scholarly journals Single-Cell Transcriptomic Comparison of Human Fetal Retina, hPSC-Derived Retinal Organoids, and Long-Term Retinal Cultures

Cell Reports ◽  
2020 ◽  
Vol 30 (5) ◽  
pp. 1644-1659.e4 ◽  
Author(s):  
Akshayalakshmi Sridhar ◽  
Akina Hoshino ◽  
Connor R. Finkbeiner ◽  
Alex Chitsazan ◽  
Li Dai ◽  
...  
Keyword(s):  
Single Cell ◽  
Fetal Retina ◽  
Retinal Cultures

Single cell capture, isolation, and long‐term in‐situ imaging using quantitative self‐interference spectroscopy

2021 ◽  
Author(s):  
Rongxin Fu ◽  
Ya Su ◽  
Ruliang Wang ◽  
Xue Lin ◽  
Xiangyu Jin ◽  
...  
Keyword(s):  
Single Cell ◽  
Cell Capture ◽  
In Situ Imaging

scholarly journals Development of single-cell-level microfluidic technology for long-term growth visualization of living cultures of Mycobacterium smegmatis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Han Wang ◽  
Gloria M. Conover ◽  
Song-I Han ◽  
James C. Sacchettini ◽  
Arum Han
Keyword(s):  
Drug Treatment ◽  
Single Cell ◽  
Mycobacterium Smegmatis ◽  
Culture Media ◽  
Low Cost ◽  
Bacterial Pathogen ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Phenotype

AbstractAnalysis of growth and death kinetics at single-cell resolution is a key step in understanding the complexity of the nonreplicating growth phenotype of the bacterial pathogen Mycobacterium tuberculosis. Here, we developed a single-cell-resolution microfluidic mycobacterial culture device that allows time-lapse microscopy-based long-term phenotypic visualization of the live replication dynamics of mycobacteria. This technology was successfully applied to monitor the real-time growth dynamics of the fast-growing model strain Mycobacterium smegmatis (M. smegmatis) while subjected to drug treatment regimens during continuous culture for 48 h inside the microfluidic device. A clear morphological change leading to significant swelling at the poles of the bacterial membrane was observed during drug treatment. In addition, a small subpopulation of cells surviving treatment by frontline antibiotics was observed to recover and achieve robust replicative growth once regular culture media was provided, suggesting the possibility of identifying and isolating nonreplicative mycobacteria. This device is a simple, easy-to-use, and low-cost solution for studying the single-cell phenotype and growth dynamics of mycobacteria, especially during drug treatment.

scholarly journals Progenitor identification and SARS-CoV-2 infection in long-term human distal lung organoid cultures

2020 ◽  
Author(s):  
Ameen A. Salahudeen ◽  
Shannon S. Choi ◽  
Arjun Rustagi ◽  
Junjie Zhu ◽  
Sean M. de la O ◽  
...  
Keyword(s):  
Lung Disease ◽  
Single Cell ◽  
Basal Cell ◽  
Human Lung ◽  
Basal Cells ◽  
Ciliated Cells ◽  
Club Cells ◽  
Distal Lung

ABSTRACTThe distal lung contains terminal bronchioles and alveoli that facilitate gas exchange and is affected by disorders including interstitial lung disease, cancer, and SARS-CoV-2-associated COVID-19 pneumonia. Investigations of these localized pathologies have been hindered by a lack of 3D in vitro human distal lung culture systems. Further, human distal lung stem cell identification has been impaired by quiescence, anatomic divergence from mouse and lack of lineage tracing and clonogenic culture. Here, we developed robust feeder-free, chemically-defined culture of distal human lung progenitors as organoids derived clonally from single adult human alveolar epithelial type II (AT2) or KRT5+ basal cells. AT2 organoids exhibited AT1 transdifferentiation potential, while basal cell organoids progressively developed lumens lined by differentiated club and ciliated cells. Organoids consisting solely of club cells were not observed. Upon single cell RNA-sequencing (scRNA-seq), alveolar organoids were composed of proliferative AT2 cells; however, basal organoid KRT5+ cells contained a distinct ITGA6+ITGB4+ mitotic population whose proliferation segregated to a TNFRSF12Ahi subfraction. Clonogenic organoid growth was markedly enriched within the TNFRSF12Ahi subset of FACS-purified ITGA6+ITGB4+ basal cells from human lung or derivative organoids. In vivo, TNFRSF12A+ cells comprised ~10% of KRT5+ basal cells and resided in clusters within terminal bronchioles. To model COVID-19 distal lung disease, we everted the polarity of basal and alveolar organoids to rapidly relocate differentiated club and ciliated cells from the organoid lumen to the exterior surface, thus displaying the SARS-CoV-2 receptor ACE2 on the outwardly-facing apical aspect. Accordingly, basal and AT2 “apical-out” organoids were infected by SARS-CoV-2, identifying club cells as a novel target population. This long-term, feeder-free organoid culture of human distal lung alveolar and basal stem cells, coupled with single cell analysis, identifies unsuspected basal cell functional heterogeneity and exemplifies progenitor identification within a slowly proliferating human tissue. Further, our studies establish a facile in vitro organoid model for human distal lung infectious diseases including COVID-19-associated pneumonia.

