Setup

knitr::opts_knit$set(
  root.dir = ".")
library(dplyr)
library(dittoSeq)
library(ggrepel)
library(ggtree)
library(parallel)
library(plotly)  # 3D plot
library(Seurat)  # Idents()
library(SeuratDisk)  # SaveH5Seurat()
library(tibble)  # rownnames_to_column
library(harmony) # RunHarmony()
#options(mc.cores = detectCores() - 1)

Read in object

pigs.merged <- readRDS("../../rObjects/brain_annotated.rds")
Idents(pigs.merged) <- pigs.merged$merged_clusters
DefaultAssay(pigs.merged) <- "RNA"
# natural-log
pigs.merged <- NormalizeData(pigs.merged, verbose = FALSE)
pigs.merged
## An object of class Seurat 
## 42773 features across 8934 samples within 2 assays 
## Active assay: RNA (21805 features, 0 variable features)
##  1 other assay present: SCT
##  3 dimensional reductions calculated: pca, harmony, umap

Annotated UMAP

# UMAP
u1 <- DimPlot(object = pigs.merged, 
              reduction = "umap",
              label = TRUE,
              label.box = TRUE,
              label.size = 4,
              repel = TRUE)
u1

microglias before re-cluster

# subset
microglia <- subset(pigs.merged, merged_clusters == "microglia")

# UMAP of microglia only 
microglia_colors <- c("gold")
u1 <- DimPlot(object = microglia, 
        reduction = "umap", 
        label = TRUE,
        label.box = TRUE,
        label.size = 4,
        repel = TRUE, 
        cols = microglia_colors) 
u1

# show microglia cells by treatment 
u2 <- DimPlot(object = microglia, 
        reduction = "umap", 
        label = TRUE,
        label.box = TRUE,
        label.size = 4,
        repel = TRUE, 
        group.by = "treatment",
        cols = treatment_colors) 
u2

## png 
##   2
## null device 
##           1
## pdf 
##   2
## null device 
##           1

Quality checks

Number of cells

# Visualize the number of cell counts per sample
data <- as.data.frame(table(microglia$sample))
colnames(data) <- c("sample","frequency")

ncells <- ggplot(data, aes(x = sample, y = frequency, fill = sample)) + 
  geom_col() +
  theme_classic() +
  geom_text(aes(label = frequency), 
            position=position_dodge(width=0.9), 
            vjust=-0.25) +
  scale_fill_manual(values = sample_colors) + 
 # scale_y_continuous(breaks = seq(0,30000, by = 5000), limits = c(0,30000)) +
  ggtitle("Cells per sample") +
  theme(legend.position =  "none") + 
  theme(axis.text.x = element_text(angle = 45, hjust=1))
ncells

## Top transcripts

df <- data.frame(row.names = rownames(microglia))
df$rsum <- rowSums(x = microglia, slot = "counts")
df$gene_name <- rownames(df)
df <- df[order(df$rsum,decreasing = TRUE),]
head(df, 10)
##           rsum gene_name
## KK-MALAT1 8629 KK-MALAT1
## ARHGAP24  3459  ARHGAP24
## UBE2E2    3375    UBE2E2
## LRMDA     3112     LRMDA
## CALCR     3093     CALCR
## PRKCB     2841     PRKCB
## GAB2      2563      GAB2
## SLC8A1    2544    SLC8A1
## RN18S     2318     RN18S
## AGAP1     2301     AGAP1

