1. Developmental Biology
  2. Stem Cells and Regenerative Medicine
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Spatiotemporal mosaic self-patterning of pluripotent stem cells using CRISPR interference

  1. Ashley RG Libby
  2. David A Joy
  3. Po-Lin So
  4. Mohammad A Mandegar
  5. Jonathon M Muncie
  6. Federico N Mendoza-Camacho
  7. Valerie M Weaver
  8. Bruce R Conklin
  9. Todd C McDevitt  Is a corresponding author
  1. Gladstone Institute of Cardiovascular Disease, United States
  2. University of California San Francisco, United States
  3. University of California Berkeley, University of California San Francisco, United States
  4. University of California, United States
Research Article
Cite this article as: eLife 2018;7:e36045 doi: 10.7554/eLife.36045
5 figures, 1 table and 2 additional files

Figures

Figure 1 with 4 supplements
CRISPRi of ROCK1 and CDH1 modulate physical properties of the cell.

(A) Schematic of ROCK1 and CDH1 within a cell. CDH1 is a trans-membrane adhesion molecule that locates to the borders of cells and ROCK1 is a cytoplasmic kinase that acts upon non-muscle myosin II. (B) Schematic of the CRISPRi system. Doxycycline addition to the hiPSC culture media leads to the expression of mCherry and dCas9-KRAB to induce knockdown of target gene. (C) qPCR and western blot quantification of knockdown timing; knockdown of both mRNA and protein were achieved by day three of DOX treatment when compared to untreated hiPSCs (p<0.05, n = 3, data represent mean ± SD). (D) Brightfield imaging of knockdown hiPSCs indicated morphological differences in colony shape (white arrows) and cell extensions (black arrows) at colony borders. (E) Live reporter fluorescence for dCas9-KRAB expression (red) and immunostaining for CDH1 (gray) demonstrated loss of CDH1 in induced CDH1 CRISPRi hiPSCs, but maintenance of CDH1 contacts in the off-target control and ROCK1 KD hiPSCs. (F) Atomic force microscopy (AFM) of knockdown populations exhibited a twofold increase in Young’s elastic modulus of ROCK1 knockdown cells compared to control and CDH1 knockdown cells (p<0.05, n = 36, 65, 72 force points for Control, ROCK1 KD, and CDH1 KD, respectively, area under curve = 1).

https://doi.org/10.7554/eLife.36045.003
Figure 1—figure supplement 1
Protein KD time course for ROCK1 and CDH1.

(A) Western blot reflecting KD time course of ROCK1 and CDH1 over 6 days. (B) Western blot of ROCK1 and CDH1 protein levels in KD cells. (C) Densitometry quantification of CDH1 and ROCK1 protein levels in both the ROCK KD cells and the CDH1 KD cells. CDH1 was only significantly different in cells where CDH1 was KD. ROCK1 protein levels exhibited a significant decrease in both CDH1 and ROCK1 (p<0.01).

https://doi.org/10.7554/eLife.36045.004
Figure 1—figure supplement 2
Morphology of ROCK1 KD hiPSCs.

Morphology of ROCK1 KD cells compared to WT cells treated with small molecule inhibitor of ROCK1, Y-27632. The ROCK1 KD and the Y-27632 treated cells displayed cell protrusions (white arrowheads) at the borders of colonies when compared to uninhibited WT cells.

https://doi.org/10.7554/eLife.36045.005
Figure 1—figure supplement 3
Maintenance of tight junctions in KD hiPSCs.

(A) Immunostaining of zona occludens 1 (ZO-1) in pure populations of hiPSCs after 6 days of induced KD of ROCK1 or CDH1. (B) Population distribution of contact angles before and after DOX treatment measured at ZO-1 junctions. The contact angles of KD cells did not differ significantly compared to the off-target CRISPRi guide control. Dotted lines delineate quartiles. (p<0.05; n = 15 colonies, 50 angles per colony).

https://doi.org/10.7554/eLife.36045.006
Figure 1—figure supplement 4
Maintenance of normal hiPSC karyotypes.

