Package 'TOAST'

Title: Tools for the analysis of heterogeneous tissues
Description: This package is devoted to analyzing high-throughput data (e.g. gene expression microarray, DNA methylation microarray, RNA-seq) from complex tissues. Current functionalities include 1. detect cell-type specific or cross-cell type differential signals 2. tree-based differential analysis 3. improve variable selection in reference-free deconvolution 4. partial reference-free deconvolution with prior knowledge.
Authors: Ziyi Li and Weiwei Zhang and Luxiao Chen and Hao Wu
Maintainer: Ziyi Li <[email protected]>
License: GPL-2
Version: 1.19.0
Built: 2024-06-30 05:44:30 UTC
Source: https://github.com/bioc/TOAST

Help Index


Align cell types when reference proportions are known

Description

Align target proportions with reference proportions by pearson correlation coefficients.

Usage

assignCellType(input,reference)

Arguments

input

Input proportiona matrix of dimension N by K.

reference

Reference proportion matrix of dimension N by K.

Value

The aligned proportion matrix, following the cell type ordering of reference proportion matrix.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhijin Wu, Peng Jin, Hao Wu. "Dissecting differential signals in high-throughput data from complex tissues."

Examples

## generate estimated proportion matrix
estProp <- matrix(abs(runif(50*4,0,1)), 50, 4)
estProp <- sweep(estProp, 1, rowSums(estProp), "/")

## generate reference proportion matrix
refProp <- matrix(abs(runif(50*4,0,1)), 50, 4)
refProp <- sweep(refProp, 1, rowSums(refProp), "/")

estProp_aligned = assignCellType(input = estProp,
reference = refProp)

Simulated methylation 450K array data with related

Description

This dataset is a list containing two matrices, one of which is methylation 450K array data of 3000 CpG sites on 50 samples, the other is methylation 450K array data of 3000 matched CpG sites on three immune cell types. The first dataset is generated by simulation. It originally has 459226 features and 50 samples.We reduce it to 3000 CpGs by random selection.

Usage

data("beta_emp")

Format

The format is: List of 2 $ Y.raw: num [1:3000, 1:50] 0.7661 0.0968 0.8882 0.0286 0.6956 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : chr [1:3000] "cg08752431" "cg14555682" "cg23086843" "cg20308511" ... .. ..$ : NULL $ ref.m: num [1:3000, 1:3] 0.7712 0.0996 0.9065 0.037 0.7242 ... ..- attr(*, "dimnames")=List of 2 .. ..$ : chr [1:3000] "cg08752431" "cg14555682" "cg23086843" "cg20308511" ... .. ..$ : chr [1:3] "CD4T" "CD8T" "BCell"

Examples

data(beta_emp)

An example dataset for partial reference-free cell composition estimation from tissue gene expression

Description

The dataset contains 511 microarray gene expressions for 20 PBMC samples (mixed_all) and PBMC microarray reference for the matched 511 genes from 5immune cell types (LM_5). It also contains the true cell compositions from cell sorting experiment (trueProp) and prior knowledge of cell compositions for 5 cell types in PBMC (prior_alpha and prior_sigma).

Usage

data("CBS_PBMC_array")

References

Newman, Aaron M., et al. "Robust enumeration of cell subsets from tissue expression profiles." Nature methods 12.5 (2015): 453.

Rahmani, Elior, et al. "BayesCCE: a Bayesian framework for estimating cell-type composition from DNA methylation without the need for methylation reference." Genome biology 19.1 (2018): 141.

Examples

data("CBS_PBMC_array")
CBS_PBMC_array$mixed_all[1:5,1:5]
head(CBS_PBMC_array$LM_5,3)
head(CBS_PBMC_array$trueProp,3)
CBS_PBMC_array$prior_alpha
CBS_PBMC_array$prior_sigma

Testing cell type specific differential signals for specified phenotype by considering DE/DM state corrleation between cell types.

Description

This function provides posterior probability of whether a feature is DE/DM in certain cell type given observed bulk data.

Usage

cedar(Y_raw, prop, design.1, design.2=NULL, factor.to.test=NULL,
            pval = NULL, p.adj = NULL, tree = NULL, p.matrix.input = NULL,
            de.state = NULL, cutoff.tree = c('fdr', 0.01), 
            cutoff.prior.prob = c('pval', 0.01),
            similarity.function = NULL, parallel.core = NULL, corr.fig = FALSE, 
            run.time = TRUE, tree.type = c('single','full'))

Arguments

Y_raw

matrix of observed bulk data, with rows representing features and columns representing samples

prop

matrix of cell type composition of samples, with rows representing samples and columns representing cell types

design.1

covariates with cell type specific effect, with rows representing samples and columns representing covariates

design.2

covariates without cell type sepcific effect, with rows representing samples and columns representing covariates

factor.to.test

A phenotype name, e.g. "disease", or a vector of contrast terms, e.g. c("disease", "case", "control").

