S100 Calcium-binding Protein Research Articles

Exploratory Transcriptomic Profiling Reveals the Role of Gut Microbiota in Vascular Dementia.

Stroke is the second most common cause of cognitive impairment and dementia. Vascular dementia (VaD), a cognitive impairment following a stroke, is common and significantly impacts the quality of life. We recently demonstrated via gut microbe transplant studies that the gut microbe-dependent trimethylamine-N-oxide (TMAO) pathway impacts stroke severity, both infarct size and long-term cognitive outcomes. However, the molecular mechanisms that underly the role of the microbiome in VaD have not been explored in depth. To address this issue, we performed a comprehensive RNA-sequencing analysis to identify differentially expressed (DE) genes in the ischemic cerebral cortex of mouse brains at pre-stroke and post-stroke day 1 and day 3. A total of 4016, 3752 and 7861 DE genes were identified at pre-stroke and post-stroke day 1 and day 3, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated pathways of neurodegeneration in multiple diseases, chemokine signaling, calcium signaling, and IL-17 signaling as the key enriched pathways. Inflammatory response genes interleukin-1 beta (Il-1β), chemokines (C-X-C motif chemokine ligand 10 (Cxcl10), chemokine ligand 2 (Ccl2)), and immune system genes (S100 calcium binding protein 8 (S100a8), lipocalin-2 (Lcn2)) were among the most significantly upregulated genes. Hypocretin neuropeptide precursor (Hcrt), a neuropeptide, and transcription factors such as neuronal PAS domain protein 4 (Npas4), GATA binding protein 3 (Gata3), and paired box 7 (Pax7) were among the most significantly downregulated genes. In conclusion, our results indicate that higher plasma TMAO levels induce differential mRNA expression profiles in the ischemic brain tissue in our pre-clinical stroke model, and the predicted pathways provide the molecular basis for regulating the TMAO-enhanced neuroinflammatory response in the brain.

Detection of synovial fluid LTF and S100A8 by chemiluminescence immunoassay for the diagnosis of periprosthetic joint infection

Background and AimsSynovial fluid lactoferrin (LTF) and S100 calcium-binding protein A8 (S100A8) have been considered as potential biomarkers for the diagnosis of periprosthetic joint infection (PJI) through our previous research. However, the detection methods of these two proteins are still immature, so a rapid, accurate and cost-effective testing method is warranted. Materials and MethodsWe developed chemiluminescent immunoassays (CLIA) for the automated detection of synovial fluid LTF and S100A8 and assessed the analytical performance for these two methods. In addition, we recruited 86 patients who were suspected of PJI after total joint replacement (TJA) and examined their synovial fluid using CLIA to explore the clinical application value of these methods and the diagnostic efficiency of synovial fluid LTF and S100A8 for PJI. ResultsOur established CLIA methods have a wide linear range of 20–10,000 ng/mL for LTF detection system and 5–5000 ng/mL for S100A8 detection system. Performance parameters such as precision, specificity, and recovery rate can meet the industry standards. Then, the established methods were used to detect LTF and S100A8 in synovial fluid samples, which showed excellent diagnostic efficiency for PJI, and the areas under ROC curve (AUC) were 0.954 (95 % CI: 0.909–0.999) and 0.958 (95 % CI: 0.918–0.997), respectively. ConclusionOur established CLIA methods have the advantages of automation, high throughput, low price, and is expected to be widely popularized in clinical applications. Synovial fluid LTF and S100A8 detected through CLIA had efficient diagnostic potentiality for predicting and diagnosing PJI.

Striatal spatial heterogeneity, clustering, and white matter association of GFAP+ astrocytes in a mouse model of Huntington's disease.