Top variable genes

# Identify the most variable genes
microglia <- FindVariableFeatures(microglia,
                                   selection.method = "vst",  # default vst
                                   nfeatures = 2000,  # default 2000
                                   verbose = FALSE)
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : pseudoinverse used at -2.472
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : neighborhood radius 0.30103
## Warning in simpleLoess(y, x, w, span, degree = degree, parametric =
## parametric, : reciprocal condition number 1.8489e-14
# view top variable genes
top40 <- head(VariableFeatures(microglia), 40)
top40
##  [1] "SULF1"              "CEMIP"              "NRG1"              
##  [4] "RORA"               "TMSB10"             "REV1"              
##  [7] "RBMS3"              "NKAIN2"             "CTNND2"            
## [10] "DLG2"               "LSAMP"              "BMP6"              
## [13] "NRXN3"              "ADAM12"             "LRP1B"             
## [16] "TCF4"               "RBFOX1"             "AUTS2"             
## [19] "ENSSSCG00000038719" "PBX1"               "DAPK1"             
## [22] "ENSSSCG00000026043" "ROBO2"              "OPCML"             
## [25] "CADM2"              "PARD3"              "NTM"               
## [28] "BNC2"               "SVIL"               "FBXL7"             
## [31] "NLGN1"              "NRXN1"              "ENSSSCG00000037775"
## [34] "RPS8"               "SLC1A2"             "GREB1L"            
## [37] "NRG3"               "NAV2"               "GPC5"              
## [40] "RN18S"
# plot variable features with labels
VarFeatPlot <- VariableFeaturePlot(microglia, cols = c("gray47","red"))
VarFeatPlotLabel <- LabelPoints(plot = VarFeatPlot, 
                    points = top40, repel = TRUE, fontface="italic", 
                    xnudge = 0, ynudge = 0, max.overlaps = 12)
VarFeatPlotLabel

## Median absolute deviation

Remove outliers with log-library size greater than 3 median absolute deviations (MADs) or below the median log-library size.

# MAD example
log.lib <- as.numeric(log10(microglia$nCount_RNA))
med <- median(log.lib)
abs.dev <- abs(log.lib - med)
mad <- median(abs.dev)
mad <- mad * 1.4826 # multiply by consistency cutoff
mad
## [1] 0.2874665
# stats function
mad <- mad(log.lib)
mad
## [1] 0.2874665
# remove outliers greater than 3 MADs
remove <- abs(log.lib - median(log.lib)) / mad(log.lib) > 3
table(remove)
## remove
## FALSE  TRUE 
##   591     2

Re-cluster

Split, transform

# split object by sample
Idents(microglia) <- microglia$sample
microglia.split <- SplitObject(microglia, split.by = "sample")

# SCTransform and regress percent.mt
microglia.split <- lapply(microglia.split, SCTransform, vars.to.regress = "percent.mt")
## Calculating cell attributes from input UMI matrix: log_umi
## Variance stabilizing transformation of count matrix of size 6812 by 166
## Model formula is y ~ log_umi
## Get Negative Binomial regression parameters per gene
## Using 2000 genes, 166 cells
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## Found 29 outliers - those will be ignored in fitting/regularization step
## Second step: Get residuals using fitted parameters for 6812 genes
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## Computing corrected count matrix for 6812 genes
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## Calculating gene attributes
## Wall clock passed: Time difference of 7.081976 secs
## Determine variable features
## Place corrected count matrix in counts slot
## Regressing out percent.mt
## Centering data matrix
## Set default assay to SCT
## Calculating cell attributes from input UMI matrix: log_umi
## Variance stabilizing transformation of count matrix of size 6961 by 86
## Model formula is y ~ log_umi
## Get Negative Binomial regression parameters per gene
## Using 2000 genes, 86 cells
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## Found 42 outliers - those will be ignored in fitting/regularization step
## Second step: Get residuals using fitted parameters for 6961 genes
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## Computing corrected count matrix for 6961 genes
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## Calculating gene attributes
## Wall clock passed: Time difference of 5.297404 secs
## Determine variable features
## Place corrected count matrix in counts slot
## Regressing out percent.mt
## Centering data matrix
## Set default assay to SCT
## Calculating cell attributes from input UMI matrix: log_umi
## Variance stabilizing transformation of count matrix of size 1939 by 45
## Model formula is y ~ log_umi
## Get Negative Binomial regression parameters per gene
## Using 1939 genes, 45 cells
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## Found 23 outliers - those will be ignored in fitting/regularization step
## Second step: Get residuals using fitted parameters for 1939 genes
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## Computing corrected count matrix for 1939 genes
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## Calculating gene attributes
## Wall clock passed: Time difference of 3.296428 secs
## Determine variable features
## Place corrected count matrix in counts slot
## Regressing out percent.mt
## Centering data matrix
## Set default assay to SCT
## Calculating cell attributes from input UMI matrix: log_umi
## Variance stabilizing transformation of count matrix of size 7569 by 296
## Model formula is y ~ log_umi
## Get Negative Binomial regression parameters per gene
## Using 2000 genes, 296 cells
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## Found 93 outliers - those will be ignored in fitting/regularization step
## Second step: Get residuals using fitted parameters for 7569 genes
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## Computing corrected count matrix for 7569 genes
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## Calculating gene attributes
## Wall clock passed: Time difference of 10.12541 secs
## Determine variable features
## Place corrected count matrix in counts slot
## Regressing out percent.mt
## Centering data matrix
## Set default assay to SCT
# Choose the features to use when integrating multiple datasets. 
# will use nfeatures as 3000 as defined by running SCTransform above
var.features <- SelectIntegrationFeatures(object.list = microglia.split, 
                                          nfeatures = 3000)

