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Live-Cell Imaging of Dual-Labeled Golgi Stacks in Tobacco BY-2 Cells Reveals Similar Behaviors for Different Cisternae during Movement and Brefeldin A Treatment

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molecular Plant 2011年第5期4卷 896-908页

作者： Stephanie L. Madison Andreas Nebenfuhr Department of Biochemistry and cellular and molecular Biology University of Tennessee Knoxville TN 37996-0840 USA

In plant cells, the Golgi apparatus consists of numerous stacks that, in turn, are composed of several flattened cisternae with a clear cis-to-trans polarity. During normal functioning within living cells, this unusual organelle displays a wide range of dynamic behaviors such as whole stack motility, constant membrane flux through the cisternae, and Golgi enzyme recycling through the ER. In order to further investigate various aspects of Golgi stack dynamics and integrity, we co-expressed pairs of established Golgi markers in tobacco BY-2 cells to distinguish sub-compartments of the Golgi during monensin treatments, movement, and brefeldin A （BFA）-induced disassembly. A combination of cis and trans markers revealed that Golgi stacks remain intact as they move through the cytoplasm. The Golgi stack orientation during these movements showed a slight preference for the cis side moving ahead, but trans cisternae were also found at the leading edge. During BFA treatments, the different sub-compartments of about half of the observed stacks fused with the ER sequentially; however, no consistent order could be detected. In contrast, the ionophore monensin resulted in swelling of trans cisternae while medial and particularly cis cisternae were mostly unaffected. Our results thus demonstrate a re- markable equivalence of the different cisternae with respect to movement and BFA-induced fusion with the ER. In addi- tion, we propose that a combination of dual-label fluorescence microscopy and drug treatments can provide a simple alternative approach to the determination of protein localization to specific Golgi sub-compartments.

关键词： Golgi apparatus Golgi stack integrity brefeldin A monensin tobacco BY-2 cells live-cell imaging.

Targeting and Regulation of Cell Wall Synthesis During Tip Growth in Plants

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Journal of Integrative Plant Biology 2013年第9期55卷 835-846页

作者： Fangwei Gu Erik Nielsen Department of molecular Cellular and Developmental Biology University of MichiganAnn Arbor Michigan 48109 USA

Root hairs and pollen tubes are formed through tip growth, a process requiring synthesis of new cell wall material and the precise targeting and integration of these components to a selected apical plasma membrane domain in the growing tips of these cells. Presence of a tip-focused calcium gradient, control of actin cytoskeleton dynamics, and formation and targeting of secretory vesicles are essential to tip growth. Similar to cells undergoing diffuse growth, cellulose, hemi-celluloses, and pectins are also deposited in the growing apices of tip-growing cells. However, differences in the manner in which these cell wall components are targeted and inserted in the expanding portion of tip-growing cells is reflected by the identification of elements of the plant cell wall synthesis machinery which have been shown to play unique roles in tip-growing cells. In this review, we summarize our current understanding of the tip growth process, with a particular focus on the subcellular targeting of newly synthesized cell wall components, and their roles in this form of plant cell expansion.

关键词： Cellulose membrane trafficking plant cell wall pollen tube root hair tip growth.

Biomarker-guided drug therapy: personalized medicine for treating Alzheimer’s disease

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Neural Regeneration Research 2021年第10期16卷 2010-2011页

作者： Charvi Syal Jing Wang Regenerative medicine Program Ottawa Hospital Research InstituteOttawaONCanada Department of cellular and molecular medicine Faculty of MedicineBrain and Mind Research InstituteUniversity of OttawaOttawaONCanada Canadian Partnership for Stroke Recovery OttawaONCanada

Alzheimer’s disease(AD)is a progressive neurodegenerative disorder associated with significant memory decline and cognitive *** is characterized by two classical neuropathological hal lmarks,namely the amyloid-beta(Aβ)plaques and neurofibril ***,there are no disease-modifying treatments available for AD,except for a couple of the US Food and Drug Administration(FDA)-approved drugs to improve cognitive function by blocking N-methyl-D-aspartate receptors or cholinesterase activity(Panza et al.,2019).

关键词： Alzheimer drugs Aβ

Effects of simulated microgravity on nitric oxide level in cardiac myocytes and its mechanism

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Science China(Life Sciences) 2003年第3期46卷 302-309页

作者：熊江辉李莹辉聂捷琳 Laboratory of Space cellular and molecular Biology Institute of Space Medico-engineering Beijing 100094 China

The depression of cardiac contractility induced by space microgravity is an important issue of aerospace medicine research, while its precise mechanism is still unknown. In the present study, we explored effects of simulated microgravity on nitric oxide (NO) level, inducible nitric oxide synthase (iNOS) expression and related regulative mechanism using electron spin resonance (ESR) spectroscopy, immunocytochemistry and in situ hybridization. We found a remarkable in-crease of NO level and up-regulation of iNOS and iNOS mRNA expression in rat cardiac myocytes under simulated microgravity. Staurosporine (a nonselective protein kinase inhibitor), calphostin C (a selective protein kinase C inhibitor), partially inhibited the effect of simulated microgravity. Thus regulative effect of simulated microgravity on iNOS expression is mediated at least partially via activation of protein kinase C. These results indicate that NO system in cardiac myocytes is sensi-tive to simulated microgravity and may play an important role in the depression of cardiac contrac-tility induced by simulated microgravity.

