GladiaTOX: R Package for Processing High Content Screening data
3 May 2019
Package
GladiaTOX 1.0.0
Contents
1 Introduction
GladiaTOX is an open-source solution for HCS data processing and reporting
that expands the tcpl package (toxcast pipeline, Filer et al., 2016). In
addition to tcpl’s functionalities (multiple dose-response fitting and best
fit selection), GladiaTOX
- Fetches raw image quantifications via a webservice layer, also allowing multiple (proprietary) systems to be integrated easily
- Computes minimal effective concentrations based also on historical data
- Exports results formatted for ToxPI GUI
- Compute exposure severity scores
- Implements a suite of functionalities for quality control and processing reporting
1.1 Installation and package load
if(!requireNamespace("BiocManager", quietly = TRUE))
install.packages("BiocManager")
BiocManager::install("GladiaTOX")
1.2 Database configuration
The GladiaTOX installation includes the deployment of a sqlite database
(sql/gladiatoxdb.sqlite folder). This file contains the database structure
already initialized with the necessary content needed for data processing (
e.g. processing methods entries).
The first step after database deployment is to configure access parameters.
The default configuration already points to the sqlite database at so no
additional configurations are needed to complete the example below.
Below the default database URL is assigned to the variable sqlite_src:
sqlite_src <- file.path(system.file(package="GladiaTOX"), "sql",
"gladiatoxdb.sqlite")The gtoxConf configuration command below initializes all necessary variables.
# sqlite database location
gtoxConf( drvr = "SQLite",
host = NA,
user = NA,
pass = NULL,
db = sqlite_src)This database will be used in next sections to load and process a second study phase. The sqlite database can be seen as a sample database used for the following example.
In case users plan to use the package in production and for multiple studies,
it is recommended to install the MySQL database
(sql/gladiatoxdb_structure.mysql). This file contains SQL instructions to
create and initialize an MySQL database.
In case you install the database schema or change location of the sqlite
database, then you must run the configuration command below and point to the
new database location. For example, in case you deploy the database schema
provided in the sql folder, then change the driver (drvr) to MySQL.
Eventually you may need to configure your user name and password.
Below is an example of configuration call pointing to an MySQL database called
my_gl_database at local.host:
gtoxConf( drvr = "MySQL",
host = "local.host",
user = "username",
pass = "********",
db = "my_gl_database")1.3 Deployed database
The deployed database already contains fully processed study, with
asid: 1 (assay source id), the unique study identifierasnm: SampleStudy (assay source name), the names of the studyasph: PhaseI (assay source phase), the study phase
The purpose of the call gtoxLoadAsid() is to list all studies available in the
database.
# List available studies
gtoxLoadAsid()
#> asid asnm asph
#> 1: 1 SampleStudy PhaseI2 Data and metadata for vignette
In this section we will explore one simple way for loading data in the database. The following chunks prepare the metadata and data in R objects (data.frame) prior database loading.
The following commands loads the data for vignette. The command loads three
objects in the environment. The content of each object is described in the
following sections. These objects are what users need to prepare before study
data can be loaded. In particular the dat object contains the raw data as
fetched from the instrument database. This database is only accessible
internally to the company, hence its content has been exported and saved in an
Rdat object . Some fields, not used by the code, are not reported.
load(system.file("extdata", "data_for_vignette.rda", package="GladiaTOX"))2.1 plate: plate metadata
The plate object stores metadata with plate information.
Most of the columns have self-contained names and content; plate is the plate
number (usually an integer); tube is the well location (H1 is row 8 column 1);
well_type is the content type of the well (c positive control, t
treatment, n is the negative control); endpoint contains assay names with no
exposure duration info appended; u_boxtrack is a plate identifier used to join
the plate metadata table with the raw data table prior data is loaded in the
GladiaTOX database.
