As an important part of the cytoskeleton, microtubules play a crucial role in many cellular processes, such as cell division, intracellular transport, and maintaining cell morphology. The MAP1 family is an important family of microtubule-associated proteins, which includes three members: MAP1A, MAP1B, and MAP1S. These proteins are widely involved in the dynamic regulation of the cytoskeleton and play a key role in the development and function of the central nervous system, especially in the development and function of neurons. This study reviews the research progress of the MAP1 family, mainly focusing on the structure and function of MAP1 family members, and paying particular attention to their roles in neuronal development and regeneration, regulatory mechanisms, and neurodegenerative diseases.
Humans ; Animals ; Microtubule-Associated Proteins/classification* ; Neurons/cytology* ; Neurodegenerative Diseases/physiopathology* ; Microtubules/physiology* ; Cytoskeleton/physiology*

Leukocyte-specific protein 1 (LSP1) is an F-actin binding protein expressed in various leukocytes, including lymphocytes, mononuclear macrophages, and neutrophils. LSP1 is highly conserved across different species. Human LSP1 protein contains 339 amino acids, featuring a Ca²⁺ binding site in the acidic NH2-terminal region and multiple F-actin binding domains along with phosphorylatable sites in the basic COOH-terminal region. Under Ca²⁺ regulation, the COOH-terminal domain of LSP1 binds to F-actin to regulate cell movement and signal transduction. Additionally, LSP1 activates the mitogen-activated protein kinase (MAPK) signaling pathway through phosphorylation mediated by protein kinase C (PKC) and MAPK-activated protein kinase-2, thereby regulating leukocyte proliferation and chemotaxis. The main effects of LSP1 on leukocytes are as follows: LSP1 plays important roles in neutrophil and macrophage migration, affecting cell adhesion, polarization and movement. LSP1 also functions in endothelial cells to regulate leukocyte transendothelial migration. In addition, LSP1 regulates macrophage phagocytosis through interaction with myosin 1e. Moreover, LSP1 regulates leukocyte proliferation and differentiation and plays significant roles in the development of leukemia and other tumors. In summary, LSP1 regulates leukocyte morphology, movement and function through interactions with cytoskeletal and signaling proteins. This review provides a comprehensive summary of these aspects.
Humans ; Leukocytes/cytology* ; Animals ; Cytoskeleton/metabolism* ; Microfilament Proteins/physiology* ; Cell Movement ; Signal Transduction

Rac1 belongs to the family of Rho GTPases, and plays important roles in the brain function. It affects the cell migration and axon guidance via regulating the cytoskeleton and cellular morphology. However, the effect of its dynamic activation in regulating physiological function remains unclear. Recently, a photoactivatable analogue of Rac1 (PA-Rac1) has been developed, allowing the activation of Rac1 by the specific wavelength of light in living cells. Thus, we constructed recombinant adeno-associated virus (AAV) of PA-Rac1 and its light-insensitive mutant PA-Rac1-C450A under the control of the mouse glial fibrillary acidic protein (mGFAP) promoter to manipulate Rac1 activity in astrocytes by optical stimulation. Primary culture of hippocampal astrocytes was infected with the recombinant AAV-PA-Rac1 or AAV-PA-Rac1-C450A. Real-time fluorescence imaging showed that the cell membrane of the astrocyte expressing PA-Rac1 protruded near the light spot, while the astrocyte expressing PA-Rac1-C450A did not. We injected AAV-PA-Rac1 and AAV-PA-Rac1-C450A into dorsal hippocampus to investigate the role of the activation of Rac1 in regulating the associative learning. With optical stimulation, the PA-Rac1 group, rather than the PA-Rac1-C450A group, showed slower learning curve during the fear conditioning compared with the control group, indicating that activating astrocytic Rac1 blocks the formation of contextual memory. Our data suggest that the activation of Rac1 in dorsal hippocampal astrocyte plays an important role in the associative learning.
Animals ; Astrocytes ; physiology ; Cell Membrane ; Cell Movement ; Conditioning, Classical ; Cytoskeleton ; Dependovirus ; Fear ; Hippocampus ; physiology ; Memory ; Mice ; Mice, Inbred C57BL ; Neuropeptides ; genetics ; physiology ; Optogenetics ; rac1 GTP-Binding Protein ; genetics ; physiology

Oligoasthenozoospermia, teratozoospermia or low sperm motility is the main cause of male infertility. Low sperm motility can be induced by abnormalities of the sperm tail structure and sperm function. The outer dense fiber protein 2 (ODF2) is a protein fiber maintaining cytoskeleton, as a major component of the mammalian sperm tail and centrosome, and its abnormality is closely related to asthenospermia. Recent studies indicate that ODF2 includes many proteins of the same name and homologous splices located in the sperm centrosomes and spindles of cleaved-embryos, necessary for animal ciliogenesis and associated with sperm capacitation. The features of ODF2 indicate that it is not a single-structural protein. This paper reviews the known functions of ODF2, paving a ground for further studies of the relationship between the ODF2 protein and fertilization.
Animals ; Asthenozoospermia ; complications ; Azoospermia ; complications ; Centrosome ; chemistry ; Cytoskeleton ; chemistry ; Heat-Shock Proteins ; physiology ; Humans ; Infertility, Male ; etiology ; Male ; Sperm Motility ; physiology ; Sperm Tail ; Spermatozoa ; physiology

OBJECTIVEThis study aimed to investigate the effects of in vitro continuous passaging on the morphological phenotype and differentiation characteristics of mouse hyaline chondrocytes, as well as on the balance of the extracellular matrix (ECM).

