Inhibition of YAP/TAZ pathway contributes to the cytotoxicity of silibinin in MCF-7 and MDA-MB-231 human breast cancer cells

Breast cancer is one of the most common cancers threatening women's health. Our previous study found that silibinin induced the death of MCF-7 and MDA-MB-231 human breast cancer cells. We noticed that silibinin-induced cell damage was accompanied by morphological changes, including the increased cell aspect ratio (cell length/width) and decreased cell area. Besides, the cytoskeleton is also destroyed in cells treated with silibinin. YAP/TAZ, a mechanical signal sensor interacted with extracellular pressure, cell adhesion area and cytoskeleton, is also closely associated with cell survival, proliferation and migration. Thus, the involvement of YAP/TAZ in the cytotoxicity of silibinin in breast cancer cells has attracted our interests. Excitingly, we find that silibinin inhibits the nuclear translocation of YAP/TAZ in MCF-7 and MDA-MB-231 cells, and reduces the mRNA expressions of YAP/TAZ target genes, ACVR1, MnSOD and ANKRD. More importantly, expression of YAP1 gene is negatively correlated with the survival of the patients with breast cancers. Molecular docking analysis reveals high probabilities for binding of silibinin to the proteins in the YAP pathways. DARTS and CETSA results confirm the binding abilities of silibinin to YAP and LATS. Inhibiting YAP pathway either by addition of verteporfin, an inhibitor of YAP/TAZ-TEAD, or by transfection of si-RNAs targeting YAP or TAZ further enhances silibinin-induced cell damage. While enhancing YAP activity by silencing LATS1/2 or overexpressing YAPS127/397A, an active form of YAP, attenuates silibinin-induced cell damage. These findings demonstrate that inhibition of the YAP/TAZ pathway contributes to cytotoxicity of silibinin in breast cancers, shedding lights on YAP/TAZ-targeted cancer therapies.

Machine learning-based morphological quantification of replicative senescence in human fibroblasts

Although aging has been investigated extensively at the organismal and cellular level, the morphological changes that individual cells undergo along their replicative lifespan have not been precisely quantified. Here, we present the results of a readily accessible machine learning-based pipeline that uses standard fluorescence microscope and open access software to quantify the minute morphological changes that human fibroblasts undergo during their replicative lifespan in culture. Applying this pipeline in a widely used fibroblast cell line (IMR-90), we find that advanced replicative age robustly increases (+28-79%) cell surface area, perimeter, number and total length of pseudopodia, and nuclear surface area, while decreasing cell circularity, with phenotypic changes largely occurring as replicative senescence is reached. These senescence-related morphological changes are recapitulated, albeit to a variable extent, in primary dermal fibroblasts derived from human donors of different ancestry, age, and sex groups. By performing integrative analysis of single-cell morphology, our pipeline further classifies senescent-like cells and quantifies how their numbers increase with replicative senescence in IMR-90 cells and in dermal fibroblasts across all tested donors. These findings provide quantitative insights into replicative senescence, while demonstrating applicability of a readily accessible computational pipeline for high-throughput cell phenotyping in aging research.

Cell morphology engineering enhances grazing resistance of Synechococcus elongatus PCC 7942 for non-sterile large-scale cultivation

In the practical scale of cyanobacterial cultivation, the golden algae Poterioochromonas malhamensis is a well-known predator that causes devastating damage to the culture, referred to as pond crash. The establishment and maintenance of monoculture conditions are ideal for large-scale cultures. However, this is a difficult challenge because microbial contamination is unavoidable in practical-scale culture facilities. In the present study, we unexpectedly observed the pond crash phenomenon during the pilot-scale cultivation of Synechococcus elongatus PCC 7942 using a 100-L photobioreactor. This was due to the contamination with P. malhamensis, which probably originated from residual fouling. Interestingly, we found that S.elongatus PCC 7942 can alter its morphological structure when subjected to continuous grazing pressure from predators, resulting in cells that were more than 100 times longer than those of the wild-type strain. These hyper-elongated S.elongatus PCC 7942 cells had mutations in the genes encoding FtsZ or Ftn2 which are involved in bacterial cell division. Importantly, the elongated phenotype remained stable during cultivation, enabling S.elongatus PCC 7942 to thrive and resist grazing. The cultivation of the elongated S.elongatus PCC 7942 mutant strain in a 100-L pilot-scale photobioreactor under non-sterile conditions resulted in increased cyanobacterial biomass without encountering pond crash. This study demonstrates an efficient strategy for cyanobacterial cell culture in practical-scale bioreactors without the need for extensive decontamination or sterilization of the growth medium and culture facility, which can contribute to economically viable cultivation and bioprocessing of microalgae.

Comparison of pulsed and continuous electromagnetic field generated by WPT system on human dermal and neural cells

In recent decades, we have seen significant technical progress in the modern world, leading to the widespread use of telecommunications systems, electrical appliances, and wireless technologies. These devices generate electromagnetic radiation (EMR) and electromagnetic fields (EMF) most often in the extremely low frequency or radio-frequency range. Therefore, they were included in the group of environmental risk factors that affect the human body and health on a daily basis. In this study, we tested the effect of exposure EMF generated by a new prototype wireless charging system on four human cell lines (normal cell lines-HDFa, NHA; tumor cell lines-SH-SY5Y, T98G). We tested different operating parameters of the wireless power transfer (WPT) device (87-207 kHz, 1.01-1.05 kW, 1.3-1.7 mT) at different exposure times (pulsed 6 × 10 min; continuous 1 × 60 min). We observed the effect of EMF on cell morphology and cytoskeletal changes, cell viability and mitotic activity, cytotoxicity, genotoxicity, and oxidative stress. The results of our study did not show any negative effect of the generated EMF on either normal cells or tumor cell lines. However, in order to be able to estimate the risk, further population and epidemiological studies are needed, which would reveal the clinical consequences of EMF impact.

The role of oxygen tension in cell fate and regenerative medicine: implications of hypoxia/hyperoxia and free radicals

Oxygen pressure plays an integral role in regulating various aspects of cellular biology. Cell metabolism, proliferation, morphology, senescence, metastasis, and angiogenesis are some instances that are affected by different tensions of oxygen. Hyperoxia or high oxygen concentration, enforces the production of reactive oxygen species (ROS) that disturbs physiological homeostasis, and consequently, in the absence of antioxidants, cells and tissues are directed to an undesired fate. On the other side, hypoxia or low oxygen concentration, impacts cell metabolism and fate strongly through inducing changes in the expression level of specific genes. Thus, understanding the precise mechanism and the extent of the implication of oxygen tension and ROS in biological events is crucial to maintaining the desired cell and tissue function for application in regenerative medicine strategies. Herein, a comprehensive literature review has been performed to find out the impacts of oxygen tensions on the various behaviors of cells or tissues.

HIV-1 Mediated Cortical Actin Disruption Mirrors ARP2/3 Defects Found in Primary T Cell Immunodeficiencies

During cell movement, cortical actin balances mechanical and osmotic forces to maintain cell function while providing the scaffold for cell shape. Migrating CD4+ T cells have a polarized structure with a leading edge containing dynamic branched and linear F-actin structures that bridge intracellular components to surface adhesion molecules. These actin structures are complemented with a microtubular network beaded with membrane bound organelles in the trailing uropod. Disruption of actin structures leads to dysregulated migration and changes in morphology of affected cells. In HIV-1 infection, CD4+ T cells have dysregulated movement. However, the precise mechanisms by which HIV-1 affects CD4+ T cell movement are unknown. Here, we show that HIV-1 infection of primary CD4+ T cells causes at least four progressive morphological differences as a result of virally induced cortical cytoskeleton disruption, shown by ultrastructural and time lapse imaging. Infection with a ΔNef virus partially abrogated the dysfunctional phenotype in infected cells and partially restored a wild-type shape. The pathological morphologies after HIV-1 infection phenocopy leukocytes which contain genetic determinants of specific T cell Inborn Errors of Immunity (IEI) or Primary Immunodeficiencies (PID) that affect the actin cytoskeleton. To identify potential actin regulatory pathways that may be linked to the morphological deformities, uninfected CD4+ T cell morphology was characterized following addition of small molecule chemical inhibitors. The ARP2/3 inhibitor CK-666 recapitulated three of the four abnormal morphologies we observed in HIV-1 infected cells. Restoring ARP2/3 function and cortical actin integrity in people living with HIV-1 infection is a new avenue of investigation to eradicate HIV-1 infected cells from the body.