Huntington's disease (HD) is a neurodegenerative disease that primarily affects the striatum, a brain region that controls movement and some forms of cognition. Neuronal dysfunction and loss in HD is accompanied by increased astrocyte density and astrocyte pathology. Astrocytes are a heterogeneous population classified into multiple subtypes depending on the expression of different gene markers. Studying whether mutant Huntingtin (HTT) alters specific subtypes of astrocytes is necessary to understand their relative contribution to HD. Here, we studied whether astrocytes expressing two different markers; glial fibrillary acidic protein (GFAP), associated with astrocyte activation, and S100 calcium-binding protein B (S100B), a marker of matured astrocytes and inflammation, were differentially altered in HD. First, we found three distinct populations in the striatum of WT and symptomatic zQ175 mice: GFAP+, S100B+, and dual GFAP+S100B+. The number of GFAP+ and S100B+ astrocytes throughout the striatum was increased in HD mice compared to WT, coinciding with an increase in HTT aggregation. Overlap between GFAP and S100B staining was expected, but dual GFAP+S100B+ astrocytes only accounted for less than 10% of all tested astrocytes and the number of GFAP+S100B+ astrocytes did not differ between WT and HD, suggesting that GFAP+ astrocytes and S100B+ astrocytes are distinct types of astrocytes. Interestingly, a spatial characterization of these astrocyte subtypes in HD mice showed that while S100B+ were homogeneously distributed throughout the striatum, GFAP+ preferentially accumulated in "patches" in the dorsomedial (dm) striatum, a region associated with goal-directed behaviors. In addition, GFAP+ astrocytes in the dm striatum of zQ175 mice showed increased clustering and association with white matter fascicles and were preferentially located in areas with low HTT aggregate load. In summary, we showed that GFAP+ and S100B+ astrocyte subtypes are distinctly affected in HD and exist in distinct spatial arrangements that may offer new insights to the function of these specific astrocytes subtypes and their potential implications in HD pathology.

Apoptotic Cell Death in Bicuspid-Aortic-Valve-Associated Aortopathy.

The bicuspid aortic valve (BAV) is the most common cardiovascular congenital abnormality and is frequently associated with proximal aortopathy. We analyzed the tissues of patients with bicuspid and tricuspid aortic valve (TAV) regarding the protein expression of the receptor for advanced glycation products (RAGE) and its ligands, the advanced glycation end products (AGE), as well as the S100 calcium-binding protein A6 (S100A6). Since S100A6 overexpression attenuates cardiomyocyte apoptosis, we investigated the diverse pathways of apoptosis and autophagic cell death in the human ascending aortic specimen of 57 and 49 patients with BAV and TAV morphology, respectively, to identify differences and explanations for the higher risk of patients with BAV for severe cardiovascular diseases. We found significantly increased levels of RAGE, AGE and S100A6 in the aortic tissue of bicuspid patients which may promote apoptosis via the upregulation of caspase-3 activity. Although increased caspase-3 activity was not detected in BAV patients, increased protein expression of the 48 kDa fragment of vimentin was detected. mTOR as a downstream protein of Akt was significantly higher in patients with BAV, whereas Bcl-2 was increased in patients with TAV, assuming a better protection against apoptosis. The autophagy-related proteins p62 and ERK1/2 were increased in patients with BAV, assuming that cells in bicuspid tissue are more likely to undergo apoptotic cell death leading to changes in the wall and finally to aortopathies. We provide first-hand evidence of increased apoptotic cell death in the aortic tissue of BAV patients which may thus provide an explanation for the increased risk of structural aortic wall deficiency possibly underlying aortic aneurysm formation or acute dissection.

Transcriptomic analysis identifies the S100 calcium-binding protein β subunit (S100B) and intercellular adhesion molecule-1 (ICAM-1) as potential diagnostic biomarkers for acute cerebral infarction

Transcriptomic analysis identifies the S100 calcium-binding protein β subunit (S100B) and intercellular adhesion molecule-1 (ICAM-1) as potential diagnostic biomarkers for acute cerebral infarction

Contribution of S100A4-expressing fibroblasts to anti-SSA/Ro-associated atrioventricular nodal calcification and soluble S100A4 as a biomarker of clinical severity.

