Characteristics of Myelogram in Patients with Extraocular Metastatic Retinoblastoma and Morphological Analysis of Tumor Cells in Bone Marrow and Cerebrospinal Fluid

BACKGROUND

Retinoblastoma (RB) is a common intraocular malignant tumor in infants and young children. However, reports on the morphological descriptions of RB tumor cells from native and foreign scholars are rare.

OBJECTIVES

To investigate the myelogram characteristics of RB with extraocular tumor extension and the morphological characteristics of tumor cells in the bone marrow and cerebrospinal fluid.

METHODS

For the period from May 2011 to February 2015, we analyzed clinical data on 18 patients in our hospital diagnosed as having metastatic RB in the extraocular and other distant regions associated with clear bone marrow metastasis. The morphology of tumor cells in the bone marrow and cerebrospinal fluid was retrospectively analyzed after staining with Wright-Giemsa stain. A summary of the cytological characteristics was also presented.

RESULTS

RB tumor cells in the bone marrow and cerebrospinal fluid not only appeared as aggregated clumps, but were distributed in a scattered manner. The tumor cells may present different characteristic morphologies in different cases, with different tumor cell smears from the same tumor mass even showing different features. According to the degree of tumor metastasis, changes in myelogram were significantly different.

CONCLUSION

The tumor cells of RB patients show unique morphological characteristics in the bone marrow and cerebrospinal fluid. Therefore, correct identification of the cells is of great value in the diagnosis, staging, and prognosis of RB.

Cellular morphological features are predictive markers of cancer cell state

Even genetically identical cells have heterogeneous properties because of stochasticity in gene or protein expression. Single cell techniques that assay heterogeneous properties would be valuable for basic science and diseases like cancer, where accurate estimates of tumor properties is critical for accurate diagnosis and grading. Cell morphology is an emergent outcome of many cellular processes, potentially carrying information about cell properties at the single cell level. Here we study whether morphological parameters are sufficient for classification of single cells, using a set of 15 cell lines, representing three processes: (i) the transformation of normal cells using specific genetic mutations; (ii) metastasis in breast cancer and (iii) metastasis in osteosarcomas. Cellular morphology is defined as quantitative measures of the shape of the cell and the structure of the actin. We use a toolbox that calculates quantitative morphological parameters of cell images and apply it to hundreds of images of cells belonging to different cell lines. Using a combination of dimensional reduction and machine learning, we test whether these different processes have specific morphological signatures and whether single cells can be classified based on morphology alone. Using morphological parameters we could accurately classify cells as belonging to the correct class with high accuracy. Morphological signatures could distinguish between cells that were different only because of a different mutation on a parental line. Furthermore, both oncogenesis and metastasis appear to be characterized by stereotypical morphology changes. Thus, cellular morphology is a signature of cell phenotype, or state, at the single cell level.

Cytokeratin-positive interstitial reticulum cell (CIRC) tumor in the lymph node: a case report of the transformation from the epithelioid cell type to the spindle cell type

Background

Cytokeratin-positive interstitial reticulum cells (CIRCs), which are a subgroup of fibroblastic reticular cells (FRCs), are known to be present in the lymph nodes. There have been only a few cases of tumors derived from CIRCs.

Case presentation

We have reported a new case involving a CIRC tumor in a 75-year-old man and reviewed the literature. The resected mediastinal lymph nodes showed epithelial-like proliferation of large atypical round and polygonal epithelioid cells. The tumor cells expressed CK8, CK18, CAM5.2, AE1/AE3, epithelial membrane antigen, vimentin, fascin, and some FRC markers, which is consistent with the diagnosis of a CIRC tumor. Following chemotherapy, the CIRC tumor was observed to have responded very well and became difficult to confirm on imaging, but a small cell lung carcinoma developed 12 months later. Chemoradiotherapy was performed, but the patient passed away 29 months after the initial diagnosis. The autopsy revealed the recurrence of the CIRC tumor, residual small cell lung carcinoma, and a very small latent carcinoma of the prostate. The relapsed CIRC tumor cells had a spindle shape; they were highly pleomorphic and had invaded the superior vena cava.

Conclusion

We first reported autopsy findings of CIRC tumors and demonstrated the transformation of the tumor from the epithelioid cell type to the spindle cell type.