pval

matrix of p-values, with rows representing features and columns representing cell types. colnames must be same as input of prop

p.adj

matrix of adjusted p-values, with rows representing features and columns representing cell types. colnames must be same as input of prop

tree

tree structure between cell types, a matrix with row representing layers andcolumn representing cell types (column name is required)

p.matrix.input

prior probability on each node of the tree structure. only work when tree structure has been specified. the dimension must be same as tree input.

de.state

DE/DM state of each feature in each cell type, with row representing features and column representing cell types (1:DE/DM, 0:non-DE/DM)

cutoff.tree

cut off used to define DE state to estimate tree could be 'fdr' or 'pval' default it 'fdr'=0.01. suggest to start with restrictive cut off and change to relative loose value when the restrictive cut off is failed

cutoff.prior.prob

cut off used to define DE state to estimate prior probs of nodes on tree could be 'fdr' or 'pval' default it 'fdr'=0.01. suggest to start with restrictive cut off and change to relative loose value when the restrictive cut off is failed

similarity.function

custom function used to calculate similarity between cell types that used for tree structure estimation. the input of the custom is assumed to be a matrix of log transformed p-value. dimension is: selected gene number * cell number

parallel.core

number of cores for parallel running, default is NULL

corr.fig

a boolean value, whether to plot corrrelation between cell types use function plotCorr()

run.time

a boolean value, whether to report running time in seconds

tree.type

tree type for inference, default is c('single','full')

Value

A list

toast_res

If pval is NULL, then TOAST result by function csTest() is returned

tree_res

matrix of posterior probability of each feature for each cell type

fig

If corr.fig = TRUE, then figure show DE/DM state correlation between cell types will be returned

time_used

If run.time = TRUE, then running time (seconds) of CeDAR will be returned

Author(s)

Luxiao Chen <[email protected]>

Examples

N <- 300 # simulation a dataset with 300 samples
K <- 3 # 3 cell types
P <- 500 # 500 features

### simulate proportion matrix
Prop <- matrix(runif(N*K, 10,60), ncol=K)
Prop <- sweep(Prop, 1, rowSums(Prop), FUN="/")
colnames(Prop) <- c("Neuron", "Astrocyte", "Microglia")

### simulate phenotype names
design <- data.frame(disease=factor(sample(0:1,size = N,replace=TRUE)),
                     age=round(runif(N, 30,50)),
                     race=factor(sample(1:3, size = N,replace=TRUE)))
Y <- matrix(rnorm(N*P, N, P), ncol = N)
rownames(Y) <- paste0('gene',1:nrow(Y))
d1 <-  data.frame('disease' = factor(sample(0:1,size = N,replace=TRUE)))

### Only provide bulk data, proportion
res <- cedar(Y_raw = Y, prop = Prop,
             design.1 = design[,1:2],
             design.2 = design[,3],
             factor.to.test = 'disease',
             cutoff.tree = c('pval',0.1),
             corr.fig = TRUE,
             cutoff.prior.prob = c('pval',0.1) )

### result of toast (independent test)
str(res$toast_res)
### posterior probability of DE/DM of cedar with single layer tree structure
head(res$tree_res$single$pp)
### posterior probability of DE/DM of cedar with muliple layer tree structure
head(res$tree_res$full$pp)
### estimated tree structure of three cell types
head(res$tree_res$full$tree_structure)
### scatter plot of -log10(pval) showing DE/DM state correlation between cell types
res$fig


### Using custom similarity function to estimate tree structure
### In CeDAR, the input is assumed to be a matrix of log transformed p-values 
### with row representing genes and columns represening cell types

sim.fun <- function(log.pval){
  similarity.res <- sqrt((1 - cor(log.pval, method = 'spearman'))/2)
  return(similarity.res)
}

res <- cedar(Y_raw = Y, prop = Prop,
             design.1 = design[,1:2],
             design.2 = design[,3],
             factor.to.test = 'disease',
             cutoff.tree = c('pval',0.1),
             similarity.function = sim.fun,
             corr.fig = FALSE,
             cutoff.prior.prob = c('pval',0.1) )

### posterior probability of DE/DM of cedar with muliple layer tree structure
head(res$tree_res$full$pp) 


### Using custom tree structure as input
### cell type 1 and cell type 3 are more similar
tree.input <- rbind(c(1,1,1),c(1,2,1),c(1,2,3))
### If column name is provided for the matrix; make sure it is same as variable Prop
colnames(tree.input) <- c("Neuron", "Astrocyte", "Microglia")

res <- cedar(Y_raw = Y, prop = Prop,
             design.1 = design[,1:2],
             design.2 = design[,3],
             factor.to.test = 'disease',
             cutoff.tree = c('pval',0.1),
             tree = tree.input,
             corr.fig = FALSE,
             cutoff.prior.prob = c('pval',0.1) )