# Merge the split object
microglia.sct.merged <- merge(x = microglia.split[[1]],
                         y = c(microglia.split[[2]], microglia.split[[3]], microglia.split[[4]]),
                         project = "LPS Pigs microglias")

# Define the variable features 
VariableFeatures(microglia.sct.merged) <- var.features

# Run PCA on the merged object
microglia.sct.merged <- RunPCA(object = microglia.sct.merged, assay = "SCT")
## PC_ 1 
## Positive:  CALCR, UBE2E2, ENSSSCG00000023479, GPM6B, ARHGAP24, PDE3B, GAB2, DOCK4, ANK1, SLC8A1 
##     NAV3, FGF1, IL1RAPL2, HK2, ENSSSCG00000033041, ENSSSCG00000012238, TCF7L2, PDE7A, ABR, EPB41L2 
##     ENSSSCG00000015645, PIK3AP1, P2RY12, SMAP2, TMCC3, CLCN5, APP, ST18, INPP5D, SLCO2B1 
## Negative:  KK-MALAT1, NOL11, FOXP1, PRKCE, HIVEP2, ZBTB16, FNBP1, HSP90AA1, DOCK1, ITPR1 
##     MED13L, ENSSSCG00000033262, CYTH1, ENSSSCG00000050772, CADM1, PARD3, NEDD4L, SORBS1, MED13, SFMBT2 
##     SNX24, OSBPL8, SSBP3, BCAS3, ANTXR2, ZBTB20, CHST11, ENSSSCG00000009327, ENSSSCG00000031462, RALGAPA1 
## PC_ 2 
## Positive:  SNX24, RBPJ, ASAP1, PTPN1, B4GALT5, ZEB2, CMIP, EXT1, CIITA, SNX9 
##     MS4A7, DENND5A, ANKHD1, PFKFB3, PLEK, LCP1, KK-MALAT1, ENSSSCG00000033909, TNS3, IRAK2 
##     KDM6A, JARID2, STAB1, GAB2, DIAPH2, KMT2C, PICALM, CD53, CDK12, RNF2 
## Negative:  ZBTB20, NEGR1, FRMD4A, TLN2, ENSSSCG00000011121, ENSSSCG00000050772, CAMTA1, DST, GPC5, NFIA 
##     PARD3, SORBS1, CALCR, DPYSL2, ENSSSCG00000048207, SLC1A3, JMJD1C, ENSSSCG00000009327, ANK1, ENSSSCG00000049691 
##     BCAS3, FOXP1, NEDD4L, SRPK2, OPHN1, FOXN3, DYNC1H1, ENSSSCG00000051610, SRGAP1, PDE4D 
## PC_ 3 
## Positive:  ENSSSCG00000017146, MX2, FOXP1, NLRC5, VAV3, ZEB2, HERC6, OAS2, EPSTI1, PARP14 
##     LRMDA, GNAQ, ARHGAP22, ANTXR2, ITSN1, ENSSSCG00000009240, ENTPD1, QKI, ENSSSCG00000033089, ITPR1 
##     SNX24, ARHGAP15, ARHGAP25, PARP12, AP3B1, FYB1, HERC5, RBM47, DNAJC13, MX1 
## Negative:  ASAP1, ST18, RNF2, ENSSSCG00000048263, NAV3, C1orf21, FGF1, MAML3, PAFAH1B1, ENSSSCG00000009327 
##     ST3GAL3, SLC7A1, EPS8, ZEB1, SBNO2, HK2, KLF12, ENSSSCG00000033041, PPARG, PIK3CD 
##     CAMKMT, TOR1AIP1, ITGA9, TPM3, STAT5B, PTK2B, CMSS1, ENSSSCG00000047147, DNAJC7, MICU2 
## PC_ 4 
## Positive:  TCF7L2, ASAP1, CIITA, ENSSSCG00000033089, HERC6, PLD1, ENSSSCG00000017146, RNF2, NIBAN1, ENSSSCG00000048263 
##     EPSTI1, MAML3, NEBL, PTK2B, PARP14, ZNF146, ENSSSCG00000030801, MX2, ETV6, EPS8 
##     KLF12, PRKCE, STK3, PIK3C2A, MX1, PIK3CD, ZBTB20, C3, SNTB1, SLC11A2 
## Negative:  DOCK2, IFNAR2, XYLT1, ENSSSCG00000000530, ARHGAP25, HPCAL1, BLNK, FYB1, RPS6KA3, PRKCB 
##     ENSSSCG00000028461, TGFBR2, ARID3A, ARHGAP22, RBM47, ENSSSCG00000033041, ZMYND8, SIN3A, CST3, ARHGAP18 
##     EHBP1L1, ZMIZ1, DGKD, DOCK8, RCSD1, ZEB2, ST6GAL1, SNX29, ENSSSCG00000028035, RRBP1 
## PC_ 5 
## Positive:  RBPJ, AGAP1, MERTK, LRMDA, SNX24, STAB1, SLC7A7, TTC7B, UBASH3B, SLC9A9 
##     WDFY3, NCOR2, VAV3, PDGFC, NCOA2, CADM1, GMDS, TLN2, FRMD4B, DST 
##     HPCAL1, CTBP2, EXT1, NEK6, PPP1R37, FRMD4A, CSF1R, DENND1A, ARHGAP18, ARHGEF10L 
## Negative:  ARHGAP15, RABGAP1L, PTPRC, FRYL, ZEB1, FOXN3, NLRC5, RUNX1, MBNL1, KLF12 
##     XYLT1, STAT1, P2RY6, CNOT4, TGFBR2, MSI2, FNBP1, LRP8, ITPR2, ZHX2 
##     RHOH, ENSSSCG00000033089, PHF20L1, NFKB1, STX11, PARP14, SNX29, SNTB1, PDE7A, ZC3HAV1

