NC1-peptide derived from collagen α3 (IV) chain is a blood-tissue barrier regulator: lesson from the testis / 亚洲男科学杂志(英文版)

Collagen α3 (IV) chains are one of the major constituent components of the basement membrane in the mammalian testis. Studies have shown that biologically active fragments, such as noncollagenase domain (NC1)-peptide, can be released from the C-terminal region of collagen α3 (IV) chains, possibly through the proteolytic action of metalloproteinase 9 (MMP9). NC1-peptide was shown to promote blood-testis barrier (BTB) remodeling and fully developed spermatid (e.g., sperm) release from the seminiferous epithelium because this bioactive peptide was capable of perturbing the organization of both actin- and microtubule (MT)-based cytoskeletons at the Sertoli cell-cell and also Sertoli-spermatid interface, the ultrastructure known as the basal ectoplasmic specialization (ES) and apical ES, respectively. More importantly, recent studies have shown that this NC1-peptide-induced effects on cytoskeletal organization in the testis are mediated through an activation of mammalian target of rapamycin complex 1/ribosomal protein S6/transforming retrovirus Akt1/2 protein (mTORC1/rpS6/Akt1/2) signaling cascade, involving an activation of cell division control protein 42 homolog (Cdc42) GTPase, but not Ras homolog family member A GTPase (RhoA), and the participation of end-binding protein 1 (EB1), a microtubule plus (+) end tracking protein (+TIP), downstream. Herein, we critically evaluate these findings, providing a critical discussion by which the basement membrane modulates spermatogenesis through one of its locally generated regulatory peptides in the testis.

Reorganization of Actin Cytoskeleton and Microtubule Array during the Chondrogenesis of Bovine MSCs

Mesenchymal stem cells (MSCs) are multipotent stem cells that are capable of self-renewal and can be committed into classical mesodermal tri-lineage differentiation (adipocytes, osteocytes and chondrocytes). During chondrogenic differentiation MSCs change their shape due to the reorganization of cytoskeletal components. This has been well documented for human and rodent models. Morphological changes of microtubule network and actin filaments that occur during the chondrogenic differentiation of MSCs from large animal models remain unknown. In this study we described the morphological changes of cell shape, area, actin structures and microtubule array that occur in bovine MSCs during the chondrogenic differentiation of bovine bone-marrow isolated MSCs. Chondrogenic differentiation of bMSCs occur more rapidly on glass substrate compared to the cells plated on vitronectin, and in 7 days after the commitment we observed clusters of small round-shaped cells that expressed glycosaminoglycans. During the differentiation microtubule (MT) array of MSCs became non-radial, and non-centrosomal MTs that grew transversely to the cell radius appeared in the inner cytoplasm and near the cell edges. At the end of differentiation process we observed the thick bundles of MTs that grew in parallel to the cell edge and basket-like structures of curved MTs around the nucleus. The main changes of actin structures in differentiating MSCs included the disappearance of thick transverse stress fibers and actin arches and reorganization of actin into chaotic network of thin cortical fibers. Our results imply the important role of both actin and MT cytoskeletal systems in chondrogenesis and reveals new perspectives for experimental regulation of these process in vitro systems.

A De Novo RAPGEF2 Variant Identified in a Sporadic Amyotrophic Lateral Sclerosis Patient Impairs Microtubule Stability and Axonal Mitochondria Distribution

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that is frequently linked to microtubule abnormalities and mitochondrial trafficking defects. Whole exome sequencing (WES) of patient-parent trios has proven to be an efficient strategy for identifying rare de novo genetic variants responsible for sporadic ALS (sALS). Using a trio-WES approach, we identified a de novo RAPGEF2 variant (c.4069G>A, p.E1357K) in a patient with early-onset sALS. To assess the pathogenic effects of this variant, we have used patient-derived skin fibroblasts and motor neuron-specific overexpression of the RAPGEF2-E1357K mutant protein in Drosophila. Patient fibroblasts display reduced microtubule stability and defective microtubule network morphology. The intracellular distribution, ultrastructure, and function of mitochondria are also impaired in patient cells. Overexpression of the RAPGEF2 mutant in Drosophila motor neurons reduces the stability of axonal microtubules and disrupts the distribution of mitochondria to distal axons and neuromuscular junction (NMJ) synapses. We also show that the recruitment of the pro-apoptotic protein BCL2-associated X (BAX) to mitochondria is significantly increased in patient fibroblasts compared with control cells. Finally, increasing microtubule stability through pharmacological inhibition of histone deacetylase 6 (HDAC6) rescues defects in the intracellular distribution of mitochondria and BAX. Overall, our data suggest that the RAPGEF2 variant identified in this study can drive ALS-related pathogenic effects through microtubule dysregulation.