Fibrosis and dystrophic calcification disrupting conduction tissue architecture are histopathological lesions characterizing cardiac manifestations of neonatal lupus (cardiac-NL) associated with maternal anti-SSA/Ro antibodies. Increased appreciation of heterogeneity in fibroblasts encourages re-examination of existing models with the consideration of multiple fibroblast subtypes (and their unique functional differences) in mind. This study addressed fibroblast heterogeneity by examining expression of α-Smooth Muscle Actin (myofibroblasts) and of S100 Calcium-Binding Protein A4 (S100A4). Using a previously established model of rheumatic scarring/fibrosis in vitro, supported by the evaluation of cord blood from cardiac-NL neonates and their healthy (anti-SSA/Ro-exposed) counterparts, and autopsy tissue from fetuses dying with cardiac-NL, the current study was initiated to more clearly define and distinguish the S100A4-positive fibroblast in the fetal cardiac environment. S100A4 immunostaining was observed in 4 cardiac-NL hearts with positional identity in the conduction system at regions of dystrophic calcification but not fibrotic zones, the latter containing only myofibroblasts. In vitro, fibroblasts cultured with supernatants of macrophages transfected with hY3 (noncoding ssRNA) differentiated into myofibroblasts or S100A4+ fibroblasts. Myofibroblasts expressed collagen while S100A4+ fibroblasts expressed pro-angiogenic cytokines and proteases that degrade collagen. Cord blood levels of S100A4 in anti-SSA/Ro-exposed neonates tracked disease severity and, in discordant twins, distinguished affected from unaffected. These findings position the S100A4+ fibroblast alongside the canonical myofibroblast in the pathogenesis of cardiac-NL. Neonatal S100A4 levels support a novel biomarker of poor prognosis.

Abstract 154: Establishment and characterization of a novel clear cell sarcoma organoid model derived from a human biopsy

Abstract Clear Cell Sarcoma (CCS) is an extremely aggressive, rare soft tissue cancer accounting for approximately 1% of all sarcomas. Often diagnosed in young adults with a median age of 25 years, CCS has a strong propensity for local recurrence and metastasis with an overall high mortality rate. Current treatment recommendations include radical surgical extirpation, followed by radiation or chemotherapy. Nonetheless, there is a need for extensive postoperative follow-up as the efficiency of adjuvant therapy in managing this disease remains poor. Consequently, it is imperative to identify clinically relevant models to advance our understanding of CCS tumor biology and facilitate the development of novel therapies. Compared to conventional preclinical tumor models, patient-derived organoids (PDOrgs) better recapitulate the patient tumor biology, genetic heterogeneity, and therapeutic responses. Here, we describe the development and validation of a human biopsy-derived CCS organoid model 1010561-T. 1010561-T was established from a male patient's metastatic paraspinal mass. This PDOrg demonstrates a moderate growth rate (doubling time of ~20 days) and pleomorphic traits, consisting mainly of solid, grape-like clusters, as well as elongated cells of mixed morphology. Furthermore, this model was successfully maintained over 7 months in culture and remained stable more than one year after cryopreservation. 1010561-T exhibits the cytogenetic hallmark of CCS which is the presence of a recurrent t(12;22)(q13;q12) chromosomal translocation, resulting in a fusion between the Ewing sarcoma gene and activating transcription factor 1 (EWS/ATF1 fusion). Reverse-transcription polymerase chain reaction (RT-PCR) confirmed that 1010561-T harbors a dual EWS/ATF1 fusion, namely EWS exon 8 to ATF1 codon 65 fusion (type 1) and EWS exon 7 to ATF1 codon 110 fusion (type 3). Quantitative RT-PCR and immunocytochemistry revealed strong expression of melanocytic differentiation markers typical of CCS including melanocyte inducing transcription factor (MITF), melan-A (MLANA), premelanosome protein (PMEL), and S100 calcium binding protein A11 (S100A11). Additionally, the gene expression profile of 1010561-T is in concordance with a well-established CCS cell line, SU-CCS-1. To our knowledge, 1010561-T is the first human CCS organoid model. It is, therefore, a valuable resource for advancing our understanding of the biology of this very rare disease, in addition to being a useful tool for validating new preclinical therapies that are undoubtedly needed to achieve better clinical outcomes for patients. To this end, 1010561-T will be transferred to the National Cancer Institute’s Patient-Derived Models Repository (https://pdmr.cancer.gov) where it will be made available to the scientific community. This project was funded in part with federal funds from the NCI, NIH, under contract no. HHSN261201800001I. Citation Format: Petreena S. Campbell, Erik D. Harris, Nancy Moore, Ralph E. Parchment, Nathan P. Coussens, Beverly A. Teicher, Alice Chen, James H. Doroshow, Annamaria Rapisarda. Establishment and characterization of a novel clear cell sarcoma organoid model derived from a human biopsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 154.