print(head(plate), row.names = FALSE)
#> stimulus stimulus concentration exposure duration plate tube well_type
#> o-anisidine 10000 uM 24h 1 A1 t
#> o-anisidine 5000 uM 24h 1 B1 t
#> o-anisidine 1000 uM 24h 1 C1 t
#> o-anisidine 200 uM 24h 1 D1 t
#> o-anisidine 0.00007 uM 24h 1 E1 t
#> o-anisidine 0.0000006 uM 24h 1 F1 t
#> vehicle_name study study.phase cell type endpoint exposure date
#> EtOH SampleStudy PhaseII NHBE GSH content 2014-06-17
#> EtOH SampleStudy PhaseII NHBE GSH content 2014-06-17
#> EtOH SampleStudy PhaseII NHBE GSH content 2014-06-17
#> EtOH SampleStudy PhaseII NHBE GSH content 2014-06-17
#> EtOH SampleStudy PhaseII NHBE GSH content 2014-06-17
#> EtOH SampleStudy PhaseII NHBE GSH content 2014-06-17
#> plate_set Biological Replicate smkid well format assay Date
#> 0 1 96-well GSH content_24h 2014-03-17
#> 0 1 96-well GSH content_24h 2014-03-17
#> 0 1 96-well GSH content_24h 2014-03-17
#> 0 1 96-well GSH content_24h 2014-03-17
#> 0 1 96-well GSH content_24h 2014-03-17
#> 0 1 96-well GSH content_24h 2014-03-17
#> u_boxtrack
#> S-000031334
#> S-000031334
#> S-000031334
#> S-000031334
#> S-000031334
#> S-0000313342.2 chnmap: assay metadata and channel mapping
The second metadata table contains assay mapping information. In the example below two assays are shown: Cytotoxicity (TIER1) and DNA damage (pH2AX).
Five endpoints are part of the cytotoxicity assay (e.g., Cell count, membranepermeability). Two endpoints are shown to be part of the DNA damage assay. Since multiple endpoints can be read from the same plate, each of them is read on a separate channel. This column will also be used later on to join meatadata and data tables.
print(head(chnmap, 7), row.names = FALSE)
#> Assay Endpoint
#> Cytotoxicity (TIER1) Cell count
#> Cytotoxicity (TIER1) Cell membrane permeability
#> Cytotoxicity (TIER1) Mitochondrial membrane potential
#> Cytotoxicity (TIER1) Mitochondrial mass
#> Cytotoxicity (TIER1) Cytochrome C release
#> DNA damage (pH2AX) Cell count
#> DNA damage (pH2AX) DNA damage (pH2AX)
#> Channel
#> SelectedObjectCountPerValidField
#> MEAN_CircAvgIntenCh2
#> MEAN_RingSpotAvgIntenCh3
#> MEAN_RingSpotTotalAreaCh3
#> MEAN_CircAvgIntenCh4
#> SelectedObjectCountPerValidField
#> MEAN_CircAvgIntenCh2The content of plate and chnmap are then combined to generate the assay
table. In the assay table, assay and endpoint are concatenated to timepoints
to generate assays entries for the database.
assay <- buildAssayTab(plate, chnmap)
print(head(assay, 4), row.names = FALSE)
#> assay timepoint component
#> Ox stress (DHE)_4h 4h Ox stress (DHE)_Oxidative stress_4h
#> Ox stress (DHE)_4h 4h Ox stress (DHE)_Oxidative stress_4h
#> Ox stress (DHE)_24h 24h Ox stress (DHE)_Oxidative stress_24h
#> Ox stress (DHE)_24h 24h Ox stress (DHE)_Oxidative stress_24h
#> endpoint channel
#> Ox stress (DHE)_Oxidative stress_4h_up MEAN_CircAvgIntenCh2
#> Ox stress (DHE)_Oxidative stress_4h_dn MEAN_CircAvgIntenCh2
#> Ox stress (DHE)_Oxidative stress_24h_up MEAN_CircAvgIntenCh2
#> Ox stress (DHE)_Oxidative stress_24h_dn MEAN_CircAvgIntenCh22.3 dat: image quantification raw data
The data table is an export from the image quantification instrument.
This table contains the raw fluorescence quantification values: measure_val;
rowi and coli are the row and column indexes; machine_name is the channel
name and is used to join this table with the assay table above; u_boxtrack
is the plate identified and is used to join the table with the plate table.
print(head(dat), row.names = FALSE)
#> measure_val rowi coli machine_name u_boxtrack
#> 134.15 1 1 SelectedObjectCountPerValidField S-000031358
#> 118.50 1 2 SelectedObjectCountPerValidField S-000031358
#> 139.05 1 3 SelectedObjectCountPerValidField S-000031358
#> 214.50 1 4 SelectedObjectCountPerValidField S-000031358
#> 226.55 1 5 SelectedObjectCountPerValidField S-000031358
#> 229.75 1 6 SelectedObjectCountPerValidField S-0000313583 Database loading
In this sections data and metadata will be loaded in the GladiaTOX database. Let’s set the study parameters, study name and phase of the new study phase to be loaded in the database and processed.