### posterior probability of DE/DM of cedar with muliple layer tree structure
head(res$tree_res$custom$pp) 



### Using custom tree structure and prior probability of each node as input
### cell type 1 and cell type 3 are more similar
tree.input <- rbind(c(1,1,1),c(1,2,1),c(1,2,3))
colnames(tree.input) <- c("Neuron", "Astrocyte", "Microglia")

p.matrix.input <- rbind(c(0.2,0.2,0.2), c(0.5,0.25,0.5), c(0.5,1,0.5))
# marginally, each cell type has 0.05 (cell 1: 0.2 * 0.5 * 0.5, cell 2: 0.2 * 0.25 * 1)
# probability to be DE for a randomly picked gene
# there will be about 50% DE genes in cell type 1 overlaped with cell type 3; 
# while there will be about 25% DE genes in cell type 1 overlaped with cell type 2

res <- cedar(Y_raw = Y, prop = Prop,
             design.1 = design[,1:2],
             design.2 = design[,3],
             factor.to.test = 'disease',
             cutoff.tree = c('pval',0.1),
             tree = tree.input,
             p.matrix.input = p.matrix.input,
             corr.fig = FALSE,
             cutoff.prior.prob = c('pval',0.1) )

### posterior probability of DE/DM of cedar with muliple layer tree structure
head(res$tree_res$custom$pp)

Choose cell type-specific markers from pure cell type profiles or single cell data

Description

Choose cell type-specific markers from pure cell type profiles generated by microarray or RNA-seq, or from single cell RNA-seq data by differential analysis.

Usage

ChooseMarker(pure_all, CellType, nMarkCT = 10, chooseSig = FALSE, verbose = TRUE)

Arguments

pure_all

Input pure cell type profile matrix or single cell data matrix. Rows are for genes, columns are for cell types or cells.

CellType

A list object consisting of cell type information for columns in pure_all. Each element is a cell type, and contains the corresponding column number in pure_all matrix. For example, CellType = list(BCell = 1:3, CD4T = 4:5).

nMarkCT

Number of markers chosen per cell type. Default is 10.

chooseSig

A boolean variable representing whether to consider the significance of selected markers. When chooseSig = FALSE, all nMarkerCT number of markers will be chosen per cell type. Otherwise the non-significant (p value > 0.05) markers will be filtered out.

verbose

A boolean variable of whether to output messages.

Details

Here we provide more details for CellType variable. This variable should be a list, with each element being the corresponding column numbers in pure_all for each cell type. For example, suppose pure_all is a 1000 by 300 matrix with row being genes and column being cells (or cell types). The first 1 to 100 columns are cell A, 101 to 200 columns are cell B, and 201 to 300 columns are cell C. Then CellType should be assigned as CellType = list(A = 1:100, B = 101:200, C = 201:300). If pure_all only has three columns for three cell types A, B and C, then CellType = list(A = 1, B = 2, C = 3).

Value

A list variable, including the selected variables for all cell types.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhenxing Guo, Ying Cheng, Peng Jin, Hao Wu. "Robust partial reference-free cell compoisiton estimation from tissue expression profiles."

Examples

## randomly simulate pure cell type profiles
pure_all <- matrix(abs(rnorm(1000*9)), 1000, 9)
CellType <- list(CellA = 1:3,
                 CellB = 4:6,
                 CellC = 7:9)

## choose significant markers
SelMarker <- ChooseMarker(pure_all, CellType,
                         nMarkCT = 30,
                         chooseSig = TRUE,
                         verbose = FALSE)

Improve reference-free deconvolution using cross-cell type differential analysis

Description

This function improve the feature selection in reference-free deconvolution through cross-cell type differential analysis

Usage

csDeconv(Y_raw, K, FUN, nMarker = 1000,
InitMarker = NULL, TotalIter = 30, bound_negative = FALSE)

Arguments

Y_raw

A G*N matrix, G is the number of features, N is the number of subjects; or a SummarizedExperiment object.

K

The number of cell types. Need to be specified a priori.

FUN

The reference-free deconvolution function, this function should take Y_raw and K, and the return values should be a N by K proportion matrix. N is the number of samples and K is the number of cell types. Default function is a wrapper of the RefFreeCellMix() function from CRAN package RefFreeEWAS.

nMarker

The number of markers used in the deconvolution. Default is 1000.