METHODSEnzymatic digestion was conducted to isolate mouse hyaline chondrocytes, which expanded over five passages in vitro. Hematoxylin-eosin stain was used to show the changes in chondrocyte morphology. Semi-quantitative polymerase chain reaction was performed to analyze the mRNA changes in the marker genes, routine genes, matrix metalloproteinases (MMPs), and tissue inhibitors of MMPs (TIMPs) in chondrocytes. Zymography was carried out to elucidate changes in gelatinase activities.

RESULTSAfter continuous expansion in vitro, the morphology of round or polygonal chondrocytes changed to elongated and spindled shape. The expression of marker genes significantly decreased (P < 0.05), and it was almost negatively expressed by P5 chondrocytes. By contrast, the down regulation of routine genes was insignificant. The gene expression levels of MMPs and TIMPs both decreased (P < 0.05), but the change in MMP-1 and TIMP-1 was not statistically significant (P > 0.05). Meanwhile, the ratio of MMPs/TIMPs was altered. At the protein level, the activities of gelatinases decreased after passaging, especially for P4 and P5 chondrocytes (P < 0.05).

CONCLUSIONSerially passaged chondrocytes dedifferentiated and lost specific phenotypic characteristics during in vitro expansion culture. Simultaneously, the anabolism and catabolism of the cartilage ECM became uncontrollable and led to the imbalance of ECM homeostasis. When hyaline chondrocytes are applied in research on relevant diseases or cartilage tissue engineering, P0-P2 chondrocytes should be used.

Animals ; Cartilage ; Cell Differentiation ; Cells, Cultured ; Chondrocytes ; physiology ; Cytoskeleton ; Extracellular Matrix ; Gelatinases ; Gene Expression ; Hyalin ; physiology ; Matrix Metalloproteinase 1 ; Matrix Metalloproteinases ; Mice ; RNA, Messenger ; Tissue Engineering ; Tissue Inhibitor of Metalloproteinase-1 ; Tissue Inhibitor of Metalloproteinases

OBJECTIVETo study the impact of the chloride channel dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR) on the cytoskeleton of Sertoli cells in the mouse.

METHODSTM4 Sertoli cells were cultured and treated with CFTR(inh)-172 at the concentrations of 1, 5, 10 and 20 μmol/L for 48 hours. Then the cytotoxicity of CFT(inh)-172 was assessed by CCK-8 assay, the expressions of F-actin and Ac-tub in the TM4 Sertoli cells detected by immunofluorescence assay, and those of N-cadherin, vimentin and vinculin determined by qPCR.

RESULTSCFTR(inh)-172 produced cytotoxicity to the TM4 Sertoli cells at the concentration of 20 μmol/L. The expressions of F-actin and Ac-tub were decreased gradually in the TM4 Sertoli cells with the prolonging of treatment time and increasing concentration of CFTR(inh)-172 (P < 0.05). The results of qPCR showed that different concentrations of CFTR(inh)-172 worked no significant influence on the mRNA expressions of N-cadherin, vimentin and vinculin in the Sertoli cells.

CONCLUSIONThe CFTR chloride channel plays an important role in maintaining the normal cytoskeleton of Sertoli cells. The reduced function and expression of the CFTR chloride channel may affect the function of Sertoli cells and consequently spermatogenesis of the testis.

Actins ; metabolism ; Animals ; Benzoates ; pharmacology ; Chloride Channels ; physiology ; Cystic Fibrosis Transmembrane Conductance Regulator ; antagonists & inhibitors ; Cytoskeleton ; drug effects ; Male ; Mice ; Sertoli Cells ; drug effects ; metabolism ; Spermatogenesis ; Thiazolidines ; pharmacology ; Time Factors

