Deciphering S100B Allosteric Signaling: The Role of a Peptide Target, TRTK-12, as an Ensemble Modulator.

Allostery is an essential biological phenomenon in which perturbation at one site in a biomolecule elicits a functional response at a distal location(s). It is integral to biological processes, such as cellular signaling, metabolism, and transcription regulation. Understanding allostery is also crucial for rational drug discovery. In this work, we focus on an allosteric S100B protein that belongs to the S100 class of EF-hand Ca2+-binding proteins. The Ca2+-binding affinity of S100B is modulated allosterically by TRTK-12 peptide binding 25 Å away from the Ca2+-binding site. We investigated S100B allostery by carrying out nuclear magnetic resonance (NMR) measurements along with microsecond-long molecular dynamics (MD) simulations on S100B/Ca2+ with/without TRTK-12 at different NaCl salt concentrations. NMR HSQC results show that TRTK-12 reorganizes how S100B/Ca2+ responds to different salt concentrations at both orthosteric and allosteric sites. The MD data suggest that TRTK-12 breaks the dynamic aromatic and hydrogen-bond interactions (not observed in X-ray crystallographic structures) between the hinge/helix and Ca2+-binding EF-hand loop of the two subunits in the homodimeric protein. This triggers rearrangement in the protein network architectures and leads to allosteric communication. Finally, computational studies of S100B at distinct ionic strengths suggest that ligand-bound species are more robust to the changing environment relative to the S100B/Ca2+ complex.

[Expression and significance of hypoxia-inducible factor 1α and Bcl-2/adenovirus E1B19kDa-interacting protein 3 in children with traumatic brain injury]. / ç¼ºæ°§è¯±å¯¼å› å­1α、Bcl-2/è ºç— æ¯’E1B19kDa相互作用蛋白3在儿童创伤性脑损伤中的表达及意义.

OBJECTIVES: To dynamically observe the changes in hypoxia-inducible factor 1α (HIF-1α) and Bcl-2/adenovirus E1B19kDa-interacting protein 3 (BNIP3) in children with traumatic brain injury (TBI) and evaluate their clinical value in predicting the severity and prognosis of pediatric TBI. METHODS: A prospective study included 47 children with moderate to severe TBI from January 2021 to July 2023, categorized into moderate (scores 9-12) and severe (scores 3-8) subgroups based on the Glasgow Coma Scale. A control group consisted of 30 children diagnosed and treated for inguinal hernia during the same period, with no underlying diseases. The levels of HIF-1α, BNIP3, autophagy-related protein Beclin-1, and S100B were compared among groups. The predictive value of HIF-1α, BNIP3, Beclin-1, and S100B for the severity and prognosis of TBI was assessed using receiver operating characteristic (ROC) curves. RESULTS: Serum levels of HIF-1α, BNIP3, Beclin-1, and S100B in the TBI group were higher than those in the control group (P<0.05). Among the TBI patients, the severe subgroup had higher levels of HIF-1α, BNIP3, Beclin-1, and S100B than the moderate subgroup (P<0.05). Correlation analysis showed that the serum levels of HIF-1α, BNIP3, Beclin-1, and S100B were negatively correlated with the Glasgow Coma Scale scores (P<0.05). After 7 days of treatment, serum levels of HIF-1α, BNIP3, Beclin-1, and S100B in both non-surgical and surgical TBI patients decreased compared to before treatment (P<0.05). ROC curve analysis indicated that the areas under the curve for predicting severe TBI based on serum levels of HIF-1α, BNIP3, Beclin-1, and S100B were 0.782, 0.835, 0.872, and 0.880, respectively (P<0.05), and for predicting poor prognosis of TBI were 0.749, 0.775, 0.814, and 0.751, respectively (P<0.05). CONCLUSIONS: Serum levels of HIF-1α, BNIP3, and Beclin-1 are significantly elevated in children with TBI, and their measurement can aid in the clinical assessment of the severity and prognosis of pediatric TBI.

Moxibustion preconditioning reduces inflammatory response in rats with cerebral ischemia-reperfusion injury by regulating PI3K / AKT / mTOR signaling pathway. / 艾灸预处理通过调控PI3K/AKT/mTORä¿¡å·é€šè·¯å‡è½»è„‘ç¼ºè¡€å†çŒæ³¨æŸä¼¤å¤§é¼ ç‚Žæ€§ååº”.