No integration

# get significant PCs
stdv <- microglia.sct.merged[["pca"]]@stdev
sum.stdv <- sum(microglia.sct.merged[["pca"]]@stdev)
percent.stdv <- (stdv / sum.stdv) * 100
cumulative <- cumsum(percent.stdv)
co1 <- which(cumulative > 90 & percent.stdv < 5)[1]
co2 <- sort(which((percent.stdv[1:length(percent.stdv) - 1] - 
                       percent.stdv[2:length(percent.stdv)]) > 0.1), 
              decreasing = T)[1] + 1
min.pc <- min(co1, co2)
min.pc
## [1] 6
# run umap
microglia.nointergration <- RunUMAP(microglia.sct.merged, dims = 1:min.pc, reduction = "pca")
## Warning: The default method for RunUMAP has changed from calling Python UMAP via reticulate to the R-native UWOT using the cosine metric
## To use Python UMAP via reticulate, set umap.method to 'umap-learn' and metric to 'correlation'
## This message will be shown once per session
## 19:18:04 UMAP embedding parameters a = 0.9922 b = 1.112
## 19:18:04 Read 593 rows and found 6 numeric columns
## 19:18:04 Using Annoy for neighbor search, n_neighbors = 30
## 19:18:04 Building Annoy index with metric = cosine, n_trees = 50
## 0%   10   20   30   40   50   60   70   80   90   100%
## [----|----|----|----|----|----|----|----|----|----|
## **************************************************|
## 19:18:04 Writing NN index file to temp file /tmp/RtmpGS27MT/file104a52102ed67
## 19:18:04 Searching Annoy index using 1 thread, search_k = 3000
## 19:18:04 Annoy recall = 100%
## 19:18:05 Commencing smooth kNN distance calibration using 1 thread
## 19:18:07 Initializing from normalized Laplacian + noise
## 19:18:07 Commencing optimization for 500 epochs, with 20562 positive edges
## 19:18:09 Optimization finished
# cluster
microglia.nointergration <- FindNeighbors(object = microglia.nointergration, dims = 1:min.pc)                     
## Computing nearest neighbor graph
## Computing SNN
# Determine the clusters for various resolutions                                
microglia.nointergration <- FindClusters(object = microglia.nointergration,resolution = seq(0.1,0.8,by=0.1))
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.9000
## Number of communities: 1
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.8302
## Number of communities: 2
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.7669
## Number of communities: 2
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.7242
## Number of communities: 3
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6942
## Number of communities: 5
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6722
## Number of communities: 5
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6503
## Number of communities: 5
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6283
## Number of communities: 5
## Elapsed time: 0 seconds
Idents(microglia.nointergration) <- "SCT_snn_res.0.1"
microglia.nointergration$seurat_clusters <- microglia.nointergration$SCT_snn_res.0.6

