The calcium-binding activity of fish scale protein hydrolysates

The calcium-binding activity of tilapia scale protein hydrolysates sequentially hydrolyzed by trypsin, flavor enzyme and pepsin were investigated. The hydrolysates were divided into four fractions using G-15 gel chromatography, and the F3 fraction has the higher calcium-binding activity of 196.3 mg/g. The UV-vis and the Fourier transform infrared spectroscopy (FTIR) demonstrate that the amino nitrogen atoms and the oxygen atoms belonging to the carboxylate groups are the primary binding sites for Ca2+. The X-ray diffraction and scanning electron microscopy (SEM) confirmed the reaction between the peptde and calcium. The results obtained indicated that this fish scale protein hydroly-sates have potential as functional foods for calcium-supplementation.

Considering calcium-binding proteins in invertebrates: multi-functional proteins that shape neuronal growth

Calcium is a critical second messenger molecule in all cells and is vital in neurons for synaptic transmission.Given this importance,calcium ions are tightly controlled by a host of molecular players including ion channels,sensors,and buffering proteins.Calcium can act directly by binding to signaling molecules or calcium’s effects can be indirect,for example by altering nuclear histones.

Diagnostic and Predictive Levels of Calcium-binding Protein A8 and Tumor Necrosis Factor Receptor-associated Factor 6 in Sepsis-associated Encephalopathy： A Prospective Observational Study

Background： Despite its high prevalence, morbidity, and mortality, sepsis-associated encephalopathy （SAE） is still poorly understood. The aim of this prospective and observational study was to investigate the clinical significance of calcium-binding protein A8 （S 100AS） in serum and tumor necrosis factor receptor-associated factor 6 （TRAF6） in peripheral blood mononuclear cells （PBMCs） in diagnosing SAE and predicting its prognosis. Methods： Data of septic patients were collected within 24 h after Intensive Care Unit admission fi-om July 2014 to March 2015. Healthy medical personnel served as the control group. SAE was defined as cerebral dysfhnction in the presence of sepsis that fulfilled the exclusion criteria. The biochemical indicators, Glasgow Coma Scale, Acute Physiology and Chronic Health Evaluation score II, TRAF6 in PBMC, serum S 100A8, S 10013, and neuron-specific enolase were evaluated in SAE patients afresh. TRAF6 and S 100A8 were also measured in the control group. Results： Of the 57 enrolled patients, 29 were diagnosed with SAE. The S 100A8 and TRAF6 concentrations in SAE patients were both significantly higher than that in no-encephalopathy （NE） patients, and higher in NE than that in controls （3.74 ± 3.13 vs. 1.08 ± 0.75 vs. 0.37 ± 0.14 ng/ml, P 〈 0.01 ; 3.18 ± 1.55 vs. 1.02 ± 0.63 vs. 0.47 ± 0.10, P 〈 0.01）. S 100A8 levels of 1.93 ng/ml were diagnostic of SAE with 92.90% specificity and 69.00% sensitivity in the receiver operating characteristic （ROC） curve, and the area under the curve was 0.86 （95% confidence interval [CI]： 0.76-0.95）. TRAF6-relative levels of 1.44 were diagnostic of SAE with 85.70% specificity and 86.20% sensitivity, and the area under the curve was 0.94 （95% CI： 0.88-0.99）. In addition, S 100A8 levels of 2.41 ng/ml predicted 28-day mortality of SAE with 90.00% specificity and 73.70% sensitivity in the ROC curve, and the area under the curve was 0.88. TRAF6 relative levels of 2.94 predicted 28-day mortality of SAE with 80.00% specificity and 68.40% sensitivity, and the area under the curve was 0.77. Compared with TRAF6, the specificity of serum S 100A8 in diagnosing SAE and predicting mortality was higher, although the sensitivity was low. In contrast, the TRAF6 had higher sensitivity for diagnosis. Conclusions： Peripheral blood levels of S 100A8 and TRAF6 in SAE patients were elevated and might be related to the severity of SAE and predict the outcome of SAE. The efficacy and specificity of S 100A8 for SAE diagnosis were superior, despite its weak sensitivity. S100A8 might be a better biomarker for diagnosis of SAE and predicting prognosis.