Adaptive architecture and mechanoresponse of epithelial cells on a torus

Curvature is a geometric feature widely observed in the epithelia and critical to the performance of fundamental biological functions. Understanding curvature-related biophysical phenomena remains challenging partly owing to the difficulty of quantitatively tuning and measuring curvatures of interfacing individual cells. In this study, we prepared confluent wild-type Madin-Darby canine kidney cells on a torus structure presenting positive, zero, and negative Gaussian curvatures with a tubule diameter of 2-7 cells and quantified the mechanobiological characteristics of individual cells. Cells on the torus surface exhibited topological sensing ability both as an individual cell and collective cell organization. Both cell bodies and nuclei, adapted on the torus, exhibited local Gaussian curvature-dependent preferential orientation. The cells on the torus demonstrated significant adjustment in the nuclear area and exhibited asymmetric nuclear position depending on the local Gaussian curvature. Moreover, cells on top of the torus, where local Gaussian curvature is near zero, exhibited more sensitive morphological adaptations than the nuclei depending on the Gaussian curvature gradient. Furthermore, the spatial heterogeneity of intermediate filament proteins related to mechanoresponsive expression of the cell body and nucleus, vimentin, keratin and lamin A, revealed local Gaussian curvature as a key factor of cellular adaptation on curved surfaces.

Mechanical force-induced morphology changes in a human fungal pathogen

Background

The initial step of a number of human or plant fungal infections requires active penetration of host tissue. For example, active penetration of intestinal epithelia by Candida albicans is critical for dissemination from the gut into the bloodstream. However, little is known about how this fungal pathogen copes with resistive forces upon host cell invasion.

Results

In the present study, we have used PDMS micro-fabrication to probe the ability of filamentous C. albicans cells to penetrate and grow invasively in substrates of different stiffness. We show that there is a threshold for penetration that corresponds to a stiffness of ~ 200 kPa and that invasive growth within a stiff substrate is characterized by dramatic filament buckling, along with a stiffness-dependent decrease in extension rate. We observed a striking alteration in cell morphology, i.e., reduced cell compartment length and increased diameter during invasive growth, that is not due to depolarization of active Cdc42, but rather occurs at a substantial distance from the site of growth as a result of mechanical compression.

Conclusions

Our data reveal that in response to this compression, active Cdc42 levels are increased at the apex, whereas active Rho1 becomes depolarized, similar to that observed in membrane protrusions. Our results show that cell growth and morphology are altered during invasive growth, suggesting stiffness dictates the host cells that C. albicans can penetrate.

Morphogo: An Automatic Bone Marrow Cell Classification System on Digital Images Analyzed by Artificial Intelligence

INTRODUCTION

The nucleated-cell differential count on the bone marrow aspirate smears is required for the clinical diagnosis of hematological malignancy. Manual bone marrow differential count is time consuming and lacks consistency. In this study, a novel artificial intelligence (AI)-based system was developed to perform cell automatic classification of bone marrow cells and determine its potential clinical applications.

MATERIALS AND METHODS

Bone marrow aspirate smears were collected from the Xinqiao Hospital of Army Medical University. First, an automated analysis system (Morphogo) scanned and generated whole digital images of bone marrow smears. Then, the nucleated marrow cells in the selected areas of the smears at a magnification of ×1,000 were analyzed by the software utilizing an AI-based platform. The cell classification results were further reviewed and confirmed independently by 2 experienced pathologists. The automatic cell classification performance of the system was evaluated using 3 categories: accuracy, sensitivity, and specificity. Correlation coefficients and linear regression equations between automatic cell classification by the AI-based system and concurrent manual differential count were calculated.

RESULTS

In 230 cases, the classification accuracy was above 85.7% for hematopoietic lineage cells. Averages of sensitivity and specificity of the system were found to be 69.4 and 97.2%, respectively. The differential cell percentage of the automated count based on 200-500 cell counts was correlated with differential cell percentage provided by the pathologists for granulocytes, erythrocytes, and lymphocytes (r ≥ 0.762, p < 0.001).

DISCUSSION/CONCLUSION

This pilot study confirmed that the Morphogo system is a reliable tool for automatic bone marrow cell differential count analysis and has potential for clinical applications. Current ongoing large-scale multicenter validation studies will provide more information to further confirm the clinical utility of the system.

Optical microscopy reveals the dynamic nature of B. pseudomallei morphology during β-lactam antimicrobial susceptibility testing

Background

In Gram-negative species, β-lactam antibiotics target penicillin binding proteins (PBPs) resulting in morphological alterations of bacterial cells. Observations of antibiotic-induced cell morphology changes can rapidly and accurately differentiate drug susceptible from resistant bacterial strains; however, resistant cells do not always remain unchanged. Burkholderia pseudomallei is a Gram-negative, biothreat pathogen and the causative agent of melioidosis, an often fatal infectious disease for humans.