Natural products as new antimitotic compounds for anticancer drug development

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death. These antitumor compounds are referred to as antimitotics. Vinca alkaloids and taxanes are natural products that target microtubules and inhibit mitosis, and their derivatives are among the most commonly used drugs in cancer therapy worldwide. However, severe adverse effects such as neuropathies are frequently observed during treatment with microtubule-targeting agents. Many efforts have been directed at developing improved antimitotics with increased specificity and decreased likelihood of inducing side effects. These new drugs generally target specific components of mitotic regulation that are mainly or exclusively expressed during cell division, such as kinases, motor proteins and multiprotein complexes. Such small molecules are now in preclinical studies and clinical trials, and many are products or derivatives from natural sources. In this review, we focused on the most promising targets for the development of antimitotics and discussed the advantages and disadvantages of these targets. We also highlighted the novel natural antimitotic agents under investigation by our research group, including combretastatins, withanolides and pterocarpans, which show the potential to circumvent the main issues in antimitotic therapy.

Effects of decline of pH value on cardiomyocyte viability of rats and the mechanism / 中华烧伤杂志

Objective@#To explore the effects of decline of pH value on cardiomyocyte viability of rats, and to analyze the possible mechanism.@*Methods@#Hearts of five newborn Sprague-Dawley rats were isolated, and then primary cardiomyocytes were cultured and used in the following experiments. (1) The primary cardiomyocytes were divided into pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups according to the random number table, with 4 wells in each group. After being routinely cultured for 48 h (similarly hereinafter), cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, and pH 6.0+ 6 h groups were cultured with pH 7.4, pH 7.0, pH 6.5, and pH 6.0 DMEM-F12 medium (similarly hereinafter), respectively, and then they were cultured for 6 h. Cells in pH 6.5+ 1 h and pH 6.5+ 3 h groups were cultured with pH 6.5 medium, and then they were cultured for 1 h and 3 h, respectively. Viability of cells was detected by methyl-thiazolyl-tetrazolium (MTT) method. (2) The primary cardiomyocytes were divided into pH 7.4, pH 6.5, and pH 6.5+ taxol groups according to the random number table, with 2 wells in each group. Cells in pH 7.4 group were cultured with pH 7.4 medium, while cells in pH 6.5 and pH 6.5+ taxol groups were cultured with pH 6.5 medium. Cells in pH 6.5+ taxol group were added with taxol of a final molarity of 0.2 μmol/L in addition, and then they were cultured for 6 h. Morphology and density of microtubule of cells was detected by immunofluorescence assay. (3) The primary cardiomyocytes were grouped and treated as in experiment (2), with 2 wells in each group. The expressions of polymerized microtubulin and free microtubulin were determined with Western blotting. (4) The primary cardiomyocytes were grouped and treated as in experiment (2), with 4 wells in each group. Viability of cells after treated with taxol was detected by MTT method. Data were processed with one-way analysis of variance and LSD-t test.@*Results@#(1) The viability of cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were 1.00±0.08, 0.90±0.08, 0.85±0.06, 0.83±0.04, 0.91±0.10, and 0.89±0.10, respectively. Compared with that in pH 7.4+ 6 h group, viability of cells in pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were all decreased in different degrees (t=2.476, 4.002, 4.996, 2.168, 2.400, P<0.05). (2) Microtubules of cells in pH 7.4 group were radially distributed around the nucleus with clear tubular structure. Compared with that in pH 7.4 group, the skeleton of microtubules of cells in pH 6.5 group was obviously damaged, with broken structure of microtubule and reduced density. Compared with that in pH 6.5 group, the damage degree of microtubules of cells in pH 6.5+ taxol group was obviously alleviated, and the structure of microtubules basically returned to normal. (3) Compared with that in pH 7.4 group, the expression of free microtubulin of cells in pH 6.5 group was significantly increased (t=3.030, P<0.05), while the expression of polymerized microtubulin of cells was significantly decreased (t=8.604, P<0.05). Compared with that in pH 6.5 group, the expression of free microtubulin of cells in pH 6.5+ taxol group was significantly decreased (t=4.559, P<0.05), while the expression of polymerized microtubulin of cells was significantly increased (t=5.472, P<0.05). (4) Viability of cells in pH 7.4, pH 6.5, and pH 6.5+ taxol groups were 1.00±0.10, 0.83±0.04, and 0.93±0.10, respectively. Compared with that in pH 7.4 group, the viability of cells in pH 6.5 group was obviously declined (t=4.412, P<0.05). Compared with that in pH 6.5 group, the viability of cells in pH 6.5+ taxol group was obviously increased (t=2.461, P<0.05).@*Conclusions@#The decline of pH value reduces the viability of cardiomyocytes of rats through destroying the skeleton of microtubule. Stabilizing microtubule skeleton can significantly reduce acidic treatment-induced damage and ameliorate cardiomyocyte viability.