Mycobacterial PE PGRS Proteins Contain Calcium-Binding Motifs with Parallel β-roll Folds

The PE_PGRS family of proteins unique to mycobacteria is demonstrated to contain multiple calcium-binding and glycine-rich sequence motifs GGXGXD/NXUX. This sequence repeat constitutes a calcium-binding parallel β-roll or parallel β-helix structure and is found in RTX toxins secreted by many Gram-negative bacteria. It is predicted that the highly homologous PE_PGRS proteins containing multiple copies of the nona-peptide motif could fold into similar calcium-binding structures. The implication of the predicted calcium-binding property of PE_PGRS proteins in the light of macrophage-pathogen interaction and pathogenesis is presented.

Co-existence of calcium-binding proteins and γ-aminobutyric acid or glycine in neurons of the rat medullary dorsal horn

Background We investigated the co-expression of calb indin-D28k (CB), calretinin (CR) and parvalbumin (PV, a combination of the three is referred to as CaBPs) with γ-aminobutyric acid (GABA) or glycine in neurons of the rat medullary dorsal horn (MDH).Methods Immunofluorescence histochemical double-staining for CaBPs and GABA or glycine was performed on the sections from rat MDH. Results CB-, CR-, PV-, GABA- and glycine-like immunoreactive (LI) neurons were differentially observed in all layers of the MDH, but particularly in lamina Ⅱ. Neurons that exhibited immunoreactivity for both CaBPs and GABA or glycine were also observed mainly in lamina Ⅱ. A few of them were found in laminae I and III. The percentages of neurons which co-expressed CB/GABA or CB/glycine out of the total numbers of CB- and GABA-LI neurons or CB- and glycine-LI neurons were 5.3% and 12.1% or 4.1% and 10.0%, respectively. The ratios of CR/GABA or CR/glycine co-existing neurons out of the total numbers of CR- and GABA-LI neurons or CR- and glycine-LI neurons were 5.8% and 7.6% or 4.4% and 7.1%, respectively. The rates of PV/GABA or PV/glycine co-localized neurons out of the total numbers of PV- and GABA-LI neurons or PV- and glycine-LI neurons were 11.1% and 5.1% or 9.9% and 5.1%, respectively. Conclusion The results indicate that some neurons in the MDH contain both CaBPs and GABA or glycine.

A novel method for evaluating microglial activation using ionized calcium-binding adaptor protein-1 staining:cell body to cell size ratio

Aim:The aim was to validate a newly developed methodology of semi-automatic image analysis to analyze microglial morphology as marker for microglial activation in ionized calcium-binding adaptor protein-1(IBA-1)stained brain sections.Methods:The novel method was compared to currently used analysis methods,visual characterization of activation stage and optical density measurement,in brain sections of young and aged rats that had undergone surgery or remained naïve.Results:The cell body to cell size ratio of microglia was strongly correlated to the visual characterization activation stage.In addition,we observed specific surgery and age-related changes in cell body size,size of the dendritic processes and cell body to cell size ratio.Conclusion:The novel analysis method provides a sensitive marker for microglial activation in the rat brain,which is quick and easy to perform and provides additional information about microglial morphology.

Exercise combined with administration of adipose-derived stem cells ameliorates neuropathic pain after spinal cord injury

Experimental studies have shown that exercise and human adipose-derived stem cells(ADSCs)play positive roles in spinal cord injury(SCI).However,whether ADSCs and/or exercise have a positive effect on SCI-induced neuropathic pain is still unclear.Thus,there is a need to explore the effects of exercise combined with administration of ADSCs on neuropathic pain after SCI.In this study,a thoracic 11(T11)SCI contusion model was established in adult C57BL/6 mice.Exercise was initiated from 7 days post-injury and continued to 28 days post-injury,and approximately 1×105 ADSCs were transplanted into the T11 spinal cord lesion site immediately after SCI.Motor function and neuropathic pain-related behaviors were assessed weekly using the Basso Mouse Scale,von Frey filament test,Hargreaves method,and cold plate test.Histological studies(Eriochrome cyanine staining and immunohistochemistry)were performed at the end of the experiment(28 days post-injury).Exercise combined with administration of ADSCs partially improved early motor function(7,14,and 21 days postinjury),mechanical allodynia,mechanical hypoalgesia,thermal hyperalgesia,and thermal hypoalgesia.Administration of ADSCs reduced white and gray matter loss at the lesion site.In addition,fewer microglia and astrocytes(as identified by expression of ionized calcium-binding adapter molecule 1 and glial fibrillary acidic protein,respectively)were present in the lumbar dorsal horn in the SCI+ADSCs and SCI+exercise+ADSCs groups compared with the sham group.Our findings suggest that exercise combined with administration of ADSCs is beneficial for the early recovery of motor function and could partially ameliorate SCIinduced neuropathic pain.