Abstract 3985: S100A10 promotes HCC development and progression via transfer in extracellular vesicles and regulating their protein cargos

Abstract Growing evidence indicates that tumor cells exhibit characteristics similar to their lineage progenitor cells. We found that S100 calcium binding protein A10 (S100A10) exhibited an expression pattern similar to that of liver progenitor genes. However, the role of S100A10 in hepatocellular carcinoma (HCC) progression is unclear. Furthermore, extracellular vesicles (EVs) or exosomes are critical mediator of tumorigenesis and metastasis, but the extracellular functions of S100A10, particularly those related to EVs (EV-S100A10), are unknown. In this study, we observed that S100A10 was upregulated at mRNA level in patients’ HCC tumors as compared to the corresponding non-tumorous livers, associated with a copy-number gain. Overexpression of S100A10 was correlated with more aggressive tumor features and poor prognosis. Furthermore, functional assays demonstrated it promoted HCC initiation and progression, including increased sphere forming ability in vitro, enhanced chemoresistance, upregulated liver cancer stemness markers and activated AKT and ERK pathways. In addition, in orthotopic injection mouse model, S100A10 enhanced both the intrahepatic and pulmonary metastasis of HCC xenografts, with upregulated epithelial-mesenchymal transition (EMT) changes. Of significance, we found that S100A10 was present in EVs secreted by HCC cells. Functionally, the EVs secreted by HCC cells promoted the migratory and invasive abilities of recipient HCC cells. Consistent with the oncogenic role of S100A10 in HCC, EVs from S100A10-overexpressing HCC cells enhanced the tumor promoting effects, while the S100A10-depleted HCC cells abrogated the effects, as compared to the vector control group. To further consolidate the tumor promoting role of S100A10-EV, we blocked the effects using neutralizing antibody (NA) by pretreating HCC cells with S100A10 NA together with EV. Indeed, the NA significantly abrogated the stemness and metastatic properties induced by S100A10-EVs both in vitro and in vivo. In addition, the EMT changes and activation of AKT and ERK were also validated in the recipient HCC cells with the S100A10-EV treatment, while they were abolished with the NA treatment. Moreover, we found that S100A10 governed the protein cargos in EVs and mediated the binding of MMP2, fibronectin and EGF to EV membranes through physical binding with integrin αV to promote the motility of recipient cells. Of note, we observed a simultaneous change of p-EGFR, indicating potential activation of AKT and ERK induced by EGFR. On the other hand, we found the plasma EV-S100A10 level was relatively higher in HCC patients than healthy donors. Collectively, the data showed that S100A10 could be transferred among cells through EVs and activated signaling pathways to facilitate metastasis. Targeting S100A10 may be a potential therapeutic strategy for HCC. Citation Format: Lu TIAN, Xia WANG, Jingyi LU, HongYang Huang, Goofy Yu-Man Tsui, Karen Man-Fong Sze, Tan-To Cheung, Irene Oi-Lin NG. S100A10 promotes HCC development and progression via transfer in extracellular vesicles and regulating their protein cargos. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3985.

LncRNA SNHG8 promotes ovarian cancer progression through serving as sponge for miR-1270 to regulate S100A11 expression.

Long non-coding RNA small nucleolar RNA host gene 8 (SNHG8) has been found correlated with cancer progression. This work was aimed to investigate the functions of SNHG8 in ovarian cancer (OC). Expression level of SNHG8 in OC tissues and cells was analyzed using real time-quantitative polymerase chain reaction (RT-qPCR) method. The biological roles of SNHG8 in OC were analyzed through proliferation assay, wound healing assay, and transwell invasion assay. Furthermore, interactions of SNHG8 or S100 calcium binding protein A11 (S100A11) and microRNA-1270 (miR-1270) were explored. Moreover, the effects of SNHG8, miR-1270, and S100A11 on the overall survival of OC patients were investigated. SNHG8 has increased expression in OC tissues and cells compared with normal counterparts, and correlated with poorer overall survival of OC patients. OC cell proliferation, migration, and invasion abilities were enhanced by SNHG8 overexpression but inhibited by its knockdown. In addition, we showed that SNHG8 regulates OC progression through targeting the miR-1270 and S100A11. Our work indicated that SNHG8 regulates OC progression through miR-1270/S100A11 axis, which may provide novel therapeutic targets for OC.

