Self-Organization of Motor-Propelled Cytoskeletal Filaments at Topographically Defined Borders

Self-organization phenomena are of critical importance in living organisms and of great interest to exploit in nanotechnology. Here we describe in vitro self-organization of molecular motor-propelled actin filaments, manifested as a tendency of the filaments to accumulate in high density close to topographically defined edges on nano- and microstructured surfaces. We hypothesized that this “edge-tracing” effect either (1) results from increased motor density along the guiding edges or (2) is a direct consequence of the asymmetric constraints on stochastic changes in filament sliding direction imposed by the edges. The latter hypothesis is well captured by a model explicitly defining the constraints of motility on structured surfaces in combination with Monte-Carlo simulations [cf. Nitta et al. (2006)] of filament sliding. In support of hypothesis 2 we found that the model reproduced the edge tracing effect without the need to assume increased motor density at the edges. We then used model simulations to elucidate mechanistic details. The results are discussed in relation to nanotechnological applications and future experiments to test model predictions.

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Molecular to organismal chirality is induced by the conserved myosin 1D

Science ◽

10.1126/science.aat8642 ◽

2018 ◽

Vol 362 (6417) ◽

pp. 949-952 ◽

Cited By ~ 34

Author(s):

G. Lebreton ◽

C. Géminard ◽

F. Lapraz ◽

S. Pyrpassopoulos ◽

D. Cerezo ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Actin Filaments ◽

De Novo ◽

Molecular Motor ◽

Break Symmetry ◽

Motor Domain ◽

Whole Body ◽

Living Organisms ◽

Chiral Interaction

The emergence of asymmetry from an initially symmetrical state is a universal transition in nature. Living organisms show asymmetries at the molecular, cellular, tissular, and organismal level. However, whether and how multilevel asymmetries are related remains unclear. In this study, we show that Drosophila myosin 1D (Myo1D) and myosin 1C (Myo1C) are sufficient to generate de novo directional twisting of cells, single organs, or the whole body in opposite directions. Directionality lies in the myosins’ motor domain and is swappable between Myo1D and Myo1C. In addition, Myo1D drives gliding of actin filaments in circular, counterclockwise paths in vitro. Altogether, our results reveal the molecular motor Myo1D as a chiral determinant that is sufficient to break symmetry at all biological scales through chiral interaction with the actin cytoskeleton.

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Current Challenges in the Development of Vaccines and Drugs Against Emerging Vector-borne Diseases

Current Medicinal Chemistry ◽

10.2174/0929867325666181105121146 ◽

2019 ◽

Vol 26 (16) ◽

pp. 2974-2986 ◽

Cited By ~ 4

Author(s):

Kwang-sun Kim

Keyword(s):

New Host ◽

In Vivo Models ◽

Vector Borne Diseases ◽

Novel Drugs ◽

Huge Impact ◽

Tick Borne Disease ◽

Vector Borne ◽

Living Organisms

Vectors are living organisms that transmit infectious diseases from an infected animal to humans or another animal. Biological vectors such as mosquitoes, ticks, and sand flies carry pathogens that multiply within their bodies prior to delivery to a new host. The increased prevalence of Vector-Borne Diseases (VBDs) such as Aedes-borne dengue, Chikungunya (CHIKV), Zika (ZIKV), malaria, Tick-Borne Disease (TBD), and scrub typhus has a huge impact on the health of both humans and livestock worldwide. In particular, zoonotic diseases transmitted by mosquitoes and ticks place a considerable burden on public health. Vaccines, drugs, and vector control methods have been developed to prevent and treat VBDs and have prevented millions of deaths. However, development of such strategies is falling behind the rapid emergence of VBDs. Therefore, a comprehensive approach to fighting VBDs must be considered immediately. In this review, I focus on the challenges posed by emerging outbreaks of VBDs and discuss available drugs and vaccines designed to overcome this burden. Research into promising drugs needs to be upgraded and fast-tracked, and novel drugs or vaccines being tested in in vitro and in vivo models need to be moved into human clinical trials. Active preventive tactics, as well as new and upgraded diagnostics, surveillance, treatments, and vaccination strategies, need to be monitored constantly if we are to manage VBDs of medical importance.