(A) Vector map of constitutive GFP cloned into WT hiPSCs to create the WT-GFP line. (B) Karyotypes of all cell lines used in experiments displayed no chromosomal defects. Passage numbers are indicated by p#.

https://doi.org/10.7554/eLife.36045.007
Figure 2 with 2 supplements
Cell-autonomous pattern emergence in mixed population colonies.

(A) Schematic of experimental timeline. WT-GFP and ROCK1- or CDH1- CRISPRi hiPSCs were pretreated with doxycycline for 6 days before aggregation in pyramidal microwells and re-plating as mixed colonies. (B) Live cell imaging of pattern emergence over time from mixing colonies. Control populations remain mixed, ROCK1 KD hiPSCs cluster radially at borders of colonies, and CDH1 KD populations sort themselves from WT-GFP hiPSCs regardless of location within colony. (C) Confocal microscopy of patterned colonies of hiPSCs with KD induction prior to mixing. (D) Quantification of the radial distribution of KD cells in pre-induced mixed colonies. The ratio of inner cell area to outer cell area normalized to total cell area is displayed (n = 25,* and # indicate significance, p<0.05). (E) Schematic of experimental timeline for WT-GFP and ROCK1- or CDH1-CRISPRi hiPSCs treated with doxycycline upon re-plating as mixed colonies. (F) Live cell imaging of pattern emergence in post-mixing induction colonies, where CRISPRi KD is induced after cell population mixing. (G) Confocal microscopy of patterned hiPSC colonies with KD induction upon mixing populations, where ROCK KD cells stack vertically with WT-GFP hiPSCs. (H) Quantification of the radial distribution of KD cells in post-induced mixed colonies. The ratio of inner cell area to outer cell area normalized to total cell area is displayed (n = 20).

https://doi.org/10.7554/eLife.36045.008
Figure 2—figure supplement 1
Pattern emergence of variable ratios of mixed populations.

Live imaging on mixed colonies of CRISPRi KD hiPSCs with WT hiPSCs, where a picture was taken every 30 min for 12 hr, 4 days after the start of KD and mixing of two populations (no color = no guide, red = KD population). The displayed images were taken at the start of day four. The ratio of CRISPRi KD cells was varied at 25%, 50%, and 75% of the overall population.

https://doi.org/10.7554/eLife.36045.009
Figure 2—figure supplement 2
Cell population change over time.

(A) Percent of CRISPRi KD cells after 5 days in mixed culture measured by flow cytometry. (n = 10,000 events, three biological reps; * indicated significance between pre and post mixed and # indicates significance from other KDs; p<0.05) (B) EdU incorporation overtime in pure populations as KD is induced by DOX treatment (n = 10,000 events).

https://doi.org/10.7554/eLife.36045.010
Figure 3 with 2 supplements
Maintenance of nuclear pluripotency markers and epithelial phenotype.

(A) Immunostaining of EpCAM for mixed colonies displayed relatively uniform expression regardless of KD. (B) Immunostaining for E-cadherin (CDH1) and OCT3/4 in patterned hiPSC colonies demonstrating nuclear localized OCT3/4 throughout the mixed populations.

https://doi.org/10.7554/eLife.36045.011
Figure 3—figure supplement 1
Maintenance of cell junction localized β-catenin in KD cells.

Immunostaining of β-catenin pure hiPSC colonies on day six of KD. β-catenin remains localized to the cell junctions in hiPSCs before and after DOX treatment to induce KD of ROCK1 and CDH1, respectively.

https://doi.org/10.7554/eLife.36045.012
Figure 3—figure supplement 2
Pluripotent and early germ layer gene expression in KD cells.

(A) Immunostaining of OCT3/4 and SOX2 in mixed colonies on day six of KD, where borders between cell populations are denoted by dotted lines. (B) Gene expression of OCT3/4 and SOX2 in ROCK1 KD and CDH1 KD hiPSCs quantified by mRNA fold change (n = 3). (C) Gene expression of markers of the primitive streak (Brachyury) and neural crest (SOX9) in pure populations of ROCK1 KD or CDH1 KD hiPSCs quantified by mRNA fold change (n = 3, * indicates significance; p<0.05).

https://doi.org/10.7554/eLife.36045.013
Figure 4 with 2 supplements
Transient gene expression changes in mixed populations.