Progressive tumor growth is dependent on angiogenesis. The mechanisms by which endothelial cells (ECs) are incorporated to develop new blood vessels are not well understood. Recent studies reveal that the ezrin radixin moesin (ERM) family members are key regulators of cellular activities such as adhesion, morphogenetic change, and migration. We hypothesized that ezrin, one of the ERM family members, may play important roles in ECs organization during angiogenesis, and new vessels formation in preexisting tissues. To test this hypothesis, in this study, we investigated the effects of ezrin gene silencing on the migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. HUVECs were transfected with plasmids with ezrin-targeting short hairpin RNA by using the lipofectamine-2000 system. Wound assay in vitro and three-dimensional culture were used to detect the migration and angiogenesis capacity of HUVECs. The morphological changes of transfected cells were observed by confocal and phase contrast microscopy. Our results demonstrated that the decreased expression of ezrin in HUVECs significantly induced the morphogenetic changes and cytoskeletal reorganization of the transfected cells, and also reduced cell migration and angiogenesis capacity in vitro, suggesting that ezrin play an important role in the process of HUVECs migration and angiogenesis.
Cell Movement ; genetics ; Cytoskeletal Proteins ; genetics ; metabolism ; Cytoskeleton ; metabolism ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; physiology ; Humans ; Neovascularization, Physiologic ; genetics

Nanosecond pulsed electric field ablation has been widely applied in clinical cancer treatment, while its molecular mechanism is still unclear. Researchers have revealed that nanosecond pulsed electric field generates nanopores in plasma membrane, leading to a rapid influx of Ca²⁺; it has specific effect on intracellular organelle membranes, resulting in endoplasmic reticulum injuries and mitochondrial membrane potential changes. In addition, it may also change cellular morphology through damage of cytoskeleton. This article reviews the recent research advances on the molecular mechanism of cell membrane and organelle changes induced by nanosecond pulsed electric field ablation.
Ablation Techniques ; Calcium ; Cell Membrane ; physiology ; Cytoskeleton ; Electricity ; Endoplasmic Reticulum ; Humans ; Membrane Potential, Mitochondrial ; Neoplasms ; therapy

BACKGROUNDIn prokaryotic organisms, the mechanism responsible for the accurate partition of newly replicated chromosomes into daughter cells is incompletely understood. Segregation of the replication terminus of the circular prokaryotic chromosome poses special problems that have not previously been addressed. The aim of this study was to investigate the roles of several protein components (MreB, MreC, and MreD) of the prokaryotic cytoskeleton for the faithful transmission of the chromosomal terminus into daughter cells.

METHODSStrain LQ1 (mreB::cat), LQ2 (mreC::cat), and LQ3 (mreD::cat) were constructed using the Red recombination system. LQ11/pLAU53, LQ12/pLAU53, LQ13/pLAU53, LQ14/pLAU53, and LQ15/pLAU53 strains were generated by P1transduction of (tetO) 240 -Gm and (lacO) 240 -Km cassettes from strains IL2 and IL29. Fluorescence microscopy was performed to observe localization pattern of fluorescently-labeled origin and terminus foci in wild-type and mutant cells. SOS induction was monitored as gfp fluorescence from PsulA-gfp in log phase cells grown in Luria-Bertani medium at 37°C by measurement of emission at 525 nm with excitation at 470 nm in a microplate fluorescence reader.

RESULTSMutational deletion of the mreB, mreC, or mreD genes was associated with selective loss of the terminus region in approximately 40% of the cells within growing cultures. This was accompanied by significant induction of the SOS DNA damage response, suggesting that deletion of terminus sequences may have occurred by chromosomal cleavage, presumably caused by ingrowth of the division septum prior to segregation of the replicated terminal.

CONCLUSIONSThese results imply a role for the MreBCD cytoskeleton in the resolution of the final products of terminus replication and/or in the specific movement of newly replicated termini away from midcell prior to completion of septal ingrowth. This would identify a previously unrecognized stage in the overall process of chromosome segregation.

Chromosome Segregation ; genetics ; physiology ; Cytoskeleton ; metabolism ; Escherichia coli ; genetics ; metabolism

OBJECTIVETo study the changes in biological behaviors of meningitis E. coli K1 strain E44 after deletion of polyphosphate kinase 1 (ppk1) gene and explore the role of ppk1 in the pathogenesis of E. coli K1-induced meningitis.

METHODSThe wild-type strain E. coli K1 and ppk1 deletion mutant were exposed to heat at 56 degrees celsius; for 6 min, and their survival rates were determined. The adhesion and invasion of the bacteria to human brain microvascular endothelial cells (HBMECs) were observed using electron microscopy and quantitative tests. HBMECs were co-incubated with wild-type strain or ppk1 deletion mutant, and the cytoskeleton rearrangement was observed under laser scanning confocal microscope.

RESULTSThe survival rate of the ppk1 deletion mutant was significantly lower than that of the wild-type strain after heat exposure. The ppk1 deletion mutant also showed lowered cell adhesion and invasion abilities and weakened ability to induce cytoskeleton rearrangement in HBMECs.

CONCLUSIONSppk1 gene is important for E.coli K1 for heat resistance, cell adhesion and invasion, and for inducing cytoskeletal rearrangement in HBMECs.

Brain ; cytology ; Cells, Cultured ; Cytoskeleton ; Endothelial Cells ; cytology ; microbiology ; Escherichia coli ; genetics ; physiology ; Escherichia coli Proteins ; genetics ; Gene Deletion ; Humans ; Phosphotransferases (Phosphate Group Acceptor) ; genetics