Results

Here, we identified β-lactam targets in B. pseudomallei by in silico analysis. Ten genes encoding putative PBPs, including PBP-1, PBP-2, PBP-3 and PBP-6, were detected in the genomes of susceptible and resistant strains. Real-time, live-cell imaging of B. pseudomallei strains demonstrated dynamic morphological changes in broth containing clinically relevant β-lactam antibiotics. At sub-inhibitory concentrations of ceftazidime (CAZ), amoxicillin-clavulanic acid (AMC), and imipenem (IPM), filamentation, varying in length and proportion, was an initial response of the multidrug-resistant strain Bp1651 in exponential phase. However, a dominant morphotype reemerged during stationary phase that resembled cells unexposed to antibiotics. Similar morphology dynamics were observed for AMC-resistant strains, MSHR1655 and 724644, when exposed to sub-inhibitory concentrations of AMC. For all B. pseudomallei strains evaluated, increased exposure time and exposure to increased concentrations of AMC at and above minimal inhibitory concentrations (MICs) in broth resulted in cell morphology shifts from filaments to spheroplasts and/or cell lysis. B. pseudomallei morphology changes were more consistent in IPM. Spheroplast formation followed by cell lysis was observed for all strains in broth containing IPM at concentrations greater than or equal to MICs, however, the time to cell lysis was variable. B. pseudomallei cell lengths were strain-, drug- and drug concentration-dependent.

Conclusions

Both resistant and susceptible B. pseudomallei strains exhibited filamentation during early exposure to AMC and CAZ at concentrations used to interpret susceptibility (based on CLSI guidelines). While developing a rapid β-lactam antimicrobial susceptibility test based on cell-shape alone requires more extensive analyses, optical microscopy detected B. pseudomallei growth attributes that lend insight into antibiotic response and antibacterial mechanisms of action.

Defective migration and dysmorphology of neutrophil granulocytes in atypical chronic myeloid leukemia treated with ruxolitinib

BACKGROUND

The identification of pathologically altered neutrophil granulocyte migration patterns bears strong potential for surveillance and prognostic scoring of diseases. We recently identified a strong correlation between impaired neutrophil motility and the disease stage of myelodysplastic syndrome (MDS). Here, we apply this assay to study quantitively increased neutrophils of a patient suffering from a rare leukemia subtype, atypical chronic myeloid leukemia (aCML).

METHODS

A 69-year-old male was analyzed in this study. Besides routine analyses, we purified the patient's neutrophils from peripheral whole blood and studied their migration behavior using time-lapse video microscopy in a standardized assay. These live cell migration analyses also allowed for the quantification of cell morphology. Furthermore, the cells were stained for the markers CD15, CD16, fMLPR, CXCR1 and CXCR2.

RESULTS

Despite cytoreductive therapy with hydroxyurea, the patient's WBC and ANC were poorly controlled and severe dysgranulopoiesis with hypogranularity was observed. Neutrophils displayed strongly impaired migration when compared to healthy controls and migrating cells exhibited a more flattened-out morphology than control neutrophils. Because of a detected CSF3R (p.T618I) mutation and constitutional symptoms treatment with ruxolitinib was initiated. Within 1 week of ruxolitinib treatment, the cell shape normalized and remained indistinguishable from healthy control neutrophils. However, neutrophil migration did not improve over the course of ruxolitinib therapy but was strikingly altered shortly before a sinusitis with fever and bleeding from a gastric ulcer. Molecular work-up revealed that under ruxolitinib treatment, the CSF3R clone was depleted, yet the expansion of a NRAS mutated subclone was promoted.

CONCLUSION

These results demonstrate the usefulness of neutrophil migration analyses to uncover corresponding alterations of neutrophil migration in rare myeloid neoplasms. Furthermore, in addition to monitoring migration the determination of morphological features of live neutrophils might represent a useful tool to monitor the effectiveness of therapeutic approaches.

Decoupling the effects of nanopore size and surface roughness on the attachment, spreading and differentiation of bone marrow-derived stem cells

The nanopore size and roughness of nanoporous surface are two critical variables in determining stem cell fate, but little is known about the contribution from each cue individually. To address this gap, we use two-dimensional nanoporous membranes with controlled nanopore size and roughness to culture bone marrow-derived mesenchymal stem cells (BMSCs), and study their behaviors such as attachment, spreading and differentiation. We find that increasing the roughness of nanoporous surface has no noticeable effect on cell attachment, and only slightly decreases cell spreading areas and inhibits osteogenic differentiation. However, BMSCs cultured on membranes with larger nanopores have significantly fewer attached cells and larger spreading areas. Moreover, these cells cultured on larger nanopores undergo enhanced osteogenic differentiation by expressing more alkaline phosphatase, osteocalcin, osteopontin, and secreting more collagen type I. These results suggest that although both nanopore size and roughness can affect BMSCs, nanopore size plays a more significant role than roughness in controlling BMSC behavior.

Extracellular vesicles in diabetes mellitus induce alterations in endothelial cell morphology and migration

Background

Inflammation-related atherosclerotic peripheral vascular disease is a major end organ complication of diabetes mellitus that results in devastating morbidity and mortality. Extracellular vesicles (EVs) are nano-sized particles that contain molecular cargo and circulate in the blood. Here, we examined EV protein cargo from diabetic individuals and whether these EVs cause functional changes in endothelial cells.