Multiomic landscape of immune pathogenesis in Kimura’s disease

Kimura's disease is a rare chronic inflammatory disorder characterized with subcutaneous masses, lymphadenopathy, and peripheral eosinophilia. So far, the disease pathogenesis remains hardly known. Here, we perform bulk-RNA sequencing and reveal a higher expression of transmembrane 176A (TMEM176A) with over-activated extracellular-signal-regulate kinase/mitogen-activated protein kinases (Erk/MAPK) signaling pathway in eosinophils of Kimura's disease compared with healthy controls. Flow cytometry analysis shows that the composition of lymphocytes, monocytes, and dendritic cell subsets are similar between Kimura's disease and healthy controls, which is further validated by scRNA-seq. Loss of S100 calcium binding protein P (S100P) is found in the CD24+ myeloid subset of Kimura's disease. Invitro functional assays show that S100P may participate in promoting reactive oxygen species (ROS) production in myeloid cells. Taken together, we are the first to study the immune pathogenesis systematically and demonstrate that Erk/MAPK signaling pathway might be a potential therapeutic target for Kimura's disease.

Expression of S100A11 Gene in Stomach Adenocarcinoma and Its Relationship with Immune Cell Infiltration and Prognosis

Stomach adenocarcinoma (STAD) is a complex biological process involving multiple factors. Given the importance of the immune-related tumor microenvironment (TME) in STAD, investigating tumor-immune interactions and identifying novel prognostic and therapeutic targets in STAD is a promising avenue of research. S100A11 (S100 calcium-binding protein 11) is a class of proteins that transduces calcium-dependent cellular regulatory signals involved in cancer formation and development. Recent studies demonstrated that S100A gene families plays important roles in regulating immune cell infiltration of cancers. However, the exact role of S100A11 in STAD has yet to be fully understood. Therefore, we examined S100A11 expression in STAD and its normal tissues using GEPIA and the Human Protein Atlas, using the UALCAN database was used to analyze the relationship between S100A11 protein expression and clinical parameters, and using the GSCA database was used to analyze the correlation between S100A11 protein expression and various subtypes of STAD. We found that S100A11 mRNA levels were significantly upregulated in STAD tissues compared to normal tissues. Elevated S100A11 was significantly associated with poor overall survival (OS), first progression (FP) and post-progression survival (PPS) in multiple STAD patient populations.

S100B Protein but Not 3-Nitrotyrosine Positively Correlates with Plasma Ammonia in Patients with Inherited Hyperammonemias: A New Promising Diagnostic Tool?

Individuals with inherited hyperammonemias often present developmental and intellectual deficiencies which are likely to be exaggerated by hyperammonemia episodes in long-term outcomes. In order to find a new, systemic marker common to the course of congenital hyperammonemias, we decided to measure the plasma level of S100 calcium-binding protein B (S100B), which is associated with cerebral impairment. Further, we analyzed three mechanistically diverged but linked with oxidative-nitrosative stress biochemical parameters: 3-nitrotyrosine (3-NT), a measure of plasma proteins' nitration; advanced oxidation protein products (AOPP), a measure of protein oxidation; and glutathione peroxidase (GPx) activity, a measure of anti-oxidative enzymatic capacity. The plasma biomarkers listed above were determined for the first time in congenital hyperammonemia. Also, the level of pro- and anti-inflammatory mediators (i.e., IL-12, IL-6, IL-8, TNF-α, IL-1β, and IL-10) and chemokines (IP-10, MCP-1, MIG, and RANTES) were quantified. S100B was positively correlated with plasma ammonia level, while noticeable levels of circulating 3-NT in some of the patients' plasma did not correlate with ammonia concentration. Overall, the linear correlation between ammonia and S100B but not standard oxidative stress-related markers offers a unique perspective for the future identification and monitoring of neurological deficits risk-linked with hyperammonemia episodes in patients with inherited hyperammonemias. The S100B measure may support the development of therapeutic targets and clinical monitoring in these disorders.

Novel serum biomarkers for predicting neurological outcomes in postcardiac arrest patients treated with targeted temperature management