Effects of colchicine on renal fibrosis and apoptosis in obstructed kidneys

BACKGROUND/AIMS: Colchicine is an established drug for microtubule stabilization that may reduce tissue injury. No data were available that its effects may depend on the dosage of colchicine. We investigated the anti-fibrotic and apoptotic effects of various dose of colchicine in a unilateral ureteral obstruction (UUO) model. METHODS: Thirty-six Sprague-Dawley rats were randomly assigned into six groups. Two sham groups were divided into a vehicle-treated or colchicine-treated group (100 μg/kg/day). Four UUO groups were treated with either vehicle or three different doses of colchicine for 7 days (30, 60, and 100 μg/kg/day, intraperitoneally). All of the animals were sacrificed on day 7. RESULTS: Colchicine treatment diminished acetylated α-tubulin and tumor growth factor-β immunoreactivities in the cortical area of the 7-day obstructed kidneys, which was in dose dependent manner. Colchicine attenuated tubulointerstitial damage and apoptosis in both cortical and medullary area, and beneficial effects of colchicine therapy were dramatically shown at the higher dosage of colchicine. The expression levels of cleaved caspase-3, ED-1, and fibronectin were decreased in UUO animals. CONCLUSIONS: We found that the proper dosage of colchicine may have anti-fibrotic and anti-apoptotic effects in obstructed kidneys. For clinical applications, an optimal dose of colchicine should be evaluated to maximize the prevention of renal disease progression.

Taxane resistance in castration-resistant prostate cancer: mechanisms and therapeutic strategies

Despite its good initial response and significant survival benefit in patients with castration-resistant prostate cancer (CRPC), taxane therapy inevitably encounters drug resistance in all patients. Deep understandings of taxane resistant mechanisms can significantly facilitate the development of new therapeutic strategies to overcome taxane resistance and improve CRPC patient survival. Multiple pathways of resistance have been identified as potentially crucial areas of intervention. First, taxane resistant tumor cells typically have mutated microtubule binding sites, varying tubulin isotype expression, and upregulation of efflux transporters. These mechanisms contribute to reducing binding affinity and availability of taxanes. Second, taxane resistant tumors have increased stem cell like characteristics, indicating higher potential for further mutation in response to therapy. Third, the androgen receptor pathway is instrumental in the proliferation of CRPC and multiple hypotheses leading to this pathway reactivation have been reported. The connection of this pathway to the AKT pathway has received significant attention due to the upregulation of phosphorylated AKT in CRPC. This review highlights recent advances in elucidating taxane resistant mechanisms and summarizes potential therapeutic strategies for improved treatment of CRPC.