(A) Schematic of experimental timeline; WT-GFP and ROCK1- or CDH1-CRISPRi hiPSCs were mixed and re-plated prior to KD induction. Different cell populations were isolated by FACS for mRNA extraction on days 1, 3, and 6 after KD induction. (n = 3 per condition). (B) Representative scatter plot of a FACS-sorted population of mCherry +cells (indicating KD induction) with >98% purity. (C,D) Plots of specific mRNA expression changes at days 1, 3, and 6 in KD cell populations that have been mixed with WT. (* and # indicate significance, p<0.05). (E,F) Heat maps display fold change expression of genes found to display significant changes in ROCK1 or CDH1 KD cells mixed with WT-GFP hiPSCs when compared to time-matched, off-target control hiPSCs. Grey color indicates non-significance. Significance (p<0.05, n = 3) was determined using a one-way analysis of variance (ANOVA) followed by post-hoc pairwise comparisons by Tukey’s tests to determine the effect of mixing populations, the effect of solely KD, and the effect of KD within a mixed population.

https://doi.org/10.7554/eLife.36045.014
Figure 4—figure supplement 1
Gene expression changes in WT-GFP cells mixed with CRISPRi cells.

(A) Heat map showing gene expression changes due to mixing two populations together without induction of CRISPRi in sub population where grey indicates non-significance. (B) Example panel of FACS-sorted population of GFP+ (i.e. WT) cells with >99% purity. (C) Heat map of significant gene expression fold changes in WT-GFP cells mixed for 6 days with OTG control, ROCK1 KD, or CDH1 KD hiPSCs when compared to time-matched, pure WT-GFP populations. Grey color indicates non-significance. Significance (p<0.05, n = 3) was determined using an ANOVA taking into account the independent effects of mixing populations, KD alone, and KD within a mixed population.

https://doi.org/10.7554/eLife.36045.015
Figure 4—figure supplement 2
Germ lineage differentiations of mixed colonies.

(A) Schematic of a 6 day ectoderm directed differentiation using dual SMAD inhibition or a complementary mesendoderm directed differentiation using CHIR treatment. (B) Quantification of PAX6 protein presence by immunofluorescence in WT and KD cells of mixed colonies after dual SMAD inhibition treatment. (n = 4 biological replicates with 25 images per biological replicate; * indicates significance; p<0.05) (C) Quantification of EOMES protein presence by immunofluorescence in WT and KD cells of mixed colonies after CHIR treatment. (D) Representative images of mixed colony differentiations with either dual SMAD inhibition or CHIR treatment stained for PAX6 and EOMES, respectively.

https://doi.org/10.7554/eLife.36045.016
Inducible pattern emergence through the KD of molecules that affect hiPSC physical properties.

(A) Schematic of working model of sub-population manipulation where controlled changes in cellular stiffness or cellular adhesion result in specific colony pattern formation. With mosaic KD, ROCK1 produces continuous radial separation of KD cells from WT, whereas CDH1 displays discrete islands of KD cells within the WT population.