## Set study parameters
std.nm <- "SampleStudy" # study name
phs.nm <- "PhaseII" # study phase3.1 Register study info in database
The following code will register metadata file content in the database,
including: assays, endpoints, treatments and controls. The status of the assay
source table (study table) before and after new study creation is displayed
below calling gtoxLoadAsid(). The purpose of the call is to list all studies
available in the database before and after the new study is added with the
function loadAnnot().
## List of studies before loading
gtoxLoadAsid()
#> asid asnm asph
#> 1: 1 SampleStudy PhaseI
## Load annotation in gtoxDB
loadAnnot(plate, assay, NULL)
#> [1] TRUE
## List of studies after loading
gtoxLoadAsid()
#> asid asnm asph
#> 1: 1 SampleStudy PhaseI
#> 2: 2 SampleStudy PhaseIIThe loadAnnot function call registers multiple study parameters in the
database, including the creation of the new assay source id (asid). The asid
identifies the pair study name, study phase. The asid is what will be used to
load raw data of the study, process the study and generate reports.
3.2 Load raw data in database
The asid just created can be retrieved by querying the database and specify
the study name and phase.
# Get assay source ID
asid = gtoxLoadAsid(fld = c("asnm", "asph"), val = list(std.nm, phs.nm))$asid
asid
#> [1] 2The asid and the dat objects are the inputs to the prepareDatForDB
function used to join metadata stored in database to the raw data stored in
the dat object.
Raw data is then loaded in the database with the gtoxWriteData function.
Study whose asid is 2 is now ready to be processed.
# Prepare and load data
dat <- prepareDatForDB(asid, dat)
gtoxWriteData(dat[ , list(acid, waid, wllq, rval)], lvl = 0, type = "mc")
#> Completed delete cascade for 34 ids (0.14 secs)
#> [1] TRUE4 Quality control: data processing and reporting
Metadata and data are now registered in the database. Next step is to select
the processing methods we want to apply on the data. There are multiple levels
of processing (see gtoxLoadMthd(lvl=3) for details). The function
assignDefaultMthds is a shortcut to assign all levels methods at once. The
methods selected would probably fit well to most users.
assignDefaultMthds(asid = asid)
#> [1] TRUEWith the default selection, raw data is normalized by computing the log2 fold change of values in each well against the median of the corresponding controls.
4.1 Compute the noise band
The package computes a noise band to discriminate concentration series that are active versus those that are not. To compute the noise band we need to process and normalize vehicle’s data running the following code:
# Run level 1 to level 3 functions
res <- gtoxRun(asid = asid, slvl = 1, elvl = 3, mc.cores = 2)The default behaviour is to compute noise band margins separately for each endpoint. Margins correspond to 3 times the baseline median absolute deviation of vehicle responses. The following code computes the cutoffs and store them in the database.
# Extract assay endpoints ids of the study
aeids <- gtoxLoadAeid(fld = "asid", val = asid)$aeid
# Compute Vehicle Median Absolute deviation
tmp <- mapply(function(xx){
tryCatch(gtoxCalcVmad(inputs = xx, aeid = xx,
notes = "computed within study"),
error = function(e) NULL)},
as.integer(aeids))Once the database is populated with noise band margins, then all chemical’s data can be processed.
# Apply all functions from level 1 to level 6
res <- gtoxRun(asid = asid, slvl = 1, elvl = 6, mc.cores = 2)In the original work (Filer et al., 2016), the default behaviour is to compute noise band margins based on the response of the lowest two concentrations of the series. That assumes that no response is observed at those concentrations. The current package overcome that assumption and extend the list of functionalities. The database design was modified accordingly.
4.2 Quality control report
Quality control is the mean to check the quality of the data produced in the lab. Each experimental plate is controlled. Plates not passing the control step are filtered out. Quality control is commonly based on a visual inspection. The package exposes functionalities to generate a self contained pdf file with plate heatmaps and positive control plots.
## QC report
gtoxReport(type = "qc", asid = asid, report_author = "report author",
report_title = "Vignette QC report", odir = outdir)An example of plate heatmap is shown below, and is what included in the quality control pdf report. The following code is used to extract the plate id we want to plot.