UMAP no integration

u1 <- dittoDimPlot(object = microglia.nointergration,
             var = "seurat_clusters",
             reduction.use = "umap",
             do.label = TRUE,
             labels.highlight = FALSE)
u1

u2 <- dittoDimPlot(object = microglia.nointergration,
             var = "seurat_clusters",
             reduction.use = "umap",
             do.label = TRUE,
             split.by = "treatment",
             labels.highlight = FALSE)
u2

# show microglia cells by treatment 
u3 <- DimPlot(object = microglia.nointergration, 
        reduction = "umap", 
        label = FALSE,
        repel = TRUE, 
        group.by = "treatment",
        cols = treatment_colors) 
u3

# show microglia cells by treatment 

#remove(u1,u2,u3)

Cells per cluster

# Cells per treatment per cluster
treatment_ncells <- FetchData(microglia.nointergration, 
                     vars = c("ident", "treatment")) %>%
  dplyr::count(ident,treatment) %>%
  tidyr::spread(ident, n)
treatment_ncells
##   treatment   0
## 1       LPS 341
## 2    Saline 252
# Cells per sample per cluster
sample_ncells <- FetchData(microglia.nointergration, 
                     vars = c("ident", "sample")) %>%
  dplyr::count(ident,sample) %>%
  tidyr::spread(ident, n)
sample_ncells
##       sample   0
## 1  10.Saline  86
## 2     12.LPS 296
## 3 4.R.Saline 166
## 4    8.R.LPS  45
# treatment
b1 <- microglia.nointergration@meta.data %>%
  group_by(seurat_clusters, treatment) %>%
  dplyr::count() %>%
  group_by(seurat_clusters) %>%
  dplyr::mutate(percent = 100*n/sum(n)) %>%
  ungroup() %>%
  ggplot(aes(x=seurat_clusters,y=percent, fill=treatment)) +
  geom_col() +
  scale_fill_manual(values = treatment_colors) +
  ggtitle("Percentage of treatment per cluster")
b1

# sample
b2 <- microglia.nointergration@meta.data %>%
  group_by(seurat_clusters, sample) %>%
  dplyr::count() %>%
  group_by(seurat_clusters) %>%
  dplyr::mutate(percent = 100*n/sum(n)) %>%
  ungroup() %>%
  ggplot(aes(x=seurat_clusters,y=percent, fill=sample)) +
  geom_col() +
  #scale_fill_manual(values = sample_colors) +
  ggtitle("Percentage of sample per cluster")
b2

#remove(b1, b2)

Integrate with harmony

# Run harmony to harmonize over samples 
microglia.integrated <- RunHarmony(object = microglia.sct.merged, 
                              group.by.vars = "sample", 
                              assay.use = "SCT",
                              reduction = "pca", 
                              plot_convergence = TRUE)
## Harmony 1/10
## Harmony 2/10
## Harmony 3/10
## Harmony 4/10
## Harmony 5/10
## Harmony 6/10
## Harmony converged after 6 iterations
## Warning: Invalid name supplied, making object name syntactically valid. New
## object name is Seurat..ProjectDim.SCT.harmony; see ?make.names for more details
## on syntax validity