Methods

We quantified inflammatory protein levels in plasma-derived EVs from a longitudinal cohort of euglycemic and diabetic individuals and used in vitro endothelial cell biological assays to assess the functional effects of these EVs with samples from a cross-sectional cohort.

Results

We found several significant associations between EV inflammatory protein levels and diabetes status. The angiogenic factor, vascular endothelial growth factor A (VEGF-A), was associated with diabetes status in our longitudinal cohort. Those with diabetes mellitus had higher EV VEGF-A levels compared to euglycemic individuals. Additionally, EV levels of VEGF-A were significantly associated with homeostatic model assessment of insulin resistance (HOMA-IR) and β-cell function (HOMA-B). To test whether EVs with different inflammatory cargo can demonstrate different effects on endothelial cells, we performed cell migration and immunofluorescence assays. We observed that EVs from diabetic individuals increased cell lamellipodia formation and migration when compared to EVs from euglycemic individuals.

Conclusions

Higher levels of inflammatory proteins were found in EVs from diabetic individuals. Our data implicate EVs as playing important roles in peripheral vascular disease that occur in individuals with diabetes mellitus and suggest that EVs may serve as an informative diagnostic tool for the disease.

Allelopathic effects of Margalefidinium polykrikoides and Gymnodinium impudicum in the growth of Gymnodinium catenatum

Harmful algae blooms (HABs) are characterized for the coexistence of phytoplankton species with dynamic and complex biotic interactions (e.g., competition, symbiosis, predation, parasitism, allelopathy), that occur at fine temporal and spatial scales, and are relevant to understand the role that different species of phytoplankton play in the regulation of HABs. In this work the allelopathic effects of Margalefidinium polykrikoides (=Cochlodinium polykrikoides) and Gymnodinium impudicum on Gymnodinium catenatum were evaluated. The allelopathic abilities of M. polykrikoides and G. impudicum were investigated in bi-algal culture experiments and in trials in which target species were co-cultured, separated by a 10 μm membrane to prevent a direct cell-to-cell contact; and also by the addition of different volumes of culture media without cells. For all trials, cells of each species were harvested during exponential phase and cultured together by triplicate at three relative abundances: 1:1 (200 Cells mL^-1 of each species, G. catenatum and M. polykrikoides or G. impudicum), 2:1 (400 Cells mL^-1 of G. catenatum and 200 Cells mL^-1 of M. polykrikoides or G. impudicum), and 1:2 (200 cells mL^-1 of G. catenatum and 400 Cells mL^-1 of M. polykrikoides or G. impudicum). All bioassays were carried out by triplicate in 250 mL Erlenmeyer flasks with 150 mL of modified GSe medium with an initial inoculum of 200 or 400 Cells mL^-1. During experiments G. catenatum abundances were enumerated daily. In bi-algal culture experiments mortalities of G. catenatum were from 50% to 100% after 48 h of cell contact with M. polykrikoides or G. impudicum. In the case of culture media without cells, only M. polykrikoides caused a decrease in the cell abundance and growth rate of G. catenatum. Morphological changes occurred in G. catenatum when in contact with M. polykrikoides and G. impudicum, such as membrane shedding, prominent nucleus, loss of flagella, cell lysis, as well as the separation of long chains into individual cells. These results suggest that in the natural environment M. polykrikoides and G. impudicum have allelopathic interactions in G. catenatum, which could negatively affect its growth and survival, indicating that these species could displace blooms of G. catenatum.

Monitoring cell endocytosis of liposomes by real-time electrical impedance spectroscopy

Evaluation and understanding the effect of drug delivery in in vitro systems is fundamental in drug discovery. We present an assay based on real-time electrical impedance spectroscopy (EIS) measurements that can be used to follow the internalisation and cytotoxic effect of a matrix metalloproteinase (MMP)-sensitive liposome formulation loaded with oxaliplatin (OxPt) on colorectal cancer cells. The EIS response identified two different cellular processes: (i) a negative peak in the cell index (CI) within the first 5 h, due to onset of liposome endocytosis, followed by (ii) a subsequent CI increase, due to the reattachment of cells until the onset of cytotoxicity with a decrease in CI. Free OxPt or OxPt-loaded Stealth liposomes did not show this two-stage EIS response; the latter can be due to the fact that Stealth cannot be cleaved by MMPs and thus is not taken up by the cells. Real-time bright-field imaging supported the EIS data, showing variations in cell adherence and cell morphology after exposure to the different liposome formulations. A drastic decrease in cell coverage as well as rounding up of cells during the first 5 h of exposure to OxPt-loaded (MMP)-sensitive liposome formulation is reflected by the first negative EIS response, which indicates the onset of liposome endocytosis. Graphical abstract.

