels of un-phosphorylated myosin light chain (MLC) and phosphorylated MLC in ASMCs were analyzed using Western blotting. RESULTS: Treatment with rS100A11 attenuated AHR in the rats. ASM contraction assays showed that rS100A11 reduced the contractile responses of isolated tracheal rings and primary ASMCs treated with ACh. In addition, rS100A11 markedly decreased the ACh-induced phosphorylation of the myosin light chain in ASMCs. Moreover, rS100A11 also suppressed the contractile response of tracheal rings in calcium-free buffer medium. CONCLUSION: These results indicate that S100A11 protein can relieve AHR by relaxing ASM independently of extracellular calcium. Our data support the idea that S100A11 is a potential therapeutic target for reducing airway resistance in asthma patients.

Extracellular HMGB1 blockade inhibits tumor growth through profoundly remodeling immune microenvironment and enhances checkpoint inhibitor-based immunotherapy.

BACKGROUND: High-mobility group box 1 (HMGB1) is a multifunctional redox-sensitive protein involved in various intracellular (eg, chromatin remodeling, transcription, autophagy) and extracellular (inflammation, autoimmunity) processes. Regarding its role in cancer development/progression, paradoxical results exist in the literature and it is still unclear whether HMGB1 mainly acts as an oncogene or a tumor suppressor. METHODS: HMGB1 expression was first assessed in tissue specimens (n=359) of invasive breast, lung and cervical cancer and the two distinct staining patterns detected (nuclear vs cytoplasmic) were correlated to the secretion profile of malignant cells, patient outcomes and the presence of infiltrating immune cells within tumor microenvironment. Using several orthotopic, syngeneic mouse models of basal-like breast (4T1, 67NR and EpRas) or non-small cell lung (TC-1) cancer, the efficacy of several HMGB1 inhibitors alone and in combination with immune checkpoint blockade antibodies (anti-PD-1/PD-L1) was then investigated. Isolated from retrieved tumors, 14 immune cell (sub)populations as well as the activation status of antigen-presenting cells were extensively analyzed in each condition. Finally, the redox state of HMGB1 in tumor-extruded fluids and the influence of different forms (oxidized, reduced or disulfide) on both dendritic cell (DC) and plasmacytoid DC (pDC) activation were determined. RESULTS: Associated with an unfavorable prognosis in human patients, we clearly demonstrated that targeting extracellular HMGB1 elicits a profound remodeling of tumor immune microenvironment for efficient cancer therapy. Indeed, without affecting the global number of (CD45+) immune cells, drastic reductions of monocytic/granulocytic myeloid-derived suppressor cells (MDSC) and regulatory T lymphocytes, a higher M1/M2 ratio of macrophages as well as an increased activation of both DC and pDC were continually observed following HMGB1 inhibition. Moreover, blocking HMGB1 improved the efficacy of anti-PD-1 cancer monoimmunotherapy. We also reported that a significant fraction of HMGB1 encountered within cancer microenvironment (interstitial fluids) is oxidized and, in opposite to its reduced isoform, oxidized HMGB1 acts as a tolerogenic signal in a receptor for advanced glycation endproducts-dependent manner. CONCLUSION: Collectively, we present evidence that extracellular HMGB1 blockade may complement first-generation cancer immunotherapies by remobilizing antitumor immune response.

Psoriasin has divergent effects on the innate immune responses of murine glial cells.

Antimicrobial peptides are an important part of the innate immune defense in the central nervous system (CNS). The expression of the antimicrobial peptides psoriasin (S100A7) is up-regulated during bacterial meningitis. However, the exact mechanisms induced by psoriasin to modulate glial cell activity are not yet fully understood. Our hypothesis is that psoriasin induced pro- and anti-inflammatory signaling pathways as well as regenerative factors to contribute in total to a balanced immune response. Therefore, we used psoriasin-stimulated glial cells and analyzed the translocation of the pro-inflammatory transcription factor nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NFκB) in murine glial cells and the expression of pro- and anti-inflammatory mediators by real time RT-PCR, ELISA technique, and western blotting. Furthermore, the relationship between psoriasin and the antioxidative stress transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) was investigated. Stimulation with psoriasin not only enhanced NFκB translocation and increased the expression of the pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF- α) but also neurotrophin expression. Evidence for functional interactions between psoriasin and Nrf2 were detected in the form of increased antioxidant response element (ARE) activity and induction of Nrf2/ARE-dependent heme oxygenase 1 (HO-1) expression in psoriasin-treated microglia and astrocytes. The results illustrate the ability of psoriasin to induce immunological functions in glia cells where psoriasin exerts divergent effects on the innate immune response.

