1
|
Song W, Tung CK, Lu YC, Pardo Y, Wu M, Das M, Kao DI, Chen S, Ma M. Dynamic self-organization of microwell-aggregated cellular mixtures. Soft Matter 2016; 12:5739-5746. [PMID: 27275624 DOI: 10.1039/c6sm00456c] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cells with different cohesive properties self-assemble in a spatiotemporal and context-dependent manner. Previous studies on cell self-organization mainly focused on the spontaneous structural development within a short period of time during which the cell numbers remained constant. However the effect of cell proliferation over time on the self-organization of cells is largely unexplored. Here, we studied the spatiotemporal dynamics of self-organization of a co-culture of MDA-MB-231 and MCF10A cells seeded in a well defined space (i.e. non-adherent microfabricated wells). When cell-growth was chemically inhibited, high cohesive MCF10A cells formed a core surrounded by low cohesive MDA-MB-231 cells on the periphery, consistent with the differential adhesion hypothesis (DAH). Interestingly, this aggregate morphology was completely inverted when the cells were free to grow. At an initial seeding ratio of 1 : 1 (MDA-MB-231 : MCF10A), the fast growing MCF10A cells segregated in the periphery while the slow growing MDA-MB-231 cells stayed in the core. Another morphology developed at an inequal seeding ratio (4 : 1), that is, the cell mixtures developed a side-by-side aggregate morphology. We conclude that the cell self-organization depends not only on the cell cohesive properties but also on the cell seeding ratio and proliferation. Furthermore, by taking advantage of the cell self-organization, we purified human embryonic stem cells-derived pancreatic progenitors (hESCs-PPs) from co-cultured feeder cells without using any additional tools or labels.
Collapse
Affiliation(s)
- Wei Song
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
| | - Chih-Kuan Tung
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA. and Department of Physics, North Carolina A&T State University, Greensboro, North Carolina 27411, USA
| | - Yen-Chun Lu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
| | - Yehudah Pardo
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
| | - Mingming Wu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
| | - Moumita Das
- School of Physics and Astronomy, Rochester Institute of Technology, Rochester, New York 14623, USA
| | - Der-I Kao
- Department of Surgery, Weill Medical College of Cornell University, New York City, New York 10065, USA
| | - Shuibing Chen
- Department of Surgery, Weill Medical College of Cornell University, New York City, New York 10065, USA
| | - Minglin Ma
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
| |
Collapse
|
2
|
Kao DI, Lacko LA, Ding BS, Huang C, Phung K, Gu G, Rafii S, Stuhlmann H, Chen S. Endothelial cells control pancreatic cell fate at defined stages through EGFL7 signaling. Stem Cell Reports 2015; 4:181-9. [PMID: 25601205 PMCID: PMC4325230 DOI: 10.1016/j.stemcr.2014.12.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 12/09/2014] [Accepted: 12/10/2014] [Indexed: 01/18/2023] Open
Abstract
Although endothelial cells have been shown to affect mouse pancreatic development, their precise function in human development remains unclear. Using a coculture system containing human embryonic stem cell (hESC)-derived progenitors and endothelial cells, we found that endothelial cells play a stage-dependent role in pancreatic development, in which they maintain pancreatic progenitor (PP) self-renewal and impair further differentiation into hormone-expressing cells. The mechanistic studies suggest that the endothelial cells act through the secretion of EGFL7. Consistently, endothelial overexpression of EGFL7 in vivo using a transgenic mouse model resulted in an increase of PP proliferation rate and a decrease of differentiation toward endocrine cells. These studies not only identified the role of EGFL7 as the molecular handle involved in the crosstalk between endothelium and pancreatic epithelium, but also provide a paradigm for using hESC stepwise differentiation to dissect the stage-dependent roles of signals controlling organogenesis. Endothelial cells play a stage-dependent role in embryonic pancreatic development Endothelial cells maintain pancreatic progenitor self-renewal by secreting EGFL7 Overexpression of EGFL7 in vivo increases pancreatic progenitor proliferation
Collapse
Affiliation(s)
- Der-I Kao
- Departments of Surgery and Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA
| | - Lauretta A Lacko
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Bi-Sen Ding
- Howard Hughes Medical Institute, Ansary Stem Cell Institute, Department of Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Chen Huang
- Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kathleen Phung
- Departments of Surgery and Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA
| | - Guoqiang Gu
- Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Shahin Rafii
- Howard Hughes Medical Institute, Ansary Stem Cell Institute, Department of Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Heidi Stuhlmann
- Department of Cell and Developmental Biology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Shuibing Chen
- Departments of Surgery and Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA.