Cell attachment area of rat mesenchymal stem cells correlates with their osteogenic differentiation level on substrates without osteoconductive property

Cell morphology is related to proliferation and differentiation. We previously reported that cell attachment area of rat mesenchymal stem cells (MSCs) is negatively correlated with their osteogenic differentiation level on osteoconductive hydroxyapatite (HAp) with various microstructures. In this study, the correlation between the cell attachment area and osteogenic differentiation level was investigated on substrates without osteoconductive property using tissue culture polystyrene (TCPS), and 3 mol% yttria-stabilized zirconia (3Y-TZP) with or without surface periodic microstructures. It was found that the osteogenic differentiation level after 3 weeks of culture increased with a decrease in cell attachment area after 3 h of culture. The square of the correlation coefficient between cell attachment area and osteocalcin secretion content was 0.845 among the three types of substrates. Thus, the negative correlation between cell attachment area and differentiation level is confirmed even when cultured on substrates without osteoconductive property. These findings suggest that the correlation between the cell attachment area of rat MSCs and osteogenic differentiation level could also apply to various types of substrate, regardless of osteoconductive property.

Co-aligned chondrocytes: Zonal morphological variation and structured arrangement of cell lacunae in tessellated cartilage

In most vertebrates the embryonic cartilaginous skeleton is replaced by bone during development. During this process, cartilage cells (chondrocytes) mineralize the extracellular matrix and undergo apoptosis, giving way to bone cells (osteocytes). In contrast, sharks and rays (elasmobranchs) have cartilaginous skeletons throughout life, where only the surface mineralizes, forming a layer of tiles (tesserae). Elasmobranch chondrocytes, unlike those of other vertebrates, survive cartilage mineralization and are maintained alive in spaces (lacunae) within tesserae. However, the functions of the chondrocytes in the mineralized tissue remain unknown. Applying a custom analysis workflow to high-resolution synchrotron microCT scans of tesserae, we characterize the morphologies and arrangements of stingray chondrocyte lacunae, using lacunar morphology as a proxy for chondrocyte morphology. We show that the cell density is comparable in unmineralized and mineralized tissue and that cells maintain similar volume even when they have been incorporated into tesserae. Our findings support previous hypotheses that elasmobranch chondrocytes, unlike those of other taxa, do not proliferate, hypertrophy or undergo apoptosis during mineralization. Tessera lacunae show zonal variation in their shapes, being flatter further from and more spherical closer to the unmineralized cartilage matrix, and larger in the center of tesserae. The lacunae show pronounced organization into parallel layers and strong orientation toward neighboring tesserae. Tesserae also exhibit local variation in lacunar density, with the density considerably higher near pores passing through the tesseral layer, suggesting pores and cells interact, and that pores may contain a nutrient source. We propose that the different lacunar types reflect the stages of the tesserae formation process, while also representing local variation in tissue architecture and cell function. Lacunae are linked by small passages (canaliculi) in the matrix to form elongated series at the tesseral periphery and tight clusters in the center of tesserae, creating a rich connectivity among cells. The network arrangement and the shape variation of chondrocytes in tesserae indicate that cells may interact within and between tesserae and manage mineralization differently from chondrocytes in other vertebrates, perhaps performing analogous roles to osteocytes in bone.

Study the antibacterial mechanism of cinnamaldehyde against drug-resistant Aeromonas hydrophila in vitro

Aeromonas hydrophila, a highly infectious pathogen, causes several infections in aquatic animals and huge economic losses. Antibiotics are often used to treat A. hydrophila infections. However, overuse and irrational usage of antibiotics has led to severe antibiotic residues and emergence of resistance. There is therefore an urgent need for a new sustainable drug to control bacterial infection. Cinnamaldehyde, a plant-derived ingredient, has been found to have good antibacterial activity against A. hydrophila in vitro, but its mechanism of action remains unknown. In this study, we investigated the mechanism of cinnamaldehyde against A. hydrophila by evaluating the effects of cinnamaldehyde on A. hydrophila cell growth, cell morphology, electrical conductivity, lactate dehydrogenase (LDH), protein metabolism and DNA. The minimal inhibitory concentration and minimum bactericidal concentration of cinnamaldehyde were 256 and 512 μg/mL, respectively. Microscopy results showed disrupted cell wall and membrane, loss of cytoplasm, interior cavitation and unusual binary fission in the cinnamaldehyde-treated group. Electrical conductivity, LDH activity content and DNA extravasation in cinnamaldehyde-treated A. hydrophila increased by 7.14%, 16.75% and 20.29 μg/mL, respectively. Furthermore, nucleic acid fluorescence intensity and density decreased over time in the cinnamaldehyde-treated group. Taken together, these findings suggest that cinnamaldehyde can inhibit the growth of A. hydrophila by disrupting cell membranes and affecting protein metabolism.