Efficient Production of Melanin by Aureobasidium Melanogenum Using a Simplified Medium and pH-Controlled Fermentation Strategy with the Cell Morphology Analysis

Natural melanin is a biopolymer with wide application prospects in medicine, food, cosmetics, environmental protection, agriculture, and so on. Microbial fermentation is an important and effective way to produce melanin. In this study, Aureobasidium melanogenum, known as black yeast with cellular pleomorphism, was used for the production of melanin. Based on the characteristic of A. melanogenum secreting melanin under oligotrophic stress, a simple medium containing only glucose, MgSO4·7H2O, and KCl was constructed for the production of melanin. The melanin titer of 6.64 ± 0.22 g/L was obtained after 20 days of fermentation without pH control. The cell morphological changes of A. melanogenum during the production of melanin were recorded, and the results showed that chlamydospore might be the most favorable cell morphology for melanin synthesis. Then, different fermentation strategies with cell morphology analysis were developed to further improve the production of melanin in a 5-L fermenter. Results showed that the maximum titer of melanin reached 18.50 g/L by using the fermentation strategy integrating pH control, ammonium salt addition, and H2O2 stimulation, which increased by 178.6% than that of the strategy without pH control. Furthermore, the melanin obtained from the fermentation broth was characterized as eumelanin containing an indole structure. This study provided a potentially feasible fermentation strategy for the industrial production of melanin.

Improving biomass yields of microalgae biofilm by coculturing two microalgae species via forming biofilms with uniform microstructures and small cell-clusters

Microalgae coculture has the potential to promote microalgae biofilm growth. Herein, three two-species cocultured biofilms were studied by determining biomass yields and detailed microstructure parameters, including porosity, average pore length, average cluster length, etc. It was found that biomass yields could reduce by 21-53 % when biofilm porosities decreased from about 35 % to 20 %; while at similar porosities (∼20 %), biomass yields of cocultured biofilms increased by 37 % when they possessed uniform microstructure and small cell-clusters (pores and clusters of 1 ∼ 10 μm accounted for 96 % and 68 %, respectively). By analyzing morphologies and surface properties of cells, it was found that cells with small size, spherical shape, and reduced surface polymers could hinder the cell-clusters formation, thereby promoting biomass yields. The study provides new insights into choosing cocultured microalgae species for improving the biomass yield of biofilm via manipulating biofilm microstructures.

RhoU forms homo-oligomers to regulate cellular responses

RhoU is an atypical member of the Rho family of small G-proteins, which has N- and C-terminal extensions compared to the classic Rho GTPases RhoA, Rac1 and Cdc42, and associates with membranes through C-terminal palmitoylation rather than prenylation. RhoU mRNA expression is upregulated in prostate cancer and is considered a marker for disease progression. Here, we show that RhoU overexpression in prostate cancer cells increases cell migration and invasion. To identify RhoU targets that contribute to its function, we found that RhoU homodimerizes in cells. We map the region involved in this interaction to the C-terminal extension and show that C-terminal palmitoylation is required for self-association. Expression of the isolated C-terminal extension reduces RhoU-induced activation of p21-activated kinases (PAKs), which are known downstream targets for RhoU, and induces cell morphological changes consistent with inhibiting RhoU function. Our results show for the first time that the activity of a Rho family member is stimulated by self-association, and this is important for its activity.

ShapeMetrics: A 3D Cell Segmentation Pipeline for Single-Cell Spatial Morphometric Analysis

There is a growing need for single-cell level data analysis in correlation with the advancements of microscopy techniques. Morphology-based statistics gathered from individual cells are essential for detection and quantification of even subtle changes within the complex tissues, yet the information available from high-resolution imaging is oftentimes sub-optimally utilized due to the lack of proper computational analysis software. Here we present ShapeMetrics, a 3D cell segmentation pipeline that we have developed to identify, analyze, and quantify single cells in an image. This MATLAB-based script enables users to extract morphological parameters, such as ellipticity, longest axis, cell elongation, or the ratio between cell volume and surface area. We have specifically invested in creating a user-friendly pipeline, aimed for biologists with a limited computational background. Our pipeline is presented with detailed stepwise instructions, starting from the establishment of machine learning-based prediction files of immuno-labeled cell membranes followed by the application of 3D cell segmentation and parameter extraction script, leading to the morphometric analysis and spatial visualization of cell clusters defined by their morphometric features.

Dataset of chicken-embryo blood cells exposed to quercetin, methyl methanesulfonate, or cadmium chloride

Toxicological analysis of the effects of natural compounds is frequently mandated to assess their safety. In addition to more simple in vitro cellular systems, more complex biological systems can be used to evaluate toxicity. This dataset is comprised of bright-field microscopy images of chicken-embryo blood cells, a complex biological model that recapitulates several features found in human organisms, including circulation in blood stream and biodistribution to different organs. In the presented collection of blood smear images, cells were exposed to the flavonoid quercetin, and the two mutagens methyl methanesulfonate (MMS) and cadmium chloride (CdCl2). In ovo models offer a unique opportunity to investigate the effects of various substances, pathogens, or cancer treatments on developing embryos, providing valuable insights into potential risks and therapeutic strategies. In toxicology, in ovo models allow for early detection of harmful compounds and their impact on embryonic development, aiding in the assessment of environmental hazards. In immunology, these models offer a controlled system to explore the developing immune responses and the interaction between pathogens and host defenses. Additionally, in ovo models are instrumental in oncology research as they enable the study of tumor development and response to therapies in a dynamic, rapidly developing environment. Thus, these versatile models play a crucial role in advancing our understanding of complex biological processes and guiding the development of safer therapeutics and interventions. The data presented here can aid in understanding the potential toxic effects of these substances on hematopoiesis and the overall health of the developing organism. Moreover, the large dataset of blood smear images can serve as a resource for training machine learning algorithms to automatically detect and classify blood cells, provided that specific optimized conditions such as image magnification and background light are maintained for comparison. This can lead to the development of automated tools for blood cell analysis, which can be useful in research. Moreover, the data is amenable to the use as teaching and learning resource for histology and developmental biology.

Bactericidal efficacy difference between air and nitrogen cold atmospheric plasma on Bacillus cereus: Inactivation mechanism of Gram-positive bacteria at the cellular and molecular level

As an emerging food processing technology, cold atmospheric plasma (CAP) has attracted great attention in the field of microbial inactivation. Although CAP has been proven to effectively inactivate a variety of foodborne pathogens, there is less research on the inactivation of Bacillus cereus, and the exact inactivation mechanism is still unclear. Elucidating the inactivation mechanism will help to develop and optimize this sterilization method, with the prospective application in industrialized food production. This study aims to explore the bactericidal efficacy difference between air and nitrogen CAP on B. cereus, a typical Gram-positive bacterium, and reveals the inactivation mechanism of CAP at the cellular and molecular level, by observing the change of the cell membrane, cell morphological damage, intracellular antioxidant enzyme activity and cellular biomacromolecules changes. The results showed that both air CAP and nitrogen CAP could effectively inactivate B. cereus, which was due to the reactive oxygen and nitrogen species (RONS) generated by the plasma causing bacterial death. The damage pathways of CAP on Gram-positive bacteria could be explained by disrupting the bacterial cell membrane and cell morphology, disturbing the intracellular redox homeostasis, and destroying biomacromolecules in the cells. The differences in active species generated by the plasma were the main reason for the different bactericidal efficiencies of air CAP and nitrogen CAP, where air CAP producing RONS with stronger oxidative capacity in a shorter time. This study indicates that air CAP is an effective, inexpensive and green technology for B. cereus inactivation, providing a basis for industrial application in food processing.

The fate of adipose tissue and adipose-derived stem cells in allograft

Utilizing adipose tissue and adipose-derived stem cells (ADSCs) turned into a promising field of allograft in recent years. The therapeutic potential of adipose tissue and ADSCs is governed by their molecular secretions, ability to sustain multi-differentiation and self-renewal which are pivotal in reconstructive, genetic diseases, and cosmetic goals. However, revisiting the existing functional capacity of adipose tissue and ADSCs and their intricate relationship with allograft is crucial to figure out the remarkable question of safety to use in allograft due to the growing evidence of interactions between tumor microenvironment and ADSCs. For instance, the molecular secretions of adipose tissue and ADSCs induce angiogenesis, create growth factors, and control the inflammatory response; it has now been well determined. Though the existing preclinical allograft studies gave positive feedback, ADSCs and adipose tissue are attracted by some factors of tumor stroma. Moreover, allorecognition is pivotal to allograft rejection which is carried out by costimulation in a complement-dependent way and leads to the destruction of the donor cells. However, extensive preclinical trials of adipose tissue and ADSCs in allograft at molecular level are still limited. Hence, comprehensive immunomodulatory analysis could ensure the successful allograft of adipose tissue and ADSCs avoiding the oncological risk.