OBJECTIVES: To observe the effect of moxibustion preconditioning on inflammatory response in rats with cerebral ischemia reperfusion injury (CIRI), so as to explore its mechanisms underlying improving CIRI. METHODS: Seventy-five male SD rats were randomly divided into sham operation, model, moxibustion preconditioning 3 days (Moxi 1), moxibustion preconditioning 5 days (Moxi 2) and moxibustion preconditioning 7 days (Moxi 3) groups, with 15 rats in each group. Moxibustion was applied at "Baihui"(GV20), "Dazhui"(GV14) and "Zusanli"(ST36) for 20 min once a day, totally for 3, 5 or 7 days. Thirty minutes after the last moxibustion treatment, the CIRI model was established by occlusion of the middle cerebral artery. The neurological deficit score was assessed by using Longa's method. The infarct size of the brain assessed after staining with 2% triphenyltetrazolium chloride (TTC). The morphological changes of cortical neurons were observed by HE staining. The contents of inflammatory factors interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), S-100ß protein (S-100ß) and neuron-specific enolase (NSE) were detected by ELISA. The expression of phosphatidylinositol-3-kinase (PI3K), p-PI3K, protein kinase B (AKT) and mammalian target of rapamycin (mTOR) proteins in the ischemic cortex tissues were detected by immunohistochemistry and Western blot. RESULTS: Compared with the sham operation group, the neurological function score and the percentage of cerebral ischemic volume were increased (P<0.01). The contents of serum IL-1ß, TNF-α, S-100ß and NSE were significantly increased (P<0.01), while the protein expressions of PI3K, p-PI3K, AKT and mTOR in the cerebral cortex were significantly decreased (P<0.01) in the model group. Compared with the model group, the neurological function score and the percentage of cerebral ischemic volume were significantly decreased (P<0.01). The contents of serum IL-1ß, TNF-α, S-100ß and NSE were significantly decreased (P<0.01), and the expressions of PI3K, p-PI3K, AKT and mTOR proteins in the cerebral cortex were significantly increased (P<0.01) in three moxibustion groups. Compared with the Moxi 1 and Moxi 2 groups, the above indicators were significantly improved in rats of the Moxi 3 group (P<0.01, P<0.05). CONCLUSIONS: Moxibustion preconditioning can significantly improve the neurological function of rats after ischemia-reperfusion, inhibit serum inflammatory factors IL-1 ß and TNF-α, inhibit brain tissue injury markers S-100ß and NSE, which may be related to the activation of PI3K/AKT/mTOR signaling pathway. The protective effect of moxibustion preconditioning for 7 days on CIRI was better than that of 5 days and 3 days.

Serum S100B protein and white matter changes in schizophrenia before and after medication.

Schizophrenia patients have abnormalities in white matter (WM) integrity in brain regions. S100B has been shown to be a marker protein for glial cells. The atypical antipsychotics have neuroprotective effects on the brain. It is not clear whether antipsychotics can induce S100B changes and improve symptoms by protecting oligodendrocytes. To investigate WM and S100B changes and associations and determine the effect of quetiapine on WM and S100B in schizophrenia patients, we determined serum S100B levels with solid phase immunochromatography and fractional anisotropy（FA）values of 36 patients and 40 healthy controls. Patients exhibited significantly higher serum concentrations of S100B and decreased FA values in left postcentral，right superior frontal，right thalamus, and left inferior occipital gyrus, while higher in right temporal cortex WM compared with healthy controls. Following treatment with quetiapine, patients had decreased S100B and higher FA values in right cerebellum，right superior frontal，right thalamus, and left parietal cortex，and decreased FA values in right temporal cortex WM compared with pre-treatment values. Furthermore, S100B were negatively correlated with PANSS positive scores and positively correlated with FA values in the left postcentral cortex. In addition，the percentage change in FA values in the right temporal cortex was positively correlated with the percentage change in the S100B, percentage reduction in PANSS scores, and percentage reduction in PANSS-positive scores. Our findings demonstrated abnormalities in S100B and WM microstructure in patients with schizophrenia. These abnormalities may be partly reversed by quetiapine treatment.

Serum S100B Level in the Management of Pediatric Minor Head Trauma: A Randomized Clinical Trial.