Glial fibrillary acidic protein levels are associated with global histone H4 acetylation after spinal cord injury in rats

Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the development and progression of several neurological diseases. Likewise, astrocytic reactivity-a wellknown process that markedly influences the tissue remodeling after a central nervous system injury-is crucial for tissue remodeling after spinal cord injury（SCI）. However, the linkage between the above-mentioned mechanisms after SCI remains poorly understood. We sought to investigate the relation between both glial fibrillary acidic protein（GFAP） and S100 calcium-binding protein B（S100B）（astrocytic reactivity classical markers） and global histone H4 acetylation levels. Sixty-one male Wistar rats（aged ~3 months） were divided into the following groups： sham; 6 hours post-SCI; 24 hours post-SCI; 48 hours post-SCI; 72 hours post-SCI; and 7 days post-SCI. The results suggested that GFAP, but not S100B was associated with global histone H4 acetylation levels. Moreover, global histone H4 acetylation levels exhibited a complex pattern after SCI, encompassing at least three clearly defined phases（first phase： no changes in the 6, 24 and 48 hours post-SCI groups; second phase： increased levels in the 72 hours post-SCI group; and a third phase： return to levels similar to control in the 7 days post-SCI group）. Overall, these findings suggest global H4 acetylation levels exhibit distinct patterns of expression during the first week post-SCI, which may be associated with GFAP levels in the perilesional tissue. Current data encourage studies using H4 acetylation as a possible biomarker for tissue remodeling after spinal cord injury.

Effect of acetyl-L-carnitine on hypersensitivity in acute recurrent caerulein-induced pancreatitis and microglial activation along the brain’s pain circuitry

BACKGROUND Acute pancreatitis(AP)and recurring AP are serious health care problems causing excruciating pain and potentially lethal outcomes due to sepsis.The validated caerulein-(CAE)induced mouse model of acute/recurring AP produces secondary persistent hypersensitivity and anxiety-like behavioral changes for study.AIM To determine efficacy of acetyl-L-carnitine(ALC)to reduce pain-related behaviors and brain microglial activation along the pain circuitry in CAE-pancreatitis.METHODS Pancreatitis was induced with 6 hly intraperitoneal(i.p.)injections of CAE(50μg/kg),3 d a week for 6 wk in male C57BL/6J mice.Starting in week 4,mice received either vehicle or ALC until experiment’s end.Mechanical hypersensitivity was assessed with von Frey filaments.Heat hypersensitivity was determined with the hotplate test.Anxiety-like behavior was tested in week 6 using elevated plus maze and open field tests.Microglial activation in brain was quantified histologically by immunostaining for ionized calcium-binding adaptor molecule 1(Iba1).RESULTS Mice with CAE-induced pancreatitis had significantly reduced mechanical withdrawal thresholds and heat response latencies,indicating ongoing pain.Treatment with ALC attenuated inflammation-induced hypersensitivity,but hypersensitivity due to abdominal wall injury caused by repeated intraperitoneal injections persisted.Animals with pancreatitis displayed spontaneous anxiety-like behavior in the elevated plus maze compared to controls.Treatment with ALC resulted in increased numbers of rearing activity events,but time spent in“safety”was not changed.After all the abdominal injections,pancreata were translucent if excised at experiment’s end and opaque if excised on the subsequent day,indicative of spontaneous healing.Post mortem histopathological analysis performed on pancreas sections stained with Sirius Red and Fast Green identified wide-spread fibrosis and acinar cell atrophy in sections from mice with CAE-induced pancreatitis that was not rescued by treatment with ALC.Microglial Iba1 immunostaining was significantly increased in hippocampus,thalamus(intralaminar nuclei),hypothalamus,and amygdala of mice with CAE-induced pancreatitis compared to naïve controls but unchanged in the primary somatosensory cortex compared to naïves.CONCLUSION CAE-induced pancreatitis caused increased pain-related behaviors,pancreatic fibrosis,and brain microglial changes.ALC alleviated CAE-induced mechanical and heat hypersensitivity but not abdominal wall injury-induced hypersensitivity caused by the repeated injections.