# Define assay component and extract assay component ID
acnm <- "DNA damage (pH2AX)_DNA damage (pH2AX)_4h"
acid <- gtoxLoadAcid(fld=c("asid", "acnm"), val=list(asid,acnm))[, acid]
# Extract assay plate ID corresponding to plate name S-000031351
apid <- gtoxLoadApid()[u_boxtrack == "S-000031351", apid]
# Load level 2 data (Raw data before normalization)
l2 <- gtoxLoadData(lvl = 2L, fld = "acid", val = acid)The plate heatmap is performed with the folliwing code.
gtoxPlotPlate(dat = l2, apid = apid, id = acid)
Figure 1: Example of heatmap of a plate raw values
Letters in well indicate the well type.
The QC report includes also dose-responses for positive control chemicals as in figure. For that we need to first extract level 4 data.
# Extract assay endpoint ID
aeid <- gtoxLoadAeid(fld = c("acid", "analysis_direction"),
val = list(acid, "up"))[, aeid]
# Extract sample ID
spid <- gtoxLoadWaid(fld = c("apid", "wllt"),
val = list(apid, "c"))[,unique(spid)]
# Collect level 4 data (normalized data)
m4id <- gtoxLoadData(lvl = 4L, fld = c("spid", "aeid"),
val = list(spid, aeid))[, m4id]Then we can plot the normalized data corresponding to the selected sample ID.
gtoxPlotM4ID(m4id = m4id, lvl = 6, bline = "coff")
Figure 2: Example of Positive control (chlorambucil chemical) plot with three concentrations, and three technical replicates per concentration
The panel on the right side shows a set of information including goodness of fit. In this particular example no info is available since the series has to few concentration to fit a model (4 concentrations is the minimum number to perform a fit).
4.2.1 Data masking
QC report is mainly used to check the quality of the plates. For example, in case the response of a positive control of an assay stays within the noiseband, then the user may decide to filter that plate out. Below is shown the code to mask plate S-000030318.
apid <- gtoxLoadApid()[u_boxtrack%in%"S-000030318", apid] # plate id
waids <- gtoxLoadWaid(fld="apid", val=apid)$waid #well ids
m0ids <- gtoxLoadData(lvl = 0, fld = "waid", val = waids)$m0id # raw data ids
gtoxSetWllq(ids = m0ids, wllq = 0, type = "mc") # set well quality to zero
#> Completed delete cascade for 7 ids (0.14 secs)
#> [1] TRUEThe masked plate will not be processed and will not be included in the final report.
5 Data processing and reporting
5.1 Process data
Now that the user has selected the processing methods, cutoffs computed, and bad quality plates masked, all information is in place to start processing the data with the following command.
res <- gtoxRun(asid = asid, slvl = 1, elvl = 6, mc.cores = 2)The gtoxRun returns a list of vectors of logical values used to check
processing status. The resulting processed data is automatically stored in the
database along with the statistics computed. Statistics include activity
concentrations (AC10 and AC50) and minimal effective concentrations (MECs).
5.2 Data reporting
The gtoxReport function, with option type = "all", triggers the generation
of the full processing report. The pdf file created includes summary tables,
dose-response curves (as seen later), and other plots for all chemicals tested
in the study.
## Processing report
gtoxReport(type = "all", asid = asid, report_author = "report author",
report_title = "Vignette Processing report", odir = outdir)Models that best fit the data are also included in the final report. In order to select the best fitting the package evaluate three models: constant, hill and gain-loss. Below is shown an example where all models are fit to the data (ochre, red and blue) from a single plate.
## Endpoint to plot
aeids <- gtoxLoadAeid(fld=c("asid", "aenm"),
val=list(asid, "DNA damage (pH2AX)_DNA damage (pH2AX)_24h_up"),
add.fld="asid")$aeid
## level 4 id to plot
m4id <- gtoxLoadData(lvl=4L)[(aeid==aeids & grepl("chromium", spid))]$m4id[1]gtoxPlotM4ID(m4id = m4id, lvl = 6, bline = "coff")
Figure 3: Best fit selection
The HILL model (marked in red on the right panel) will be selected as best fit since minimizing the Akaike information criteria (AIC).
All winning models are combined into a single plot that is included in the pdf report. An example of winning model plot is shown in figure, for the very same chemical and endpoint used above.