关键词： simulated microgravity, cardiac myocytes, nitric oxide, nitric oxide synthase, protein kinase C, signal transduction.

Restriction Endonuclease Analysis of Mitochondrial DNA of Muntjacs and Related Deer

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Science China Chemistry 1994年第3期37卷 294-302页

作者：兰宏施立明 The Laboratory of cellular and molecular Evolution Kunming Institute of Zoology Academia Sinica Kunming 650223 PRC

Twelve restriction endonucleases were employed to analyze the mitochondrial DNA of four species of muntjacs and two related species of deer: red muntjac (M. muntjak), Gongshan muntjac (M. gongshanensis ), black muntjac (M. crinifrons), Chinese muntjac (M. reevesi), tufted deer (Elaphodus cephalophus), and forest musk deer (Moschus berezovskii). A total of 170 restriction fragments were detected among the samples. Fragments data were used to calculate the genetic distance (i. e. percent sequence divergency) among species, which in turn were used to construct a phylogenetic tree and to estimate divergency times. Our analysis indicates that the black muntjac and the Gongshan muntjac are most closely related, and that they are closely realted to the red muntjac and the Chinese muntjac. Additionally, the tufted deer is genetically closer to muntjacs than the musk deer is.

关键词： muntjacs mitochondrial DNA restriction fragments.

Androgens and estrogens in skeletal sexual dimorphism

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Asian Journal of Andrology 2014年第2期16卷 213-222,I0008页

作者： Michael Laurent Leen Antonio Mieke Sinnesael Vanessa Dubois Evelien Gielen Frank Classens Dirk Vanderschueren Laboratory of molecular Endocrinology Department of Cellular and Molecular Medicine Gerontology and Geriatrics Department of Clinical and Experimental Medicine KU Leuven Leuven Begum Geriatric medicine University Hospitals Leuven Leuven Belgium Clinical and Experimental Endccrinology Department of Clinical and Experimental Medicine KU Leuven Leuven Belgium Endocrinology and Andrology Centre for Metabolic Bone Diseases Laboratory medicine University Hospitals Leuven Leuven Belgium.

Bone is an endocrine tissue expressing androgen and estrogen receptors as well as steroid metabolizing enzymes. The bioactivity of circulating sex steroids is modulated by sex hormone-binding globulin and local conversion in bone tissue, for example, from testosterone （T） to estradiol （E2） by aromatase, or to dihydrotestosterone by 5（x-reductase enzymes. Our understanding of the structural basis for gender differences in bone strength has advanced considerably over recent years due to increasing use of （high resolution） peripheral computed tomography. These microarchitectural insights form the basis to understand sex steroid influences on male peak bone mass and turnover in cortical vs trabecular bone. Recent studies using Cre/LoxP technology have further refined our mechanistic insights from global knockout mice into the direct contributions of sex steroids and their respective nuclear receptors in osteoblasts, osteoclasts, osteocytes, and other cells to male osteoporosis. At the same time, these studies have reinforced the notion that androgen and estrogen deficiency have both direct and pleiotropic effects via interaction with, for example, insulin-like growth factor 1, inflammation, oxidative stress, central nervous system control of bone metabolism, adaptation to mechanical loading, etc., This review will summarize recent advances on these issues in the field of sex steroid actions in male bone homeostasis.

关键词： androgen receptor bone mineral density estradiol estrogen receptor male osteoblast osteoclast osteocyte osteoporosis sex hormone-binding globulin testosterone

Possibilities for arthroscopic treatment of the ageing sternoclavicular joint

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World Journal of Orthopedics 2017年第7期8卷 536-544页

作者： Martin Rathcke J?rgen Tranum-Jensen Michael Rindom Krogsgaard Section for Sportstraumatology M51 Bispebjerg-Frederiksberg Hospital Department of cellular and molecular medicine University of Copenhagen