ObjectiveTo determine the clinical feasibility of novel serum biomarkers in out-of-hospital cardiac arrest (OHCA) patients treated with target temperature management (TTM).MethodsThis study was a prospective observational study conducted on OHCA patients who underwent TTM. We measured conventional biomarkers, neuron‑specific enolase and S100 calcium-binding protein (S-100B), as well as novel biomarkers, including tau protein, neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), and ubiquitin C-terminal hydrolase-L1 (UCH-L1), at 0, 24, 48, and 72 h after the return of spontaneous circulation identified by SIMOA immunoassay. The primary outcome was poor neurological outcome at 6 months after OHCA.ResultsA total of 100 patients were included in this study from August 2018 to May 2020. Among the included patients, 46 patients had good neurologic outcomes at 6 months after OHCA. All conventional and novel serum biomarkers had the ability to discriminate between the good and poor neurological outcome groups (p < 0.001). The area under the curves of the novel serum biomarkers were highest at 72 h after cardiac arrest (CA) (0.906 for Tau, 0.946 for NFL, 0.875 for GFAP, and 0.935 for UCH-L1). The NFL at 72 h after CA had the highest sensitivity (77.1%, 95% CI 59.9–89.6) in predicting poor neurological outcomes while maintaining 100% specificity.ConclusionNovel serum biomarkers reliably predicted poor neurological outcomes for patients with OHCA treated with TTM when life-sustaining therapy was not withdrawn. Cutoffs from two large existing studies (TTM and COMACARE substudy) were externally validated in our study. The predictive power of the novel biomarkers was the highest at 72 h after CA.

Astrocyte responses to postnatal erythropoietin and nano-erythropoietin treatments in a valproic acid-induced animal model of autism

BackgroundDespite ample evidence of the potential protective effects of erythropoietin (EPO) on the developing brain, no study has addressed the effects of postnatal EPO on behaviors and brain tissue of animal models of autism. In the present study, we examined the therapeutic effects of postnatal erythropoietin on stereotypic behaviors and astrocyte responses via glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100B) immunohistochemistry in a valproic acid (VPA) animal model of autism. Also, we compared the effects of EPO with EPO-loaded solid lipid nanoparticles (NEPO) because the blood-brain barrier has limited permeability to EPO. MethodsPregnant rats received a single dose of VPA (600 mg/kg) at gestational day 12.5. EPO (2000 U/kg) and EPO-loaded solid lipid nanoparticles (NEPO1000 and 2000 U/kg) were injected intraperitoneally from postnatal days 1–5. Repetitive behaviors in male offspring were assessed by a marble burying test. The immune-staining method was performed to evaluate S100B and GFAP-positive cells in the prefrontal cortex and hippocampal CA1 region. ResultsVPA animal models revealed more repetitive behavior and displayed higher astrogliosis in the prefrontal cortex (PFC) and hippocampus (CA1) regions. The repetitive behaviors were ameliorated relatively in VPA groups with NEPO2000 treatment, and astrogliosis was reduced even when VPA rats were treated with a lower dosage of NEPO. ConclusionOur results indicate beneficial effects of postnatal NEPO exposure in the VPA animal model of autism, which proposes it as an early treatment in infants with, or at risk of, autism.

Temporal changes in biomarkers in individuals with and without acute mountain sickness following rapid ascent

BackgroundField studies have reported conflicting results regarding changes in biomarkers at high altitude. This study measured temporal changes in biomarkers and compared the differences between individuals with and without acute mountain sickness (AMS). Materials and methodsThis study included 34 nonacclimatized healthy participants. Ten-milliliters of blood were collected at four time points: 3 days before ascent (T0), on two successive nights at 3150 m (T1 and T2), and 2 days after descent (T3). Participants were transported by bus from 555 m to 3150 m within 3 hours. AMS was diagnosed using the self-reported Lake Louise Scoring (LLS) questionnaire. ResultsCompared with T0, significant increases in E-selectin and decreases in vascular endothelial growth factor (VEGF) levels were observed at high altitude. Significantly increased C-reactive protein (CRP), monocyte chemoattractant protein-1 (MCP-1), and S100 calcium-binding protein B (S100B) levels were observed at T2, and significantly decreased vascular cell adhesion molecule-1 (VCAM-1) levels were observed at T3. Eighteen (53%) participants developed AMS. Changes in E-selectin, CRP, MCP-1, and S100B levels were independent of AMS. Relative to individuals without AMS, those with AMS had significantly higher atrial natriuretic peptide (ANP) and VCAM-1 levels and lower plasminogen activator inhibitor-1 (PAI-1) levels at T1 and higher brain natriuretic peptide and lower VEGF and PAI-1 levels at T3. LLSs were positively correlated with ANP and VCAM-1 levels and negatively correlated with PAI-1 levels measured at T1. ConclusionsAfter acute ascent, individuals with and without AMS exhibited different trends in biomarkers associated with endothelial cell activation and natriuretic peptides.