Quorum quenching acylase impacts the viability and morphological change of Agrobacterium tumefaciens cells

Acylase is known as a quorum quenching enzyme that degrades N-acyl-homoserine lactones (AHLs), a key signaling molecule in a quorum sensing (QS) mechanism. Acylase I cleaves the acyl-chain in the chemical structures of AHLs, thereby exerting an anti-biofilm effect by the inhibition of bacterial cell-cell communication and resultant secretion of extracellular polymeric substances (EPS). However, the physical and physiological impacts of acylase on bacterial cells remain to be systematically elucidated. This study, therefore, investigated the effect of active and inactive acylase addition on the growth, viability, and cell morphologies of Agrobacterium tumefaciens. For comparison, active and inactive lysozymes were taken as positive controls. The results showed that active acylase inhibited A. tumefaciens cell growth at concentrations ranging from 0.1 to 1000 μg mL^-1, and so did active lysozyme. Fluorescent detection by Live/Dead staining underpinned that cell viability of A. tumefaciens decreased at concentrations higher than 0.1 μg mL^-1 for both acylase and lysozyme, although lysozyme inflicted higher degree of cellular damage. Moreover, atomic force microscopy unraveled a noticeable distortion of A. tumefaciens cells by both acylase and lysozyme. Together, the results showed that acylase not only blocked AHLs-based QS mechanisms but also compromised cell viability and altered surface morphology of A. tumefaciens cells, as observed by the addition of hydrolase.

Discovery of thieno[2,3-d]pyrimidin-4(3H)-one derivatives as a new class of ROCK inhibitors

Herein, we report the discovery of a series of thieno[2,3-d]pyrimidin-4(3H)-one derivatives as a new class of ROCK inhibitors. Structure-activity relationship studies of these compounds led to the identification of the most potent compound, 3-(3-methoxybenzyl)-6-(1H-pyrrolo[2,3-b]pyridin-4-yl)thieno[2,3-d]pyrimidin-4(3H)-one (8k), which showed IC₅₀ values of 0.004 μM and 0.001 μM against ROCK Ⅰ and ROCK Ⅱ, respectively. In vitro, 8k significantly reduced the phosphorylation level of ROCK downstream signaling protein and induce changes in cell morphology and migration. Overall, this study provides a promising lead compound for drug discovery targeting ROCKs.

Nanosecond pulsed current under plasma-producing conditions induces morphological alterations and stress fiber formation in human fibrosarcoma HT-1080 cells

Cold atmospheric plasma (CAP) is a promising means for various biomedical applications, including cancer therapy. Although the biological action of CAP is considered to be brought about by synergistic effects of reactive species and electrical factors of CAP, limited information is currently available on the contribution of electrical factors to CAP-induced cell responses. We have previously demonstrated that nanosecond pulsed current (nsPC) under CAP-producing conditions significantly promoted the motility of human HT-1080 cells. In this study, we explored the effects of nsPC on cell morphology associated with cell motility. We observed that nsPC stimulation caused extended cell shape, membrane protrusion formation, and increased cell surface area, but not cell death induction. nsPC stimulation also caused elevated intracellular ROS and Ca²⁺. HT-1080 cells can undergo two modes of cell motility, namely mesenchymal and ameboid motility, and we found that morphological features of mesenchymal motility was partly shared with nsPC-stimulated cells. Furthermore, nsPC-stimulated cells had extended stress fibers composed of filamentous actin. Taken together, this study provides a novel insight into the electrical aspect of CAP action, and we speculate that nsPC activates a certain mechanism involving intracellular signaling for stress fiber formation, leading to altered cell morphology and increased cell motility.

High production of triterpenoids in Yarrowia lipolytica through manipulation of lipid components

BACKGROUND

Lupeol exhibits novel physiological and pharmacological activities, such as anticancer and immunity-enhancing activities. However, cytotoxicity remains a challenge for triterpenoid overproduction in microbial cell factories. As lipophilic and relatively small molecular compounds, triterpenes are generally secreted into the extracellular space. The effect of increasing triterpene efflux on the synthesis capacity remains unknown.

RESULTS

In this study, we developed a strategy to enhance triterpene efflux through manipulation of lipid components in Y. lipolytica by overexpressing the enzyme Δ9-fatty acid desaturase (OLE1) and disturbing phosphatidic acid phosphatase (PAH1) and diacylglycerol kinase (DGK1). By this strategy combined with two-phase fermentation, the highest lupeol production reported to date was achieved, where the titer in the organic phase reached 381.67 mg/L and the total production was 411.72 mg/L in shake flasks, exhibiting a 33.20-fold improvement over the initial strain. Lipid manipulation led to a twofold increase in the unsaturated fatty acid (UFA) content, up to 61-73%, and an exceptionally elongated cell morphology, which might have been caused by enhanced membrane phospholipid biosynthesis flux. Both phenotypes accelerated the export of toxic products to the extracellular space and ultimately stimulated the capacity for triterpenoid synthesis, which was proven by the 5.11-fold higher ratio of extra/intracellular lupeol concentrations, 2.79-fold higher biomass accumulation and 2.56-fold higher lupeol productivity per unit OD in the modified strains. This strategy was also highly efficient for the biosynthesis of other triterpenes and sesquiterpenes, including α-amyrin, β-amyrin, longifolene, longipinene and longicyclene.