Intraspecific variation in muscle growth of two distinct populations of Port Jackson sharks under projected end-of-century temperatures

Although pervasive, the effects of climate change vary regionally, possibly resulting in differential behavioral, physiological, and/or phenotypic responses among populations within broadly distributed species. Juvenile Port Jackson sharks (Heterodontus portusjacksoni) from eastern and southern Australia were reared at their current (17.6 °C Adelaide, South Australia [SA]; 20.6 °C Jervis Bay, New South Wales [NSW]) or projected end-of-century (EOC) temperatures (20.6 °C Adelaide, SA; 23.6 °C Jervis Bay, NSW) and assessed for morphological features of skeletal muscle tissue. Nearly all skeletal muscle properties including cellularity, fiber size, myonuclear domain, and satellite cell density did not differ between locations and thermal regimes. However, capillary density was significantly influenced by thermal treatment, where Adelaide sharks raised at current temperatures had a lower capillarity than Jervis Bay sharks raised at ambient or projected EOC temperatures. This may indicate higher metabolic costs at elevated temperatures. However, our results suggest that regardless of the population, juvenile Port Jackson sharks may have limited acclimatory potential to alter muscle metabolic features under a temperature increase, which may make this species vulnerable to climate change.

The effects of non-functionalized polystyrene nanoparticles with different diameters on human erythrocyte membrane and morphology

In this study, the potential toxicity of non-functionalized polystyrene nanoparticles (PS-NPs) in human erythrocytes has been assessed. The effect of PS-NPs with different diameters (∼30 nm, ∼45 nm, ∼70 nm) on fluidity of erythrocytes membrane, red blood cells shape, as well as haemolysis of these cells has been investigated. Erythrocytes were incubated for 24 h with non-functionalized PS-NPs in concentrations ranging from 0.001 to 200 μg/mL in order to study haemolysis and from 0.001 to 10 μg/mL to determine other parameters. Fluidity was estimated by electron paramagnetic resonance (EPR) and the fluorimetric method. It has been shown that PS-NPs induced haemolysis, caused changes in the fluidity of red blood cells membrane, and altered their shape. Non-functionalized PS-NPs increased the membrane stiffness in the hydrophobic region of hydrocarbon chains of fatty acids. The observed changes in haemolysis and morphology were dependent on the size of the nanoparticles. The smallest PS-NPs of ∼30 nm (with the smallest absolute value of the negative zeta potential -29.68 mV) induced the greatest haemolysis, while the largest PS-NPs of ∼70 nm (with the highest absolute value of the negative zeta potential -42.00 mV) caused the greatest changes in erythrocyte shape and stomatocytes formation.

Renal Proximal Tubular Epithelial Cells: From Harvesting to Use in Studies

The kidneys are the body's main excretion organ with several additional functions, and the nephron represents their central structural unit. It is comprised of endothelial, mesangial, glomerular, and tubular epithelial cells, as well as podocytes. Treatment of acute kidney injury or chronic kidney disease (CKD) is complex due to broad etiopathogenic mechanisms and limited regeneration potential as kidney cells finish their differentiation after 34 weeks of gestation. Despite the ever-increasing prevalence of CKD, very limited treatment modalities are available. The medical community should therefore strive to improve existing treatments and develop new ones. Furthermore, polypharmacy is present in most CKD patients, while current pharmacologic study designs lack effectiveness in predicting potential drug-drug interactions and the resulting clinically relevant complications. An opportunity for addressing these issues lies in developing in vitro cell models based on patient-derived renal cells. Currently, several protocols have been described for isolating desired kidney cells, of which the most isolated are the proximal tubular epithelial cells. These play a significant role in water homeostasis, acid-base control, reabsorption of compounds, and secretion of xenobiotics and endogenous metabolites. When developing a protocol for the isolation and culture of such cells, one must focus on several steps. These include harvesting cells from biopsy specimens or after nephrectomies, using different digestion enzymes and culture mediums to facilitate the selective growth of only the desired cells. The literature reports several existing models, from simple 2D in vitro cultures to more complex ones created with bioengineering methods, such as kidney-on-a-chip models. While their creation and use depend on the target research, one should consider factors such as equipment, cost, and, even more importantly, source tissue quality and availability.

Sub-inhibitory concentrations of ampicillin affect microbial Fe(III) oxide reduction

Antibiotics are ubiquitous in the iron-rich environments but their roles in microbial reduction of Fe(III) oxides are still unclear. Using ampicillin and Geobacter soli, this study investigated the underlying mechanism by which antibiotic regulated microbial reduction of Fe(III) oxides. Results showed that sub-minimal inhibitory concentrations (sub-MIC) of ampicillin significantly affected ferrihydrite reduction by G. soli, with a stimulatory effect at 1/64 and 1/32 MIC and an inhibitory effect at 1/8 MIC. Increasing ampicillin concentration resulted in increasing cell length and decreasing bacterial zeta potential that were beneficial for ferrihydrite reduction, and decreasing outer membrane permeability that was unfavorable for ferrihydrite reduction. The respiratory metabolism ability was enhanced by 1/64 and 1/32 MIC ampicillin and reduced by 1/8 MIC ampicillin, which was also responsible for regulation of ferrihydrite reduction by ampicillin. The ferrihydrite reduction showed a positive correlation with the redox activity of extracellular polymeric substances (EPS) which was tied to the cytochrome/polysaccharide ratio and the content of α-helices and β-sheet in EPS. These results suggested that ampicillin regulated microbial Fe(III) oxide reduction through modulating the bacterial morphology, metabolism activity and extracellular electron transfer ability. Our findings provide new insights into the environmental factors regulating biogeochemical cycling of iron.

Hydrogels with stiffness-degradation spatial patterns control anisotropic 3D cell response

In nature, tissues are patterned, but most biomaterials used in human applications are not. Patterned biomaterials offer the opportunity to mimic spatially segregating biophysical and biochemical properties found in nature. Engineering such properties allows to study cell-matrix interactions in anisotropic matrices in great detail. Here, we developed alginate-based hydrogels with patterns in stiffness and degradation, composed of distinct areas of soft non-degradable (Soft-NoDeg) and stiff degradable (Stiff-Deg) material properties. The hydrogels exhibit emerging patterns in stiffness and degradability over time, taking advantage of dual crosslinking: Diels-Alder covalent crosslinking (norbornene-tetrazine, non degradable) and UV-mediated peptide crosslinking (matrix metalloprotease sensitive peptide, enzymatically degradable). The materials were mechanically characterized using rheology for single-phase and surface micro-indentation for patterned materials. 3D encapsulated mouse embryonic fibroblasts (MEFs) allowed to characterize the anisotropic cell-matrix interaction in terms of cell morphology by employing a novel image-based quantification tool. Live/dead staining showed no differences in cell viability but distinct patterns in proliferation, with higher cell number in Stiff-Deg materials at day 14. Patterns of projected cell area became visible already at day 1, with larger values in Soft-NoDeg materials. This was inverted at day 14, when larger projected cell areas were identified in Stiff-Deg. This shift was accompanied by a significant decrease in cell circularity in Stiff-Deg. The control of anisotropic cell morphology by the material patterns was also confirmed by a significant increase in filopodia number and length in Stiff-Deg materials. The novel image-based quantification tool was useful to spatially visualize and quantify the anisotropic cell response in 3D hydrogels with stiffness-degradation spatial patterns. Our results show that patterning of stiffness and degradability allows to control cell anisotropic response in 3D and can be quantified by image-based strategies. This allows a deeper understanding of cell-matrix interactions in a multicomponent material.

HAI-1 is required for the novel role of FGFBP1 in maintenance of cell morphology and F-actin rearrangement in human keratinocytes

Formation and maintenance of skin barrier function require tightly controlled membrane-associated proteolysis, in which the integral membrane Kunitz-type serine protease inhibitor, HAI-1, functions as the primary inhibitor of the membrane-associated serine proteases, matriptase and prostasin. Previously, HAI-1 loss in HaCaT human keratinocytes resulted in an expected increase in prostasin proteolysis but a paradoxical decrease in matriptase proteolysis. The paradoxical decrease in shed active matriptase is further investigated in this study with an unexpected discovery of novel functions of fibroblast growth factor-binding protein 1 (FGFBP1), which acts as an extracellular ligand that can rapidly elicit F-actin rearrangement and subsequently affect the morphology of human keratinocytes. This novel growth factor-like function is in stark contrast to the canonical activity of this protein through interactions with FGFs for its pathophysiological functions. This discovery began with the observation that HAI-1 KO HaCaT cells lose the characteristic cobblestone morphology of the parental cells and exhibit aberrant F-actin formation along with altered subcellular targeting of matriptase and HAI-2. The alterations in cell morphology and F-actin status caused by targeted HAI-1 deletion can be restored by treatment with conditioned medium from parental HaCaT cells, in which FGFBP1 was identified by tandem mass spectrometry. Recombinant FGFBP1 down to 1 ng/ml was able to revert the changes caused by HAI-1 loss. Our study reveals a novel function of FGFBP1 in the maintenance of keratinocyte morphology, which depends on HAI-1.