Effects of epinephrine on angiogenesis-related gene expressions in cultured rat cardiomyocytes

Epinephrine is often used for the treatment of patients with heart failure, low cardiac output and cardiac arrest. It can acutely improve hemodynamic parameters; however, it does not seem to improve longer term clinical outcomes. Therefore, we hypothesized that epinephrine may induce unfavorable changes in gene expression of cardiomyocyte. Thus, we investigated effects of epinephrine exposure on the mediation or modulation of gene expression of cultured cardiomyocytes at a genome-wide scale. Our investigation revealed that exposure of cardiomyocytes to epinephrine in an in vitro environment can up-regulate the expression ofangiopoietin-2 gene （~ 2.1 times）, and down-regulate the gene expression of neuregulin 1 （-3.7 times）, plasminogen activator inhibitor-1 （-2.4 times） and SPARC-related modular calcium-binding protein-2 （-4.5 times）. These changes suggest that epinephrine exposure may induce inhibition of angiogenesis-related gene expressions in cultured rat cardiomyocytes. The precise clinical significance of these changes in gene expression, which was induced by epinephrine exposure, warrants further experimental and clinical investigations.

The ethanol response gene Cab45 can modulate the impairment elicited by ethanol and ultraviolet in PC12 cells

High consumption of ethanolic beverages facilitates neurodegeneration, but the mechanism of this process still remained elusive. Suppression subtractive hybridization （SSH） is a technique for detection of rare transcripts. With SSH approach, we identified one ethanol response gene Cab45, which was down-regulated by ethanol with time-dependent manner in B104 cells. The full-length sequence of Cab45 gene was obtained by 5＇-RACE （5＇Rapid Amplification of cDNA Ends） for the first time in rat. Based on the sequence of deduced amino acid of rat Cab45, the alignment was conducted with its counterparts in different species and displayed a high conservation. Using different tissues in rat and cell lines, Cab45 was characterized by a ubiquitous expression and differentiation dependent down-regulation. Given that ethanol facilitates some cell differentiation, we hypothesize that Cab45 is involved in ethanol-mediated differentiation. With transient transfection, the function of Cab45 was investigated by up-regulation and down-regulation in PC12 cells. Ethanol treatment and UV exposure were conducted subsequently and cell proliferations were detected by MTT （Methyl Thiazolyl Tetrazolium） approach. It revealed that the up-regulation of Cab45 modulated the impairment elicited by ethanol and UV in transfected cells. As a member of new calcium binding protein family, the exact role of Cab45 still remains unclear.

DISTRIBUTION OF PARVALBUMIN, CALBINDIN-D28 AND CALRETININ IMMUNOREACTIVE NEURONS AND FIBERS IN THE MONKEY BASAL GANGLIA

Objective To investigate the cellular localization of parvalbumin (PV), calbindin-D28k (CB) and calretinin (CR) in the monkey basal ganglia.Methods Immunocytochemical technique was used to detect PV,CB and CR immunoreactivity in the basal ganglia. Results In the striatum, CB labeled medium-sized spiny projection neurons whereas PV and CR marked two separate classes of aspiny interneurons. The striatal matrix compartment was markedly enriched with CB while striatal patches displayed a CR-rich neuropil. In the pallidum, virtually all neurons contained PV but none express CB. CR occured only in a small subpopulation of large and small pallidal neurons. In the subthalamic nucleus, there existed a multitude of PV-positive cells and fibers but the number of CR and CB-positive neuronal elements was small. In the substantia nigra / ventral tegmental area complex, CB and CR occured principally in dopaminergic neurons of the dorsal tier of the pars compacta and in those of the ventral tegmental area. PV was strickly confined to the GABAergic neurons of the pars reticular and lateralis. CB-rich fibers abounded in the pars reticular and lateralis, while CR-positive axons were confined to the pars compacta. Conclusion CB and PV were distributed according to a strikingly complementary pattern in primate basal ganglia, and the use of CB and PV immunocytochemistry may be considered as an excellent tool to define distinct chemoarchitectonic and functional domains within the complex organization of the basal ganglia. CR was less ubiquitous but occured in small basal ganglia components where it labeled distinct subsets of neurons. Such highly specific patterns of distribution indicate that CB, PV and CR may work in synery within primate basal ganglia.

