Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive impairment.We found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic stroke.In addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic stroke.Serum phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic stroke.Furthermore,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein levels.Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein levels.Taken together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

Phosphorylated cellulose nanofibers establishing reliable ion-sieving barriers for durable lithium-sulfur batteries

The shuttle effect is among the most characteristic and formidable challenges in the pursuit of high-performance lithium-sulfur(Li-S)batteries.Herein,phosphorylated cellulose nanofibers(pCNF)are intentionally engineered to establish an ion-sieving barrier against polysulfide shuttling and thereby improve battery performance.The phosphorylation,involving the grafting of phosphate groups onto the cellulose backbone,imparts an exceptional electronegativity that repels the polysulfide anions from penetrating through the separator.Moreover,the electrolyte wettability and Li^(+)transfer can be significantly promoted by the polar nature of pCNF and the facile Li^(+)disassociation.As such,rational ion management is realized,contributing to enhanced reversibility in both sulfur and lithium electrochemistry.As a result,Li-S cells equipped with the self-standing pCNF separator demonstrate outstanding long-term cyclability with a minimum fading rate of 0.013%per cycle over 1000 cycles at 1 C,and a decent areal capacity of 5.37 mA h cm^(-2) even under elevated sulfur loading of 5.0 mg cm^(-2) and limited electrolyte of 6.0 mL g^(-1).This work provides a facile and effective pathway toward the well-tamed shuttle effect and highly durable Li-S batteries.

Apoptosis of colon cancer CT-26 cells induced polysaccharide from Cyclocarya paliurus and its phosphorylated derivative via intrinsic mitochondrial passway

In this study,the antitumor properties and the possible molecular mechanisms of Cyclocarya paliurus polysaccharide(CP)and its phosphorylated derivative(P-CP)on CT-26 mouse colon carcinoma cells were investigated.Results found that CP had high inhibition ratio against CT-26 cells.The flow cytometry results found that CP treatment could cause the intracellular acidification,arrest the cell cycle in the S phase and increase reactive oxygen species generation.Additionally,CP treatment triggered mitochondrial membrane potential depolarization and Ca^(2+)overloading,and broke down the balance of antioxidant system,Na^(+)/K^(+)-ATPase and Ca^(2+)-ATPase.Further analysis found CP induced cell apoptosis through improving the activities of caspase-3 and caspase-9,and increasing the level of cytochrome C.Furthermore,the comparative study of antitumor effect on CT-26 cells displayed that the phosphorylation enhanced antitumor activities of polysaccharides.These results suggest CP is a potential natural therapeutic agent for colon cancer and phosphorylation represents an effective method of enhancing the antitumor activity of CP.

Comparative analysis of primate and pig cells reveals primate-specific PINK1 expression and phosphorylation

PTEN-induced putative kinase 1(PINK1),a mitochondrial kinase that phosphorylates Parkin and other proteins,plays a crucial role in mitophagy and protection against neurodegeneration.Mutations in PINK1 and Parkin can lead to loss of function and early onset Parkinson's disease.However,there is a lack of strong in vivo evidence in rodent models to support the theory that loss of PINK1 affects mitophagy and induces neurodegeneration.Additionally,PINK1 knockout pigs(Sus scrofa)do not appear to exhibit neurodegeneration.In our recent work involving non-human primates,we found that PINK1 is selectively expressed in primate brains,while absent in rodent brains.To extend this to other species,we used multiple antibodies to examine the expression of PINK1 in pig tissues.In contrast to tissues from cynomolgus monkeys(Macaca fascicularis),our data did not convincingly demonstrate detectable PINK1expression in pig tissues.Knockdown of PINK1 in cultured pig cells did not result in altered Parkin and BAD phosphorylation,as observed in cultured monkey cells.A comparison of monkey and pig striatum revealed more PINK1-phosphorylated substrates in the monkey brain.Consistently,PINK1 knockout in pigs did not lead to obvious changes in the phosphorylation of Parkin and BAD.These findings provide new evidence that PINK1expression is specific to primates,underscoring the importance of non-human primates in investigating PINK1function and pathology related to PINK1 deficiency.

Novel insights into D-Pinitol based therapies:a link between tau hyperphosphorylation and insulin resistance

Alzheimer’s disease is a neurodegenerative disorder characterized by the amyloid accumulation in the brains of patients with Alzheimer’s disease.The pathogenesis of Alzheimer’s disease is mainly mediated by the phosphorylation and aggregation of tau protein.Among the multiple causes of tau hyperphosphorylation,brain insulin resistance has generated much attention,and inositols as insulin sensitizers,are currently considered candidates for drug development.The present narrative review revises the interactions between these three elements:Alzheimer’s disease-tau-inositols,which can eventually identify targets for new disease modifiers capable of bringing hope to the millions of people affected by this devastating disease.