Importance: Minor head trauma (HT) is one of the most common causes of hospitalization in children. A diagnostic test could prevent unnecessary hospitalizations and cranial computed tomographic (CCT) scans. Objective: To evaluate the effectiveness of serum S100B values in reducing exposure to CCT scans and in-hospital observation in children with minor HT. Design, Setting, and Participants: This multicenter, unblinded, prospective, interventional randomized clinical trial used a stepped-wedge cluster design to compare S100B biomonitoring and control groups at 11 centers in France. Participants included children and adolescents 16 years or younger (hereinafter referred to as children) admitted to the emergency department with minor HT. The enrollment period was November 1, 2016, to October 31, 2021, with a follow-up period of 1 month for each patient. Data were analyzed from March 7 to May 29, 2023, based on the modified intention-to-treat and per protocol populations. Interventions: Children in the control group had CCT scans or were hospitalized according to current recommendations. In the S100B biomonitoring group, blood sampling took place within 3 hours after minor HT, and management depended on serum S100B protein levels. If the S100B level was within the reference range according to age, the children were discharged from the emergency department. Otherwise, children were treated as in the control group. Main Outcomes and Measures: Proportion of CCT scans performed (absence or presence of CCT scan for each patient) in the 48 hours following minor HT. Results: A total of 2078 children were included: 926 in the control group and 1152 in the S100B biomonitoring group (1235 [59.4%] boys; median age, 3.2 [IQR, 1.0-8.5] years). Cranial CT scans were performed in 299 children (32.3%) in the control group and 112 (9.7%) in the S100B biomonitoring group. This difference of 23% (95% CI, 19%-26%) was not statistically significant (P = .44) due to an intraclass correlation coefficient of 0.32. A statistically significant 50% reduction in hospitalizations (95% CI, 47%-53%) was observed in the S100B biomonitoring group (479 [41.6%] vs 849 [91.7%]; P < .001). Conclusions and Relevance: In this randomized clinical trial of effectiveness of the serum S100B level in the management of pediatric minor HT, S100B biomonitoring yielded a reduction in the number of CCT scans and in-hospital observation when measured in accordance with the conditions defined by a clinical decision algorithm. Trial Registration: ClinicalTrials.gov Identifier: NCT02819778.

Secondary Modification of S100B Influences Anti Amyloid-ß Aggregation Activity and Alzheimer's Disease Pathology.

Proteinaceous aggregates accumulate in neurodegenerative diseases such as Alzheimer's Disease (AD), inducing cellular defense mechanisms and altering the redox status. S100 pro-inflammatory cytokines, particularly S100B, are activated during AD, but recent findings reveal an unconventional molecular chaperone role for S100B in hindering Aß aggregation and toxicity. This suggests a potential protective role for S100B at the onset of Aß proteotoxicity, occurring in a complex biochemical environment prone to oxidative damage. Herein, we report an investigation in which extracellular oxidative conditions are mimicked to test if the susceptibility of S100B to oxidation influences its protective activities. Resorting to mild oxidation of S100B, we observed methionine oxidation as inferred from mass spectrometry, but no cysteine-mediated crosslinking. Structural analysis showed that the folding, structure, and stability of oxidized S100B were not affected, and nor was its quaternary structure. However, studies on Aß aggregation kinetics indicated that oxidized S100B was more effective in preventing aggregation, potentially linked to the oxidation of Met residues within the S100:Aß binding cleft that favors interactions. Using a cell culture model to analyze the S100B functions in a highly oxidative milieu, as in AD, we observed that Aß toxicity is rescued by the co-administration of oxidized S100B to a greater extent than by S100B. Additionally, results suggest a disrupted positive feedback loop involving S100B which is caused by its oxidation, leading to the downstream regulation of IL-17 and IFN-α2 expression as mediated by S100B.

S100b treatment overcomes RAGE signaling deficits in myoblasts on advanced glycation end-product cross-linked collagen and promotes myogenic differentiation.

Advanced glycation end-products (AGEs) stochastically accrue in skeletal muscle and on collagen over an individual's lifespan, stiffening the muscle and modifying the stem cell (MuSC) microenvironment while promoting proinflammatory, antiregenerative signaling via the receptor for advanced glycation end-products (RAGEs). In the present study, a novel in vitro model was developed of this phenomenon by cross linking a 3-D collagen scaffold with AGEs and investigating how myoblasts responded to such an environment. Briefly, collagen scaffolds were incubated with d-ribose (0, 25, 40, 100, or 250 mM) for 5 days at 37°C. C2C12 immortalized mouse myoblasts were grown on the scaffolds for 6 days in growth conditions for proliferation, and 12 days for differentiation and fusion. Human primary myoblasts were also used to confirm the C2C12 data. AGEs aberrantly extended the DNA production stage of C2C12s (but not in human primary myoblasts) which is known to delay differentiation in myogenesis, and this effect was prevented by RAGE inhibition. Furthermore, the differentiation and fusion of myoblasts were disrupted by AGEs, which were associated with reductions in integrins and suppression of RAGE. The addition of S100b (RAGE agonist) recovered the differentiation and fusion of myoblasts, and the addition of RAGE inhibitors (FPS-ZM1 and Azeliragon) inhibited the differentiation and fusion of myoblasts. Our results provide novel insights into the role of the AGE-RAGE axis in skeletal muscle aging, and future work is warranted on the potential application of S100b as a proregenerative factor in aged skeletal muscle.NEW & NOTEWORTHY Collagen cross-linked by advanced glycation end-products (AGEs) induced myoblast proliferation but prevented differentiation, myotube formation, and RAGE upregulation. RAGE inhibition occluded AGE-induced myoblast proliferation, while the delivery of S100b, a RAGE ligand, recovered fusion deficits.