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Self-replication of a quantum artificial organism driven by single-photon pulses

Scientific Reports ◽

10.1038/s41598-021-96048-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Daniel Valente

Keyword(s):

Self Assembly ◽

Artificial Life ◽

Single Photon ◽

Self Organization ◽

Physical Systems ◽

Self Organized ◽

Living Organisms ◽

A Chain ◽

Thermodynamic Mechanism ◽

Self Replication

AbstractImitating the transition from inanimate to living matter is a longstanding challenge. Artificial life has achieved computer programs that self-replicate, mutate, compete and evolve, but lacks self-organized hardwares akin to the self-assembly of the first living cells. Nonequilibrium thermodynamics has achieved lifelike self-organization in diverse physical systems, but has not yet met the open-ended evolution of living organisms. Here, I look for the emergence of an artificial-life code in a nonequilibrium physical system undergoing self-organization. I devise a toy model where the onset of self-replication of a quantum artificial organism (a chain of lambda systems) is owing to single-photon pulses added to a zero-temperature environment. I find that spontaneous mutations during self-replication are unavoidable in this model, due to rare but finite absorption of off-resonant photons. I also show that the replication probability is proportional to the absorbed work from the photon, thereby fulfilling a dissipative adaptation (a thermodynamic mechanism underlying lifelike self-organization). These results hint at self-replication as the scenario where dissipative adaptation (pointing towards convergence) coexists with open-ended evolution (pointing towards divergence).

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Functionalized Nanoplastics (NPs) Increase the Toxicity of Metals in Fish Cell Lines

International Journal of Molecular Sciences ◽

10.3390/ijms22137141 ◽

2021 ◽

Vol 22 (13) ◽

pp. 7141

Author(s):

Carmen González-Fernández ◽

Francisco Guillermo Díaz Baños ◽

María Ángeles Esteban ◽

Alberto Cuesta

Keyword(s):

Sparus Aurata ◽

Gilthead Seabream ◽

Fish Cell ◽

Test Model ◽

Fish Cell Lines ◽

Polystyrene Nanoparticles ◽

Commercial Fish ◽

Cellular Protection ◽

Marine Life

Nanoplastics (NPs) are one of the most abundant environment-threatening nanomaterials on the market. The objective of this study was to determine in vitro if functionalized NPs are cytotoxic by themselves or increase the toxicity of metals. For that, we used 50 nm polystyrene nanoparticles with distinct surface functionalization (pristine, PS-Plain; carboxylic, PS-COOH; and amino PS-NH2) alone or combined with the metals arsenic (As) and methylmercury (MeHg), which possess an environmental risk to marine life. As test model, we chose a brain-derived cell line (SaB-1) from gilthead seabream (Sparus aurata), one of the most commercial fish species in the Mediterranean. First, only the PS-NH2 NPs were toxic to SaB-1 cells. NPs seem to be internalized into the cells but they showed little alteration in the transcription of genes related to oxidative stress (nrf2, cat, gr, gsta), cellular protection against metals (mta) or apoptosis (bcl2, bax). However, NPs, mainly PS-COOH and PS-NH2, significantly increased the toxicity of both metals. Since the coexistence of NPs and other pollutants in the aquatic environment is inevitable, our results reveal that the combined effect of NPs with the rest of pollutants deserves more attention.

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2P195 Observation of the tug of war movement of microtubules by kinesin and dynein molecules in vitro(37. Molecular motor (II),Poster Session,Abstract,Meeting Program of EABS & BSJ 2006)

Seibutsu Butsuri ◽

10.2142/biophys.46.s344_3 ◽

2006 ◽

Vol 46 (supplement2) ◽

pp. S344

Author(s):

Hideyo Tsurusawa ◽

Hisashi Tadakuma ◽

Tomohiro Shima ◽

Reiko Ohkura ◽

Takahide Kon ◽

...