Find significant PCs

First metric

# Determine percent of variation associated with each PC
stdv <- microglia.integrated[["pca"]]@stdev
sum.stdv <- sum(microglia.integrated[["pca"]]@stdev)
percent.stdv <- (stdv / sum.stdv) * 100

# Calculate cumulative percents for each PC
cumulative <- cumsum(percent.stdv)

# Determine which PC exhibits cumulative percent greater than 90% and
# and % variation associated with the PC as less than 5
co1 <- which(cumulative > 90 & percent.stdv < 5)[1]
co1
## [1] 45

Second metric

# Determine the difference between variation of PC and subsequent PC
co2 <- sort(which(
  (percent.stdv[1:length(percent.stdv) - 1] - 
     percent.stdv[2:length(percent.stdv)]) > 0.1), 
  decreasing = T)[1] + 1

# last point where change of % of variation is more than 0.1%.
co2
## [1] 6

Usually, we would choose the minimum of these two metrics as the PCs covering the majority of the variation in the data.

# Minimum of the two calculation
min.pc <- min(co1, co2)
min.pc
## [1] 6

Use min.pc we just calculated to generate the clusters. We can plot the elbow plot again and overlay the information determined using our metrics:

# Create a dataframe with values
plot_df <- data.frame(pct = percent.stdv, 
           cumu = cumulative, 
           rank = 1:length(percent.stdv))

# Elbow plot to visualize 
  ggplot(plot_df, aes(cumulative, percent.stdv, label = rank, color = rank > min.pc)) + 
  geom_text() + 
  geom_vline(xintercept = 90, color = "grey") + 
  geom_hline(yintercept = min(percent.stdv[percent.stdv > 5]), color = "grey") +
  theme_bw()
## Warning in min(percent.stdv[percent.stdv > 5]): no non-missing arguments to min;
## returning Inf

Run UMAP and Cluster

# Run UMAP
microglia.integrated <- RunUMAP(microglia.integrated,
                           dims = 1:min.pc,
                           reduction = "pca",
                           n.components = 3) # set to 3 to use with VR
## 19:18:15 UMAP embedding parameters a = 0.9922 b = 1.112
## 19:18:15 Read 593 rows and found 6 numeric columns
## 19:18:15 Using Annoy for neighbor search, n_neighbors = 30
## 19:18:15 Building Annoy index with metric = cosine, n_trees = 50
## 0%   10   20   30   40   50   60   70   80   90   100%
## [----|----|----|----|----|----|----|----|----|----|
## **************************************************|
## 19:18:15 Writing NN index file to temp file /tmp/RtmpGS27MT/file104a57049adff
## 19:18:15 Searching Annoy index using 1 thread, search_k = 3000
## 19:18:15 Annoy recall = 100%
## 19:18:16 Commencing smooth kNN distance calibration using 1 thread
## 19:18:17 Initializing from normalized Laplacian + noise
## 19:18:17 Commencing optimization for 500 epochs, with 20562 positive edges
## 19:18:20 Optimization finished
# Determine the K-nearest neighbor graph
microglia.integrated <- FindNeighbors(object = microglia.integrated,dims = 1:min.pc)
## Computing nearest neighbor graph
## Computing SNN
# Determine the clusters for various resolutions                                
microglia.unannotated <- FindClusters(object = microglia.integrated,resolution = seq(0.1,0.8,by=0.1))
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.9000
## Number of communities: 1
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.8302
## Number of communities: 2
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.7669
## Number of communities: 2
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.7242
## Number of communities: 3
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6942
## Number of communities: 5
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6722
## Number of communities: 5
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6503
## Number of communities: 5
## Elapsed time: 0 seconds
## Modularity Optimizer version 1.3.0 by Ludo Waltman and Nees Jan van Eck
## 
## Number of nodes: 593
## Number of edges: 19402
## 
## Running Louvain algorithm...
## Maximum modularity in 10 random starts: 0.6283
## Number of communities: 5
## Elapsed time: 0 seconds
Idents(microglia.unannotated) <- "SCT_snn_res.0.6"