https://doi.org/10.7554/eLife.36045.017

Tables

Key resources table
Reagent type (species)
or resource
DesignationSource or referenceIdentifiersAdditional
information
Cell line
(H. sapien, male)
WT-GFPthis paperhiPSC line containing
constitutative GFP
in AAVS1 locus
Cell line
(H. sapien, male)
CRISPRi no guideMandegar et al., 2016;
DOI 10.1016/j.stem.2016.01.022
hiPSC line containing DOX inducible dCas9KRAB
Cell line
(H. sapien, male)
CRISPRi controlMandegar et al., 2016; DOI 10.1016/j.stem.2016.01.022hiPSC line containing DOX inducible dCas9KRAB and gRNA to KCNH2
Cell line
(H. sapien, male)
CRISPRi ROCK1Mandegar et al., 2016; DOI 10.1016/j.stem.2016.01.022hiPSC line containing
DOX inducible dCas9KRAB and gRNA to ROCK1
Cell line
(H. sapien, male)
CRISPRi CDH1this paperhiPSC line containing
DOX inducible dCas9KRAB and gRNA to CDH1
Antibodymouse anti-ROCK1AbCAMab58305(1:200)
Antibodymouse anti-CDH1AbCAMab1416(1:200)
Antibodygoat anti-GAPDHInvitrogenPA1-9046(1:10000)
Antibodygoat anti-OCT3/4SantaCruzsc8629(1:400)
Antibodymouse anti-SOX2AbCAMab7935(1:400)
Antibodymouse anti-Zo1LifeTechnologieslifetech 339100(1:400)
Antibodyrabbit anti
-NANOG
AbCAMab21624(1:300)
Antibodymouse anti-BcateninBD BiosciencesBD610154(1:200)
Antibodymous anti-EpCAMMilliporeMAB4444(1:200)
AntibodyAlexa 488- or 647- secondariesLife
Technologies
(1:500)
OtherHoescht stainLifeTechnologies(1:10000)
Recombinant
DNA reagent
gRNA-CKB
(plasmid)
Mandegar et al., 2016; DOI 10.1016/j.stem.2016.01.022vector containing gRNA and selection markers (blasticidin resistance, mKate fluorescence)
Software,
algorithm
GraphPad
Prism
GraphPad Prism (https://graphpad.com)RRID:SCR_015807
Software,
algorithm
ImageJImageJ (http://imagej.nih.gov/ij/)RRID:SCR_003070
Software,
algorithm
Python,
scikit image
scikit-image contributors et al., 2014: DOI 10.7717/peerj.453
Chemical compound, drugmTeSR1 mediumSTEMCELL TechnologiesSTEMCELL Technologies: 85850
Chemical
compound, drug
MatrigelCorning Life SciencesCorning Life Sciences: 356231
Chemical compound, drugAccutaseSTEMCELL
Technologies
STEMCELL Technologies: 7920
Chemical
compound, drug
BlasticidinThermoFisher ScientificThermoFisher Scientific: R21001
Chemical
compound, drug
DoxycyclineSigma AldrichSigma Aldrich: D9891
Chemical
compound, drug
Y-27632 ROCK inhibitorSelleckchemSelleckchem: S1049
Chemical
compound, drug
PuromycinSigma AldrichSigma Aldrich: P8833
Chemical
compound, drug
SB 435142StemgentStemgent: 04-0010-05
Chemical
compound, drug
LDN 193189SelleckchemSelleckchem: S2618
Chemical
compound, drug
CHIR 99021SelleckchemSelleckchem: CT99021
Chemical
compound, drug
TRIzol LS ReagentThermoFisher
Scientific
ThermoFisher Scientific: 10296028
Sequenced-based reagentgRNAsThis paperSee Supplementary file 1
Sequenced-based reagentRT-qPCR primersThis paperSee Supplementary file 1
Commercial
assay or kit
MycoAlert Mycoplasma
Detection Kit
LonzaLonza: LT07218
Commercial
assay or kit
Pierce BCA Protein
Assay kit
ThermoFisher ScientificThermoFisher Scientific: 23250
Commercial
assay or kit
RNeasy Mini KitQIAGENQIAGEN: 74106
Commercial
assay or kit
iScript cDNA
Synthesis kit
BIORADBIORAD: 1708891
Commercial
assay or kit
Fast SYBR Green
Master Mix
ThermoFisher ScientificThermoFisher Scientific: 4385612
Commercial
assay or kit
Click-iT EdU
Alexa 647 Imaging Kit
ThermoFisher ScientificThermoFisher Scientific: C10340
Commercial
assay or kit
Direct-zol RNA
MiniPrep Plus kit
ZYMO ResearchZYMO: R2061

Data availability

All data generated or analyzed in this study are included in the manuscript or supplementary files.

Additional files

Supplementary file 1

Supplementary tables.

(1) Table 1 displays guide RNA sequences used for CRISPRi knockdown. (2) Table 2 outlines primer sequences used for gene expression analysis by quantitative PCR. (3) Table 3 shows gene targets and primer sequences used for the Fluidigm 96.96 array gene expression analysis.

https://doi.org/10.7554/eLife.36045.018
Transparent reporting form
https://doi.org/10.7554/eLife.36045.019

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