Combining biomarkers of BNIP3 L, S100B, NSE, and accessible measures to predict sepsis-associated encephalopathy: a prospective observational study.

BACKGROUND: Accurate identification of delirium in sepsis patients is crucial for guiding clinical diagnosis and treatment. However, there are no accurate biomarkers and indicators at present. We aimed to identify which combinations of cognitive impairment-related biomarkers and other easily accessible assessments best predict delirium in sepsis patients. METHODS: One hundred and one sepsis patients were enrolled in a prospective study cohort. S100B, NSE, and BNIP3 L biomarkers were detected in plasma and cerebrospinal fluid and patients' optic nerve sheath diameter (ONSD). The optimal biomarkers identified by Logistic regression are combined with other factors such as ONSD to filter out the perfect model to predict delirium in sepsis patients through Logistic regression, Naïve Bayes, decision tree, and neural network models. MAIN RESULTS: Among all biomarkers, compared with BNIP3 L (AUC = .706, 95% CI = .597-.815) and NSE (AUC = .711, 95% CI = .609-.813) in cerebrospinal fluid, plasma S100B (AUC = .729, 95% CI = .626-.832) had the best discrimination performance for delirium in sepsis patients. Logistic regression analysis showed that the combination of cerebrospinal fluid BNIP3 L with plasma S100B, ONSD, neutrophils, and age provided the best discrimination to cognitive impairment in sepsis patients (accuracy = .901, specificity = .923, sensitivity = .911), which was better than Naïve Bayes, decision tree, and neural network models. Neutrophils, ONSD, and cerebrospinal fluid BNIP3 L were consistently the major contributors in a few models. CONCLUSIONS: The logistic regression showed that the combination model was strongly correlated with cognitive dysfunction in sepsis patients.

Concentrations of S100B and neurofilament light chain in blood as biomarkers for checkpoint inhibitor-induced CNS inflammation.

BACKGROUND: Cancer treatment with immune checkpoint inhibition (ICI) can cause immune-related adverse events in the central nervous system (CNS irAE). There are no blood biomarkers to detect CNS irAE. We investigated if concentrations of S100-calcium-binding protein B (S100B) and neurofilament light chain (NfL) in blood can be used as biomarkers for CNS irAE and assessed the incidence of CNS irAE in a cohort of ICI-treated patients. METHODS: In this single-centre, retrospective cohort study, we examined medical records and laboratory data of 197 consecutive patients treated with combined CTLA-4 and PD-1 inhibition (ipilimumab; ipi + nivolumab; nivo) for metastatic melanoma or renal cell carcinoma. CNS irAE was diagnosed using established criteria. Concentrations of S100B and NfL in blood were measured in patients with CNS irAE and in 84 patients without CNS irAE. FINDINGS: Nine of 197 patients (4.6%) fulfilled criteria for CNS irAE. S100B and NfL in blood increased during CNS inflammation and normalized during immunosuppression. CNS irAE was detected with a sensitivity of 100% (S100B) and 79% (NfL) and a specificity of 89% (S100B) and 74% (NfL). Patients with CNS irAE had simultaneous increased concentration of C-reactive protein (CRP) (9/9) and alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) in blood (8/9). INTERPRETATION: Analysis of S100B, NfL and CRP in blood facilitates the diagnosis of CNS irAE. CNS irAE may be more common than previously reported. There may be shared immune mechanisms between CNS and hepatitis irAE. FUNDING: Supported by funding from the Swedish Cancer Foundation, the ALF-agreement, and Jubileumsklinikens Cancerfond.

The Multifaceted S100B Protein: A Role in Obesity and Diabetes?

The S100B protein is abundant in the nervous system, mainly in astrocytes, and is also present in other districts. Among these, the adipose tissue is a site of concentration for the protein. In the light of consistent research showing some associations between S100B and adipose tissue in the context of obesity, metabolic disorders, and diabetes, this review tunes the possible role of S100B in the pathogenic processes of these disorders, which are known to involve the adipose tissue. The reported data suggest a role for adipose S100B in obesity/diabetes processes, thus putatively re-proposing the role played by astrocytic S100B in neuroinflammatory/neurodegenerative processes.