A simple and accurate method to quantify real-time contraction of vascular smooth muscle cell in vitro

Vascular smooth muscle cells (VSMCs) constitute the medial layer of the blood vessel wall. Their contractile state regulates blood flow in physiological and pathological conditions. Current methods for assessing the contractility of VSMCs are not amenable to the high-throughput screening of pharmaceutical compounds. This study aimed to develop a method to address this shortcoming in the field. Real-time contraction was visualized in living VSMCs using the exogenous expression of green fluorescent protein (GFP). Image-Pro Plus software (IPPS) was used to measure various morphological cell indices. In phenylephrine-treated VSMCs, GFP fluorescence imaging was more accurate than brightfield imaging or phalloidin staining in representing VSMC morphology, as measured using IPPS. Among the multiple indices of VSMC shape, area and mean-diameter were more sensitive than length in reflecting the morphological changes in VSMC. We developed a new index, compound length, by combining the mean-diameter and length to differentiate contracted and uncontracted VSMCs. Based on the compound length, we further generated a contraction index to define a single-VSMC contractile status as single-VSMC contraction-index (SVCI). Finally, compound length and SVCI were validated to effectively assess cell contraction in VSMCs challenged with U46619 and KCl. In conclusion, GFP-based indices of compound length and SVCI can accurately quantify the real-time contraction of VSMCs. In future, the new method will be applied to high-throughput drug screening or basic cardiovascular research.

Review on Cell Structure Regulation and Performances Improvement of Porous Poly (Lactic Acid)

Recent advances in the cell structure regulation and performances improvement of porous poly (lactic acid) (PLA) materials (PPMs) are systematically reviewed in this feature article. Firstly, the typical processing methods, including template method, non-solvent induced phase separation (NIPS), freeze-drying, supercritical CO₂ foaming and so on, of PPMs are introduced emphatically. Their various cell morphologies by different processing methods are summarized: finger-like, honeycomb-like, fiber-like, through cell, open cell, closed cell, ball-like and flower-like. Meanwhile, the transformation among different cell morphologies as well as the changes in cell size and cell density, having impact on the performances, are described. Secondly, the influence of stereo-complex crystals on the cell structure of PPMs is emphatically reviewed. Furthermore, the relationships between cell structure and properties that includes mechanical properties, thermal stability, heat insulation and hydrophobicity, are elaborated. Eventually, the issues of PPMs worthy of further study are discussed in this paper. This article is protected by copyright. All rights reserved.

Effects of pro-inflammatory cytokines and cell interactions on cell area and cytoskeleton of rheumatoid arthritis synoviocytes and immune cells

Rheumatoid synovitis is infiltrated by immune cells that interact with synoviocytes, leading to the pannus formation. Inflammation or cell interaction effects are mainly evaluated with cytokine production, cell proliferation or migration. Few studies interest on cell morphology. Here, the purpose was to deepen some morphological changes of synoviocytes or immune cells under inflammatory conditions. Inflammatory cytokines, IL-17 and TNF that are largely involved in RA pathogenesis, induced a change in synoviocyte morphology, inducing a retracted cell with higher number of pseudopodia. Several morphological parameters decreased in inflammatory conditions: cell confluence, area and motility speed. The same impact on cell morphology was observed in co-culture of synoviocytes and immune cells in inflammatory/non-inflammatory conditions or with cell activation (miming the in vivo situation), affecting both cell types: synoviocytes were retracted and inversely immune cells proliferated, indicating that cell activation induced a morphological change of cells. In contrast, with RA but not control synoviocytes, cell interactions were not sufficient to affect PBMC and synoviocyte morphology. The morphological effect came only from the inflammatory environment. These findings reveal that the inflammatory environment or cell interactions induced massive changes in control synoviocytes, with cell retraction and increase of pseudopodia number, leading to better interactions with other cells. Except in the case of RA, the inflammatory environment was absolutely required for such changes.

MorphoMacro for in vivo and ex vivo quantitative morphometric analysis of microglia

Microglia cells dynamically survey the central nervous system microenvironment and, in response to tissue damage inflicted by radiation therapy, disease or infection, undergo morphological and functional changes that culminate in microglia activation. Cell shape transformation can be assessed descriptively or, alternatively, it can be quantified as a continuous variable for parameters including total cell size as well as protrusion length, ramification and complexity. The purpose of the MorphoMacro method is to quantitatively profile multiple and single microglia cells using the available ImageJ platform. This method outlines the required steps and ImageJ plugins to convert fluorescence and bright-field photomicrographs into representative binary and skeletonized images and to analyze them using the MorphoMacro software plugin for multiparametric and multilevel description of microglia cell morphology in vivo and ex vivo. Overall, the protocol provides a quantitative and comprehensive tool that can be used to identify, stratify, and monitor diverse microglia morphologies in homeostatic, different disease conditions and subsequent therapeutic monitoring.

CRISPR-Cas9-Mediated NPC1 Gene Deletion Enhances HEK 293 T Cell Adhesion by Regulating E-Cadherin

NPC1 gene encodes a transmembrane glycoprotein on the late endosome/lysosomal membrane. Its mutation leads to a rare and aggravated autosomal recessive neurovisceral condition, termed Niemann-Pick disease type C1 (NPC1), which is characterized by progressive neurodegeneration, visceral symptoms, and premature death. To investigate the influence of NPC1 gene deletion on cell morphology, adhesion, proliferation, and apoptosis, CRISPR-Cas9 technology was used to knockout the NPC1 gene in HEK 293 T cells. Sanger sequencing, western blotting, and immunofluorescence were used to confirm successful NPC1 ablation. Filipin staining results indicated that deletion of NPC1 gene led to accumulation of unesterified cholesterol in HEK 293 T cells. Phalloidin staining results revealed cell aggregation, synapse shortening, nuclear enlargement, and cytoskeleton filamentous actin thinning in HEK 293 T cells with NPC1 gene mutation. Furthermore, NPC1 gene mutated HEK 293 T cell showed enhanced cell adhesion, inhibited cell proliferation, and increased cell apoptosis. In addition, NPC1 gene mutations significantly increased the protein expression levels of E-cadherin and γ-catenin and significantly decreased the protein expression levels of Wnt 3a, c-Myc, and cyclin D1. These results suggest that NPC1 may regulate cell adhesion by affecting the cadherin-catenin complex through E-cadherin, and that the classical Wnt signaling pathway may be inhibited by restricting β-catenin from entering the nucleus to inhibit cell proliferation.

Geometrical analysis identified morphological features of hydrogel-induced cancer stem cells in synovial sarcoma model cells

Cancer stem cells (CSCs) has been a key target to cure cancer patients completely. Although many CSC markers have been identified, they are frequently cancer type-specific and those expressions are occasionally variable, which becomes an obstacle to elucidate the characteristics of the CSCs. Here we scrutinized the relationship between stemness elevation and geometrical features of single cells. The PAMPS hydrogel was utilized to create the CSCs from mouse myoblast C2C12 and its synovial sarcoma model cells. qRT-PCR analysis confirmed the significant increase in expression levels of Sox2, Nanog, and Oct3/4 on the PAMPS gel, which was higher in the synovial sarcoma model cells. Of note, the morphological heterogeneity was appeared on the PAMPS gel, mainly including flat spreading, elongated spindle, and small round cells, and the Sox2 expression was highest in the small round cells. To examine the role of morphological differences in the elevation of stemness, over 6,400 cells were segmented along with the Sox2 intensity, and 12 geometrical features were extracted at single cell level. A nonlinear mapping of the geometrical features by using uniform manifold approximation and projection (UMAP) clearly revealed the existence of relationship between morphological differences and the stemness elevation, especially for C2C12 and its synovial sarcoma model on the PAMPS gel in which the small round cells possess relatively high Sox2 expression on the PAMPS gel, which supports the strong relationship between morphological changes and the stemness elevation. Taken together, these geometrical features can be useful for morphological profiling of CSCs to classify and distinguish them for understanding of their role in disease progression and drug discovery.

Studying the Effects of Glycosaminoglycans in Cell Morphological Aspect with Scanning Electron Microscopy

Glycosaminoglycans, the building blocks of proteoglycans, play a central role in the extracellular matrix and regulate a number of cellular processes. Therefore, any imbalance in their levels can lead to significant changes in cell behavior and phenotype. Additionally, glycosaminoglycans and their derivatives can be deployed as therapeutic agents in pathological conditions. Since cell morphology is a critical indicator of specialized cellular functions, its study can provide valuable insight. Scanning electron microscopy is a high-resolution imaging technique that makes for an ideal tool to observe the cellular appearance in 2D and 3D cultures under different conditions and/or substrates. In this chapter we provide a step-by-step protocol to study the influence of exogenously added glycosaminoglycans in the morphology of cells using scanning electron microscopy.

Digital Holographic Microscopy to Assess Cell Behavior

Digital holographic microscopy is an imaging technique particularly well suited to the study of living cells in culture, as no labeling is required and computed phase maps produce high contrast, quantitative pixel information. A full experiment involves instrument calibration, cell culture quality checks, selection and setup of imaging chambers, a sampling plan, image acquisition, phase and amplitude map reconstruction, and parameter map post-processing to extract information about cell morphology and/or motility. Each step is described below, focusing on results from imaging four human cell lines. Several post-processing approaches are detailed, with an aim of tracking individual cells and dynamics of cell populations.