Relevant coexpression of STMN1, MELK and FOXM1 in glioblastoma and review of the impact of STMN1 in cancer biology / Coexpressão relevante de STMN1, MELK e FOXM1 em glioblastoma e revisão do impacto de stmn1 na biologia do câncer

OBJECTIVE: To analyze the associated expression of STMN1, MELK and FOXM1 in search of alternative drugable target in glioblastoma (GBM) and to review relevant functional roles of STMN1 in cancer biology. METHOD: STMN1, MELK and FOXM1 expressions were studied by quantitative PCR and their coexpressions were analyzed in two independent glioblastoma cohorts. A review of articles in indexed journals that addressed the multiple functional aspects of STMN1 was conducted, focusing on the most recent reports discussing its role in cancer, in chemoresistance and in upstream pathways involving MELK and FOXM1. RESULTS: Significant associated expressions of MELK and FOXM1 were observed with STMN1 in GBM. Additionally, the literature review highlighted the relevance of STMN1 in cancer progression. CONCLUSION: STMN1 is very important to induce events in cancer development and progression, as cellular proliferation, migration, and drug resistance. Therefore, STMN1 can be an important therapeutic target for a large number of human cancers. In glioblastoma, the most aggressive brain tumor, the MELK/FOXM1/STMN1 presented significant associated expressions, thus pointing MELK and FOXM1 as alternative targets for therapy instead of STMN1, which is highly expressed in normal brain tissue. Continuous functional research to understand the STMN1 signaling pathway is worthwhile to improve the therapeutic approaches in cancer.

OBJETIVO: Analisar as expressões associadas de STMN1, MELK e FOXM1 na procura de alvos alternativos de tratamento em glioblastoma (GBM) e revisar os papeis funcionais relevantes de STMN1 na biologia do câncer. MÉTODO: As expressões de STMN1, MELK e FOXM1 foram estudadas por PCR quantitativo e suas coexpressões foram analisadas em dois coortes independentes de GBM. A revisão dos artigos publicados em revistas indexadas na procura dos aspectos funcionais múltiplos de STMN1 foi conduzida focando-se nos estudos mais recentes discutindo o seu papel em câncer, quimiorresistência e vias de sinalização envolvendo MELK e FOXM1. RESULTADOS: Observou-se expressões associadas significantes de MELK e FOXM1 com STMN1. Adicionalmente, a revisão da literatura salientou a relevância do STMN1 na progressão do câncer. CONCLUSÃO: STMN1 é muito importante nos eventos relacionados ao desenvolvimento e progressão do câncer, como proliferação celular, migração e resistência ao tratamento. Desta forma, STMN1 pode ser um forte alvo terapêutico em um grande número de cânceres humanos. Em GBM, o tumor cerebral mais agressivo, MELK/FOXM1/STMN1 apresentaram significativa associação em suas expressões gênicas, indicando, portanto, MELK e FOXM1 como alvos alternativos para terapia em substituição ao STMN1, que apresenta alta expressão no tecido cerebral normal. Perseverar nos estudos funcionais para o entendimento da via de sinalização do STMN1 é relevante para melhorar os esquemas terapêuticos para câncer.

Effect of sevoflurane postconditioning on microtubule structure during myocardial ischemia-reperfu-sion in mice / 中华麻醉学杂志

Objective To evaluate the effect of sevoflurane postconditioning on microtubule struc-ture during myocardial ischemia-reperfusion(I∕R)in mice. Methods Thirty-two healthy male C57 mice, aged 7-8 weeks, wighing 20-30 g, were divided into 4 groups(n=8 each)using a random number table:sham operation group(Sham group), group I∕R, sevoflurane postconditioning group(group SP), and mi-crotubule depolymerizer colchicine plus sevoflurane postconditioning group(group CSP). Myocardial I∕R was produced by occlusion of the left anterior descending branch of coronary artery for 30 min followed by 120 min reperfusion in I∕R, SP and CSP groups. Colchicine 004 μmol∕kg was intraperitoneally injected at 30 min before ischemia in group CSP. In SP and CSP groups, 24% sevoflurane was inhaled for 15 min starting from onset of reperfusion. Mice were sacrificed at 120 min of reperfusion, and myocardial speci-mens were obtained for determination of myocardial infarct size and expression of α-tubulin(by Western blot). Results Compared with group Sham, the myocardial infarct size was significantly increased, and the expression of α-tubulin was down-regulated in the other three groups(P<005). Compared with group I∕R, the myocardial infarct size was significantly decreased, and the expression of α-tubulin was up-regula-ted in group SP, and no significant change was found in the parameters mentioned above in group CSP(P>005). Compared with group SP, the myocardial infarct size was significantly increased, and the expres-sion of α-tubulin was down-regulated in group CSP(P<005). Conclusion The mechanism by which sevoflurane postconditionning reduces myocardial I∕R injury is related to stabilizing microtubule structure of mice.