Palmitic acid, but not other long-chain saturated fatty acids, increases S100B protein and TNF-α secretion by astrocytes.

Obesity is a health problem that involves fat accumulation in adipose and other tissues and causes cell dysfunction. Long-chain saturated fatty acids can induce and propagate inflammation, which may also contribute to the brain alterations found in individuals with obesity. Fatty acids accumulate in astrocytes in situations of blood‒brain barrier disruption, such as inflammatory conditions. Furthermore, the increase in tumor necrosis factor-alpha (TNF-α) and S100 calcium-binding protein B (S100B) secretion is considered an essential component of the inflammatory response. We hypothesize that through their action on astrocytes, long-chain saturated fatty acids mediate some of the brain alterations observed in individuals with obesity. Here, we investigate the direct effect of long-chain fatty acids on astrocytes. Primary astrocyte cultures were incubated for 24 hours with myristic, palmitic, stearic, linoleic, or α-linolenic acids (25-100 µM). All saturated fatty acids tested led to an increase in TNF-α secretion, but only palmitic acid, one of the most common fatty acids, increased S100B secretion, indicating that S100B secretion is probably not caused in response to TNF-α release. Palmitic acid also caused nuclear migration of nuclear factor kappa B. Long-chain saturated fatty acids did not alter cell viability or redox status. In conclusion, long-chain saturated fatty acids can alter astrocytic homeostasis and may contribute to brain disorders associated with obesity, such as neuroinflammation.

Clinical value of S100B in detecting intracranial injury in elderly patients with mild traumatic brain injury.

OBJECTIVE: The biomarker S100B is a sensitive biomarker to detect traumatic intracranial injury in patients mild traumatic brain injury (mTBI). Higher blood values of S100B, resulting in lower specificity and decreased head computed tomography (CT) reduction has been regarded as one of shortcomings in patients over 65 years of age. The purpose of this study was to assess the accuracy of plasma S100B to detect intracranial injury in elderly patients with mTBI. METHODS: A posthoc analysis was performed of a larger prospective cohort study. Previous recorded patient variables and plasma values of S100B from patients with mTBI who presented to the Emergency Department (ED) within 6 h of injury, underwent a head CT and had a blood sample drawn as part of their routine clinical care, were partitioned at 65 years of age. Sensitivity, specificity, negative predictive value, and positive predictive value of plasma S100B for predicting traumatic intracranial lesions on head CT, with a cut-off set at 0.105 µg/L, were calculated. Results were compared with data from an additional systematic review on the accuracy of S100B to detect intracranial injury in elderly patients with mTBI. RESULTS: Data of 240 patients (48.4 %) of 65 years or older were analyzed. Sensitivity and NPV of S100B were 89 % and 86 % respectively, which is lower than among younger patients (both 97 %). The specificity decreased stepwise with older age: 22 %, 18 %, and 5 % for the age groups 65-74, 75-84, and ≥ 85 years old, respectively. The meta-analysis comprised 4 studies and the current study with data from 2166 patients. Pooled data estimated the sensitivity of s100B as 97.4 % (95 % CI 83.3-100 %) and specificity as 17.3 % (95 % CI 9.5-29.3 %) to detect intracranial injury in elderly patients with mTBI. CONCLUSION: The biomarker S100B at the routine threshold has a limited clinical value in the management of elderly mTBI patients mainly due to a poor specificity leading to only a small decrease in head CTs. Alternate cut-off values and combining several plasma biomarkers with clinical variables may be useful strategies to increase the accuracy of S100B in (subgroups of) elderly mTBI patients.

S-100ß level is closely associated with myocardial work in patients with acute ischemic stroke.

BACKGROUND: The more severe the acute stroke is, the more serious myocardial damage is. This study aimed to determine the relationship between myocardial work and S100ß, a quantitative biomarker of active cerebral lesions, in patients with acute ischemic stroke (AIS). METHODS: A total of 63 patients with AIS were examined by myocardial work echocardiography, 4D echocardiography with the measurement of left ventricular (LV) myocardial work, volume and function within 24-48 h of symptom onset, respectively. Their plasma S100ß was measured from a peripheral blood sample within 2-6 h of symptom onset. RESULTS: Patients with elevated S-100ß level had significantly increased ratios of peak early diastolic transmitral filling velocity to peak early diastolic lateral mitral annulus tissue velocity(E/e') and global longitudinal strain (GLS), and significantly reduced global work index(GWI) and global constructive work (GCW) compared with those with normal S-100ß level (p < 0.05). S-100ß positively correlated with E/e'(r = 0.878, p < 0.0001) and GLS (r = 0.511, p = 0.002) but negatively correlated with GWI(r = -0.409, p = 0.034) and GCW(r = -0.353, p = 0.041). S-100ß showed an excellent ability to differentiate if a reduced GWI [cut-off value, 120.79 pg/mL; area under receiver operating characteristic curve (AUC), 1.000; sensitivity, 100%; specificity, 100%], GCW (cut-off value, 120.79 pg/mL;AUC,1.000; sensitivity,100%; specificity, 100%) and an increased E/e' (cut-off value, 91.1 pg/mL;AUC,0.913; sensitivity,80%; specificity, 100%) or not, but poor ability to differentiate if an increased GLS(cut-off value, 91.1 pg/mL; AUC,0.576; sensitivity,63.64%; specificity, 83.33%) or not. CONCLUSION: S-100ß level is closely associated with LV function. It is highly competent in determining an impaired myocardial work in patients with AIS.