α-Synuclein pathology from the body to the brain:so many seeds so close to the central soil

α-Synuclein is a protein that mainly exists in the presynaptic terminals.Abnormal folding and accumulation of α-synuclein are found in several neurodegenerative diseases,including Parkinson’s disease.Aggregated and highly phospho rylated a-synuclein constitutes the main component of Lewy bodies in the brain,the pathological hallmark of Parkinson s disease.For decades,much attention has been focused on the accumulation of α-synuclein in the brain parenchyma rather than considering Parkinson s disease as a systemic disease.Recent evidence demonstrates that,at least in some patients,the initial α-synuclein pathology originates in the peripheral organs and spreads to the brain.Injection of α-synuclein preformed fibrils into the gastrointestinal tra ct trigge rs the gutto-brain propagation of α-synuclein pathology.However,whether α-synuclein pathology can occur spontaneously in peripheral organs independent of exogenous α-synuclein preformed fibrils or pathological α-synuclein leakage from the central nervous system remains under investigation.In this review,we aimed to summarize the role of peripheral α-synuclein pathology in the pathogenesis of Parkinson’s disease.We also discuss the pathways by which α-synuclein pathology spreads from the body to the brain.

Raf kinase inhibitor protein combined with phosphorylated extracellular signal-regulated kinase offers valuable prognosis in gastrointestinal stromal tumor

BACKGROUND Gastrointestinal stromal tumors(GISTs)are the most common mesenchymal tumors of the gastrointestinal tract.Tyrosine kinase inhibitors,such as imatinib,have been used as first-line therapy for the treatment of GISTs.Although these drugs have achieved considerable efficacy in some patients,reports of resistance and recurrence have emerged.Extracellular signal-regulated kinase 1/2(ERK1/2)protein,as a member of the mitogen-activated protein kinase(MAPK)family,is a core molecule of this signaling pathway.Nowadays,research reports on the important clinical and prognostic value of phosphorylated-ERK(P-ERK)and phosphorylated-MAPK/ERK kinase(P-MEK)proteins closely related to raf kinase inhibitor protein(RKIP)have gradually emerged in digestive tract tumors such as gastric cancer,colon cancer,and pancreatic cancer.However,literature on the expression of these downstream proteins combined with RKIP in GIST is scarce.This study will focus on this aspect and search for answers to the problem.AIM To detect the expression of RKIP,P-ERK,and P-MEK protein in GIST and to analyze their relationship with clinicopathological characteristics and prognosis of this disease.Try to establish a new prognosis evaluation model using RKIP and PERK in combination with analysis and its prognosis evaluation efficacy.METHODS The research object of our experiment was 66 pathologically diagnosed GIST patients with complete clinical and follow-up information.These patients received surgical treatment at China Medical University Affiliated Hospital from January 2015 to January 2020.Immunohistochemical method was used to detect the expression of RKIP,PERK,and P-MEK proteins in GIST tissue samples from these patients.Kaplan-Meier method was used to calculate the survival rate of 63 patients with complete follow-up data.A Nomogram was used to represent the new prognostic evaluation model.The Cox multivariate regression analysis was conducted separately for each set of risk evaluation factors,based on two risk classification systems[the new risk grade model vs the modified National Institutes of Health(NIH)2008 risk classification system].Receiver operating characteristic(ROC)curves were used for evaluating the accuracy and efficiency of the two prognostic evaluation systems.RESULTS In GIST tissues,RKIP protein showed positive expression in the cytoplasm and cell membrane,appearing as brownish-yellow or brown granules.The expression of RKIP was related to GIST tumor size,NIH grade,and mucosal invasion.P-ERK protein exhibited heterogeneous distribution in GIST cells,mainly in the cytoplasm,with occasional presence in the nucleus,and appeared as brownish-yellow granules,and the expression of P-ERK protein was associated with GIST tumor size,mitotic count,mucosal invasion,and NIH grade.Meanwhile,RKIP protein expression was negatively correlated with P-ERK expression.The results in COX multivariate regression analysis showed that RKIP protein expression was not an independent risk factor for tumor prognosis.However,RKIP combined with P-ERK protein expression were identified as independent risk factors for prognosis with statistical significance.Furthermore,we establish a new prognosis evaluation model using RKIP and P-ERK in combination and obtained the nomogram of the new prognosis evaluation model.ROC curve analysis also showed that the new evaluation model had better prognostic performance than the modified NIH 2008 risk classification system.CONCLUSION Our experimental results showed that the expression of RKIP and P-ERK proteins in GIST was associated with tumor size,NIH 2008 staging,and tumor invasion,and P-ERK expression was also related to mitotic count.The expression of the two proteins had a certain negative correlation.The combined expression of RKIP and P-ERK proteins can serve as an independent risk factor for predicting the prognosis of GIST patients.The new risk assessment model incorporating RKIP and P-ERK has superior evaluation efficacy and is worth further practical application to validate.