CONCLUSIONS

In conclusion, we successfully created a high-yield lupeol-producing strain via lipid manipulation. We demonstrated that the enhancement of lupeol efflux and synthesis capacity was induced by the increased UFA content and elongated cell morphology. Our study provides a novel strategy to promote the biosynthesis of valuable but toxic products in microbial cell factories.

Adaptation mechanisms of Rhodococcus sp. CNS16 under different temperature gradients: Physiological and transcriptome

Rhodococcus exhibits strong adaptability to environmental stressors and plays a crucial role in environmental bioremediation. However, seasonal changes in ambient temperature, especially rapid temperature drops exert an adverse effect on in situ bioremediation. In this paper, we studied the cell morphology and fatty acid composition of an aniline-degrading strain Rhodococcus sp. CNS16 at temperatures of 30 °C, 20 °C, and 10 °C. At suboptimal temperatures, cell morphology of CNS16 changed from short rod-shaped to long rod or irregular shaped, and the proportion of unsaturated fatty acids was upregulated. Transcriptomic technologies were then utilized to gain detailed insights into the adaptive mechanisms of CNS16 subjected to suboptimal temperatures. The results showed that the number of gene responses was significantly higher at 10 °C than that at 20 °C. The inhibition of peptidoglycan synthase expression and up-regulation of Filamentous Temperature Sensitive as well as unsaturated fatty acid synthesis genes at suboptimal temperatures might be closely related to corresponding changes in cell morphology and fatty acids composition. Strain CNS16 showed loss of catalase and superoxide dismutase activity, and utilized thioredoxin-dependent thiol peroxidase to resist oxidative stress. The up-regulation of carotenoid and Vitamin B2 synthesis at 10 °C might also be involved in the resistance to oxidative stress. Amino acid metabolism, coenzyme and vitamin metabolism, ABC transport, and energy metabolism are essential for peptidoglycan synthesis and regulation of cellular metabolism; therefore, synergistically resisting environmental stress. This study provides a mechanistic basis for the regulation of aniline degradation in Rhodococcus sp. CNS16 at low temperatures.

Regulation of Stem Cell Functions by Micro-Patterned Structures

Micro-patterned surfaces have been broadly used to control the morphology of stem cells for investigation of the influence of physiochemical and biological cues on stem cell functions. Different structures of micro-patterned surfaces can be prepared by photolithography through designing the photomask features. Cell spreading area, geometry, aspect ratio, and alignment can be regulated by the micro-patterned structures. Their influences on adipogenic, osteogenic, and smooth muscle differentiation of the human bone marrow-derived mesenchymal stem cells are compared and investigated in details. Variation of cell morphology can trigger rearrangement of cytoskeleton, generating cytoskeletal mechanical stimulation and consequently inducing differentiation of mesenchymal stem cells into different lineages. This chapter summarizes the latest development of regulation of mesenchymal stem cell morphology by micro-patterns and the influence on the behaviors and differentiation of the mesenchymal stem cells.

Investigating the mechanisms behind extensive death in human cancer cells following nanoparticle assisted photo-thermo-radiotherapy

We have recently reported the synthesis and characterization of gold-coated iron oxide nanoparticle and demonstrated such a nanoparticle (Au@Fe₂O₃ NP) was able to significantly enhance the lethal effects of photo-thermo-radiotherapy. The purpose of this study was to determine the mechanisms behind such an enhancement by investigating the changes induced in cancer cell viability, proliferation, and morphology as well as monitoring the alteration of some genes which play important role in the process of cell death. Using MTT assay and transmission electron microscopy (TEM), the KB cells viability and morphology were assessed after treating with various combinations of NPs, photothermal therapy (PTT), and radiotherapy (RT). Clonogenic assay was used to assess the proliferation ability of treated KB cells. Nanoparticle internalization into the cells was investigated by TEM and inductively coupled plasma (ICP). During the treatment procedures, temperature changes were monitored using an IR-camera. Furthermore, the changes occurred in Bax, BCL2 and HSP70 genes expression level were measured using real-time PCR. The results showed that combination of NP, PTT, and RT caused more cell death compared to PTT or RT alone. Following such a combination therapy, massive cell injury was detected. We also observed an extensive increase in Bax/Bcl2 ratio and HSP70 expression for the KB cells treated by combination therapy procedure. Our results showed that massive cell injury and apoptosis induction are the main reasons of extensive cell death observed in cancer cells when a nanoparticle assisted photo-thermo-radiotherapy procedure is applied.