Research Progress in Anti-tumor Drugs Based on Microtubules Targets / 中国药师

Microtubules are the important components in cytoskeleton, which are found in all eukaryotic cells. Microtubules can assemble with the other proteins to form spindle, centriole and neural tube structure. Microtubules play important roles in cell mitosis, intracellular transportation, cell shape maintenance and signal transduction process. Microtubules are the important targets in many drug discoveries. The antitumor drugs acting on microtubules are the most effective clinical drugs, which can inhibit the polymerization of microtubules, destroy microtubules dynamic balance and spindle, block cell cycle and induce tumor cells necrosis. The paper re-viewed the effects and action mechanisms of microtubules targeted antitumor drugs, and discussed their application prospects in clinics.

Antitumor Effect of KX-01 through Inhibiting Src Family Kinases and Mitosis / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: KX-01 is a novel dual inhibitor of Src and tubulin. Unlike previous Src inhibitors that failed to show clinical benefit during treatment of breast cancer, KX-01 can potentially overcome the therapeutic limitations of current Src inhibitors through inhibition of both Src and tubulin. The present study further evaluates the activity and mechanism of KX-01 in vitro and in vivo. MATERIALS AND METHODS: The antitumor effect of KX-01 in triple negative breast cancer (TNBC) cell lines was determined by MTT assay. Wound healing and immunofluorescence assays were performed to evaluate the action mechanisms of KX-01. Changes in the cell cycle and molecular changes induced by KX-01 were also evaluated. A MDA-MB-231 mouse xenograft model was used to demonstrate the in vivo effects. RESULTS: KX-01 effectively inhibited the growth of breast cancer cell lines. The expression of phospho-Src and proliferative-signaling molecules were down-regulated in KX-01-sensitive TNBC cell lines. In addition, migration inhibition was observed by wound healing assay. KX-01-induced G2/M cell cycle arrest and increased the aneuploid cell population in KX-01-sensitive cell lines. Multi-nucleated cells were significantly increased after KX-01 treatment. Furthermore, KX-01 effectively delayed tumor growth in a MDA-MB-231 mouse xenograft model. CONCLUSION: KX-01 effectively inhibited cell growth and migration of TNBC cells. Moreover, this study demonstrated that KX-01 showed antitumor effects through the inhibition of Src signaling and the induction of mitotic catastrophe. The antitumor effects of KX-01 were also demonstrated in vivo using a mouse xenograft model.

Ultraestructura dendrítica en neuronas piramidales de ratones inoculados con virus de la rabia / Dendritric ultrastructure on pyramidal neurons of mice inoculated with rabies virus

Objetivos: Estudiar el efecto de la infección con rabia sobre la ultraestructura dendrítica de las neuronas piramidales de la corteza cerebral en ratones inoculados con el virus por vía intramuscular. Métodos: Ratones adultos inoculados con el virus de la rabia y ratones inoculados con solución vehículo sin el virus (controles) fueron fijados por perfusión intracardiaca, con una solución que contenía paraformaldehído al 4% y glutaraldehído al 2%, cuando los animales infectados manifestaron signos avanzados de la enfermedad. Los encéfalos fueron extraídos y cortados en plano coronal en un vibrátomo. Fragmentos pequeños y delgados de estos cortes, que contenían el área de la corteza cerebral motora, fueron procesados para microscopía electrónica de transmisión. Resultados: En las dendritas distales de las neuronas piramidales de los animales controles se observaron mitocondrias largas y estrechas, así como abundantes microtúbulos organizados en paralelo con la membrana celular. En las dendritas distales de las neuronas piramidales de los ratones infectados con el virus se observaron unas estructuras electrodensas de forma irregular semejantes a figuras de mielina, pero no se observaron las mitocondrias alargadas y los microtúbulos fueron escasos. Algunas dendritas también exhibieron la formación de vacuolas que interrumpían la continuidad del citoplasma y los microtúbulos. Conclusión: La infección con virus de la rabia generó cambios ultraestructurales en las dendritas de las neuronas piramidales corticales que aparentemente no se conocían. Estos resultados son coherentes con hallazgos previos, usando otras técnicas y modelos experimentales, en donde se ha demostrado patología dendrítica inducida por la infección con rabia.