Surviving winter on the Qinghai-Xizang Plateau:Extensive reversible protein phosphorylation plays a dominant role in regulating hypometabolism in hibernating Nanorana parkeri

Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high altitudes.To test the hypothesis that protein abundance and phosphorylation change in response to winter hibernation,we conducted a comprehensive and quantitative proteomic and phosphoproteomic analysis of the liver of the Xizang plateau frog,Nanorana parkeri,living on the Qinghai-Xizang Plateau.In total,5170 proteins and 5695 phosphorylation sites in 1938 proteins were quantified.Based on proteomic analysis,674 differentially expressed proteins(438 up-regulated,236 down-regulated)were screened in hibernating N.parkeri versus summer individuals.Functional enrichment analysis revealed that higher expressed proteins in winter were significantly enriched in immune-related signaling pathways,whereas lower expressed proteins were mainly involved in metabolic processes.A total of 4251 modified sites(4147 up-regulated,104 down-regulated)belonging to 1638 phosphoproteins(1555 up-regulated,83 down-regulated)were significantly changed in the liver.During hibernation,RPP regulated a diverse array of proteins involved in multiple functions,including metabolic enzymatic activity,ion transport,protein turnover,signal transduction,and alternative splicing.These changes contribute to enhancing protection,suppressing energy-consuming processes,and inducing metabolic depression.Moreover,the activities of phosphofructokinase,glutamate dehydrogenase,and ATPase were all significantly lower in winter compared to summer.In conclusion,our results support the hypothesis and demonstrate the importance of RPP as a regulatory mechanism when animals transition into a hypometabolic state.

Combined Oxidative Phosphorylation Deficiency-20-Exome as a Diagnostic Implement

Mitochondrial disorders are phenotypically varied, with serious clinical repercussions. Among them, there is the deficiency of combined oxidative phosphorylation of type 20, which occurs due to a defect in the VARS2 gene. This article presents a case of a 2-year-old female with progressive myoclonic epilepsy and psychomotor regression, with refractoriness to multiple anticonvulsants. The diagnosis was only made after the examination was carried out. Therefore, this article highlights the aspects of this rare disease and the importance of the exome for the diagnosis of rare conditions.

Unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neuropathology and behavioral deficits in parkinsonian rats withα-synucleinopathy

Parkinsonism by unilateral,intranigralβ-sitosterolβ-D-glucoside administration in rats is distinguished in that theα-synuclein insult begins unilaterally but spreads bilaterally and increases in severity over time,thus replicating several clinical features of Parkinson’s disease,a typicalα-synucleinopathy.As Nurr1 repressesα-synuclein,we evaluated whether unilateral transfected of rNurr1-V5 transgene via neurotensin-polyplex to the substantia nigra on day 30 after unilateralβ-sitosterolβ-D-glucoside lesion could affect bilateral neuropathology and sensorimotor deficits on day 30 post-transfection.This study found that rNurr1-V5 expression but not that of the green fluorescent protein(the negative control)reducedβ-sitosterolβ-D-glucoside-induced neuropathology.Accordingly,a bilateral increase in tyrosine hydroxylase-positive cells and arborization occurred in the substantia nigra and increased tyrosine hydroxylase-positive ramifications in the striatum.In addition,tyrosine hydroxylase-positive cells displayed less senescence markerβ-galactosidase and more neuron-cytoskeleton markerβIII-tubulin and brain-derived neurotrophic factor.A significant decrease in activated microglia(positive to ionized calcium-binding adaptor molecule 1)and neurotoxic astrocytes(positive to glial fibrillary acidic protein and complement component 3)and increased neurotrophic astrocytes(positive to glial fibrillary acidic protein and S100 calcium-binding protein A10)also occurred in the substantia nigra.These effects followed the bilateral reduction inα-synuclein aggregates in the nigrostriatal system,improving sensorimotor behavior.Our results show that unilateral rNurr1-V5 transgene expression in nigral dopaminergic neurons mitigates bilateral neurodegeneration(senescence and loss of neuron-cytoskeleton and tyrosine hydroxylase-positive cells),neuroinflammation(activated microglia,neurotoxic astrocytes),α-synuclein aggregation,and sensorimotor deficits.Increased neurotrophic astrocytes and brain-derived neurotrophic factor can mediate the rNurr1-V5 effect,supporting its potential clinical use in the treatment of Parkinson’s disease.