Glycyrrhizic acid inhibits myeloid differentiation of hematopoietic stem cells by binding S100 calcium binding protein A8 to improve cognition in aged mice

BackgroundGlycyrrhizic acid (GA), a saponin compound often used as a flavoring agent, can elicit anti-inflammatory and anti-tumor effects, and alleviate aging. However, the specific mechanism by which GA alters immune cell populations to produce these beneficial effects is currently unclear.ResultsIn this study, we systematically analyzed single-cell sequencing data of peripheral blood mononuclear cells from young mice, aged mice, and GA-treated aged mice. Our in vivo results show that GA reduced senescence-induced increases in macrophages and neutrophils, and increased numbers of lymphoid lineage subpopulations specifically reduced by senescence. In vitro, GA significantly promoted differentiation of Lin−CD117+ hematopoietic stem cells toward lymphoid lineages, especially CD8+ T cells. Moreover, GA inhibited differentiation of CD4+ T cells and myeloid (CD11b+) cells by binding to S100 calcium-binding protein 8 (S100A8) protein. Overexpression of S100A8 in Lin− CD117+ hematopoietic stem cells enhanced cognition in aged mice and the immune reconstitution of severely immunodeficient B-NDG (NOD.CB17-Prkdcscid/l2rgtm1/Bcgen) mice.ConclusionsCollectively, GA exerts anti-aging effects by binding to S100A8 to remodel the immune system of aged mice.

Secreted S100A4 causes asthmatic airway epithelial barrier dysfunction induced by house dust mite extracts via activating VEGFA/VEGFR2 pathway

The airway epithelial barrier dysfunction plays a crucial role in pathogenesis of asthma and causes the amplification of downstream inflammatory signal pathway. S100 calcium binding protein A4 (S100A4), which promotes metastasis, have recently been discovered as an effective inflammatory factor and elevated in bronchoalveolar lavage fluid in asthmatic mice. Vascular endothelial growth factor-A (VEGFA), is considered as vital regulator in vascular physiological activities. Here, we explored the probably function of S100A4 and VEGFA in asthma model dealt with house dust mite (HDM) extracts. Our results showed that secreted S100A4 caused epithelial barrier dysfunction, airway inflammation and the release of T-helper 2 cytokines through the activation of VEGFA/VEGFR2 signaling pathway, which could be partial reversed by S100A4 polyclonal antibody, niclosamide and S100A4 knockdown, representinga potential therapeutic target for airway epithelial barrier dysfunction in asthma.

Abstract P3-05-22: Serum S100A8/S100A9 levels are associated with increased risk of brain metastasis in patients with aggressive breast cancer

Abstract Background: Inflammatory breast cancer (IBC) is a rare and extremely aggressive form of breast cancer with an increased propensity to disseminate to distant organs such as the brain; indeed, a previous study reported that 37% of patients with HER2+ IBC present with brain metastasis as the first site of relapse. Our group recently generated new sublines from HER2+ IBC that exhibited a high brain metastatic propensity and further demonstrated that the stress response protein N-myc downstream regulated gene 1 (NDRG1) is a driver of breast cancer brain metastasis. Transcriptome analysis comparing NDRG1-expressing brain-metastasizing and NDRG1-depleted brain-non-metastasizing cells revealed prominent downregulation of two S100 calcium binding proteins, S100A8 and S100A9, in NDRG1-depleted cells. S100A8/S100A9 are known to facilitate the homing of tumor cells to the brain and lung pre-metastatic niche. Recent studies elegantly demonstrated a critical role for S100A9 in brain relapse and radioresistance in brain metastasis mouse models. The purpose of the present study was to evaluate whether S100A8/S100A9 serum levels predict the risk of brain metastasis in aggressive breast cancers. Methods: In a retrospective cohort of 304 IBC patients, we measured serum S100A8/S100A9 levels by using ELISA. Overall survival (OS) and breast cancer-specific survival (BCSS) were analyzed using Kaplan-Meier curves, log-rank test, and Cox proportional hazard regression. Results: The overall median follow-up time was 64 months. Forty-six percent of patients had estrogen receptor (ER)-negative tumors, 61.3% were stage III-IV, 77% high grade, 16.8% received adjuvant chemotherapy and 53.6% received adjuvant radiation. On univariate analysis, S100A8/S100A9 levels, disease stage, ER status, PR status, HER2 status, adjuvant chemotherapy, and adjuvant radiation therapy were significantly associated with OS and BCSS. Patients with high S100A8/S100A9 serum levels (&amp;gt;3rd quartile vs. ≤ 3rd quartile) had poor OS (p=0.01) and BCSS (p=0.006). Also, patients with high S100A8/S100A9 serum levels had a higher risk of developing brain metastasis (p=0.01). S100A8/S00A9 serum levels was not significantly correlated with any other metastasis. On multivariate analysis, high S100A8/S100A9 serum levels was independently associated with reduced OS (hazard ratio [HR] = 1.8, 95% CI 1.1 to 3.0, p=0.01), reduced BCSS (HR = 1.8, 95% CI 1.2 to 2.8, p=0.006) and increased risk of developing brain metastasis (HR = 2.1, 95% CI 1.2 to 3.8, p=0.01). Conclusions: We found that having high levels of serum S100A8/S100A9 is an independent prognostic factor for reduced OS and BCSS and for the development of brain metastasis in patients with IBC. Thus, S100A8/S100A9 may represent a biomarker for unfavorable clinical outcome and brain metastasis in patients with aggressive breast cancers. Citation Format: Emilly S. Villodre, Xiaoding Hu, Juhee Song, Kristen Gomez, Xiaoping Su, James Reuben, Naoto T. Ueno, Debu Tripathy, Savitri Krishnamurthy, Bisrat Debeb. Serum S100A8/S100A9 levels are associated with increased risk of brain metastasis in patients with aggressive breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-22.