Construction and characterization of a genome-scale ordered mutant collection of Bacteroides thetaiotaomicron

BACKGROUND

Ordered transposon-insertion collections, in which specific transposon-insertion mutants are stored as monocultures in a genome-scale collection, represent a promising tool for genetic dissection of human gut microbiota members. However, publicly available collections are scarce and the construction methodology remains in early stages of development.

RESULTS

Here, we describe the assembly of a genome-scale ordered collection of transposon-insertion mutants in the model gut anaerobe Bacteroides thetaiotaomicron VPI-5482 that we created as a resource for the research community. We used flow cytometry to sort single cells from a pooled library, located mutants within this initial progenitor collection by applying a pooling strategy with barcode sequencing, and re-arrayed specific mutants to create a condensed collection with single-insertion strains covering >2500 genes. To demonstrate the potential of the condensed collection for phenotypic screening, we analyzed growth dynamics and cell morphology. We identified both growth defects and altered cell shape in mutants disrupting sphingolipid synthesis and thiamine scavenging. Finally, we analyzed the process of assembling the B. theta condensed collection to identify inefficiencies that limited coverage. We demonstrate as part of this analysis that the process of assembling an ordered collection can be accurately modeled using barcode sequencing data.

CONCLUSION

We expect that utilization of this ordered collection will accelerate research into B. theta physiology and that lessons learned while assembling the collection will inform future efforts to assemble ordered mutant collections for an increasing number of gut microbiota members.

[Sternal bone marrow cell morphology evaluation utility for diagnostic categorization in patients with acquired hypocellular bone marrow failure syndromes]

Objective: Diagnostic value assessment of sternal bone marrow cell morphology in patients with acquired hypocellular bone marrow failure syndromes (BMFS) characterized by normal cytogenetics. Methods: A total of 194 eligible patients with an acquired hypocellular BMFS pre-sternum diagnosis in Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College from June 2014 to January 2019 were reviewed. Sternal bone marrow evaluation was performed, and a post-sternum diagnosis was made. Clinical characteristics and overall survival (OS) were then compared among patients with different post-sternum diagnosis. Binary logistic regression was used to develop a predictive scoring system. Results: In 152 patients with pre-sternum AA diagnosis, 29 patients with a pre-sternum idiopathic cytopenia of undetermined significance (ICUS) diagnosis, and 13 patients with a pre-sternum clonal cytopenia of undetermined significance (CCUS) diagnosis, sternal bone marrow evaluation resulted in a change of diagnosis to hypocellular myelodysplastic syndrome (hypo-MDS) in 42.8% (65/152) , 24.1% (7/29) , and 30.8% (4/13) , respectively. Patients with a post-sternum hypo-MDS diagnosis showed a significant difference in OS compared with patients with a post-sternum AA diagnosis (P=0.005) . Patients with ICUS/CCUS showed no difference in OS compared with AA and hypo-MDS (P=0.095 and P=0.480, respectively) . A 4-item predictive scoring system to identify hypocellular BMFS patients that need sternal bone marrow evaluation was developed, including age > 60 years old (OR=6.647, 95% CI 1.954-22.611, P=0.002, 2 points) , neutrophil alkaline phosphatase score ≤ 160 (OR=2.654, 95% CI 1.214-5.804, P=0.014, 1 point) , abnormal erythroid markers evaluated by flow cytometry on iliac bone marrow (OR=6.200, 95% CI 1.165-32.988, P=0.032, 2 points) , and DAT (DNMT3A, ASXL1, TET2) genes mutation (OR=4.809, 95% CI 1.587-14.572, P=0.005, 1 point) . The Akaike information criterin (AIC) was 186.1. Conclusion: Patients with a pre-sternum acquired hypocellular BMFS diagnosis characterized by normal cytogenetics may not reach accurate diagnostic categorization without sternal bone marrow cell morphology evaluation, which could be considered a diagnostic tool for this patient population. A predictive scoring system was developed, and when the total score is ≥ 2 points, sternal bone marrow evaluation should be performed for accurate diagnostic categorization that is critical to optimal patient care.

On the Variability in Cell and Nucleus Shapes

Cell morphology is an important regulator of cell function. Many abnormalities in cellular behavior can be discerned from changes in the shape of the cell and its organelles, typically the nucleus. Two major challenges for developing such phenotypic assays are reconstructing 3D surfaces of individual cells and nuclei from confocal images and developing characterizations of these surfaces for comparisons. We demonstrate two algorithms - 3D active contours and 3D condensed-attention UNet - to segment cells and nuclei from confocal images. The cell and nuclear surfaces are then converted into vectors using a reversible, spherical transform - i.e., shapes can be recovered from the vectors. Typical methods for characterizing shapes using size, shape, and image parameters such as area, volume, shape factor, solidity, and pixel intensities are not amenable to such reverse transformation. Our vector representation's principal component analysis shows that the significant modes of variability among cell and nucleus shapes are scaling and flattening. We benchmark these modes using a known mechanical model for nucleus morphology. Subsequent modes alter the eccentricity of the nucleus and translate and rotate it with respect to the cell. Our vector-space representation of cell and nucleus shape helps physically interpret the variability sources. It may further help to guide mechanical models and identify molecular mechanisms driving cell and nuclear shape changes.

Expression of growth arrest specific 1 (Gas1) in the distal tubules and collecting ducts in normal kidney and in the early stages of diabetic nephropathy

The Growth Arrest-Specific protein 1 (Gas1) has been recently described in kidney as an endogenous inhibitor of cell proliferation in mesangial cells and with an important role in the maintenance of nephron progenitor cells. Furthermore, the expression of Gas1 was demonstrated in NCAM + progenitor parietal cells of Bowman's capsule. Thus, the aim of this study was to analyze the expression of Gas1 in the collecting ducts (CD) of healthy rats and to examine whether high glucose levels modify its expression during the early stages of diabetes in STZ-treated rats. Immunofluorescence reveals that principal cells AQP2 + express Gas1 in both healthy and diabetic conditions. Western blot from enriched fractions of medullary CD suggests that diabetes promotes the increase of Gas1. AQP2 + cells are also positive for the expression of CD24 and CD1133 in diabetic rats. In addition, diabetes modifies the cell morphology in the CD and favors the increase of principal cells (AQP2+/Gas1+), induces a significant decrease of intercalated cells (V-ATPase+/Gas1-) and the presence of intermediate cells (Gas1+/V-ATPase+) which express both principal and intercalated cell markers. The expression of Gas1 in the distal tubules was also determined by immunofluorescence, western blot and ELISA in diabetic rats. The results identify Gas1 as a specific marker of principal cells in healthy and diabetic rats and suggest that diabetes promotes the expression of Gas1. Gas1 may have an important role in the maintenance and differentiation to principal cells in the CD during early stages of diabetes.

Toxic effects of fludioxonil on the growth, photosynthetic activity, oxidative stress, cell morphology, apoptosis, and metabolism of Chlorella vulgaris

Fludioxonil is widely used in the control of crop diseases because of its broad spectrum and high activity, but its presence is now common in waterways proximate to treated areas. This study examined the toxic effects and mechanisms of fludioxonil on the microalgal taxa Chlorella vulgaris. The results showed that fludioxonil limited the growth of C. vulgaris and the median inhibitory concentration at 96 h was 1.87 mg/L. Concentrations of 0.75 and 3 mg/L fludioxonil reduced the content of photosynthetic pigments in algal cells to different degrees. Fludioxonil induced oxidative damage by altering C. vulgaris antioxidant enzyme activities and increasing reactive oxygen species levels. Fludioxonil at 0.75 mg/L significantly increased the activity of antioxidant enzymes. The highest level of activity was 1.60 times that of the control group. Both fludioxonil treatment groups significantly increased ROS levels, with the highest increase being 1.90 times that of the control group. Transmission electron microscope showed that treatment with 3 mg/L fludioxonil for 96 h disrupted cell integrity and changed cell morphology, and flow cytometer analysis showed that fludioxonil induced apoptosis. Changes in endogenous substances indicated that fludioxonil negatively affects C. vulgaris via altered energy metabolism, biosynthesis of amino acids, and unsaturated fatty acids. This study elucidates the effects of fludioxonil on microalgae and the biological mechanisms of its toxicity, providing insights into the importance of the proper management of this fungicide.