Valores de referencia de la proteína S100beta en población pediátrica / Serum S100Beta protein reference values in a paediatric population

INTRODUCCIÓN: La proteína S100β se ha propuesto como posible biomarcador en patología neurológica, tanto crónica como aguda. Los valores normales de esta proteína están bien definidos en adultos, no así en niños, en los que los valores séricos parecen variar con la edad. Nuestro objetivo es describir valores de referencia de S100β sérica en niños de 0 a 14 años. MATERIAL Y MÉTODOS: Estudio prospectivo en 257 niños sanos. Se establecieron 3 grupos por edad (menores de 12 meses, de 12 a 24 meses y mayores de 24 meses). RESULTADOS: Se incluyó a 179 niños y 78 niñas. La edad media ± DE fue de 5,5 ± 3,75 años. La concentración sérica media de la proteína S100β en todo el grupo fue 0,156 (0,140-0,172) μg/l. En los menores de 12 meses, la concentración sérica de S100β fue de 0,350 (0,280-0,421) μg/l; 0,165 (0,139-0,190) μg/l en el grupo entre 12 y 24 meses y 0,121 (0,109-0,133) μg/l en el grupo de niños mayores de 24 meses. Se observó una relación inversa entre la edad y la concentración sérica de S100β, que desciende conforme se incrementa la edad. No se observaron diferencias en cuanto al sexo. CONCLUSIONES: La concentración de S100β permanece estable a partir de los 2 años de edad, siendo posible establecer unos valores de referencia de S100β para mayores de 2 años. En los 2 primeros años de vida, la concentración de S100β sérica es más elevada cuanto menor es la edad del niño. No se observan diferencias en el valor de S100β sérica entre ambos sexos

INTRODUCTION: S100β protein has been proposed as a potential biomarker for both chronic and acute neurological disorders. Reference values of this protein are well defined in adults but not in children, in whom serum levels appear to vary with age. Reference values for serum S100β in children from 0 to 14 years are presented. MATERIALS AND METHODS: A prospective study was conducted on 257 healthy children, who were divided into three age groups (under 12 months, 12 to 24 months and over 24 months). RESULTS: The study included179 boys and 78 girls, with a mean age of 5.5 (3.75) years. The mean serum concentration of protein S100β was 0.156 (0.140-0.172) μg/l. In children under 12 months, serum S100β concentration was 0.350 (0.280-0.421) μg/l; 0.165 (0.139-0.190) μg/l in the group between 12 and 24 months and 0.121 (0.109-0.133) μg/l in children older than 24 months. An inverse relationship was observed between age and serum S100β, which declines as age increases. No differences were observed between sexes. CONCLUSIONS: The concentration of S100β remains stable after two years of age, being possible to establish a baseline of S100β for over two years. During the first two years of life, S100β serum concentration is higher, the lower the age of the child. No differences in serum S100β levels between sexes are observed

Respuesta a valores de referencia de la proteína S100β en población pediátrica / Response to serum S100β protein reference values in a paediatric population

No disponible

Systemic ocular antigen immunization leads only to a minor secondary immune response.

The immunization with optic nerve homogenate antigen (ONA) or S100 induced retinal degeneration. Since many neurological diseases are reinforced or initiated by immune cells, leucocytes were analyzed. CD3(+) T-cells in the retina increased slightly in ONA rats, but not in S100 treated retinas. No CD45R(+) B-cells and granulocytes could be detected in the retinas. At early stages, CD3(+) cells, Iba1(+) macrophages and granulocytes of the secondary lymphoid organs were not affected. Yet, the sole injection of pertussis toxin led to a shift to fewer CD45R(+) cells and more granulocytes in spleens. Later, splenic Iba1(+) macrophages were increased in both groups. We conclude that the retinal infiltration of lymphocytes is not crucial for the degeneration process and rather an epiphenomenon.

Disulphide-reduced psoriasin is a human apoptosis-inducing broad-spectrum fungicide.

The unexpected resistance of psoriasis lesions to fungal infections suggests local production of an antifungal factor. We purified Trichophyton rubrum-inhibiting activity from lesional psoriasis scale extracts and identified the Cys-reduced form of S100A7/psoriasin (redS100A7) as a principal antifungal factor. redS100A7 inhibits various filamentous fungi, including the mold Aspergillus fumigatus, but not Candida albicans. Antifungal activity was inhibited by Zn(2+), suggesting that redS100A7 interferes with fungal zinc homeostasis. Because S100A7-mutants lacking a single cysteine are no longer antifungals, we hypothesized that redS100A7 is acting as a Zn(2+)-chelator. Immunogold electron microscopy studies revealed that it penetrates fungal cells, implicating possible intracellular actions. In support with our hypothesis, the cell-penetrating Zn(2+)-chelator TPEN was found to function as a broad-spectrum antifungal. Ultrastructural analyses of redS100A7-treated T. rubrum revealed marked signs of apoptosis, suggesting that its mode of action is induction of programmed cell death. TUNEL, SYTOX-green analyses, and caspase-inhibition studies supported this for both T. rubrum and A. fumigatus. Whereas redS100A7 can be generated from oxidized S100A7 by action of thioredoxin or glutathione, elevated redS100A7 levels in fungal skin infection indicate induction of both S100A7 and its reducing agent in vivo. To investigate whether redS100A7 and TPEN are antifungals in vivo, we used a guinea pig tinea pedes model for fungal skin infections and a lethal mouse Aspergillus infection model for lung infection and found antifungal activity in both in vivo animal systems. Thus, selective fungal cell-penetrating Zn(2+)-chelators could be useful as an urgently needed novel antifungal therapeutic, which induces programmed cell death in numerous fungi.