## Get chemical id to plot
chid <- gtoxLoadChem(field = "chnm", val = "chromium",
include.spid = FALSE)$chid
## Plot dose-response curves
gtoxPlotWin(chid = chid, aeid = aeids, bline = "bmad", collapse = TRUE)
Figure 4: Example of dose-response curves
The plot shows all replicated dose-response curves. Each curve represents the fitting result on an experimental plate. Only best fits are reported.
6 Additional reporting plots
Additional reporting plots, not included in the full report, can be obtained as described below. Boxplot of minimal effective concentrations can be obtained running the following chunk. An example of boxplot is reported below. MEC values are shown as dots. Low MECs correspond to high toxicity.
fname <- paste0(format(Sys.Date(), format="%y%m%d"), "_ASID", asid,"_MEC.pdf")
fname <- file.path(outdir, fname)
pdf(fname, width = 11, height = 7)
glPlotStat(asid)
dev.off()
Figure 5: Example of MEC boxplot
The MEC plot shows an example of MEC boxplot. In the example the GSH assay is shown along with the two endpoints (GSH content and Cell count). Chemicals are listed in the legend to the right. Each dot in the plot represents an MEC value.
MEC values can also be reported in a piechart. Below an example.
chnms <- c("mercury", "o-cresol", "p-cresol")
glPlotPie(asid, chnms = chnms)
Figure 6: Example of pie plots
The figure shows three chemicals and all endpoints.
The pie plot reports the mean MECs for all endpoints measured in the study. Time points are reported to the right (4h, 24h). Each slice is associated to an endpoint. Numbers on the slides indicate the corresponding MEC means.
Severity scores can also be computed and displayed. This score indicate the average impact of chemicals across multiple endpoints.
glPlotToxInd(asid)
Figure 7: Example of severity score plot
Example of severity score plot reporting the full list of chemicals used in the study; y-axis reports the severity score value (normalized between 0 and 1); x-axis in just the index of the chemical.
7 Session Info
sessionInfo()
#> R version 3.6.0 (2019-04-26)
#> Platform: x86_64-w64-mingw32/x64 (64-bit)
#> Running under: Windows Server 2012 R2 x64 (build 9600)
#>
#> Matrix products: default
#>
#> locale:
#> [1] LC_COLLATE=C
#> [2] LC_CTYPE=English_United States.1252
#> [3] LC_MONETARY=English_United States.1252
#> [4] LC_NUMERIC=C
#> [5] LC_TIME=English_United States.1252
#>
#> attached base packages:
#> [1] stats graphics grDevices utils datasets methods base
#>
#> other attached packages:
#> [1] RColorBrewer_1.1-2 xtable_1.8-4 GladiaTOX_1.0.0
#> [4] data.table_1.12.2 BiocStyle_2.12.0
#>
#> loaded via a namespace (and not attached):
#> [1] tidyselect_0.2.5 xfun_0.6 reshape2_1.4.3
#> [4] purrr_0.3.2 colorspace_1.4-1 htmltools_0.3.6
#> [7] yaml_2.2.0 blob_1.1.1 XML_3.98-1.19
#> [10] rlang_0.3.4 pillar_1.3.1 glue_1.3.1
#> [13] DBI_1.0.0 bit64_0.9-7 plyr_1.8.4
#> [16] stringr_1.4.0 munsell_0.5.0 gtable_0.3.0
#> [19] evaluate_0.13 memoise_1.1.0 labeling_0.3
#> [22] knitr_1.22 parallel_3.6.0 highr_0.8
#> [25] Rcpp_1.0.1 scales_1.0.0 BiocManager_1.30.4
#> [28] bit_1.1-14 brew_1.0-6 png_0.1-7
#> [31] ggplot2_3.1.1 RMySQL_0.10.17 digest_0.6.18
#> [34] stringi_1.4.3 bookdown_0.9 dplyr_0.8.0.1
#> [37] ggrepel_0.8.0 RJSONIO_1.3-1.1 numDeriv_2016.8-1
#> [40] grid_3.6.0 tools_3.6.0 bitops_1.0-6
#> [43] magrittr_1.5 lazyeval_0.2.2 RCurl_1.95-4.12
#> [46] tibble_2.1.1 RSQLite_2.1.1 crayon_1.3.4
#> [49] tidyr_0.8.3 pkgconfig_2.0.2 assertthat_0.2.1
#> [52] rmarkdown_1.12 R6_2.4.0 compiler_3.6.0