Recent Advance of S100B Proteins in Spontaneous Intracerebral Hemorrhage and Aneurysmal Subarachnoid Hemorrhage.

Human health is seriously endangered by spontaneous intracerebral hemorrhage (ICH) and aneurysmal subarachnoid hemorrhage (aSAH). Because the majority of ICH and aSAH survivors experience disability, increased risk of stroke recurrence, cognitive decline, and systemic vascular disease, ICH and aSAH assume special importance in neurological disease. Early detection and prediction of neurological function and understanding of etiology and correction are the basis of successful treatment. ICH and aSAH cause complex inflammatory cascades in the brain. In order to establish precise staging and prognosis, as well as provide a basis for treatment selection and monitoring, it is imperative to determine appropriate biological markers according to pathological and physiological mechanisms. In this review, we focus on the research progress of S100B, an endogenous danger signaling molecule, as a potential biomarker for ICH and aSAH, assisting in the development of further basic research and clinical translational studies.

Effects of dexmedetomidine combined with etomidate on postoperative cognitive function in older patients undergoing total intravenous anaesthesia: a randomized, double-blind, controlled trial.

BACKGROUND: Etomidate has been advocated for anesthesia in older and critically ill patients because of its hemodynamic stability. Clinical studies have shown that dexmedetomidine has neuroprotective and anti-inflammatory properties and improves postoperative cognitive dysfunction in older patients. The present study was to evaluate the effects of the combination of etomidate and dexmedetomidine with different anaesthesia time on postoperative cognitive function in older patients. METHODS: A total of 132 older patients undergoing ureteroscopic holmium laser lithotripsy were randomly divided into EN group and ED group equally. Patients whose surgery time was less than or equal to 1 h in each group were allocated to short-time surgery group (EN1 group and ED1 group), and whose surgery time was more than 1h were allocated to long-term surgery group (EN2 group and ED2 group). The primary outcome was the score of the Mini-Mental State Examination. The secondary outcomes were State-Trait Anxiety Inventory scores, Riker sedation agitation scores, Zung Self-Rating Depression Scale scores, the memory span for Arabic numerals, the plasma concentrations of S-100 calcium-binding protein B and neuron specific enolase, the time to spontaneous respiration, recovery, and extubation. RESULTS: The MMSE scores at t2-3 were higher in ED1 and ED2 groups than in EN1 and EN2 groups (p<0.05). Compared with ED1 and ED2 groups, the ZSDS scores, the S-AI scores and the T-AI scores at t1-2 were higher in EN1 and EN2 groups (p<0.05), respectively. The recalled Arabic numbers at t1-3 were higher in ED2 group than in EN2 group (p<0.05). The plasma concentration of S-100ß at t1-2 in EN1 group and t1-3 in EN2 group were higher than that in ED1 and ED2 groups (p<0.05), respectively. Compared with ED1 and ED2 groups, the plasma concentrations of NSE were higher at t1-3 in EN1 group and t1-4 in EN2 group (p<0.05), respectively. CONCLUSION: The administration of dexmedetomidine could improve postoperative cognitive dysfunction, emergence agitation, depression and anxiety, attenuate the plasma concentrations of S-100ß and NSE in older patients undergoing total intravenous anaesthesia with etomidate. TRIAL REGISTRATION: Registration number: ChiCTR1800015421, Date: 29/03/2018.

The Role of Glycogen Synthase Kinase-3ß in the Zinc-Mediated Neuroprotective Effect of Metformin in Rats with Glutamate Neurotoxicity.