# save
saveRDS(microglia.unannotated,"../../rObjects/microglia_unannotated.rds")

microglias after re-cluster

UMAP

DefaultAssay(microglia.unannotated) <- "RNA"
#microglia.unannotated <- NormalizeData(microglia.unannotated, verbose = FALSE)
microglia.unannotated$seurat_clusters <- microglia.unannotated$SCT_snn_res.0.6

u1 <- dittoDimPlot(object = microglia.unannotated,
             var = "seurat_clusters",
             reduction.use = "umap",
             do.label = TRUE,
             labels.highlight = FALSE)
u1

u2 <- dittoDimPlot(object = microglia.unannotated,
             var = "seurat_clusters",
             reduction.use = "umap",
             do.label = TRUE,
             split.by = "treatment",
             labels.highlight = FALSE)
u2

# show microglia cells by treatment 
u3 <- DimPlot(object = microglia.unannotated, 
        reduction = "umap", 
        label = FALSE,
        repel = TRUE, 
        group.by = "treatment",
        cols = treatment_colors) 
u3

remove(u1,u2,u3)

Cluster tree

cluster_colors <- c("gold","firebrick1","dodgerblue","green",
                    "cyan","chocolate4","gray40","purple", "blue")

microglia.unannotated <- BuildClusterTree(object = microglia.unannotated,
                                     dims = 1:min.pc,
                                     reorder = FALSE,
                                     reorder.numeric = FALSE)

tree <- microglia.unannotated@tools$BuildClusterTree
tree$tip.label <- paste0("Cluster ", tree$tip.label)

p <- ggtree::ggtree(tree, aes(x, y)) +
  scale_y_reverse() +
  ggtree::geom_tree() +
  ggtree::theme_tree() +
  ggtree::geom_tiplab(offset = 1) +
  ggtree::geom_tippoint(color = cluster_colors[1:length(tree$tip.label)], shape = 16, size = 5) +
  coord_cartesian(clip = 'off') +
  theme(plot.margin = unit(c(0,2.5,0,0), 'cm'))
## Scale for 'y' is already present. Adding another scale for 'y', which will
## replace the existing scale.
p

Cells per cluster

# Cells per treatment per cluster
treatment_ncells <- FetchData(microglia.unannotated, 
                     vars = c("ident", "treatment")) %>%
  dplyr::count(ident,treatment) %>%
  tidyr::spread(ident, n)
treatment_ncells
##   treatment  0   1  2  3  4
## 1       LPS 88 111 57 45 40
## 2    Saline 95  17 60 46 34
# Cells per sample per cluster
sample_ncells <- FetchData(microglia.unannotated, 
                     vars = c("ident", "sample")) %>%
  dplyr::count(ident,sample) %>%
  tidyr::spread(ident, n)
sample_ncells
##       sample  0  1  2  3  4
## 1  10.Saline 34  6 17 27  2
## 2     12.LPS 77 96 42 41 40
## 3 4.R.Saline 61 11 43 19 32
## 4    8.R.LPS 11 15 15  4 NA
# treatment
b1 <- microglia.unannotated@meta.data %>%
  group_by(seurat_clusters, treatment) %>%
  dplyr::count() %>%
  group_by(seurat_clusters) %>%
  dplyr::mutate(percent = 100*n/sum(n)) %>%
  ungroup() %>%
  ggplot(aes(x=seurat_clusters,y=percent, fill=treatment)) +
  geom_col() +
  scale_fill_manual(values = treatment_colors) +
  ggtitle("Percentage of treatment per cluster")
b1

# sample
b2 <- microglia.unannotated@meta.data %>%
  group_by(seurat_clusters, sample) %>%
  dplyr::count() %>%
  group_by(seurat_clusters) %>%
  dplyr::mutate(percent = 100*n/sum(n)) %>%
  ungroup() %>%
  ggplot(aes(x=seurat_clusters,y=percent, fill=sample)) +
  geom_col() +
  #scale_fill_manual(values = sample_colors) +
  ggtitle("Percentage of sample per cluster")
b2

remove(b1, b2)

Conserved markers

# set levels
microglia.unannotated$treatment <- factor(microglia.unannotated$treatment,
                                       levels = c("LPS","Saline"))
microglia.unannotated$SCT_snn_res.0.6 <- factor(microglia.unannotated$SCT_snn_res.0.6)
# initialize df
conserved.markers <- data.frame()
all.clusters <- unique(microglia.unannotated$SCT_snn_res.0.6)

