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Pharmacological Research Jun 2024The global incidence of cardiac diseases is increasing, imposing a substantial socioeconomic burden on healthcare systems. The pathogenesis of cardiovascular disease is... (Review)
Review
The global incidence of cardiac diseases is increasing, imposing a substantial socioeconomic burden on healthcare systems. The pathogenesis of cardiovascular disease is complex and not fully understood, and the physiological function of the heart is inextricably linked to well-regulated cardiac muscle movement. Myosin light chain kinase (MLCK) is essential for myocardial contraction and diastole, cardiac electrophysiological homeostasis, vasoconstriction of vascular nerves and blood pressure regulation. In this sense, MLCK appears to be an attractive therapeutic target for cardiac diseases. MLCK participates in myocardial cell movement and migration through diverse pathways, including regulation of calcium homeostasis, activation of myosin light chain phosphorylation, and stimulation of vascular smooth muscle cell contraction or relaxation. Recently, phosphorylation of myosin light chains has been shown to be closely associated with the activation of myocardial exercise signaling, and MLCK mediates systolic and diastolic functions of the heart through the interaction of myosin thick filaments and actin thin filaments. It works by upholding the integrity of the cytoskeleton, modifying the conformation of the myosin head, and modulating innervation. MLCK governs vasoconstriction and diastolic function and is associated with the activation of adrenergic and sympathetic nervous systems, extracellular transport, endothelial permeability, and the regulation of nitric oxide and angiotensin II. Additionally, MLCK plays a crucial role in the process of cardiac aging. Multiple natural products/phytochemicals and chemical compounds, such as quercetin, cyclosporin, and ML-7 hydrochloride, have been shown to regulate cardiomyocyte MLCK. The MLCK-modifying capacity of these compounds should be considered in designing novel therapeutic agents. This review summarizes the mechanism of action of MLCK in the cardiovascular system and the therapeutic potential of reported chemical compounds in cardiac diseases by modifying MLCK processes.
PubMed: 38944220
DOI: 10.1016/j.phrs.2024.107276 -
The Journal of Comparative Neurology Jul 2024Dendritic spines are sites of synaptic plasticity and their head size correlates with the strength of the corresponding synapse. We recently showed that the distribution...
Dendritic spines are sites of synaptic plasticity and their head size correlates with the strength of the corresponding synapse. We recently showed that the distribution of spine head sizes follows a lognormal-like distribution even after blockage of activity or plasticity induction. As the cytokine tumor necrosis factor (TNF) influences synaptic transmission and constitutive TNF and receptor (TNF-R)-deficiencies cause changes in spine head size distributions, we tested whether these genetic alterations disrupt the lognormality of spine head sizes. Furthermore, we distinguished between spines containing the actin-modulating protein synaptopodin (SP-positive), which is present in large, strong and stable spines and those lacking it (SP-negative). Our analysis revealed that neither TNF-deficiency nor the absence of TNF-R1, TNF-R2 or TNF-R 1 and 2 (TNF-R1/R2) degrades the general lognormal-like, skewed distribution of spine head sizes (all spines, SP-positive spines, SP-negative spines). However, TNF, TNF-R1 and TNF-R2-deficiency affected the width of the lognormal distribution, and TNF-R1/2-deficiency shifted the distribution to the left. Our findings demonstrate the robustness of the lognormal-like, skewed distribution, which is maintained even in the face of genetic manipulations that alter the distribution of spine head sizes. Our observations are in line with homeostatic adaptation mechanisms of neurons regulating the distribution of spines and their head sizes.
Topics: Animals; Dendritic Spines; Mice; Receptors, Tumor Necrosis Factor, Type I; Mice, Knockout; Dentate Gyrus; Tumor Necrosis Factor-alpha; Mice, Inbred C57BL; Receptors, Tumor Necrosis Factor, Type II; Neurons; Male; Microfilament Proteins
PubMed: 38943486
DOI: 10.1002/cne.25645 -
Developmental Biology Jun 2024In most mollusks (conchiferans), the early tissue responsible for shell development, namely, the shell field, shows a common process of invagination during...