Assessment of cell viability in four novel endodontic sealers

Objective

The aim of this study was to evaluate the viability of human periodontal ligament (PDL) cells on MTA-Fillapex, GuttaFlow 2, TotalFill Sealer, and BioRoot™ RCS in comparison to conventional epoxy resin-based (AH Plus) and zinc oxide-eugenol-based (Roth's 801) sealers.

Materials and Methods

Sealers were divided into two groups, and five coverslips for each material per group were prepared. In the first group, PDLs were added immediately after the preparation of sealers (Fresh Group), and in the second, PDLs were added after 24 h. PDLs were cultured for 72 h and afterward, counted using standard hematocytometry. A Mann-Whitney U-test and Kruskal-Wallis test were used for the statistical analysis. The level of significance was set at 5%. Furthermore, cell morphology was assessed by confocal microscopy.

Results

The number of viable cells for the 24 h-set groups was higher than the freshly mixed in all sealers except Roth's 801. In both groups, GuttaFlow 2 presented the highest number of viable cells. In a descending order of cells' survival, TotalFill, BioRoot, and MTA-Fillapex are following and the conventional sealers, AH Plus and Roth's 801, seem not to exhibit the biological properties of the others. Cells grown on GuttaFlow 2, TotalFill, and BioRoot were observed to be well-formed. In contrast, MTA-Fillapex exhibited untypical morphology. No cells were detected on the surfaces of AH Plus, as well as Roth's 801.

Conclusions

All novel sealers presented increased cell viability in comparison to conventional sealers. GuttaFlow 2 exhibited the highest cell viability.

Betaine suppresses cell proliferation by increasing oxidative stress-mediated apoptosis and inflammation in DU-145 human prostate cancer cell line

Prostate cancer is the main cause of cancer-related mortality in men around the world and an important health problem. DU-145 human prostate cancer cells provide an opportunity to investigate prostate cancer. Betaine has a number of anticancer effects, such as inactivation of carcinogens, inhibition of cancer cell proliferation, angiogenesis, and metastasis. However, there is no study investigating the effects of betaine on DU-145 cells. The aim of this study was to evaluate the effects of different concentrations of betaine on the oxidative stress, apoptosis, and inflammation on DU-145 cells. Firstly, we proved the cytotoxic activity of betaine (0 to 150 mg/ml) on DU-145 cells by using 3-(4, 5-dimethylthiazol, 2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and defined the optimal concentration of betaine. Then, by employing the doses found in MTT, the levels of antioxidant (GSH, SOD, CAT, and TAS) and oxidant (MDA and TOS) molecules, pro-inflammatory cytokines (TNF-a and IL-6), apoptotic proteins (CYCS and CASP3), and DNA fragmentation were measured. Morphological changes and apoptosis were evaluated using H&E technique, Bax and Bcl-2 immunohistochemistry. Results suggested that betaine caused oxidative stress, inflammation, inhibition of cell growth, apoptosis, and morphological alterations in DU-145 cells dose-dependently. Furthermore, treatments with increasing betaine concentrations decreased the antioxidant levels in cells. We actually revealed that betaine, known as an antioxidant, may prevent cell proliferation by acting as an oxidant in certain doses. In conclusion, betaine may act as a biological response modifier in prostate cancer treatment in a dose-dependent manner.

Ilyomonas limi gen. nov., sp. nov., a new member of the family Chitinophagaceae isolated from mud

A Gram-strain negative, aerobic, catalase and oxidase positive, non-motile, short rod-shaped bacterium, designated 17mud1-8^T, was isolated from mud collected from Nowon-gu, Seoul, South Korea. The strain was found to be able to grow at 10-40 °C (optimum 28-30 °C), pH 5.0-8.0 (optimum 7.0), and in the absence of NaCl. The nearly full-length 16S rRNA gene of strain 17mud1-8^T exhibits sequence similarity of 94.1% with that of Panacibacter ginsenosidivorans Gsoil 1550^T, followed by 93.6% sequence similarity with Parafilimonas terrae DSM 28286^T. Phylogenetic analysis indicated that strain 17mud1-8^T belongs to the family Chitinophagaceae, sharing approximately 94.1-91.9% sequence similarity with members of closely related genera. The respiratory quinone was identified as MK-7. The predominant fatty acids were found to consist of iso-C_15:0, iso-C_17:1ω5c and iso-C_15:1 G. The polar lipids were identified as phosphatidylethanolamine, an unidentified aminophospholipid, an unidentified glycolipid, ten unidentified aminolipids and seven unidentified lipids. The draft genome of 17mud1-8^T has G+C content of 40.9 mol% and a 5.8 Mb chromosome. On the basis of the phenotypic and genotypic properties, and phylogenetic inference, strain 17mud1-8^T was found to represent a novel genus in the family Chitinophagaceae, for which the name Ilyomonas limi gen. nov., sp. nov. is proposed, with the type strain 17mud1-8^T(=KCTC 52874^T = NBRC 112826^T).