InitMarker

A vector of length L to represent the selection of inital markers. L should be equal or smaller than G. If G is large, it is recommended that L is much smaller than G. If not specified, the most variable nMarker features will be used.

TotalIter

The total number of iterations of applying cross-cell type differential analysis. Default is 30.

bound_negative

Whether to bound all negative parameter estimators to zero.

Value

allProp

A list of estimated proportions from all iterations.

allRMSE

A vector of root mean squared errors (RMSE) from all iteratoins.

estProp

A N*K matrix representing the mixture proportions of K cell types in N subjects, chosen from allProp with the smallest RMSE.

updatedInx

Selected variable index from the algorithm.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li and Hao Wu. "Improving reference-free cell composition estimation by cross-cell type differential analysis".

Examples

Y_raw <- abs(matrix(runif(10000*20, 0,1),10000,20))
K <- 3

## wrap your reference-free
## deconvolution method into a function
## this function should take Y and K as input
## and output a N by K proprotion matrix
## here we use RefFreeCellMix() as an example
outT <- csDeconv(Y_raw, K)

RefFreeCellMix_wrapper <- function(Y, K){
     outY = myRefFreeCellMix(Y,
     mu0=myRefFreeCellMixInitialize(Y,
     K = K))
     Prop0 = outY$Omega
     return(Prop0)
}

outT <- csDeconv(Y_raw, K,
            FUN = RefFreeCellMix_wrapper)

Testing differential signals for specified phenotype and cell type(s).

Description

This function conducts statistical tests for specified phenotype and cell type(s).

Usage

csTest(fitted_model, coef = NULL, cell_type = NULL,
       contrast_matrix = NULL, var_shrinkage = TRUE,
       verbose = TRUE, sort = TRUE)

Arguments

fitted_model

The output from fitModel() function.

coef

A phenotype name, e.g. "disease", or a vector of contrast terms, e.g. c("disease", "case", "control").

cell_type

A cell type name, e.g. "celltype1", or "neuron". If cell_type is NULL or specified as "ALL", compound effect of coef in all cell types will be tested.

contrast_matrix

If contrast_matrix is specified, coef and cell_type will be ignored! A matrix (or a vector) to specify contrast, e.g., cmat <- matrix(0, 2, 6); cmat[1,3] <- 1: cmat[2,4] <- 1 is to test whether the 3rd parameter and 4th parameter are zero simultaneously i.e. beta3 = beta4 = 0.

var_shrinkage

Whether to apply shrinkage on estimated MSE or not. Applying shrinkage helps remove extremely small variance estimation and stablize statistics.

verbose

A boolean parameter. Testing information will be printed if verbose = TRUE.

sort

A boolean parameter. The output results will be sorted by p value if sort = TRUE.

Value

A matrix including the results from testing the phenotype in specified cell type(s).

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhijin Wu, Peng Jin, Hao Wu. "Dissecting differential signals in high-throughput data from complex tissues."

Examples

N <- 300 # simulation a dataset with 300 samples
K <- 3 # 3 cell types
P <- 500 # 500 features

### simulate proportion matrix
Prop <- matrix(runif(N*K, 10,60), ncol=K)
Prop <- sweep(Prop, 1, rowSums(Prop), FUN="/")
colnames(Prop) <- c("Neuron", "Astrocyte", "Microglia")

### simulate phenotype names
design <- data.frame(disease=factor(sample(0:1,
                             size = N,replace=TRUE)),
                     age=round(runif(N, 30,50)),
                     race=factor(sample(1:3, size = N,replace=TRUE)))
Y <- matrix(rnorm(N*P, N, P), ncol = N)

### generate design matrix and fit model
Design_out <- makeDesign(design, Prop)
fitted_model <- fitModel(Design_out, Y)

### check the names of cell types and phenotypes
fitted_model$all_cell_types
fitted_model$all_coefs

### detect age effect in neuron
test <- csTest(fitted_model, coef = "age",
cell_type = "Neuron", contrast_matrix = NULL)

## coef can be specified in different ways:
#### jointly test a phenotype:
test <- csTest(fitted_model, coef = "age",
cell_type = "joint", contrast_matrix = NULL)

#### if I do not specify cell_type
test <- csTest(fitted_model, coef = "age",
cell_type = NULL, contrast_matrix = NULL)
## this is exactly the same as
test <- csTest(fitted_model, coef = "age",
contrast_matrix = NULL)

#### other examples
test <- csTest(fitted_model, coef = "race",
cell_type = "Astrocyte", contrast_matrix = NULL)
test <- csTest(fitted_model, coef = "age",
cell_type = "Microglia", contrast_matrix = NULL)