Metformin has been suggested to have protective effects on the central nervous system, but the mechanism is unknown. The similarity between the effects of metformin and the inhibition of glycogen synthase kinase (GSK)-3ß suggests that metformin may inhibit GSK-3ß. In addition, zinc is an important element that inhibits GSK-3ß by phosphorylation. In this study, we investigated whether the effects of metformin on neuroprotection and neuronal survival were mediated by zinc-dependent inhibition of GSK-3ß in rats with glutamate-induced neurotoxicity. Forty adult male rats were divided into 5 groups: control, glutamate, metformin + glutamate, zinc deficiency + glutamate, and zinc deficiency + metformin + glutamate. Zinc deficiency was induced with a zinc-poor pellet. Metformin was orally administered for 35 days. D-glutamic acid was intraperitoneally administered on the 35th day. On the 38th day, neurodegeneration was examined histopathologically, and the effects on neuronal protection and survival were evaluated via intracellular S-100ß immunohistochemical staining. The findings were examined in relation to nonphosphorylated (active) GSK-3ß levels and oxidative stress parameters in brain tissue and blood. Neurodegeneration was increased (p < 0.05) in rats fed a zinc-deficient diet. Active GSK-3ß levels were increased in groups with neurodegeneration (p < 0.01). Decreased neurodegeneration, increased neuronal survival (p < 0.01), decreased active GSK-3ß (p < 0.01) levels and oxidative stress parameters, and increased antioxidant parameters were observed in groups treated with metformin (p < 0.01). Metformin had fewer protective effects on rats fed a zinc-deficient diet. Metformin may exert neuroprotective effects and increase S-100ß-mediated neuronal survival by zinc-dependent inhibition of GSK-3ß during glutamate neurotoxicity.

TAT-W61 peptide attenuates neuronal injury through blocking the binding of S100b to the V-domain of Rage during ischemic stroke.

Ischemic stroke is a devastative nervous system disease associated with high mortality and morbidity rates. Unfortunately, no clinically effective neuroprotective drugs are available now. In ischemic stroke, S100 calcium-binding protein b (S100b) binds to receptor for advanced glycation end products (Rage), leading to the neurological injury. Therefore, disruption of the interaction between S100B and Rage can rescue neuronal cells. Here, we designed a peptide, termed TAT-W61, derived from the V domain of Rage which can recognize S100b. Intriguingly, TAT-W61 can reduce the inflammatory caused by ischemic stroke through the direct binding to S100b. The further investigation demonstrated that TAT-W61 can improve pathological infarct volume and reduce the apoptotic rate. Particularly, TAT-W61 significantly improved the learning ability, memory, and motor dysfunction of the mouse in the ischemic stroke model. Our study provides a mechanistic insight into the abnormal expression of S100b and Rage in ischemic stroke and yields an invaluable candidate for the development of drugs in tackling ischemic stroke. KEY MESSAGES: S100b expression is higher in ischemic stroke, in association with a high expression of many genes, especially of Rage. S100b is directly bound to the V-domain of Rage. Blocking the binding of S100b to Rage improves the injury after ischemic stroke.

Admission S100B fails as neuro-marker but is a good predictor for intrahospital mortality in major trauma patients.

BACKGROUND: S100 B is an extensively studied neuro-trauma marker, but its specificity and subsequently interpretation in major trauma patients might be limited, since extracerebral injuries are known to increase serum levels. Thus, we evaluated the potential role of S100B in the assessment of severe traumatic brain injury (TBI) in multiple injured patients upon emergency room (ER) admission and the first days of intensive care unit (ICU) stay. METHODS: Retrospective study employing trauma registry data derived from a level 1 trauma center. Four cohorts of patients were grouped: isolated TBI (iTBI), polytrauma patients with TBI (PT + TBI), polytrauma patients without TBI (PT-TBI) and patients without polytrauma or TBI (control). S100B-serum levels were assessed immediately after admission in the emergency room and during the subsequent ICU stay. Values were correlated with injury severity score (ISS), Glasgow Coma Score (GCS) and in-hospital mortality. RESULTS: 780 predominantly male patients (76 %) with a median age of 48 (30-63) and a median ISS of 24 (17-30) were enrolled in the study. Admission S100B correlated with ISS and TBI severity defined by the GCS (both p < 0.0001) but not with head abbreviated injury score (AIS) (p = 0.38). Compared with survivors, non-survivors had significantly higher median S100B levels in the ER (6.14 µg/L vs. 2.06 µg/L; p < 0.0001) and at ICU-day 1 (0.69 µg/L vs. 0.17 µg/L; p < 0.0001). S100B in the ER predicted mortality with an area under curve (AUC) of 0.77 (95 % CI 0,70-0,83, p < 0.0001), vs. 0.86 at ICU-day 1 (95 % CI 0,80-0,91, p < 0.0001). CONCLUSION: In conclusion, S100B is a valid biomarker for prediction of mortality in major trauma patients with a higher accuracy when assessed at the first day of ICU stay vs. immediately after ER admission. Since S100B did not correlate with pathologic TBI findings in multiple injured patients, it failed as predictive neuro-marker because extracerebral injuries demonstrated a higher influence on admission levels than neurotrauma. Although S100B levels are indicative for injury severity they should be interpreted with caution in polytrauma patients.