AIM To investigate if there are typical degenerative changes in the ageing sternoclavicular joint(SCJ), potentially accessible for arthroscopic *** Both SCJs were obtained from 39 human cadavers(mean age: 79 years, range: 59-96, 13 F/26 M). Each frozen specimen was divided frontally with a band saw, so that both SCJs were opened in the same section through the center of the discs. After thawing of the specimens, the condition of the discs was evaluated by probing and visual inspection. The articular cartilages were graded according to Outerbridge, and disc attachments were probed. Cranio-caudal heights of the joint cartilages were measured. Superior motion of the clavicle with inferior movement of the lateral clavicle was *** Degenerative changes of the discs were common. Only 22 discs(28%) were fully attached and the discs were thickest superiorly. We found a typical pattern: Detachment of the disc inferiorly in connection with thinning, fraying and fragmentation of the inferior part of the disc, and detachment from the anterior and/or posterior capsule. Severe joint cartilage degeneration ≥ grade 3 was more common on the clavicular side(73%) than on the sternal side(54%) of the joint. In cadavers< 70 years 75% had ≤ grade 2 changes while this was the case for only 19% aged 90 years or more. There was no difference in cartilage changes when right and left sides were compared, and no difference between sexes. Only one cadaver-a woman aged 60 years-had normal cartilages. CONCLUSION Changes in the disc and cartilages can be treated by resection of disc, cartilage, intraarticular osteophytes or medial clavicle end. Reattachment of a degenerated disc is not possible.

关键词： Sternoclavicular Degenerative Cartilage Disc Arthroscopy

Hsp90 inhibition induces destabilization of actin cytoskeleton in tumor cells:functional significance of Hsp90 interaction with F-actin

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Asian Pacific Journal of Tropical medicine 2010年第9期3卷 715-722页

作者： Vishal Chaturvedi Amere Subbarao Sreedhar Centre for cellular and molecular Biology Uppal RoadHyderabad 500 007India

Objective:To examine the role of heat shock protein 90(Hsp90) in the maintenance of actin cytoskeleton in human neuroblastoma tumor ***:Co-precipitation experiments were performed to examine Hsp90 interaction with ***90 and actin interactions were evaluated by protein refolding and acto-myosin motility assays.17-(AUylamino)-17- demethoxygeldanamycin(17AAG) induced actin-cytoskeleton re-organization was examined by laser scanning confocal ***:It was shown that inhibition of Hsp90 by 17AAC accelerates detergent induced cell lysis of neuroblastoma tumor cells through destabilization of actin *** in vitro co-precipitation experiments showed that functional but not mutant Hsp90 binds with *** biochemical modifications,phopshorylation and oligomerization enhanced Hsp90 binding with F-actin.F-actin binding to Hsp90 interfered with Hsp90 chaperone activity in protein refolding assays,and Hsp90 binding to F-actin interfered with actin motility on myosin coated flow *** the combination treatment,17AAG irreversibly augmented the effect of cytochalasin D,an inhibitor of actin ***:It can be concluded that Hsp90 binds to F-actin in tumor cells and maintains the cellular integrity. The results display a novel element of Hsp90 inhibition in destabilizing the actin cytoskeleton of tumor cells,therefore suggest that 17AAG combination with cytoskeletal disruptor may be effective in combating cancer.

关键词： Hsp90 F-actin Cytoskeleton 17AAG Tumor cells Combination treatment

Therapeutic application of mesenchymal stem cells-derived extracellular vesicles in colorectal cancer

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BIOCELL 2023年第3期47卷 455-464页

作者： MOHADESEH NEMATI YOUSEF RASMI JAFAR REZAIE Department of Biochemistry School of MedicineUrmia University of Medical SciencesUrmiaIran Solid Tumor Research Center Cellular and Molecular Medicine InstituteUrmia University of Medical SciencesUrmiaIran

Colorectal cancer(CRC)is the third most common cancer and the leading cause of cancer death *** to therapy is a challenge for CRC *** stem cells(MSCs)have become one of the furthermost effective approaches for tumor treatment due to their specific feature;however,their therapeutic function is ***,extracellular vesicles(EVs)derived from MSCs(MSCs-EVs)have attracted extensive research attention due to their promising role in CRC *** are cell-derived vesicles that transfer different biomolecules between cells,contributing to intracellular ***-EVs can suppress CRC by delivering therapeutic agents to tumor *** studies indicate that MSCs-EVs can serve as a drug delivery system for the treatment of different *** methods are used to modify(engineer)MSCs-EVs for loading therapeutic *** MSCs-EVs have improved specificity,targeting ability,and immunogenicity compared to synthetic ***,CRC-EVs participate in regulating different cells,such as immune cells,fibroblasts,and endothelial cells,promoting ***-EVs-based therapy indicates a high potential in the treatment of cancer;however,the majority of studies have been conducted in the pre-clinical,and their clinical applications need further *** this review,we describe the biogenesis of EVs,focusing on the effect of MSCs-EVs on CRC cells and CRC-derived EVs on other ***,MSCs-EVs as a drug delivery system for cancers is also reviewed,and perspectives regarding the therapeutic application of MSCs-EVs are discussed.

关键词： Colorectal cancer Cancer therapy MSCs Extracellular vesicles