In most mollusks (conchiferans), the early tissue responsible for shell development, namely, the shell field, shows a common process of invagination during morphogenesis. Moreover, lines of evidence indicated that shell field invagination is not an independent event, but an integrated output reflecting the overall state of shell field morphogenesis. Nevertheless, the underlying mechanisms of this conserved process remain largely unknown. We previously found that actomyosin networks (regularly organized filamentous actin (F-actin) and myosin) may play essential roles in this process by revealing the evident aggregation of F-actin in the invaginated region and demonstrating that nonmuscle myosin II (NM II) is required for invagination in the gastropod Lottia peitaihoensis (= Lottia goshimai). Here, we investigated the roles of the Rho family of small GTPases (RhoA, Rac1, and Cdc42) to explore the upstream regulators of actomyosin networks. Functional assays using small molecule inhibitors suggested that Cdc42 modulates key events of shell field morphogenesis, including invagination and cell rearrangements, while the roles of RhoA and Rac1 may be nonspecific or negligible. Further investigations revealed that the Cdc42 protein was concentrated on the apical side of shell field cells and colocalized with F-actin aggregation. The aggregation of these two molecules could be prevented by treatment with Cdc42 inhibitors. These findings suggest a possible regulatory cascade of shell field morphogenesis in which Cdc42 recruits F-actin (actomyosin networks) on the apical side of shell field cells, which then generates resultant mechanical forces that mediate correct shell field morphogenesis (cell shape changes, invagination and cell rearrangement). Our results emphasize the roles of the cytoskeleton in early shell development and provide new insights into molluscan shell evolution.
PubMed: 38942110
DOI: 10.1016/j.ydbio.2024.06.012 -
Journal of Cell Science Jun 2024Desmosomes are relatives of ancient cadherin-based junctions, which emerged late in evolution to ensure the structural integrity of vertebrate tissues by coupling the... (Review)
Review
Desmosomes are relatives of ancient cadherin-based junctions, which emerged late in evolution to ensure the structural integrity of vertebrate tissues by coupling the intermediate filament cytoskeleton to cell-cell junctions. Their ability to dynamically counter the contractile forces generated by actin-associated adherens junctions is particularly important in tissues under high mechanical stress, such as the skin and heart. Much more than the simple cellular 'spot welds' depicted in textbooks, desmosomes are in fact dynamic structures that can sense and respond to changes in their mechanical environment and external stressors like ultraviolet light and pathogens. These environmental signals are transmitted intracellularly via desmosome-dependent mechanochemical pathways that drive the physiological processes of morphogenesis and differentiation. This Cell Science at a Glance article and the accompanying poster review desmosome structure and assembly, highlight recent insights into how desmosomes integrate chemical and mechanical signaling in the epidermis, and discuss desmosomes as targets in human disease.
Topics: Desmosomes; Humans; Animals; Epidermis
PubMed: 38940346
DOI: 10.1242/jcs.261899 -
Journal of Integrative Neuroscience Jun 2024Alcohol abuse, a prevalent global health issue, is associated with the onset of cognitive impairment and neurodegeneration. Actin filaments (F-actin) and microtubules...
BACKGROUND
Alcohol abuse, a prevalent global health issue, is associated with the onset of cognitive impairment and neurodegeneration. Actin filaments (F-actin) and microtubules (MTs) polymerized from monomeric globular actin (G-actin) and tubulin form the structural basis of the neuronal cytoskeleton. Precise regulation of the assembly and disassembly of these cytoskeletal proteins, and their dynamic balance, play a pivotal role in regulating neuronal morphology and function. Nevertheless, the effect of prolonged alcohol exposure on cytoskeleton dynamics is not fully understood. This study investigates the chronic effects of alcohol on cognitive ability, neuronal morphology and cytoskeleton dynamics in the mouse hippocampus.
METHODS
Mice were provided access to 5% (v/v) alcohol in drinking water and were intragastrically administered 30% (v/v, 6.0 g/kg/day) alcohol for six weeks during adulthood. Cognitive functions were then evaluated using the Y maze, novel object recognition and Morris water maze tests. Hippocampal histomorphology was assessed through hematoxylin-eosin (HE) and Nissl staining. The polymerized and depolymerized states of actin cytoskeleton and microtubules were separated using two commercial assay kits and quantified by Western blot analysis.
RESULTS
Mice chronically exposed to alcohol exhibited significant deficits in spatial and recognition memory as evidenced by behavioral tests. Histological analysis revealed notable hippocampal damage and neuronal loss. Decreased ratios of F-actin/G-actin and MT/tubulin, along with reduced levels of polymerized F-actin and MTs, were found in the hippocampus of alcohol-treated mice.
CONCLUSIONS
Our findings suggest that chronic alcohol consumption disrupted the assembly of the actin cytoskeleton and MTs in the hippocampus, potentially contributing to the cognitive deficits and pathological injury induced by chronic alcohol intoxication.