LATS1 Promotes B-ALL Tumorigenesis by Regulating YAP1 Phosphorylation and Subcellular Localization

Objective YAP1 plays a dual role as an oncogene and tumor suppressor gene in several tumors;differentiating between these roles may depend on the YAP1 phosphorylation pattern.The specific function of YAP1 in B cell acute lymphoblastic leukemia(B-ALL),however,is currently unclear.Thus,in the present study,the role of YAP1 in B-ALL was investigated using relevant cell lines and patient datasets.Methods The effects of shRNA-mediated knockdown on YAP1 and LATS1 levels in the NALM6 and MOLT-4 cell lines were examined using Western blotting,quantitative real-time polymerase chain reaction,flow cytometry,immunostaining,and nude mouse subcutaneous tumorigenesis experiments.Gene expression levels of Hippo pathway-related molecules before and after verteporfin(VP)treatment were compared using RNA-Seq to identify significant Hippo pathway-related genes in NALM6 cells.Results Patients with ALL showing high YAP1 expression and low YAP1-Ser127 phosphorylation levels had worse prognoses than those with low YAP1 protein expression and high YAP1-Ser127 phosphorylation levels.YAP1-Ser127 phosphorylation levels were lower in NALM6 cells than in MOLT-4 and control cells;YAP1 was distributed in the nuclei in NALM6 cells.Knockdown of YAP1 inhibited MOLT-4 and NALM6 cell proliferation and arrested the NALM6 cell cycle in the G0/G1 phase.Before and after VP treatment,the expression of the upstream gene LATS1 was upregulated;its overexpression promoted YAP1-Ser127 phosphorylation.Further,YAP1 was distributed in the plasma.Conclusion LATS1 may downregulate YAP1-Ser127 phosphorylation and maintain B-ALL cell function;thus,VP,which targets this axis,may serve as a new therapeutic method for improving the outcomes for B-ALL patients.

Cardioprotective Potential of Cymbopogon citratus Essential Oil against Isoproterenol-induced Cardiomyocyte Hypertrophy:Possible Involvement of NLRP3 Inflammasome and Oxidative Phosphorylation Complex Subunits

Objective:Cymbopogon citratus(DC.)Stapf is a medicinal and edible herb that is widely used for the treatment of gastric,nervous and hypertensive disorders.In this study,we investigated the cardioprotective effects and mechanisms of the essential oil,the main active ingredient of Cymbopogon citratus,on isoproterenol(ISO)-induced cardiomyocyte hypertrophy.Methods:The compositions of Cymbopogon citratus essential oil(CCEO)were determined by gas chromatography-mass spectrometry.Cardiomyocytes were pretreated with 16.9µg/L CCEO for 1 h followed by 10µmol/L ISO for 24 h.Cardiac hypertrophy-related indicators and NLRP3 inflammasome expression were evaluated.Subsequently,transcriptome sequencing(RNA-seq)and target verification were used to further explore the underlying mechanism.Results:Our results showed that the CCEO mainly included citronellal(45.66%),geraniol(23.32%),and citronellol(10.37%).CCEO inhibited ISO-induced increases in cell surface area and protein content,as well as the upregulation of fetal gene expression.Moreover,CCEO inhibited ISO-induced NLRP3 inflammasome expression,as evidenced by decreased lactate dehydrogenase content and downregulated mRNA levels of NLRP3,ASC,CASP1,GSDMD,and IL-1β,as well as reduced protein levels of NLRP3,ASC,pro-caspase-1,caspase-1(p20),GSDMD-FL,GSDMD-N,and pro-IL-1β.The RNA-seq results showed that CCEO inhibited the increase in the mRNA levels of 26 oxidative phosphorylation complex subunits in ISO-treated cardiomyocytes.Our further experiments confirmed that CCEO suppressed ISO-induced upregulation of mt-Nd1,Sdhd,mt-Cytb,Uqcrq,and mt-Atp6 but had no obvious effects on mt-Col expression.Conclusion:CCEO inhibits ISO-induced cardiomyocyte hypertrophy through the suppression of NLRP3 inflammasome expression and the regulation of several oxidative phosphorylation complex subunits.