Ca^(2+)-dependent TaCCD1 cooperates with TaSAUR215 to enhance plasma membrane H^(+)-ATPase activity and alkali stress tolerance by inhibiting PP2C-mediated dephosphorylation of TaHA2 in wheat

Alkali stress is a major constraint for crop production in many regions of saline-alkali land.However,little is known about the mechanisms through which wheat responds to alkali stress.In this study,we identified a calcium ion-binding protein from wheat,TaCCD1,which is critical for regulating the plasma membrane(PM)H^(+)-ATPase-mediated alkali stress response.PM H+-ATPase activity is closely related to alkali tolerance in the wheat variety Shanrong 4(SR4).We found that two D-clade type 2C protein phosphatases,TaPP2C.D1 and TaPP2C.D8(TaPP2C.D1/8),negatively modulate alkali stress tolerance by dephosphorylating the penultimate threonine residue(Thr926)of TaHA2 and thereby inhibiting PM H+-ATPase activity.Alkali stress induces the expression of TaCCD1 in SR4,and TaCCD1 interacts with TaSAUR215,an early auxin-responsive protein.These responses are both dependent on calcium signaling triggered by alkali stress.TaCCD1 enhances the inhibitory effect of TaSAUR215 on TaPP2C.D1/8 activity,thereby promoting the activity of the PM H^(+)-ATPase TaHA2 and alkali stress tolerance in wheat.Functional and genetic analyses verified the effects of these genes in response to alkali stress,indicating that TaPP2C.D1/8 function downstream of TaSAUR215 and TaCCD1.Collectively,this study uncovers a new signaling pathway that regulates wheat responses to alkali stress,in which Ca^(2+)-dependent TaCCD1 cooperates with TaSAUR215 to enhance PM H+-ATPase activity and alkali stress tolerance by inhibiting TaPP2C.D1/8-mediated dephosphorylation of PM H+-ATPase TaHA2 in wheat.

Effect of Electroacupuncture Preconditioning on Serum S100 β and NSE in Patients undergoing Craniocerebral Tumor Resection

Objective：To investigate the effect of electroacupuncture preconditioning on the serum level of S100 calcium-binding protein beta（S100β）and neuron-specific enolase（NSE）in patients undergoing craniocerebral tumor operation.Methods：A total of 32 patients,who would go through craniocerebral tumor resection under general anesthesia,were randomly assigned to two groups,16 in each group.Patients in the electroacupuncture（EA）group received electroacupuncture on Fengfu acupoint（Du16）and Fengchi acupoint （GB20）for 30 min,2 h before operation.The stimulus is 1-4 mA with a density wave frequency of 2/15 Hz. Patients in the control group received no pretreatment.Anesthesia was maintained with remifentanil at the dose of 4-8 mg/kg per hour,pumped intravenous drip of vecuronium at 1.0-2.0μg/kg each hour,and discontinuous intravenous dripped with vecuronium bromide at 0.5-1 mg.The serum levels of S100βand NSE were measured with ELISA before operation,before skin incision,after tumor removal,at the end of operation,and at 24 h after operation.Results：The serum level of S100βand NSE did not change before skin incision.The serum level of NSE increased significantly and the level of S100βincreased insignificantly after the tumor resection. The serum levels of S100βand NSE in the EA group and the control group were 1.16±0.28μg/L vs 1.47±0.33μg/L,24.7±13.3μg/L vs 31.4±14.1μg/L at the end of the operation,respectively.Twenty-four h after operation,the correspondence indices were 1.18±0.31μg/L vs 1.55±0.26μg/L,and 25.5±12.4μg/L vs 32.4±11.7μg/L.The two indices at these two time points were significantly increased than those before operation, respectively（P〈0.05）.At the end of the operation and 24 h post-operation,the serum levels of S100βand NSE in the EA group were significantly lower than those in the control group（P〈0.05）.Conclusion：Electroacupuncture Fengchi and Fengfu for 30 min before craniocerbral tumor operation could decrease the serum level of S100βand NSE,thus may have potential protective effect on brain damage,which needs to befurther studied.

S100A8 promotes epithelial-mesenchymal transition and metastasis under TGF-β/USF2 axis in colorectal cancer