Topics: Animals; Hippocampus; Microtubules; Actin Cytoskeleton; Male; Ethanol; Mice; Mice, Inbred C57BL; Central Nervous System Depressants; Disease Models, Animal; Behavior, Animal
PubMed: 38940085
DOI: 10.31083/j.jin2306118 -
Nature Communications Jun 2024Flowering plants rely on the polarized growth of pollen tubes to deliver sperm cells (SCs) to the embryo sac for double fertilization. In pollen, the vegetative nucleus...
Flowering plants rely on the polarized growth of pollen tubes to deliver sperm cells (SCs) to the embryo sac for double fertilization. In pollen, the vegetative nucleus (VN) and two SCs form the male germ unit (MGU). However, the mechanism underlying directional transportation of MGU is not well understood. In this study, we provide the first full picture of the dynamic interplay among microtubules, actin filaments, and MGU during pollen germination and tube growth. Depolymerization of microtubules and inhibition of kinesin activity result in an increased velocity and magnified amplitude of VN's forward and backward movement. Pharmacological washout experiments further suggest that microtubules participate in coordinating the directional movement of MGU. In contrast, suppression of the actomyosin system leads to a reduced velocity of VN mobility but without a moving pattern change. Moreover, detailed observation shows that the direction and velocity of VN's movement are in close correlations with those of the actomyosin-driven cytoplasmic streaming surrounding VN. Therefore, we propose that while actomyosin-based cytoplasmic streaming influences on the oscillational movement of MGU, microtubules and kinesins avoid MGU drifting with the cytoplasmic streaming and act as the major regulator for fine-tuning the proper positioning and directional migration of MGU in pollen.
Topics: Microtubules; Actin Cytoskeleton; Kinesins; Pollen; Actomyosin; Pollen Tube; Cell Nucleus; Arabidopsis; Cytoplasmic Streaming; Germination
PubMed: 38937444
DOI: 10.1038/s41467-024-49323-9 -
Cell Death & Disease Jun 2024In eukaryotes, the nucleolus is the critical non-membranous organelle within nuclei that is responsible for ribosomal DNA (rDNA) transcription and ribosome biogenesis....
In eukaryotes, the nucleolus is the critical non-membranous organelle within nuclei that is responsible for ribosomal DNA (rDNA) transcription and ribosome biogenesis. The transcription of rDNA, a rate-limiting step for ribosome biogenesis, is tightly regulated to meet the demand for global protein synthesis in response to cell physiology, especially in neurons, which undergo rapid changes in morphology and protein composition during development and synaptic plasticity. However, it is unknown how the pre-initiation complex for rDNA transcription is efficiently assembled within the nucleolus in neurons. Here, we report that the nucleolar protein, coronin 2B, regulates rDNA transcription and maintains nucleolar function through direct interaction with upstream binding factor (UBF), an activator of RNA polymerase I transcriptional machinery. We show that coronin 2B knockdown impairs the formation of the transcription initiation complex, inhibits rDNA transcription, destroys nucleolar integrity, and ultimately induces nucleolar stress. In turn, coronin 2B-mediated nucleolar stress leads to p53 stabilization and activation, eventually resulting in neuronal apoptosis. Thus, we identified that coronin 2B coordinates with UBF to regulate rDNA transcription and maintain proper nucleolar function in neurons.
Topics: Apoptosis; Cell Nucleolus; Neurons; Animals; Pol1 Transcription Initiation Complex Proteins; Humans; DNA, Ribosomal; Microfilament Proteins; Transcription, Genetic; Tumor Suppressor Protein p53; Mice; Stress, Physiological
PubMed: 38937439
DOI: 10.1038/s41419-024-06852-x -
In Vivo (Athens, Greece) 2024Cold physical plasma (CPP) has emerged as an effective therapy in oncology by inducing cytotoxic effects in various cancer cells, including chondrosarcoma (CS), Ewing's...
BACKGROUND/AIM
Cold physical plasma (CPP) has emerged as an effective therapy in oncology by inducing cytotoxic effects in various cancer cells, including chondrosarcoma (CS), Ewing's sarcoma (ES), and osteosarcoma (OS). The current study investigated the impact of CPP on cell motility in CS (CAL-78), ES (A673), and OS (U2-OS) cell lines, focusing on the actin cytoskeleton.
MATERIALS AND METHODS
The CASY Cell Counter and Analyzer was used to study cell proliferation and determine the optimal concentrations of fetal calf serum to maintain viability without stimulation of cell proliferation. CellTiter-BlueCell viability assay was used to determine the effects of CPP on the viability of bone sarcoma cells. The Radius assay was used to determine cell migration. Staining for Deoxyribonuclease I, G-actin, and F-actin was used to assay for the effects on the cytoskeleton.