IL-17 induces NSCLC cell migration and invasion by elevating MMP19 gene transcription and expression through the interaction of p300-dependent STAT3-K631 acetylation and its Y705-phosphorylation

The cancer cell metastasis is a major death reason for patients with non-small cell lung cancer(NSCLC).Although researchers have disclosed that interleukin 17(IL-17)can increase matrix metalloproteinases(MMPs)induction causing NSCLC cell metastasis,the underlying mechanism remains unclear.In the study,we found that IL-17 receptor A(IL-17RA),p300,p-STAT3,Ack-STAT3,and MMP19 were up-regulated both in NSCLC tissues and NSCLC cells stimulated with IL-17.p300,STAT3 and MMP19 overexpression or knockdown could raise or reduce IL-17-induced p-STAT3,Ack-STAT3 and MMP19 level as well as the cell migration and invasion.Mechanism investigation revealed that STAT3 and p300 bound to the same region(−544 to−389 nt)of MMP19 promoter,and p300 could acetylate STAT3-K631 elevating STAT3 transcriptional activity,p-STAT3 or MMP19 expression and the cell mobility exposed to IL-17.Meanwhile,p300-mediated STAT3-K631 acetylation and its Y705-phosphorylation could interact,synergistically facilitating MMP19 gene transcription and enhancing cell migration and invasion.Besides,the animal experiments exhibited that the nude mice inoculated with NSCLC cells by silencing p300,STAT3 or MMP19 gene plus IL-17 treatment,the nodule number,and MMP19,Ack-STAT3,or p-STAT3 production in the lung metastatic nodules were all alleviated.Collectively,these outcomes uncover that IL-17-triggered NSCLC metastasis involves up-regulating MMP19 expression via the interaction of STAT3-K631 acetylation by p300 and its Y705-phosphorylation,which provides a new mechanistic insight and potential strategy for NSCLC metastasis and therapy.

Localization of Phosphorylated Histone H3 at Mitosis and Meiosis in Wheat

One of the prominent cell cycle related modifications of histone proteins, whose function is correlated with chromosome condensation, is the phosphorylation of histone H3. Wheat (Triticum aestivum L.) mitotic and meiotic cells were analyzed with indirect immunoflurorescence labeling with an antibody recognizing histone H3 phosphorylated at Serine 10 to study the localization of phosphorylated histone H3 at mitosis and meiosis. Our results showed that, during mitotic division, the phosphoryiation of H3 started from early prophase and vanished at telophase, remaining mainly in the pericentromeric regions at metaphase and anaphase. During meiotic division, phosphorylation of H3 initiated at the transition from leptotene to zygotene and remained uniform, along the chromosomes from prophase I until telophase whereas it showed slightly stronger in the pericentromeric regions than along the chromosome arms from metaphase II until Lelophase II The different patterns of H3 phophorylation at mitosis and meiosis in wheat suggested that this evolutionarily conserved post-translational chromatin modification might be involved in more roles besides chromosome condensation.

Icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels in the hippocampus of the senescence-accelerated mouse

At 8 weeks after intragastric administration of icariin to senescence-accelerated mice （P8 strain）, Morris water maze results showed that escape latency was shortened, and the number of platform crossings was increased. Immunohistochemical staining and western blot assay detected significantly increased levels of cyclic adenosine monophosphate response element binding protein These results suggest that icariin upregulates phosphorylated cyclic adenosine monophosphate response element binding protein levels and improves learning and memory functions in hippocampus of the senescence-accelerated mouse.

Phosphorylated mesoporous carbon as effective catalyst for the selective fructose dehydration to HMF

Phosphorylated mesoporous carbons （PMCs） were investigated as catalysts in the dehydration of fructose to hydroxymethylfurfural （HMF）. The acidic PMCs show better selectivity to HMF compared to sulfonated carbon catalyst （SC） despite lower activity. The concentration of P-O groups on the PMC was correlated with the activity/selectivity of the catalysts; the higher the P-O concentration, the higher the activity. However, the higher the P-O content, the lower the selectivity to HME Indeed, a lower concentration of the P-O groups minimized the degradation of HMF to levulinic acid and the formation of by-products, such as humines. Stability tests showed that these systems deactivate due to the formation of humines and water insoluble by-products derived from the dehydration of fructose which blocked the catalytically active sites.