Objectives: To study the effect of rabies infection on the dendritic ultrastructure of pyramidal neurons in the cerebral cortex of mice intramuscularly inoculated with rabies virus. Methods: Adult mice inoculated with rabies virus and mice inoculated with vehicle solution without the virus (controls) were fixed by intracardiac perfusion with a solution containing 4% paraformaldehyde and 2% glutaraldehyde. When infected animals showed advanced signs of disease, their brains were extracted and cut into the coronal plane on a vibratome. Small and thin fragments of these cuts containing motor cortex area were processed for transmission electron microscopy. Results: Distal dendrites of pyramidal neurons of control animals showed long and narrow mitochondria and abundant microtubules arranged in parallel with the cell membrane. In distal dendrites of pyramidal neurons of rabiesinfected mice some irregular shape electrondense structures similar to myelin figures were observed but elongated mitochondria were not observed, and microtubules were scarce. Some dendrites also exhibited vacuole formation interrupting the continuity of cytoplasm and microtubules. Conclusion: Infection with rabies virus produced ultrastructural changes within dendrites of the cortical pyramidal neurons that apparently were not known. These results are consistent with previous findings using other techniques and experimental models where it has been shown dendritic pathology induced by infection with rabies.

Clinical phenotypes and pathological features in myopathies with tubular aggregates / 中华神经科杂志

Objective To summarize clinical phenotypes and pathological characteristics in myopathies with tubular aggregates (TAs).Methods We reviewed 5 697 patients who performed muscle biopsies in our department between January 2001 and July 2015.We collected the cases with TAs and made classification based on their clinical diagnoses and pathological changes.Results Fifty-seven patients (1.00％) showed TAs in muscle specimens,including 50 (87.72％) males and 7 (12.28％) females.According to clinical,neurophysiological,pathological and genetic analysis,the diagnoses included 23 (40.35％) cases of periodic paralysis,7 (12.28％) cases of chronic alcohol intoxication,6 (10.53％) cases of congenital myasthenic syndrome,5 (8.77％) cases of exercise-induced cramps,3 (5.26％) cases of necrotizing myopathy,1 (1.75％) case of stromal interaction molecule 1-associated myopathy,limbgirdle muscular dystrophy 2E,myotonic dystrophy,myotonia congenita,paramyotonia congenitia,hypothyroid myopathy respectively.Other cases of unknown cause included unclassified distal myopathy,external ophthalmoplegia,white matter lesions,mental retardation,stroke,early onset weakness,pulmonary arterial hypertension.Besides TAs,pathological changes also included necrosis of muscle fibers (3 cases,5.26％),neurogenic changes (3 cases,5.26％) and muscular dystrophic changes (1 case,1.75％).Conclusions Our results indicated that TAs are usually found in males and could present in many types of hereditary or acquired neuromuscular disease as independent or accompanying changes.Periodic paralysis,chronic alcohol intoxication and congenital myasthenic syndrome are 3 major diseases causing myopathies with TAs.

Taxane resistance in metastatic breast cancer and novel microtubule-targeting agents / 国际肿瘤学杂志

The development of primary or acquired taxane resistance inevitably becomes to be the main problem.Ixabepilone is effective in metastatic breast cancer (MBC) patients including those heavily pretreated or resistant to taxanes.Eribulin has been used for the treatment of MBC patients who have received at least two prior chemotherapy regimens.New microtubule-targeting agents are promising to be effective options for patients progressing after standard taxane-containing chemotherapy.