Outlier Analysis for Acute Blood Biomarkers of Moderate and Severe Traumatic Brain Injury.

Blood biomarkers have been studied to improve the clinical assessment and prognostication of patients with moderate-severe traumatic brain injury (mo/sTBI). To assess their clinical usability, one needs to know of potential factors that might cause outlier values and affect clinical decision making. In a prospective study, we recruited patients with mo/sTBI (n = 85) and measured the blood levels of eight protein brain pathophysiology biomarkers, including glial fibrillary acidic protein (GFAP), S100 calcium-binding protein B (S100B), neurofilament light (Nf-L), heart-type fatty acid-binding protein (H-FABP), interleukin-10 (IL-10), total tau (T-tau), amyloid ß40 (Aß40) and amyloid ß42 (Aß42), within 24 h of admission. Similar analyses were conducted for controls (n = 40) with an acute orthopedic injury without any head trauma. The patients with TBI were divided into subgroups of normal versus abnormal (n = 9/76) head computed tomography (CT) and favorable (Glasgow Outcome Scale Extended [GOSE] 5-8) versus unfavorable (GOSE <5) (n = 38/42, 5 missing) outcome. Outliers were sought individually from all subgroups from and the whole TBI patient population. Biomarker levels outside Q1 - 1.5 interquartile range (IQR) or Q3 + 1.5 IQR were considered as outliers. The medical records of each outlier patient were reviewed in a team meeting to determine possible reasons for outlier values. A total of 29 patients (34%) combined from all subgroups and 12 patients (30%) among the controls showed outlier values for one or more of the eight biomarkers. Nine patients with TBI and five control patients had outlier values in more than one biomarker (up to 4). All outlier values were > Q3 + 1.5 IQR. A logical explanation was found for almost all cases, except the amyloid proteins. Explanations for outlier values included extremely severe injury, especially for GFAP and S100B. In the case of H-FABP and IL-10, the explanation was extracranial injuries (thoracic injuries for H-FABP and multi-trauma for IL-10), in some cases these also were associated with abnormally high S100B. Timing of sampling and demographic factors such as age and pre-existing neurological conditions (especially for T-tau), explained some of the abnormally high values especially for Nf-L. Similar explanations also emerged in controls, where the outlier values were caused especially by pre-existing neurological diseases. To utilize blood-based biomarkers in clinical assessment of mo/sTBI, very severe or fatal TBIs, various extracranial injuries, timing of sampling, and demographic factors such as age and pre-existing systemic or neurological conditions must be taken into consideration. Very high levels seem to be often associated with poor prognosis and mortality (GFAP and S100B).

Application value of serum S100B combined with glucose metabolism indexes in predicting adverse pregnancy outcomes of patients with severe preeclampsia.

S100 calcium-binding protein B (S100B) and glucose control are reflective of maternal-fetal risks. We investigated the value of serum S100B combined with fasting blood glucose (FBG)/hemoglobin A1c (HbA1c) in evaluating the pregnancy outcomes of patients with severe preeclampsia (SPE). The clinical characteristics of SPE patients/controls were collected. FBG/HbA1c and serum S100B levels were measured, with their correlations analyzed. SPE patients were subdivided into adverse/non-adverse outcome groups based on follow-up results. The value of different indexes in predicting pregnancy outcomes was analyzed. SPE patients showed higher systolic blood pressure, diastolic blood pressure, urine protein, and body mass index and lower platelets, gestational age at delivery, and infant birth weight than healthy controls. FBG and HbA1c were positively correlated with serum S100B. SPE patients with adverse outcomes exhibited increased serum S100B and FBG/HbA1c levels. The area under the curve of serum S100B + FBG/HbA1c in evaluating adverse pregnancy outcomes of SPE patients was 0.8412 (77.05% sensitivity/84.21% specificity), higher than either alone. Serum S100B and FBG/HbA1c were independent risk factors for adverse outcomes of SPE patients. Overall, serum S100B positively-correlates with FBG/HbA1c in SPE patients. Serum S100B and FBG/HbA1c are independent risk factors, and their combination has high value on predicting adverse pregnancy outcomes of SPE patients.