| |
Collapse
|
3
|
Song W, An D, Kao DI, Lu YC, Dai G, Chen S, Ma M. Nanofibrous microposts and microwells of controlled shapes and their hybridization with hydrogels for cell encapsulation. ACS Appl Mater Interfaces 2014; 6:7038-44. [PMID: 24806031 PMCID: PMC4039346 DOI: 10.1021/am502046h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 05/07/2014] [Indexed: 05/24/2023]
Abstract
A simple, robust, and cost-effective method is developed to fabricate nanofibrous micropatterns particularly microposts and microwells of controlled shapes. The key to this method is the use of an easily micropatternable and intrinsically conductive metal alloy as a template to collect electrospun fibers. The micropatterned alloy allows conformal fiber deposition with high fidelity on its topographical features and in situ formation of diverse, free-standing micropatterned nanofibrous membranes. Interestingly, these membranes can serve as structural frames to form robust hydrogel micropatterns that may otherwise be fragile on their own. These hybrid micropatterns represent a new platform for cell encapsulation where the nanofiber frames enhance the mechanical integrity of hydrogel and the micropatterns provide additional surface area for mass transfer and cell loading.
Collapse
Affiliation(s)
- Wei Song
- Department
of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Duo An
- Department
of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Der-I Kao
- Department
of Surgery, Weill Medical College of Cornell
University, New York, New York 10065, United
States
| | - Yen-Chun Lu
- Department
of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Guohao Dai
- Center
for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Shuibing Chen
- Department
of Surgery, Weill Medical College of Cornell
University, New York, New York 10065, United
States
| | - Minglin Ma
- Department
of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| |
Collapse
|
4
|
Abstract
Diabetes mellitus, which affects 346 million people, is one of the leading causes of death worldwide. Pancreatic β-cells, existing in the islets of Langerhans, play central roles in the progression of diabetes. An efficient strategy to produce functional pancreatic β-cells is important for both transplantation therapy and disease modeling of diabetes. Human pluripotent stem cells, including human embryonic stem cells and induced pluripotent stem cells, provide unlimited starting materials to generate differentiated cells for regenerative studies. Significant progress has been made in human embryonic/induced pluripotent stem cell differentiation in the last several years. However, efficient generation of mature pancreatic β-cells with complete functional capabilities has not yet been accomplished. Here, we review recent successes as well as the technical and theoretical challenges in the use of pluripotent stem cell-derived pancreatic β-cells for disease modeling and replacement therapy of diabetes.
Collapse
Affiliation(s)
- Der-I Kao
- Department of Surgery, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Shuibing Chen
- Department of Biochemistry, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| |
Collapse
|
5
|
Kao DI, Aldridge GM, Weiler IJ, Greenough WT. Altered mRNA transport, docking, and protein translation in neurons lacking fragile X mental retardation protein. Proc Natl Acad Sci U S A 2010; 107:15601-6. [PMID: 20713728 PMCID: PMC2932564 DOI: 10.1073/pnas.1010564107] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Fragile X syndrome is caused by the absence of functional fragile X mental retardation protein (FMRP), an RNA binding protein. The molecular mechanism of aberrant protein synthesis in fmr1 KO mice is closely associated with the role of FMRP in mRNA transport, delivery, and local protein synthesis. We show that GFP-labeled Fmr1 and CaMKIIalpha mRNAs undergo decelerated motion at 0-40 min after group I mGluR stimulation, and later recover at 40-60 min. Then we investigate targeting of mRNAs associated with FMRP after neuronal stimulation. We find that FMRP is synthesized closely adjacent to stimulated mGluR5 receptors. Moreover, in WT neurons, CaMKIIalpha mRNA can be delivered and translated in dendritic spines within 10 min in response to group I mGluR stimulation, whereas KO neurons fail to show this response. These data suggest that FMRP can mediate spatial mRNA delivery for local protein synthesis in response to synaptic stimulation.