#### specify contrast levels
test <- csTest(fitted_model, coef = c("race", 3, 2),
cell_type = "Neuron", contrast_matrix = NULL)
#### specify contrast levels in all cell types
test <- csTest(fitted_model, coef = c("race", 3, 2),
cell_type = "joint", contrast_matrix = NULL)

#### csTest can tolerate different ways of specifying contrast level
#### note race=1 is used as reference when fitting model
#### we can here specify race=2 as reference
test <- csTest(fitted_model, coef = c("race", 1, 2),
cell_type = "Neuron", contrast_matrix = NULL)
## get exactly the same results as
test <- csTest(fitted_model, coef = c("race", 2, 1),
cell_type = "Neuron", contrast_matrix = NULL)

#### specify a contrast matrix:
cmatrix = rep(0,15)
cmatrix[c(4,5)] = c(1,-1)
test <- csTest(fitted_model, coef = NULL,
cell_type = NULL, contrast_matrix = cmatrix)
#### specific a contrast matrix with two rows:
cmatrix = matrix(rep(0,30),2,15)
cmatrix[1,4] = 1
cmatrix[2,5] = 1
test <- csTest(fitted_model, coef = NULL,
contrast_matrix = cmatrix)

Feature selection for reference-free deconvolution using cross-cell type differential analysis

Description

This function selects cross-cell type differential features for reference-free deconvolution.

Usage

DEVarSelect(Y_raw, Prop0, nMarker, bound_negative)

Arguments

Y_raw

A data matrix containing P features and N samples; or a SummarizedExperiment object.

Prop0

A N by K proportion matrix with K as number of cell types.

nMarker

Number of markers selected.

bound_negative

Whether to bound all negative parameter estimators to zero.

Value

Selected markers using cross-cell type differential analysis.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhijin Wu, Peng Jin, Hao Wu. "Dissecting differential signals in high-throughput data from complex tissues."

Examples

Y_raw <- matrix(runif(5000*20, 0, 1), 5000, 20)
tmp <- matrix(runif(20*4), 20, 4)
Prop0 <- sweep(tmp, 1, rowSums(tmp), "/")
varlist <- DEVarSelect(Y_raw, Prop0,
                       nMarker=1000,
                       bound_negative=FALSE)

findRefinx

Description

Find index for marker genes with largest coefficient of variation based on raw data.

Usage

findRefinx(rawdata, nmarker=1000, sortBy = "var")

Arguments

rawdata

A data matrix with rows representing features and columns represeting samples; or a SummarizedExperiment object.

nmarker

Desired number of markers after selection. Default is 1000.

sortBy

Desired method to select features. "var" represents selecting by largest variance. "cv" represents selecting by largest coefficients of variation. Default is "var".

Value

A vector of index for the selected markers.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhijin Wu, Peng Jin, Hao Wu. "Dissecting differential signals in high-throughput data from complex tissues."

Examples

Y_raw <- matrix(runif(5000*20, 0, 1), 5000, 20)
idx <- findRefinx(Y_raw, nmarker=500)
idx2 <- findRefinx(Y_raw, nmarker=500, sortBy = "cv")

Fit model with proportions and phenotypes.

Description

This function receives design matrix from makeDesign() and fits the model including all cell types and phenotypes.

Usage

fitModel(Design_out, Y)

Arguments

Design_out

The output from function makeDesign().

Y

A G*N matrix, G is the number of features, N is the number of subjects; or a SummarizedExperiment object.

Value

Design_out

The input Design_out object.

N

Number of samples from matrix Y.

coefs

Estimated coefficients (beta) in the model.

coefs_var

Estimated variance of the coefficients (beta variance) in the model.

Y

Observation Y matrix.

Ypred

Predicted Y from the fitted model.

all_coefs

The names of all phenotypes.

all_cell_types

The names of all cell types.

MSE

Estimated mean squared error.

model_names

The names of all terms in the fitted model.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhijin Wu, Peng Jin, Hao Wu. "Dissecting differential signals in high-throughput data from complex tissues."

Examples

N = 300 # simulation a dataset with 300 samples
K = 3 # 3 cell types
P <- 500 # 500 features

### simulate proportion matrix
Prop = matrix(runif(N*K, 10,60), ncol=K)
Prop = sweep(Prop, 1, rowSums(Prop), FUN="/")
colnames(Prop) = c("Neuron", "Astrocyte", "Microglia")
Y <- matrix(rnorm(N*P, N, P), ncol = N)

### simulate phenotype names
design <- data.frame(disease=factor(sample(0:1,
                     size = N,replace=TRUE)),
                     age=round(runif(N, 30,50)),
                     race=factor(sample(1:3, size = N,replace=TRUE)))
Design_out <- makeDesign(design, Prop)

### fit model
fitted_model <- fitModel(Design_out, Y)

Get prior knowledge for supported tissue types

Description

Users can use this function to get priors provided in this package. Users can also directly specify tisuse type in MDeconv function.