Time-Dependent Changes in the Biofluid Levels of Neural Injury Markers in Severe Traumatic Brain Injury Patients-Cerebrospinal Fluid and Cerebral Microdialysates: A Longitudinal Prospective Pilot Study.

Monitoring protein biomarker levels in the cerebrospinal fluid (CSF) can help assess injury severity and outcome after traumatic brain injury (TBI). Determining injury-induced changes in the proteome of brain extracellular fluid (bECF) can more closely reflect changes in the brain parenchyma, but bECF is not routinely available. The aim of this pilot study was to compare time-dependent changes of S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), total Tau, and phosphorylated Tau (p-Tau) levels in matching CSF and bECF samples collected at 1, 3, and 5 days post-injury from severe TBI patients (n = 7; GCS 3-8) using microcapillary-based western analysis. We found that time-dependent changes in CSF and bECF levels were most pronounced for S100B and NSE, but there was substantial patient-to-patient variability. Importantly, the temporal pattern of biomarker changes in CSF and bECF samples showed similar trends. We also detected two different immunoreactive forms of S100B in both CSF and bECF samples, but the contribution of the different immunoreactive forms to total immunoreactivity varied from patient to patient and time point to time point. Our study is limited, but it illustrates the value of both quantitative and qualitative analysis of protein biomarkers and the importance of serial sampling for biofluid analysis after severe TBI.

The critical role of KLF4 in regulating the activation of A1/A2 reactive astrocytes following ischemic stroke

BackgroundWe have previously demonstrated that the expression of kruppel-like transcription factor-4 (KLF-4) is upregulated in astrocytes following acute ischemic stroke (AIS) and found that KLF4 confers vascular protection against cerebral ischemic injury. However, the functional role of KLF4 in astrocyte after AIS is far from clear.MethodsThe intrinsic relationship between KLF4 and A1/A2 reactive astrocytes and the impact of astrocytic KLF4 on the activation of A1/A2 subtype astrocytes were evaluated in middle cerebral artery occlusion (MCAO) mice and oxygen–glucose deprivation and restoration (OGD/R) astrocytes.ResultsOur results demonstrated that astrocytic KLF4 expression and complement C3-positive A1 and S100 calcium binding protein A10 (S100A10)-positive A2 astrocytes were induced in the ischemic penumbra following focal cerebral ischemia, and the time course of upregulation of astrocytic KLF4 correlated closely with the activation of A2 astrocytes. The dual immunofluorescent studies displayed that in the ischemic hemisphere, where the high levels of KLF4 were expressed, there were relatively low levels of C3 expressed in the reactive astrocytes and vice versa, but KLF4 was always co-stained well with S100A10. Mechanistic analyses revealed that astrocytic KLF4 inhibited the activation of A1 astrocyte but promoted A2 astrocyte polarization after OGD/R by modulating expressions of nuclear factor-kB.ConclusionsAstrocyte-derived KLF4 has a critical role in regulating the activation of A1/A2 reactive astrocytes following AIS.