Discrete protein metric (DPM): A new image similarity metric to calculate accuracy of deep learning-generated cell focal adhesion predictions

Understanding cell behaviors can provide new knowledge on the development of different pathologies. Focal adhesion (FA) sites are important sub-cellular structures that are involved in these processes. To better facilitate the study of FA sites, deep learning (DL) can be used to predict FA site morphology based on limited microscopic datasets (e.g., cell membrane images). However, calculating the accuracy score of these predictions can be challenging due to the discrete/point pattern like nature of FA sites. In the present work, a new image similarity metric, discrete protein metric (DPM), was developed to calculate FA prediction accuracy. This metric measures differences in distribution (d), shape/size (s), and angle (a) of FA sites between predicted and ground truth microscopy images. Performance of the DPM was evaluated by comparing it to three other commonly used image similarity metrics: Pearson correlation coefficient (PCC), feature similarity index (FSIM), and Intersection over Union (IoU). A sensitivity analysis was performed by comparing changes in each metric value due to quantifiable changes in FA site location, number, aspect ratio, area, or orientation. Furthermore, accuracy score of DL-generated predictions was calculated using all four metrics to compare their ability to capture variation across samples. Results showed better sensitivity and range of variation for DPM compared to the other metrics tested. Most importantly, DPM had the ability to determine which FA predictions were quantitatively more accurate and consistent with qualitative assessments. The proposed DPM hence provides a method to validate DL-generated FA predictions and has the potential to be used for investigation of other sub-cellular protein aggregates relevant to cell biology.

Establishing and characterising a new cell line from Calliphora vicina (diptera: calliphoridae) fly embryonic tissues

Insect cell lines represent a promising and expanding field as they have several research applications including biotechnology, virology, immunity, toxicology, cell signalling mechanisms and evolution. They constitute a powerful tool having a direct impact on human and veterinary medicine and agriculture. Although more than 1000 cell lines have currently been established from various insect species, Calliphora vicina-derived fly cell lines are lacking. This study was aimed at establishing a new C. vicina embryonic tissue-derived cell line. Adult flies were collected and embryonated eggs were mechanically homogenised and seeded in four types of culture media (L15, Grace's insect medium, Grace's/L15 and DMEM). Cell growth and morphological characteristics were recorded and cytogenetic and molecular patterns were determined. The CV-062020-PPB cell line was established and was shown to have optimal growth in Grace's/L15 medium. CV-062020-PPB cell monolayers that had been sub-cultured over 16 times consisted of firmly adhering cells having different morphologies; a fibroblast-like shape dominated and the karyotype had a 12-chromosome diploid number. RAPD-PCR analysis of the CV-062020-PPB cell line revealed a high similarity index and strong intraspecific relationship with C. vicina adult flies and a weaker relationship with the Lutzomyia longipalpis-derived cell line (Lulo). The CV-062020-PPB cell line constitutes the first cell line obtained from C. vicina embryonic tissues and represents an important basic and applied research tool.

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A new C. vicina embryonic tissue-derived cell line is here reported.

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Fibroblast-like cells were predominant.

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The cell-line karyotype was 2n = 12 diploid chromosomes.

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The DNA profile enabled discriminating its molecular identity.

Responses of Prorocentrum cordatum (Ostenfeld) Dodge, 1975 (Dinoflagellata) to copper nanoparticles and copper ions effect

In the present study, changes were determined in morphological, structural-functional, and fluorescent parameters of Prorocentrum cordatum with the addition of CuO nanoparticles (NPs) and copper ions (CuSO₄). A stimulating effect of low Cu²⁺ concentrations (30 μg L^-1) on algal growth characteristics was observed. Higher Cu²⁺ concentration of 60-600 μg L^-1 and CuO NPs concentration of 100-520 μg L^-1 inhibited algal growth. Ionic copper is more toxic to P. cordatum than NPs. After 72 h of algae cultivation in the medium supplemented with CuSO₄ and CuO NPs, EC₅₀ values (calculated based on cell abundance) were of 60 and 300 μg L^-1 (in terms of copper ions), respectively. Reduction in algal growth rate is due to disruption in cell cycle, changes in nuclear morphology, chromatin dispersion, and DNA damage. The studied pollutants slightly affected the efficiency of P. cordatum photosynthetic apparatus. Addition of the pollutants resulted in an increased production of reactive oxygen species (ROS). At a concentration of Cu²⁺ of 120 μg L^-1 and a concentration of CuO NPs 0-300 μg L^-1 of CuO NPs increase in ROS production is short-term with a decrease at later stages of the experiment. This is probably due to the activation of antioxidant mechanisms in cells and an increase in the concentration of carotenoids (peridinin) in cells. The high values of ROS production persisted throughout the experiment at sublethal copper concentrations (400-600 μg L^-1 of CuSO₄ and 520 μg L^-1 of CuO NPs). Sublethal concentrations of pollutants caused restructuring of cell membranes in P. cordatum. Shedding of cell membranes (ecdysis) and formation of immobile stages (temporary or resting cysts) were recorded. The pronounced mechanical impact of NPs on the cell surface was observed such as-deformation and damage of a cell wall, its "wrinkling" and shrinkage, and adsorption of NP aggregates.

Improved osmotic stress tolerance in brewer's yeast induced by wheat gluten peptides

The influences of three wheat gluten peptides (WGP-LL, WGP-LML, and WGP-LLL) on the osmotic stress tolerance and membrane lipid component in brewer's yeast were investigated. The results demonstrated that the growth and survival of yeast under osmotic stress were enhanced by WGP supplementation. The addition of WGP upregulated the expressions of OLE1 (encoded the delta-9 fatty acid desaturase) and ERG1 (encoded squalene epoxidase) genes under osmotic stress. At the same time, WGP addition enhanced palmitoleic acid (C16:1) content, unsaturated fatty acids/saturated fatty acids ratio, and the amount of ergosterol in yeast cells under osmotic stress. Furthermore, yeast cells in WGP-LL and WGP-LLL groups were more resistant to osmotic stress. WGP-LL and WGP-LLL addition caused 25.08% and 27.02% increase in membrane fluidity, 22.36% and 29.54% reduction in membrane permeability, 18.38% and 14.26% rise in membrane integrity in yeast cells, respectively. In addition, scanning electron microscopy analysis revealed that the addition of WGP was capable of maintaining yeast cell morphology and reducing cell membrane damage under osmotic stress. Thus, alteration of membrane lipid component by WGP was an effective approach for increasing the growth and survival of yeast cells under osmotic stress. KEY POINTS: •WGP addition enhanced cell growth and survival of yeast under osmotic stress. •WGP addition increased unsaturated fatty acids and ergosterol contents in yeast. •WGP supplementation improved membrane homeostasis in yeast at osmotic stress.

Human dermal microvascular endothelial cell morphological response to fluid shear stress

As the cells that line the vasculature, endothelial cells are continually exposed to fluid shear stress by blood flow. Recent studies suggest that the morphological response of endothelial cells to fluid shear stress depends on the endothelial cell type. Thus, the present study characterizes the morphological response of human dermal microvascular endothelial cells (HMEC-1) and nuclei to steady, laminar, and unidirectional fluid shear stress. Cultured HMEC-1 monolayers were exposed to shear stress of 0.3 dyn/cm², 16 dyn/cm², or 32 dyn/cm² for 72 h with hourly live-cell imaging capturing both the nuclear and cellular morphology. Despite changes in elongation and alignment occurring with increasing fluid shear stress, there was a lack of elongation and alignment over time under each fluid shear stress condition. Conversely, changes in cellular and nuclear area exhibited dependence on both time and fluid shear stress magnitude. The trends in cellular morphology differed at shear stress levels above and below 16 dyn/cm², whereas the nuclear orientation was independent of fluid shear stress magnitude. These findings show the complex morphological response of HMEC-1 to fluid shear stress.

Taxonomy and phylogeny of the freshwater tintinnid Tintinnopsis tubuformis Chiang, 1956 (Ciliophora, Oligotrichea) and a proposed synonymization of T. longa nom. corr. Chiang, 1956

Tintinnid ciliates are traditionally identified by their loricae; however, increasing evidence indicates that some lorica features (e.g., its length, spiralled structures) are not reliable. The vast majority of tintinnids inhabit the marine pelagial; merely, about thirty species live in freshwater. In the present study, two morphotypes with similar lorica shapes and opening diameters but deviating lorica lengths were isolated from freshwater samples collected at different water temperatures near Chongming Island in the Yangtze Estuary, China. The specimens were studied in vivo and after protargol staining, and their phylogenetic placement was inferred from three ribosomal RNA markers; further, cell division was investigated in the short morphotype. Based on the original descriptions, the longer morphotype is identified as Tintinnopsis longa nom. corr. Chiang, 1956 and the shorter one as Tintinnopsis tubuformis Chiang, 1956. Despite distinct differences in the lorica lengths, the identity of the three molecular markers in both morphotypes suggests conspecificity, which is supported by overlapping ranges in the lorica opening diameters and the length-independent features of the somatic ciliary pattern (e.g., number of kineties). Hence, we synonymised T. longa nom. corr. with T. tubuformis and neotypified the later species.