Usage

GetPrior(alpha = NULL, sigma = NULL)

Arguments

alpha

A string chosen from "human pbmc","human liver", "human brain", "human pancreas", "human skin", or a nuemric vector for manually specified alpha.

sigma

Keep it as NULL for supported tissues. Otherwise a numeric vector for manuallly specified sigma.

Value

alpha_prior

Prior knowledge for the mean of proportions.

sigma_prior

Prior knowledge for the sigma of proprotions.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhenxing Guo, Ying Cheng, Peng Jin, Hao Wu. "Robust partial reference-free cell compoisiton estimation from tissue expression profiles."

Examples

GetPrior("human pbmc")
GetPrior("human liver")
GetPrior("human brain")
GetPrior("human skin")
GetPrior("human pancreas")

Generate design matrix from input phenotypes and proportions.

Description

This function generate design matrix and make preparations for following fitModel and csTest.

Usage

makeDesign(design, Prop)

Arguments

design

A N by P phenotype matrix, with rows as samples and columns as phenotypes (e.g. age, gender, disease, etc.).

Prop

A N by K proportion matrix, with rows as samples and columns as cell types

Value

design_matrix

A comprehensive design matrix incorporated phenotype and proportion information.

Prop

The input proportion matrix.

design

The input design/phenotype matrix.

all_coefs

The names of all phenotypes.

all_cell_types

The names of all cell types.

formula

The formula of the tested model, including all phenotypes, cell types and interaction terms.

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhijin Wu, Peng Jin, Hao Wu. "Dissecting differential signals in high-throughput data from complex tissues."

Examples

N = 300 # simulation a dataset with 300 samples
K = 3 # 3 cell types

### simulate proportion matrix
Prop = matrix(runif(N*K, 10,60), ncol=K)
Prop = sweep(Prop, 1, rowSums(Prop), FUN="/")
colnames(Prop) = c("Neuron", "Astrocyte", "Microglia")

### simulate phenotype names
design <- data.frame(disease=factor(sample(0:1, size = N,replace=TRUE)),
                     age=round(runif(N, 30,50)),
                     race=factor(sample(1:3, size = N,replace=TRUE)))
Design_out <- makeDesign(design, Prop)

Estimate cell compoisitons via partial reference-free deconvolution.

Description

This function is the wrapper for TOAST/-P (partial reference-free deconvolution without prior) and TOAST/+P (with prior). It guides cell compoisition estimation through extra biological information, including cell type specific markers and prior knowledge of compoisitons.

Usage

MDeconv(Ymat, SelMarker,
alpha = NULL, sigma = NULL,
epsilon = 0.001, maxIter = 1000,
verbose = TRUE)

Arguments

Ymat

A gene expression data matrix from complex tissues. Rows represent genes and columns represent samples. Row names (e.g. gene symbol or ID) are needed. There is no need to filter data matrix by marker genes.

SelMarker

A list variable with each element includes cell type-specific markers for this cell type. The marker list can be selected from pure cell type profiles or single cell data using ChooseMarker(). It can also be easily created manually. Please see details section below and example for more information.

alpha

A vector including the prior mean for all cell types.

sigma

A vector including the prior standard deviation for all cell types.

epsilon

A numeric variable to control the level of convergence. With a large epsilon, it converges quickly and the algorithm may not converge well. With a small epsilon, it converges slower and the algorithm may converge "too much". The default value is 1e-3, which we find is a reasonable threshold.

maxIter

Number of maximum iterations.

verbose

A boolean variable of whether to output messages.

Details

More about SelMarker: in addition to selecting markers using ChooseMarker(), we can manually specific marker list. For example, if we know there are two cell type-specific markers for cell type A "Gene1" and "Gene2", and two cell type-specific markers for cell type B "Gene3" and "Gene4", we can create marker list by SelMarker = list(CellA = c("Gene1","Gene2"), CellB = c("Gene3","Gene4")).

One thing to note is that, the genes in marker list should have matches in row names of Ymat. If not, the unmatched markers will be removed duing analysis.

Value

A list including

H

Estimated proportion matrix, rows for cell types and columns for samples.

W

Estimated pure cell type profile matrix, rows for genes and columns for cell types

Author(s)

Ziyi Li <[email protected]>

References

Ziyi Li, Zhenxing Guo, Ying Cheng, Peng Jin, Hao Wu. "Robust partial reference-free cell compoisiton estimation from tissue expression profiles."