RESULTS
Reductions in cell viability and motility were observed across all cell lines following CPP treatment. CPP induced changes in the actin cytoskeleton, leading to decreased cell motility.
CONCLUSION
CPP effectively reduces the motility of bone sarcoma cells by altering the actin cytoskeleton. These findings underscore CPP's potential as a therapeutic tool for bone sarcomas and highlight the need for further research in this area.
Topics: Humans; Cell Movement; Plasma Gases; Cell Line, Tumor; Bone Neoplasms; Cell Survival; Cell Proliferation; Cytoskeleton; Actin Cytoskeleton; Osteosarcoma; Actins; Sarcoma
PubMed: 38936915
DOI: 10.21873/invivo.13607 -
Cellular Signalling Jun 2024Tumor-associated macrophages (TAMs) secrete cytokines, chemokines, and growth factors in the tumor microenvironment (TME) to support cancer progression. Higher TAM...
Tumor-associated macrophages (TAMs) secrete cytokines, chemokines, and growth factors in the tumor microenvironment (TME) to support cancer progression. Higher TAM infiltration in the breast TME is associated with a poor prognosis. Previous studies have demonstrated the role of macrophages in stimulating long-range intercellular bridges referred to as tunneling nanotubes (TNTs) in cancer cells. Intercellular communication between cancer cells via TNTs promotes cancer growth, invasion, metastasis, and therapy resistance. Given the important role of TNTs and macrophages in cancer, the role of macrophage-induced TNTs in chemotherapy drug doxorubicin resistance is not known. Furthermore, the mechanism of macrophage-mediated TNT formation is elusive. In this study, it is shown that the macrophage-conditioned medium (MΦCM) partially mimicked inflammatory TME, induced an EMT phenotype, and increased migration in MCF-7 breast cancer cells. Additionally, secreted proteins in MΦCM induced TNT formation in MCF-7 cells, which led to increased resistance to doxorubicin. Transcriptomic analysis of MΦCM-treated MCF-7 cells showed enrichment of the NF-κB and focal adhesion pathways, as well as upregulation of genes involved in EMT, extracellular remodeling, and actin cytoskeleton reorganization. Interestingly, inhibitors of PKC, Src, NF-κB, and p38 decreased macrophage-induced TNT formation in MCF-7 cells. These results reveal the novel role of PKC and Src in inducing TNT formation in cancer cells and suggest that inhibition of PKC and Src activity may likely contribute to reduced macrophage-breast cancer cell interaction and the potential therapeutic strategy of cancer.
PubMed: 38936787
DOI: 10.1016/j.cellsig.2024.111274 -
PloS One 2024Colorectal cancer (CRC) is the third most common malignancy cause of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) promotes cancer...
Colorectal cancer (CRC) is the third most common malignancy cause of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) promotes cancer metastasis and a tumour-based Glasgow EMT score was associated with adverse clinical features and poor prognosis. In this study, the impact of using the established five tumour-based EMT markers consisting of E-cadherin (E-cad), β-catenin (β-cat), Snail, Zeb-1, and Fascin in combination with the stromal periostin (PN) on the prediction of CRC patients' prognosis were invesigated. Formalin-fixed paraffin-embedded tissues of 202 CRC patients were studies the expressions of E-cad, β-cat, Snail, Zeb-1, Fascin, and PN by immunohistochemistry. Individually, cytoplasmic Fascin (Fc), cytoplasmic Snail (Sc), nuclear Snail (Sn), stromal Snail (Ss), and stromal PN (Ps) were significantly associated with reduced survival. A combination of Ps with Fc, Fs, and Sn was observed in 2 patterns including combined Fc, Fs, and Ps (FcFsPs) and Fc, Sn, and Ps (FcSnPs). These combinations enhanced the prognostic power compared to individual EMT markers and were independent prognostic markers. As the previously established scoring method required five markers and stringent criteria, its clinical use might be limited. Therefore, using these novel combined prognostic markers, either FcFsPs or FcSnPs, may be useful in predicting CRC patient outcomes.
Topics: Humans; Colorectal Neoplasms; Snail Family Transcription Factors; Cell Adhesion Molecules; Prognosis; Female; Male; Middle Aged; Carrier Proteins; Microfilament Proteins; Epithelial-Mesenchymal Transition; Aged; Biomarkers, Tumor; Adult; Cadherins; Transcription Factors; beta Catenin; Aged, 80 and over; Periostin
PubMed: 38935747
DOI: 10.1371/journal.pone.0304666