scholarly journals More than efficacy revealed by single-cell analysis of antiviral therapeutics

2019 ◽  
Author(s):  
Wu Liu ◽  
Mehmet U. Caglar ◽  
Zhangming Mao ◽  
Andrew Woodman ◽  
Jamie J. Arnold ◽  
...  
Keyword(s):  
Single Cell ◽  
Drug Targets ◽  
Single Cell Analysis ◽  
Single Cells ◽  
Principal Component ◽  
Viral Population ◽  
Cell Analysis ◽  
Toxic Dose ◽  
Time Required

SUMMARYDevelopment of antiviral therapeutics emphasizes minimization of the effective dose and maximization of the toxic dose, first in cell culture and later in animal models. Long-term success of an antiviral therapeutic is determined not only by its efficacy but also by the duration of time required for drug-resistance to evolve. We have developed a microfluidic device comprised of ~6000 wells, with each well containing a microstructure to capture single cells. We have used this device to characterize enterovirus inhibitors with distinct mechanisms of action. In contrast to population methods, single-cell analysis reveals that each class of inhibitor interferes with the viral infection cycle in a manner that can be distinguished by principal component analysis. Single-cell analysis of antiviral candidates reveals not only efficacy but also properties of the members of the viral population most sensitive to the drug, the stage of the lifecycle most affected by the drug, and perhaps even if the drug targets an interaction of the virus with its host.

scholarly journals Rapid and Simple Cryopreservation of Anaerobic Ammonium-Oxidizing Bacteria

2012 ◽  
Vol 78 (8) ◽  
pp. 3010-3013 ◽  
Author(s):  
Kim Heylen ◽  
Katharina Ettwig ◽  
Ziye Hu ◽  
Mike Jetten ◽  
Boran Kartal
Keyword(s):  
Cell Culture ◽  
Single Cell ◽  
Anammox Bacteria ◽  
Content Type ◽  
Growth Recovery ◽  
Activity Recovery ◽  
Simple Protocol ◽  
Single Cell Culture ◽  
Preservation Conditions

ABSTRACTA quick and simple protocol for long-term cryopreservation of anaerobic ammonium-oxidizing bacteria (anammox bacteria) was developed. After 29 weeks of preservation at −80°C, activity recovery for all tested cultures under at least one of the applied sets of preservation conditions was observed. Growth recovery was also demonstrated for a single-cell culture of “CandidatusKuenenia stuttgartiensis.”

scholarly journals Dependence of Spreading and Differentiation of Mesenchymal Stem Cells on Micropatterned Surface Area

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Wei Song ◽  
Naoki Kawazoe ◽  
Guoping Chen
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Single Cell ◽  
Adipogenic Differentiation ◽  
Cell Spreading ◽  
Poly Vinyl Alcohol ◽  
Cell Array ◽  
Cell Functions