Examples

# simulate mixed data from complex tissue
# without prior
Wmat <- matrix(abs(rnorm(60*3, 4, 4)), 60, 3)
SelMarker <- list(CellA = 1:20,
                  CellB = 21:40,
                  CellC = 41:60)
for(i in 1:3) {
     Wmat[SelMarker[[i]], i] <- abs(rnorm(20, 50, 10))
}
Hmat <- matrix(runif(3*25), 3, 25)
Hmat <- sweep(Hmat, 2, colSums(Hmat), "/")
Ymat <- Wmat %*% Hmat + abs(rnorm(60*25))
rownames(Ymat) <- 1:60

# deconvolution with TOAST/-P (TOAST without prior)
res <- MDeconv(Ymat, SelMarker, verbose = FALSE)
print(dim(Ymat))
cor(t(res$H), t(Hmat))

# supporse we observe the proportions
# for the same tissue from another study
alpha_prior <- rep(0.33, 3)
sigma_prior <- rep(1, 3)

# deconvolution with TOAST/+P (TOAST with prior)
res2 <- MDeconv(Ymat, SelMarker,
                alpha = alpha_prior, sigma = sigma_prior,
                verbose = FALSE)
cor(t(res2$H), t(Hmat))

Replicate the function myprojectMix() from RefFreeEWAS package

Description

Replicate the function myprojectMix() from RefFreeEWAS package (https://cran.r-project.org/web/packages/RefFreeEWAS/index.html) as that package is not in CRAN anymore

Usage

myprojectMix(Y, Xmat, nonnegative=TRUE, sumLessThanOne=TRUE, lessThanOne=!sumLessThanOne)

Arguments

Y

Matrix (m CpGs x n Subjects) of DNA methylation beta values

Xmat

Matrix (m CpGs x K cell types) of cell-type specific methylomes

nonnegative

All coefficients >=0?

sumLessThanOne

Coefficient rows should sum to less than one?

lessThanOne

Every value should be less than one (but possibly sum to value greater than one)?

Details

Function for projecting methylation values (Y) onto space of methyomes (Xmat), with various constraints. This is the reference-based method described in Houseman et al. (2012) and also appearing in the minfi package.

Value

Projection coefficients resulting from constrained projection


Replicate the function RefFreeCellMix() from RefFreeEWAS package

Description

Replicate the function RefFreeCellMix() from RefFreeEWAS package (https://cran.r-project.org/web/packages/RefFreeEWAS/index.html) as that package is not in CRAN anymore

Usage

myRefFreeCellMix(Y,mu0=NULL,K=NULL,iters=10,Yfinal=NULL,verbose=TRUE)

Arguments

Y

Matrix (m CpGs x n Subjects) of DNA methylation beta values

mu0

Matrix (m CpGs x K cell types) of *initial* cell-type specific methylomes

K

Number of cell types (ignored if mu0 is provided)

iters

Number of iterations to execute

Yfinal

Matrix (m* CpGs x n Subjects) of DNA methylation beta values on which to base final methylomes

verbose

Report summary of errors after each iteration?

Details

Reference-free decomposition of DNA methylation matrix into cell-type distributions and cell-type methylomes, Y = Mu Omega^T. Either an initial estimate of Mu must be provided, or else the number of cell types K, in which case RefFreeCellMixInitialize will be used to initialize. Note that the decomposition will be based on Y, but Yfinal (=Y by default) will be used to determine the final value of Mu based on the last iterated value of Omega.

Value

Object of S3 class RefFreeCellMix, containing the last iteration of Mu and Omega.

Author(s)

E. Andres Houseman

References

Houseman, E. Andres, Kile, Molly L., Christiani, David C., et al. Reference-free deconvolution of DNA methylation data and mediation by cell composition effects. BMC bioinformatics, 2016, vol. 17, no 1, p. 259.


Replicate the function RefFreeCellMixInitialize() from RefFreeEWAS package

Description

Replicate the function RefFreeCellMixInitialize() from RefFreeEWAS package (https://cran.r-project.org/web/packages/RefFreeEWAS/index.html) as that package is not in CRAN anymore

Usage

myRefFreeCellMixInitialize(Y,K=2,Y.Distance=NULL, Y.Cluster=NULL,
    largeOK=FALSE, dist.method = "euclidean", ...)

Arguments

Y

Matrix (m CpGs x n Subjects) of DNA methylation beta values

K

Number of cell types

Y.Distance

Distance matrix (object of class "dist") to use for clustering.

Y.Cluster

Hiearchical clustering object (from hclust function)

largeOK

OK to calculate distance matrix for large number of subjects? (See details.)

dist.method

Method for calculating distance matrix

...