Keyword(s):

Poster Session ◽

Molecular Motor ◽

Meeting Program

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The Promise of Patient-Derived Colon Organoids to Model Ulcerative Colitis

Inflammatory Bowel Diseases ◽

10.1093/ibd/izab161 ◽

2021 ◽

Author(s):

Babajide A Ojo ◽

Kelli L VanDussen ◽

Michael J Rosen

Keyword(s):

Ulcerative Colitis ◽

Self Organization ◽

Great Promise ◽

Preclinical Model ◽

Intestinal Epithelial ◽

Epigenetic Changes ◽

Nutrient Delivery ◽

3 Dimensional ◽

Tissue Systems

Abstract Physiologic, molecular, and genetic findings all point to impaired intestinal epithelial function as a key element in the multifactorial pathogenesis of ulcerative colitis (UC). The lack of epithelial-directed therapies is a conspicuous weakness of our UC therapeutic armamentarium. However, a critical barrier to new drug discovery is the lack of preclinical human models of UC. Patient tissue–derived colon epithelial organoids (colonoids) are primary epithelial stem cell–derived in vitro structures capable of self-organization and self-renewal that hold great promise as a human preclinical model for UC drug development. Several single and multi-tissue systems for colonoid culture have been developed, including 3-dimensional colonoids grown in a gelatinous extracellular matrix, 2-dimensional polarized monolayers, and colonoids on a chip that model luminal and blood flow and nutrient delivery. A small number of pioneering studies suggest that colonoids derived from UC patients retain some disease-related transcriptional and epigenetic changes, but they also raise questions regarding the persistence of inflammatory transcriptional programs in culture over time. Additional research is needed to fully characterize the extent to which and under what conditions colonoids accurately model disease-associated epithelial molecular and functional aberrations. With further advancement and standardization of colonoid culture methodology, colonoids will likely become an important tool for realizing precision medicine in UC.

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Daily Indexes for Predation and Growth of Nematophagous Mushrooms Species of Hohenbuehelia (Pleurotaceae) on Panagrellus redividus

Journal of Agricultural Science ◽

10.5539/jas.v10n3p276 ◽

2018 ◽

Vol 10 (3) ◽

pp. 276

Author(s):

Cleonice Lubian ◽

Danielle Dutra Martinha ◽

Roberto Luis Portz ◽

Alexandre Gonçalves dos Santos e Silva Filho ◽

Vagner Gularte Cortez ◽

...

Keyword(s):

Biological Control ◽

Growth Speed ◽

Test Evaluation ◽

Biological Control Agents ◽

Panagrellus Redivivus ◽

Mycelia Growth ◽

Living Organisms

Biological control is a method of controlling pests through the use of other living organisms. The purposes of this study were to test Hohenbuehelia species as biological control agents against Panagrellus redivivus in vitro, evaluating nematodes influence on mycelia growth; establishing daily indexes for predation and growth and setting predation percentage. Five species previously identified as 436-Hohenbuehelia mastrucata (Nematoctonus hamatus), 528-H. bullulifera (not described so far), 581-H. paraguayensis (N. sp.), 582-H. sp. (N. sp.) and 631-H. portegna (N. campylosporus) were submitted to anamorphic purification directly from basidioma. Afterwards, 100 nematodes were added to each pure colony for predation test. Evaluation started right after 24 hours of nematode-fungus interaction. Immobilized and/or penetrated nematodes were counted and mycelia growth was measured. Results were subjected to variance analyses. Hohenbuehelia mastrucata had the best performance in growth speed, followed by H. portegna and H. paraguayensis; Nematodes multiplyied much but none specie grew more as an influence of their movement under mycelium, however all species formed trap devices and some of them produced adhesive or repelent substances. Trap devices were formed in control plates also. The plates of H. paraguayensis without nematodes grew more than treatments. Cumulative predation of H. portegna was the highest at 24 (195.5%) and 48 hours (235%). At the last evaluation day, H. paraguayensis preyed the same amount (185.75%) than H. portegna, followed by H. mastrucata (109.51%). Resulst of predation daily indexes displayed chronological activity for each isolate, where H. portegna was very reactive at first 24 hours, H. mastrucata raised its predacious activity in 48 hours being constant from this time on and H. paraguayensis pointed out itself at 72 hours. Other species presented low predation and growth indexes throughout experiment.