A study of the antibacterial mechanism of pinocembrin against multidrug-resistant Aeromonas hydrophila

Aeromonas hydrophila is a common pathogen in fish that has caused severe economic losses in aquaculture worldwide. With the emergence of bacterial resistance, it is necessary to develop new drugs to combat bacterial infection, particularly for multidrug-resistant bacteria. In this study, the antibacterial activity of pinocembrin was investigated by observing bacterial growth and microscopic structure, and its mechanism of action was identified by investigating its effect on protein and DNA. The antibacterial susceptibility test indicated that pinocembrin inhibits A. hydrophila growth. The minimal inhibitory concentration and minimum bactericidal concentration were 256 μg/mL and 512 μg/mL, respectively. Ultrastructurally, the bacteria treated with pinocembrin showed surface roughness and plasmolysis. When bacteria were treated with 512 μg/mL pinocembrin, lactate dehydrogenase activity and soluble protein content decreased significantly, and electrical conductivity and DNA exosmosis levels increased by 4.21 ± 0.64% and 15.98 ± 1.93 mg/L, respectively. Staining with 4', 6-Diamidino-2-phenylindole showed that the nucleic acid fluorescence intensity and density decreased after the treatment with pinocembrin. Pinocembrin may inhibit the growth of A. hydrophila by increasing cell membrane permeability and affecting protein and DNA metabolism. Thus, pinocembrin is a candidate drug for the treatment of A. hydrophila infection in aquaculture.

Microplastics impacts in seven flagellate microalgae: Role of size and cell wall

The toxicity of microplastic particles (MPs) on aquatic environments has been widely reported; however, their effects on protists are still contradictory. For example, it is unclear if cell size and cell wall have a role in shaping the response of flagellates to MPs. In this study, seven marine flagellated microalgae (six Dinoflagellates and one Raphidophyceae) were incubated with 10 mg L^-1 MPs (polystyrene plastic micro-spheres, 1 μm diameter) to address the above question by measuring different response variables, i.e., growth, optimal photochemical efficiency (F_v/F_m), chlorophyll-a (Chl-a) content, superoxide dismutase (SOD) activity, and cell morphology. The effect of MPs on growth and F_v/F_m showed species-specificity effects. Maximum and minimum MPs-induced inhibitions were detected in Karenia mikimotoi (76.43%) and Akashiwo sanguinea (10.16%), respectively, while the rest of the species showed intermediate responses. The presence of MPs was associated with an average reduction of Chl-a content in most cases and with a higher superoxide dismutase activity in all cases. Seven species were classified into two groups by the variation of Chl-a under MPs treatment. One group (Prorocentrum minimum and Karenia mikimotoi) showed increased Chl-a, while the other (P. donghaiense, P. micans, Alexandrium tamarense, Akashiwo sanguinea, Heterosigma akashiwo) showed decreased Chl-a content. The MPs-induced growth inhibition was negatively correlated with cell size in the latter group. SEM images further indicated that MPs-induced malformation in the smaller cells (e.g., P. donghaiense and K. mikimotoi) was more severe than the bigger cells (e.g., A. sanguinea and P. micans), probably due to a relatively higher ratio of the cell surface to cell volume in the former. These results implicate that the effect of MPs on marine flagellated microalgae was related to the cell size among most species but not cell wall. Thus plastic pollution may have size-dependent effects on phytoplankton in future scenarios.

Toxicity of the novel fungicide oxathiapiprolin to Chlorella vulgaris: Assessments at different levels of biological organization

Oxathiapiprolin (Otp) is the first successful oxysterol-binding protein (OSBP) inhibitor in oomycete control. It is regarded as a significant milestone in the history of fungicide discoveries and has vast application prospects. There is little available information on the ecotoxicity of Otp to aquatic organisms. In this study, we evaluated the toxic effects of Otp in the Chlorella vulgaris (C. vulgaris). The results revealed the acute toxicity of Otp to C. vulgaris, with a 96-h median effective concentration for growth inhibition of 0.74 mg/L. When algal cells were exposed to 0.5 and 1.5 mg/L Otp, their chlorophyll and carotenoid contents dropped dramatically. As suggested by the significant increase in reactive oxygen species (ROS) and malondialdehyde (MDA) levels and the remarkable changes in the activity of a series of antioxidant enzymes, Otp induces production of ROS, resulting in oxidative damage. In addition, Otp can damage cell structures and could destroy membrane integrity. Finally, the changes in endogenous substances indicated that Otp can perturb energy metabolism and photosynthesis in C. vulgaris cells. The experimental results suggest that Otp can have toxic effects on algal cells by disturbing photosynthesis and causing oxidative damage and abnormal energy metabolism in C. vulgaris cells.

Relationship of matrix stiffness and cell morphology in regulation of osteogenesis and adipogenesis of BMSCs

BACKGROUNDS

Matrix stiffness has been found to regulate cell morphology, while both cell morphology and matrix stiffness are verified as important factors directing BMSCs (bone marrow mesenchymal stem cells) differentiation. This study aimed to investigate whether matrix stiffness depended on cell morphology to regulate osteogenesis and adipogenesis of BMSCs on 2D substrates.

METHODS AND RESULTS

First, we seeded BMSCs on tissue culture plates (TCPs) with different fibronectin (FN) concentrations and cytoskeleton inhibitor cytochalasin D, and FN was found to promote cell spreading and osteogenesis while inhibiting adipogenesis of BMSCs through F-actin reorganization. Based on these, we modulated BMSCs morphology on 0.5 kPa and 32 kPa CytoSoft® substrates through FN. High concentration of FN (300 μg/ml) coated on 0.5 kPa substrates promoted cell spreading to similar levels with 32 kPa substrates coated with 100 μg/ml of FN, and cells in both groups dominantly commit osteogenesis. On the other hand, low FN concentration (30 μg/ml) on 32 kPa substrates induced restricted cell morphology similar with 0.5 kPa substrates coated with 100 μg/ml of FN, and cells in both groups mainly commit adipogenesis. Immunofluorescence indicated nuclear translocation and higher intensity of YAP/TAZ when cells spread to larger areas, regardless of matrix stiffness. However, when cell spreading areas were fixed as similar levels, matrix stiffness didn't significantly affect YAP/TAZ intensity or location.

CONCLUSIONS

Matrix stiffness failed to regulate BMSCs differentiation and YAP/TAZ activity without corresponding cell morphology. Cell spreading area could mediate effects of matrix stiffness on osteogenesis and adipogenesis of BMSCs.

Physiological responses of Pichia stipitis to imidazolium chloride ionic liquids with different carbon chain length

Ionic liquids (ILs) are used as detoxication agents for fermentation of lignin into ethanol because of their good applicability. However, the residual ILs may be toxic to the yeast. In order to improve the use of ILs for fermentation and protected environment, the toxicity of ILs with different carbon chain length to Pichia stipitis was studied in this paper. Four kinds of common imidazolium chloride ILs ([C₄mim]Cl, [C₆mim]Cl, [C₈mim]Cl and [C₁₀mim]Cl) were selected. ILs can inhibit the proliferation of Pichia stipitis and increase their mortality. Oxidative stress reaction occurred in the cells, and the activities of antioxidant enzymes are affected. Comparing with the integrated biomarker response (IBR) index, it was found that the toxicity increases with increasing chain length. ILs may enter cells by damaging cell membranes and reduce ethanol production by damaging organelles such as mitochondria. ILs caused wrinkles and dents on the surface of cells up to cell deformation and even rupture. The toxicity sequence was as follows: [C₁₀mim]Cl> [C₈mim]Cl>[C₆mim]Cl>[C₄mim]Cl. Due to this toxicity to Pichia stipitis, these compounds should be used carefully in the fermentation process and also to avoid toxic effects on other organisms in the environment.

Trace elements, peripheral blood film, and gene expression status in adolescents living near an industrial area in the Colombian Caribbean Coastline

BACKGROUND

Trace elements comprise both nutritionally essential and non-essential, and their presence in organisms plays important role in human health.

OBJECTIVE

The aim of this study was to evaluate the levels of trace elements, together with cellular and molecular biomarkers, in adolescents from Tierrabomba Island, a Caribbean community located near an industrial area, comparing them with a group living in San Onofre, a reference community.

METHODS

Hair and blood samples were obtained from 238 individuals aged 11-18 years old, 131 from Tierrabomba Island and 107 from San Onofre. Trace elements were quantified in hair using ICP-MS. The hematological evaluation was done by peripheral blood smears, and gene expression analysis was carried out through RT-PCR.

RESULTS

Thirteen elements were analyzed; eight showed significant differences between sites. In Tierrabomba, arsenic (As) and tungsten (W) registered mean values greater than in San Onofre. In contrast, in the reference site, average values for boron (B), cobalt (Co), zinc (Zn), yttrium (Y), tin (Sn), and barium (Ba) were greater. The peripheral blood film showed differences between populations. Mean lymphocyte percentage was higher in the Island, while eosinophil and monocyte percentages displayed greater means in San Onofre. Some correlations between trace elements and hematological parameters were found, mainly with platelets in Tierrabomba. This trend remained even when partial correlation coefficients were adjusted for age. Levels of gene expression of metallothionein 1X (MT1X) and superoxide dismutase (SOD) registered significant differences between sites, being greater in Tierrabomba. Negative correlations between SOD and As were observed in both sampling sites. Discriminant analysis suggested sampling locations could be differentiated by Zn, Mo, Ba, and MT1X levels.