Additional parameters for hclust function

Details

Initializes the methylome matrix "Mu" for RefFreeCellMix by computing the mean methylation (from Y) over K clusters of Y, determined by the Y.Cluster object. If Y.Cluster object does not exist, it will be created from Y.Distance (using additional clustering parameters if supplied). If Y.Distance does not exist, it will be created from t(Y). As a protection against attempting to fit a very large distance matrix, the program will stop if the number of columns of Y is > 2500, unless largeOK is explicitly set to TRUE.

Value

An m x K matrix of mean methylation values.

Author(s)

E. Andres Houseman


Show DE/DM state correlation between cell types

Description

This function generates -log10 transformed p-values for each pair of cell types and calculate corresponding Pearson correlation and odds ratio - a modification of function 'ggpairs' in package 'GGally'.

Usage

plotCorr(pval, de.state=NULL, pval.thres=NULL, fdr.thres=NULL, p.size = 0.2,
         p.color = grDevices::adjustcolor( "black", alpha.f = 0.2),
         fig.margin = c(1,1,1,1),
         fig.margin.unit = 'in', line.type = 'dashed', line.color = 'blue')

Arguments

pval

matrix of p-values, with rows representing features and columns representing cell types.

de.state

(optional) matrix of DE/DM states (1: DE/DM, 0:non-DE/DM), with rows representing features and columns representing cell types.

pval.thres

threshold of p-value to define DE/DM, required if de.state not provided.

fdr.thres

threshold of FDR to define DE/DM, required if de.state not provided and FDR is prefered than p-value.

p.size

point size for scatter plot

p.color

point color for scatter plot

fig.margin

figure margin

fig.margin.unit

unit of figure margin

line.type

line type in scatter plot

line.color

line color in scater plot

Value

A figure contains scatter plots, Pearson correlaiton and odds ration of -log10 transformed p-values for each pair of cell types.

Author(s)

Luxiao Chen <[email protected]>

Examples

pval.1 <- runif(1000,0,1)
pval.2 <- pval.1 + rnorm(1000,0,0.01)
pval.2[pval.2 < 0] =0
pval.3 <- runif(1000,0,1)

pval.input <- data.frame('cell.1'=pval.1,
                         'cell.2'=pval.2,
                         'cell.3'=pval.3)

plotCorr(pval = pval.input, pval.thres = 0.05)

An example dataset for cellular proportion estimation and multiple factor design

Description

The dataset contains normalized beta valutes for 3000 CpGs from 100 samples (50 Rheumatoid arthritis patients and 50 controls) and their phenotypes (disease status, age, and gender). The dataset also contains a sub-setted blood reference matrix for the matched 3000 CpGs. This data was obtained and processed based on GSE42861.

Usage

data("RA_100samples")

References

Liu Y, Aryee MJ, Padyukov L, Fallin MD et al. Epigenome-wide association data implicate DNA methylation as an intermediary of genetic risk in rheumatoid arthritis. Nat Biotechnol 2013 Feb;31(2):142-7. PMID: 23334450

Examples

data(RA_100samples)
RA_100samples$Y_raw[1:5,1:5]
head(RA_100samples$Pheno)
head(RA_100samples$Blood_ref)

Complete Deconvolution of DNA methylation data based on TOAST and SISAL

Description

A function to conduct complete reference-free deconvolution on DNA methylation data. If a full reference or a partial reference panel is provided, this function also automatically annotate the solved proportions to known cell types.

Usage

Tsisal(Y_raw, K = NULL, knowRef = NULL, possibleCellNumber = 3:15)

Arguments

Y_raw

The DNA methylation 450K array data from complex tissues, rows for CpG sites and columns for samples.

K

The number of pure cell types, we allow users to pre-specify or use our method to estimate.

knowRef

The external reference panel for cell type label assignment.

possibleCellNumber

Range of possible number of cell types. Default is 3:15.

Value

estProp

Estimated proportions.

selMarker

Selected cell type-specific markers.

K

Optional number of cell types.

Author(s)

Weiwei Zhang <[email protected]>

References

Complete deconvolution of DNA methylation signals from complex tissues: a geometric approach. Weiwei Zhang, Hao Wu and Ziyi Li.

Examples

### generate a simulation data
knowRef <- matrix(runif(5000*5), 5000, 5)
colnames(knowRef) <- paste0("CellType", 1:5)
Y_raw <- matrix(runif(5000*20), 5000, 20)
rownames(Y_raw) <- paste0("CpG", 1:5000)
colnames(Y_raw) <- paste0("Sample", 1:20)

Tsisal(Y_raw = Y_raw, K = 5, knowRef = knowRef)

## if cell type number is unknown
# Tsisal(Y.raw = Y_raw, K = NULL, knowRef = knowRef, possibleCellNumber = 4:10)