Micropatterning technology is a highly advantageous approach for directly assessing and comparing the effects of different factors on stem cell functions. In this study, poly(vinyl alcohol)- (PVA-) micropatterned polystyrene surfaces were prepared using photoreactive PVA and ultraviolet photolithography with a photomask. The micropatterned surface was suitable for single-cell array formation and long-term cell culture due to the nanometer thickness of nonadhesive PVA layer. Different degrees of cell spreading with the same cell shape were established by adjusting the sizes of circular, cell-adhesive polystyrene micropatterns. Cell spreading and differentiation of mesenchymal stem cells (MSCs) on the micropatterns were investigated at the single-cell level. The assembly and organization of the cytoskeleton were regulated by the degree of cell spreading. Individual MSCs on large circular micropatterns exhibited a more highly ordered arrangement of actin filaments than did those on the small circular micropatterns. Furthermore, the differentiation of MSCs was dependent on the degree of cell spreading. Increased cell spreading facilitated the osteogenic differentiation but suppressed the adipogenic differentiation of MSCs. This micropatterning method is valuable for stem cell research in tissue engineering and regenerative medicine.

scholarly journals Proteorhodopsin Overproduction Enhances the Long-Term Viability of Escherichia coli

2019 ◽  
Vol 86 (1) ◽  
Author(s):  
Yizhi Song ◽  
Michaël L. Cartron ◽  
Philip J. Jackson ◽  
Paul A. Davison ◽  
Mark J. Dickman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Raman Spectroscopy ◽  
Cell Membrane ◽  
Single Cell ◽  
Marine Bacteria ◽  
Membrane Area ◽  
Content Type ◽  
E Coli ◽  
Wide Range

ABSTRACT Genes encoding the photoreactive protein proteorhodopsin (PR) have been found in a wide range of marine bacterial species, reflecting the significant contribution that PR makes to energy flux and carbon cycling in ocean ecosystems. PR can also confer advantages to enhance the ability of marine bacteria to survive periods of starvation. Here, we investigate the effect of heterologously produced PR on the viability of Escherichia coli. Quantitative mass spectrometry shows that E. coli, exogenously supplied with the retinal cofactor, assembles as many as 187,000 holo-PR molecules per cell, accounting for approximately 47% of the membrane area; even cells with no retinal synthesize ∼148,000 apo-PR molecules per cell. We show that populations of E. coli cells containing PR exhibit significantly extended viability over many weeks, and we use single-cell Raman spectroscopy (SCRS) to detect holo-PR in 9-month-old cells. SCRS shows that such cells, even incubated in the dark and therefore with inactive PR, maintain cellular levels of DNA and RNA and avoid deterioration of the cytoplasmic membrane, a likely basis for extended viability. The substantial proportion of the E. coli membrane required to accommodate high levels of PR likely fosters extensive intermolecular contacts, suggested to physically stabilize the cell membrane and impart a long-term benefit manifested as extended viability in the dark. We propose that marine bacteria could benefit similarly from a high PR content, with a stabilized cell membrane extending survival when those bacteria experience periods of severe nutrient or light limitation in the oceans. IMPORTANCE Proteorhodopsin (PR) is part of a diverse, abundant, and widespread superfamily of photoreactive proteins, the microbial rhodopsins. PR, a light-driven proton pump, enhances the ability of the marine bacterium Vibrio strain AND4 to survive and recover from periods of starvation, and heterologously produced PR extends the viability of nutrient-limited Shewanella oneidensis. We show that heterologously produced PR enhances the viability of E. coli cultures over long periods of several weeks and use single-cell Raman spectroscopy (SCRS) to detect PR in 9-month-old cells. We identify a densely packed and consequently stabilized cell membrane as the likely basis for extended viability. Similar considerations are suggested to apply to marine bacteria, for which high PR levels represent a significant investment in scarce metabolic resources. PR-stabilized cell membranes in marine bacteria are proposed to keep a population viable during extended periods of light or nutrient limitation, until conditions improve.

Long-Term Gene-Silencing Effects of siRNA Introduced by Single-Cell Electroporation into Postmitotic CNS Neurons

2011 ◽  
Vol 36 (8) ◽  
pp. 1482-1489 ◽  
Author(s):  
Masahiko Tanaka ◽  
Minami Asaoka ◽  
Yuchio Yanagawa ◽  
Naohide Hirashima
Keyword(s):  
Gene Silencing ◽  
Single Cell ◽  
Cell Electroporation ◽  
Cns Neurons ◽  
Single Cell Electroporation
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