Role of PI3K/Akt signal pathway in BMSCs migration induced by serum of rats with severely burn / 重庆医学

Objective To study the effects of severely burned rats serum on migration of BMSCs and mechanism.Methods Severely burned rats model was established,and the preparation of severely burned rats serum.Experimental groups:normal train-ing group(containing 10% fetal bovine serum,group C),burn serum group(containing 10% burns in the rat serum,group B),burn serum+blockers(10% burns in the rat serum+final concentration of 10 μmol/L PI3K signaling pathway inhibitor LY294002 train-ing,group B+LY).Activity of cells was examined with MTT;migration of cells was examined with Transwell chambers testing;protein expression of p-AKT/AKT was determined with Western blot;microtubule structure of cells was examined with immuno-fluorescence.Results Compared with group C,group B burn serum treatment after 24 h,BMSCs activity(P <0.01),p-AKT levels (P <0.05),increased migration quantity(P <0.001);cell microtubule structures appear rupture,after adding inhibitor,compared with group B,group B+LY BMSCs activity(P <0.01),to reduce the number of migration(P <0.001),p-lower AKT(P <0.05), cell microtubule structure similar to the normal group.Conclusion Severely burned rats serum can promote BMSCs migration,may burn serum cytokine activation of PI3K/AKT signal pathway,resulting in cell microtubule structure change,promote the migration of BMSCs.

Understanding Schizophrenia as a Disorder of Consciousness: Biological Correlates and Translational Implications from Quantum Theory Perspectives

From neurophenomenological perspectives, schizophrenia has been conceptualized as "a disorder with heterogeneous manifestations that can be integrally understood to involve fundamental perturbations in consciousness". While these theoretical constructs based on consciousness facilitate understanding the 'gestalt' of schizophrenia, systematic research to unravel translational implications of these models is warranted. To address this, one needs to begin with exploration of plausible biological underpinnings of "perturbed consciousness" in schizophrenia. In this context, an attractive proposition to understand the biology of consciousness is "the orchestrated object reduction (Orch-OR) theory" which invokes quantum processes in the microtubules of neurons. The Orch-OR model is particularly important for understanding schizophrenia especially due to the shared 'scaffold' of microtubules. The initial sections of this review focus on the compelling evidence to support the view that "schizophrenia is a disorder of consciousness" through critical summary of the studies that have demonstrated self-abnormalities, aberrant time perception as well as dysfunctional intentional binding in this disorder. Subsequently, these findings are linked with 'Orch-OR theory' through the research evidence for aberrant neural oscillations as well as microtubule abnormalities observed in schizophrenia. Further sections emphasize the applicability and translational implications of Orch-OR theory in the context of schizophrenia and elucidate the relevance of quantum biology to understand the origins of this puzzling disorder as "fundamental disturbances in consciousness".

Microtubule-Targeting Agents Enter the Central Nervous System (CNS): Double-edged Swords for Treating CNS Injury and Disease / 대한배뇨장애요실금학회지

Microtubules have been among the most successful targets in anticancer therapy and a large number of microtubule-targeting agents (MTAs) are in various stages of clinical development for the treatment of several malignancies. Given that injury and diseases in the central nervous system (CNS) are accompanied by acute or chronic disruption of the structural integrity of neurons and that microtubules provide structural support for the nervous system at cellular and intracellular levels, microtubules are emerging as potential therapeutic targets for treating CNS disorders. It has been postulated that exogenous application of MTAs might prevent the breakdown or degradation of microtubules after injury or during neurodegeneration, which will thereby aid in preserving the structural integrity and function of the nervous system. Here we review recent evidence that supports this notion and also discuss potential risks of targeting microtubules as a therapy for treating nerve injury and neurodegenerative diseases.