SIGNIFICANCE

Trace elements and the relative gene expression associated with metal exposure are critical exposure biomarkers for coastal communities.

Comparative analysis between cytomorphology and flow cytometry methods in central nervous system infiltration assessment in oncohematological patients

INTRODUCTION

Oncohematological patients require the evaluation for possible infiltration of the central nervous system (CNS) by neoplastic cells at diagnosis and/or during the monitoring of the chemotherapeutic treatment. Morphological analysis using conventional microscopy is considered the method of choice to evaluate the cerebrospinal fluid (CSF) samples, despite technical limitations.

OBJECTIVE

This study aimed to compare the performance of the cytomorphology and flow cytometric immunophenotyping (FC) in the detection of CNS infiltration.

METHOD

We evaluated 520 CSF samples collected from 287 oncohematological patients for whom the detection of neoplastic cells was simultaneously requested by cytomorphology and FC.

RESULTS

Laboratory analyses revealed 435/520 (83.7%) conclusive results by the two methods evaluated, among which 385 (88.5%) were concordant. Discordance between the methods was observed in 50/435 (11.5%) samples, 45 (90%) being positive by FC. Furthermore, the FC defined the results in 69/72 (95.8%) inconclusive samples by cytomorphology. The positivity of FC was particularly higher among hypocellular samples. Among 431 samples with a cell count of < 5/μL, the FC identified neoplastic cells in 75 (17.4%), while the cytomorphology reported positive results in 26 (6%). Among the samples that presented adequate cell recovery for evaluation by both methods (506/520), the comparative analysis between FC and cytomorphology revealed a Kappa coefficient of 0.45 (CI: 0.37-0.52), interpreted as a moderate agreement.

CONCLUSION

The data showed that the CSF analysis by FC helps in the definition of CNS infiltration by neoplastic cells, particularly in the cases with dubious morphological analysis or in the evaluation of samples with low cellularity.

Investigation of the potential direct and cross protection effects of sublethal injured Salmonella Typhimurium induced by radio frequency heating stress

Many studies demonstrated that radio frequency (RF) was an effective pasteurization method for low-moisture foods (LMFs), and our previous study confirmed RF heating stress generated sublethal injured cells (SICs) of Salmonella enterica serovar Typhimurium (S. Typhimurium) in red pepper powder with initial a_w ≥ 0.53. So this study investigated the potential direct protection and cross protection effects of the SICs of S. Typhimurium to multiple stresses, and analyzed fatty acid composition and cell morphology. Results showed that the SICs were repaired after incubating for 5 h, and there were no obvious direct and cross protection effects by exposing to different external stresses (heat, 15% ethanol, pH 3.0 acid buffer solution, 10% salt). According to the fatty acid composition analysis, no significant difference (p > 0.05) between the ratio of unsaturated to saturated fatty acids (UFA/SFA) was observed for SICs of S. Typhimurium and control cells, indicating the same membrane fluidity which can support the experimental results. This study investigated and confirmed there are no direct and cross protection effects for the SICs of S. Typhimurium induced by RF heating stress, and it would be helpful for deeply understand the response of pathogens under RF heating stress.

Substrate stiffness affects the morphology, proliferation, and radiosensitivity of cervical squamous carcinoma cells

Cervical cancer is associated with the highest morbidity rate among gynecological cancers. Radiotherapy plays an important role in the treatment of cervical cancer. However, a considerable number of patients are radiation resistant, leading to a poor prognosis. Matrix stiffness is related to the occurrence, development, and chemoresistance of solid tumors. The association between matrix stiffness and radiosensitivity in cervical cancer cells remains unknown. Here, we sought to determine the effect of matrix stiffness on the phenotype and radiosensitivity of cervical cancer cells. Cervical squamous carcinoma SiHa cells were grown on substrates of different stiffnesses (0.5, 5, and 25 kPa). Cell morphology, proliferation, and radiosensitivity were examined. Cells grown on hard substrates displayed stronger proliferative activity, larger size, and higher differentiation degree, which was reflected in a more mature skeleton assembly, more abundant pseudopodia formation, and smaller nuclear/cytoplasmic ratio. In addition, SiHa cells exhibited stiffness-dependent resistance to radiation, possibly via altered apoptosis-related protein expression. Our findings demonstrate that matrix stiffness affects the morphology, proliferation, and radiosensitivity of SiHa cells. Tissue stiffness may be an indicator of the sensitivity of a patient to radiotherapy. Thus, the data provide insights into the diagnosis of cervical cancer and the design of future radiotherapies.

Effect of bound water content on cell adhesion strength to water-insoluble polymers

Adhesion of cells on biomaterials plays an essential role in modulating cellular functions. Although hydration of biomaterials occurs under biological conditions, it is challenging to systematically evaluate the correlation of hydrated water content in biomaterials with the cell adhesion strength. In this report, we investigated the effect of bound water content on the adhesion strength of cells on poly(2-methoxyethyl acrylate) (PMEA) analogue substrates. Water-insoluble PMEA analogues were synthesized to fabricate substrates with a systemically controlled bound water content. To assess the surface properties of their substrates, contact angle measurement, atomic force microscopy (AFM), and fluorescence measurement were conducted. To reflect the effect of bound water of PMEA analogues, the relationship between the bound water content and cell adhesion behavior was evaluated under serum-free condition. From the single cell force spectrometry (SCFS) and microscopic analysis, it revealed that the increment of bound water content on the substrates decreased cell adhesion strength and cell spreading on the substrates. The bound water content exhibited a good correlation with adhesion strength, spreading area, circularity, and aspect ratio of cells. Our findings indicate that the bound water content could contribute to the development of a novel biomaterial and evaluation of cell behaviors on biomaterials. STATEMENT OF SIGNIFICANCE: For coordinating cell functions, such as growth, mobility, and differentiation, modulating the adhesion strength between cells and their environments is important. Although the hydration to biomaterials has been reported to be closely related to a antifouling property, the effect of hydration water on the cell adhesion behavior is not well understood. We present the first demonstration of essential relationship between cell adhesion strength and hydrated water on a biomaterials surface using the water-insoluble polymers with different hydrated water content. The results reveal that the hydrated water content of polymer substrates strong correlation with adhesion strength of cells. Collectively, the hydrated water content of the biomaterials will be a predominant factor affecting the cell adhesion strength and behavior.

Morphological, fractal, and textural features for the blood cell classification: the case of acute myeloid leukemia

Microscopic examination of stained peripheral blood smears is, nowadays, an indispensable tool in the evaluation of patients with hematological and non-hematological diseases. While a rapid automated quantification of the regular blood cells is available, recognition and counting of immature white blood cells (WBC) still relies mostly on the microscopic examination of blood smears by an experienced observer. Recently, there are efforts to improve the prediction by various machine learning approaches. An open dataset collection including the recently digitalized single-cell images for 200 patients, from peripheral blood smears at 100 × magnification, was used. We studied different morphological, fractal, and textural descriptors for WBC classification, with an aim to indicate the most reliable parameters for the recognition of certain cell types. Structural properties of both the mature and non-mature leukocytes obtained from (i) acute myeloid leukemia patients, or (ii) non-malignant controls, were studied in depth, with a sample size of about 25 WBC per group. We quantified structural and textural differences and, based on the statistical ranges of parameters for different WBC types, selected eight features for classification: Cell area, Nucleus-to-cell ratio, Nucleus solidity, Fractal dimension, Correlation, Contrast, Homogeneity, and Energy. Classification Precision of up to 100% (80% on average) was achieved.

l-glycine and l-glutamic acid protect Pediococcus pentosaceus R1 against oxidative damage induced by hydrogen peroxide

The effects of l-glycine (Gly) and l-glutamic acid (Glu) on oxidative damage induced by hydrogen peroxide (H₂O₂) in Pediococcus pentosaceus R1 were investigated. Gly and Glu significantly reduce the production of intracellular reactive oxygen species and the levels of malondialdehyde and carbonylated proteins and concomitantly increase ATP levels in P. pentosaceus R1 under H₂O₂-induced stress (P < 0.05). Transmission electron microscopy and atomic force microscopy of bacteria under H₂O₂-induced stress revealed that Gly and Glu suppress bacterial membrane deformation and cell damage. Gly exhibited stronger ferrous ion-chelating ability, whereas Glu has higher radical scavenging activities and reducing power (P < 0.05). The abilities of Gly and Glu to inhibit lipid peroxidation are comparable. Gly and Glu significantly enhance the activities of superoxide dismutase and glutathione peroxidase, respectively, and increase the total antioxidant capacity of bacteria (P < 0.05). These findings indicate that Gly and Glu alleviate H₂O₂-induced oxidative stress via direct antioxidant effects and increase the activities of bacterial antioxidant enzyme.