Background:The transforming growth factor-β(TGF-β)pathway plays a pivotal role in inducing epithelial-mesenchymal transition(EMT),which is a key step in cancer invasion and metastasis.However,the regulatory mechanism of TGF-βin inducing EMT in colorectal cancer(CRC)has not been fully elucidated.In previous studies,it was found that S100A8 may regulate EMT.This study aimed to clarify the role of S100A8 in TGF-β-induced EMT and explore the underlying mechanism in CRC.Methods:S100A8 and upstream transcription factor 2(USF2)expression was detected by immunohistochemistry in 412 CRC tissues.Kaplan-Meier survival analysis was performed.In vitro,Western blot,and migration and invasion assays were performed to investigate the effects of S100A8 and USF2 on TGF-β-induced EMT.Mouse metastasis models were used to determine in vivo metastasis ability.Luciferase reporter and chromatin immunoprecipitation assay were used to explore the role of USF2 on S100A8 transcription.Results:During TGF-β-induced EMT in CRC cells,S100A8 and the transcription factor USF2 were upregulated.S100A8 promoted cell migration and invasion and EMT.USF2 transcriptionally regulated S100A8 expression by directly binding to its promoter region.Furthermore,TGF-βenhanced the USF2/S100A8 signaling axis of CRC cells whereas extracellular S100A8 inhibited the USF2/S100A8 axis of CRC cells.S100A8 expression in tumor cells was associated with poor overall survival in CRC.USF2 expression was positively related to S100A8 expression in tumor cells but negatively related to S100A8-positive stromal cells.Conclusions:TGF-βwas found to promote EMT and metastasis through the USF2/S100A8 axis in CRC while extracellular S100A8 suppressed the USF2/S100A8 axis.USF2 was identified as an important switch on the intracellular and extracellular S100A8 feedback loop.

Revealing the Precise Role of Calretinin Neurons in Epilepsy: We Are on the Way

Epilepsy is a common neurological disorder characterized by hyperexcitability in the brain.Its pathogenesis is classically associated with an imbalance of excitatory and inhibitory neurons.Calretinin(CR)is one of the three major types of calcium-binding proteins present in inhibitory GABAergic neurons.The functions of CR and its role in neural excitability are still unknown.Recent data suggest that CR neurons have diverse neurotransmitters,morphologies,distributions,and functions in different brain regions across various species.Notably,CR neurons in the hippocampus,amygdala,neocortex,and thalamus are extremely susceptible to excitotoxicity in the epileptic brain,but the causal relationship is unknown.In this review,we focus on the heterogeneous functions of CR neurons in different brain regions and their relationship with neural excitability and epilepsy.Importantly,we provide perspectives on future investigations of the role of CR neurons in epilepsy.

Low expression of SLOOP associated with paclitaxel resistance in ovarian cancer cell line

Background Recent studies indicate that S100P expression may be a biomarker that can predict the success of cancer chemotherapy. Whether it is relevant to chemotherapeutics in ovarian cancer is unknown. In this study, we investigated the association of S100P expression with paclitaxel sensitivity in ovarian cancer cell lines. Methods We measured S100P expression and paclitaxel resistance profiles in parent SKOV3 and OVCAR3 cell lines. Then, the two cell lines were transiently transfected with S100P siRNA. We also constructed an OVCAR3 cell clone that stably overexpressed S100P. The effect of S100P expression level on the survival of cells exposed to paclitaxel was measured using the MTT assay. S100P expression was evaluated by semi-quantitative RT-PCR and Western blotting. Significance of differences was calculated using independent samples t-test and one way analysis of variance （ANOVA）. Results Lower S100P expression was associated with a survival advantage in OVCAR3 cells exposed to paclitaxel; the survival advantage in SKOV3 cells was smaller （P 〈0.05）. The survival advantage associated with decreased S100P expression was even greater for SKOV3 and OVCAR3 cells that had been transfected with S100P siRNA before being exposed to paclitaxel （P 〈0.05）. Consistent with this, the OVCAR3 cell clone that was transfected to overexpress S100P was more sensitive to paclitaxel （P 〈0.05）. Conclusions Low S100P expression contributes to drug resistance to paclitaxel in ovarian cancer cell lines. S100P expression thus might be a marker that can predict the effectiveness of paclitaxel based chemotherapy. Such a marker could be helpful in improving individual medication regimens for ovarian cancer patients.

Structural basis for prokaryotic calciummediated regulation by a Streptomyces coelicolor calcium binding protein

The important and diverse regulatory roles of Ca2+in eukaryotes are conveyed by the EF-hand containing calmodulin superfamily.However,the calcium-regulatory proteins in prokaryotes are still poorly understood.In this study,we report the three-dimensional structure of the calcium-binding protein from Streptomyces coelicolor,named CabD,which shares low sequence homology with other known helix-loop-helix EF-hand proteins.The CabD structure should provide insights into the biological role of the prokaryotic calcium-binding proteins.The unusual structural features of CabD compared with prokaryotic EF-hand proteins and eukaryotic sarcoplasmic calcium-binding proteins,including the bending conformation of the first C-terminalα-helix,unpaired ligand-binding EF-hands and the lack of the extreme Cterminal loop region,suggest it may have a distinct and significant function in calcium-mediated bacterial physiological processes,and provide a structural basis for potential calcium-mediated regulatory roles in prokaryotes.