Resveratrol-downregulated Phosphorylated Liver Kinase B1 Is Involved in Senescence of Acute Myeloid Leukemia Stem Cells

Summary： Senescence is an important obstacle to cancer development. Engaging a senescent response may be an effective way to cure acute myeloid leukemia （AML）. The aim of this study was to examine the effect of resveratrol-downregulated phosphorylated liver kinase B1 （pLKB1） on the senescence of acute myeloid leukemia （AML） stem cells. The protein expressions of pLKB 1 and Sirtuin 1 （SIRT1）, a regulator ofpLKB1, were measured in CD34＋CD38-KGla cells treated with resveratrol （40 μmol/L） or not by Western blotting. Senescence-related factors were examined, including p21 mRNA tested by real-time PCR, cell morphology by senescence-associated β-galactosidase （SA-β-gal） staining, cell pro- liferation by MTT assay and cell cycle by flow cytometry. Besides, apoptosis was flow cytometrically determined. The results showed that pLKB1 was highly expressed in CD34＋CD38- KGla cells, and resveratrol, which could downregulate pLKB1 through activation of SIRT1, induced senescence and apoptosis of CD34＋CD38- KGla cells. It was concluded that resveratrol-downregulated pLKB1 is in- volved in the senescence of AML stem cells.

REINFORCEMENT OF CALCIUM PHOSPHATE CEMENTS WITH PHOSPHORYLATED CHITIN

Phosphorylated chitins (P-chitins) as the additives of calcium phosphate cements (CPCs) were prepared by the phosphorylation of chitin with phosphorus pentoxide in methanesulfonic acid. Their physical properties and effects on CPCs from monocalcium phosphate monohydrate (MCPM) and calcium oxide (CaO) or dicalcium phosphate dihydrate (DCPD) and calcium hydroxide [Ca(OH)(2)] were investigated. Addition of P-chitin (M-w = 2.60 x 10(4); degree of substitution, DS = 0.68) to the liquid phase in amounts up to 3 wt.% for MCPM and CaO cements or 1.5 wt.% for DCPD and Ca(OH)(2) cements could enhance the mechanical strength considerably, while little influence on the setting time was observed. However, further addition of P-chitin will cause no setting.

Dynamic distribution of Ser-10 phosphorylated histone H3 in cytoplasm of MCF-7 and CHO cells during mitosis

The dynamic distribution of phosphorylated Histone H3 on Ser10 (phospho-H3) in cells was investigated to determineits function during mitosis. Human breast adenocarcinoma cells MCF-7, and Chinese hamster cells CHO were analyzedby indirect immunofluorescence staining with an antibody against phospho-H3. We found that the phosphorylationbegins at early prophase, and spreads throughout the chromosomes at late prophase. At metaphase, most of the phospho-H3 aggregates at the end of the condensed entity of chromosomes at equatorial plate. During anaphase and telophase,the fluorescent signal of phospho-H3 is detached from chromosomes into cytoplasm. At early anaphase, phospho-H3shows ladder bands between two sets of separated chromosome, and forms “sandwich-like structure” when the chro-mosomes condensed. With the cleavage progressing, the “ladders” of the histone contract into a bigger bright dot. Thenthe histone aggregates and some of compacted microtubules in the midbody region are composed into a “bar-like”complex to separate daughter cells. The daughter cells seal their plasma membrane along with the ends of the “bar”,inside which locates microtubules and modified histones, to finish the cytokinesis and keep the “bar complex” out of thecells. The specific distribution and kinetics of phospho-H3 in cytoplasm suggest that the modified histones may takepart in the formation of midbody and play a crucial role in cytokinesis.

The Special Feature of Calponin on Myosins Phosphorylated by MLCK and PKA Respectively

Objective: To reveal the special feature of calponin (CaP) on myosins of different states. Methods: Myosin phosphorylation determination, myosin Mg^(2+)-ATPase measurement and protein binding assay were used in this study. The lowest CaP/myosin ratio used in the assay was 1/10000(mol/mol), which was 10 thousands-fold lower than the CaP/myosin ratio used in previous studies. Results: In the absence of actin, micro-amount of calponin (MAC) stimulated the Mg^(2+)-ATPase activities of myosin in different states slightly but significantly; and more importantly, MAC significantly increased the precipitations of unphosphorylated myosin, Ca^(2+)-dependently and independently phosphorylated myosins by MLCK but not the myosin phosphorylated by PKA. Conclusion: MAC has a high efficient and selective effect on myosin in the absence of actin.