Collapse
MESH Headings
- Animals
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/genetics
- Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism
- Cells, Cultured
- Dendrites/metabolism
- Fragile X Mental Retardation Protein/genetics
- Fragile X Mental Retardation Protein/metabolism
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Hippocampus/cytology
- In Situ Hybridization, Fluorescence
- Kinetics
- Methoxyhydroxyphenylglycol/analogs & derivatives
- Methoxyhydroxyphenylglycol/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Fluorescence
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Protein Binding
- Protein Biosynthesis
- RNA Transport
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Metabotropic Glutamate 5
- Receptors, Metabotropic Glutamate/genetics
- Receptors, Metabotropic Glutamate/metabolism
- Time Factors
Collapse
Affiliation(s)
- Der-I Kao
- Department of Cell and Developmental Biology
- Beckman Institute
| | | | | | - William T. Greenough
- Department of Cell and Developmental Biology
- Beckman Institute
- Neuroscience Program, and
- Departments of Psychology and Psychiatry, University of Illinois at Urbana–Champaign, Urbana, IL 61801
| |
Collapse
|
6
|
Chen CH, Kao DI, Chan SP, Kao TC, Lin JY, Cheng SC. Functional links between the Prp19-associated complex, U4/U6 biogenesis, and spliceosome recycling. RNA 2006; 12:765-74. [PMID: 16540691 PMCID: PMC1440898 DOI: 10.1261/rna.2292106] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The Prp19-associated complex, consisting of at least eight protein components, is involved in spliceosome activation by specifying the interaction of U5 and U6 with pre-mRNA for their stable association with the spliceosome after U4 dissociation. We show here that yeast cells depleted of one or two of the Prp19-associated components, accumulate the free form of U4. In NTC25-deleted cells, the level of U6 was also reduced. Extracts prepared from NTC25-deleted cells contained neither free U4 nor U6 and were ineffective in spliceosome recycling in the in vitro splicing reaction. Overexpression of U6 partially rescued the temperature-sensitive growth defect and decreased the relative amount of free U4 in NTC25-deleted cells, indicating that the accumulation of free U4 was a consequence of insufficient amounts of U6 snRNA. Extracts prepared from U6-overproducing NTC25-deleted cells containing free-form U6 were capable of spliceosome recycling, suggesting a role of free U6 RNP in spliceosome recycling. Our results demonstrate that in addition to direct participation in spliceosome activation, the Prp19-associated complex has an indirect role in spliceosome recycling through affecting the biogenesis of U4/U6 snRNP in the in vivo splicing reaction.
Collapse
Affiliation(s)
- Chun-Hong Chen
- Institute of Molecular Biology, Academia Sinica, Nankang, Taiwan, Republic of China
| | | | | | | | | | | |
Collapse
|
7
|
Abstract
During spliceosome activation, a large structural rearrangement occurs that involves the release of two small nuclear RNAs, U1 and U4, and the addition of a protein complex associated with Prp19p. We show here that the Prp19p-associated complex is required for stable association of U5 and U6 with the spliceosome after U4 is dissociated. Ultraviolet crosslinking analysis revealed the existence of two modes of base pairing between U6 and the 5' splice site, as well as a switch of such base pairing from one to the other that required the Prp19p-associated complex during spliceosome activation. Moreover, a Prp19p-dependent structural change in U6 small nuclear ribonucleoprotein particles was detected that involves destabilization of Sm-like (Lsm) proteins to bring about interactions between the Lsm binding site of U6 and the intron sequence near the 5' splice site, indicating dynamic association of Lsm with U6 and a direct role of Lsm proteins in activation of the spliceosome.
Collapse
Affiliation(s)
- Shih-Peng Chan
- Institute of Microbiology and Immunology, National Yang-Ming University, Shih-Pai, Taiwan, Republic of China
| | | | | | | |
Collapse
|