Regulatory volume decrease in Leishmania mexicana: effect of anti-microtubule drugs

The trypanosomatid cytoskeleton is responsible for the parasite's shape and it is modulated throughout the different stages of the parasite's life cycle. When parasites are exposed to media with reduced osmolarity, they initially swell, but subsequently undergo compensatory shrinking referred to as regulatory volume decrease (RVD). We studied the effects of anti-microtubule (Mt) drugs on the proliferation of Leishmania mexicana promastigotes and their capacity to undergo RVD. All of the drugs tested exerted antiproliferative effects of varying magnitudes [ansamitocin P3 (AP3)> trifluoperazine > taxol > rhizoxin > chlorpromazine]. No direct relationship was found between antiproliferative drug treatment and RVD. Similarly, Mt stability was not affected by drug treatment. Ansamitocin P3, which is effective at nanomolar concentrations, blocked amastigote-promastigote differentiation and was the only drug that impeded RVD, as measured by light dispersion. AP3 induced 2 kinetoplasts (Kt) 1 nucleus cells that had numerous flagella-associated Kts throughout the cell. These results suggest that the dramatic morphological changes induced by AP3 alter the spatial organisation and directionality of the Mts that are necessary for the parasite's hypotonic stress-induced shape change, as well as its recovery.

Experimental research on stabilizing microtubules to decrease myocardial injury / 第二军医大学学报

Objective: To study whether stabilizing microtubules can decrease myocardial ischaemic-reperfusion injury. Methods: (1) The isolated rat hearts were divided into four groups (n = 15): control group, ischemic group, ischemic+0. 1 μmol/L Taxol group, and ischemic+1 μmol/L Taxol group. All the groups were given a 15-min equilibration and then followed by different treatments: control group, 50 min normoxic superfusion; ischemia group, 20 min normoxic superfusion plus 30 min ischemia; and Taxol groups, 20 min normoxic superfusion plus 30 min ischemia, plus 0. 1 or 1 μmol/L Taxol throughout 50-min superfusion period. Arrthymias scores were assessed and compared between different groups; the structure of the microtubules was observed and its breakage score was obtained. (2) The isolated rat hearts were divided into 3 groups (n = 8): normal control group, ischemic/reperfusion (I/R) group, and 1 μmol/L Taxol group. The I/R group was Langendorff-perfused; the left anterior descending branch was ligated for 30 min and reperfused for 120 min. The Taxol group received 1 μmol/L Taxol and other treatments were similar to the I/R group. Evans blue perfusion was used to observe the infarct size of each group. Results: Stabilizing microtubules with Taxol (0. 1 μmol/L or 1 μmol/L) reduced ischaemic ventricular arrhythmia in a dose-dependent fashion (P < 0. 05); it also significantly reduced arrhythmia scores and the incidence of ventricular tachycardia (P < 0. 05). Taxol at 0. 1 μmol/L greatly decreased microtubule breakage score, and at 1 μmol/L significantly reduced the infarct size compared with the control group (P < 0. 05). Conclusion: Stabilizing microtubules can reduce myocardial ischaemic-reperfusion injury.

Interference of curcumin in cycle of HepG2 cells by regulating microtubule system / 中草药

Objective: To investigate the effect of curcumin (Cur) on cycle in HepG2 cells and the action of microtubule system for it. Methods: The proliferation inhibition of Cur on HepG2 cells was evaluated by MTT assay; The effect of Cur on the cycle of HepG2 cells was analyzed by flow cytometry; Confocal laser scanning microscopy (CLSM) was used to observe the changes of microtubule in HepG2 cells after treated with Cur; Western blotting was performed to determine the expression of α-tubulin; The in vitro effects of Cur on tubulin polymerization and depolymerization activities were studied. Results: Cur inhibited the proliferation of HepG2 cells in a dose- and time-dependent manner. With Cur concentration increasing, the proportion of HepG2 cells arrested in G2/M phase was also increased. CLSM showed that Cur could seriously destroy the cell microtubule structure and change the polymerization state of tubulin. Western blotting showed that the decrease of the expression level of α-tubulin was related to Cur concentration. Cur could also interfere the microtubule polymerization and depolymerization activities. Conclusion: Cur could inhibit the proliferation of HepG2 cells by destroying the microtubule structure and downregulating the expression of α-tubulin, and make HepG2 cells arrested in G2/M phase.