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Geometric Effect for Biological Reactors and Biological Fluids

Bioengineering ◽

10.3390/bioengineering5040110 ◽

2018 ◽

Vol 5 (4) ◽

pp. 110 ◽

Cited By ~ 2

Author(s):

Kazusa Beppu ◽

Ziane Izri ◽

Yusuke Maeda ◽

Ryota Sakamoto

Keyword(s):

Biological Fluids ◽

Biological Systems ◽

Self Organization ◽

Active Matter ◽

Confined Space ◽

Self Organized ◽

Motile Cells ◽

Recent Developments ◽

A Cell

As expressed “God made the bulk; the surface was invented by the devil” by W. Pauli, the surface has remarkable properties because broken symmetry in surface alters the material properties. In biological systems, the smallest functional and structural unit, which has a functional bulk space enclosed by a thin interface, is a cell. Cells contain inner cytosolic soup in which genetic information stored in DNA can be expressed through transcription (TX) and translation (TL). The exploration of cell-sized confinement has been recently investigated by using micron-scale droplets and microfluidic devices. In the first part of this review article, we describe recent developments of cell-free bioreactors where bacterial TX-TL machinery and DNA are encapsulated in these cell-sized compartments. Since synthetic biology and microfluidics meet toward the bottom-up assembly of cell-free bioreactors, the interplay between cellular geometry and TX-TL advances better control of biological structure and dynamics in vitro system. Furthermore, biological systems that show self-organization in confined space are not limited to a single cell, but are also involved in the collective behavior of motile cells, named active matter. In the second part, we describe recent studies where collectively ordered patterns of active matter, from bacterial suspensions to active cytoskeleton, are self-organized. Since geometry and topology are vital concepts to understand the ordered phase of active matter, a microfluidic device with designed compartments allows one to explore geometric principles behind self-organization across the molecular scale to cellular scale. Finally, we discuss the future perspectives of a microfluidic approach to explore the further understanding of biological systems from geometric and topological aspects.

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A novel mechanism for BCR-ABL action: stimulated secretion of CCN3 is involved in growth and differentiation regulation

Blood ◽

10.1182/blood-2006-04-016113 ◽

2006 ◽

Vol 108 (5) ◽

pp. 1716-1723 ◽

Cited By ~ 45

Author(s):

Lynn McCallum ◽

Susan Price ◽

Nathalie Planque ◽

Bernard Perbal ◽

Andrew Pierce ◽

...

Keyword(s):

Tyrosine Kinase ◽

Protein Tyrosine Kinase ◽

Direct Consequence ◽

Suppressor Gene ◽

Hematopoietic Stem ◽

Protein Levels ◽

Abl Kinase ◽

Abl Tyrosine Kinase ◽

Ccn3 Expression

Chronic myeloid leukemia (CML) is characterized by the presence of the constitutively active BCR-ABL protein tyrosine kinase. Using a multipotent hemopoietic cell line, FDCP-Mix, expressing BCR-ABL tyrosine kinase, we investigated the initial effects of this kinase in primitive hematopoietic stem cells. We identified down-regulation of a novel gene, CCN3, as a direct consequence of BCR-ABL kinase activity. CCN3 has been reported to function as a tumor suppressor gene in solid tumors. Northern and Western blotting plus immunocytochemical analysis confirmed CCN3 expression is decreased and is tyrosine-phosphorylated in BCR-ABL kinase active FDCP-Mix cells. Decreased cellular CCN3 correlated with increased CCN3 secretion in BCR-ABL kinase active cells. In vitro treatment of human CML cell lines with imatinib or siRNA directed against BCR-ABL significantly reduced BCR-ABL while increasing CCN3 expression. Cells from patients responding to imatinib showed a similar decrease in BCR-ABL and increase in CCN3. CML CD34+ cells treated with imatinib in vitro demonstrated increased CCN3 protein. Transfecting CCN3 into BCR-ABL+ cells inhibited proliferation and decreased clonogenic potential. CCN3 plays an important role in internal and external cell-signaling pathways. Thus, BCR-ABL can regulate protein levels by governing secretion, a novel mechanism for this tyrosine kinase.

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