# loop through each cluster
for (i in all.clusters) {
  
  # print the cluster you're on
  print(i)
  
  # find conserved marker in cluster vs all other clusters
  markers <- FindConservedMarkers(microglia.unannotated,
                                  ident.1 = i, # subset to single cluster
                                  grouping.var = "treatment", # compare by treatment
                                  only.pos = TRUE, # only positive markers
                                  min.pct = 0.1, # default
                                  logfc.threshold = 0.25, # default
                                  test.use = "MAST"
                                  )
  
  # skip if none
  if(nrow(markers) == 0) {
    next
  }
  
  # make rownames a column
  markers <- rownames_to_column(markers, var = "gene")
  
  # make cluster number a column
  markers$cluster <- i
  
  # add to final table
  conserved.markers <- rbind(conserved.markers, markers)
}
## [1] "3"
## Testing group Saline: (3) vs (4, 0, 2, 1)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## Testing group LPS: (3) vs (1, 0, 2, 4)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "4"
## Testing group Saline: (4) vs (3, 0, 2, 1)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## Testing group LPS: (4) vs (1, 0, 2, 3)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "0"
## Testing group Saline: (0) vs (3, 4, 2, 1)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## Testing group LPS: (0) vs (1, 2, 3, 4)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "2"
## Testing group Saline: (2) vs (3, 4, 0, 1)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## Testing group LPS: (2) vs (1, 0, 3, 4)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "1"
## Testing group Saline: (1) vs (3, 4, 0, 2)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## Testing group LPS: (1) vs (0, 2, 3, 4)
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
# create delta_pct
conserved.markers$Saline_delta_pct <- abs(conserved.markers$Saline_pct.1 - 
                                         conserved.markers$Saline_pct.2)
conserved.markers$LPS_delta_pct <- abs(conserved.markers$LPS_pct.1 - 
                                            conserved.markers$LPS_pct.2)
  
# more stringent filtering
markers.strict <- conserved.markers[
  conserved.markers$Saline_delta_pct > summary(conserved.markers$Saline_delta_pct)[5],]
markers.strict <- conserved.markers[
  conserved.markers$LPS_delta_pct > summary(conserved.markers$LPS_delta_pct)[5],]
markers.strict$gene_name <- markers.strict$gene
markers.strict$row.num <- 1:nrow(markers.strict)

# compare 
table(conserved.markers$cluster)
## 
##   0   1   2   3   4 
## 225 207 231 474 382
table(markers.strict$cluster)
## 
##   0   1   2   3   4 
##  19   9  11 266  75
saveRDS(conserved.markers, paste0("../../rObjects/brain_conserved_markers_", cell, ".rds"))

# subset
cluster0 <- markers.strict[markers.strict$cluster == 0,]
cluster1 <- markers.strict[markers.strict$cluster == 1,]
cluster2 <- markers.strict[markers.strict$cluster == 2,]
cluster3 <- markers.strict[markers.strict$cluster == 3,]
cluster4 <- markers.strict[markers.strict$cluster == 4,]

Cluster Annotations

Cluster 0

VlnPlot(microglia.unannotated, 
        features = cluster0$gene[1:19],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)
## The default behaviour of split.by has changed.
## Separate violin plots are now plotted side-by-side.
## To restore the old behaviour of a single split violin,
## set split.plot = TRUE.
##       
## This message will be shown once per session.

### Cluster 1

VlnPlot(microglia.unannotated, 
        features = cluster1$gene[1:9],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)

### Cluster 2

VlnPlot(microglia.unannotated, 
        features = cluster2$gene[1:11],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)

Cluster 3

VlnPlot(microglia.unannotated, 
        features = cluster3$gene[1:21],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)

VlnPlot(microglia.unannotated, 
        features = cluster3$gene[21:40],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)

### Cluster 4

VlnPlot(microglia.unannotated, 
        features = cluster4$gene[1:20],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)

VlnPlot(microglia.unannotated, 
        features = cluster4$gene[21:40],
        split.by = "seurat_clusters",
        cols = cluster_colors,
        flip = TRUE,
        stack = TRUE)

# microglia markers

# 

Annotation

# umap with annotations 

Differential expression

LPS vs Saline within each cluster

cell_types <- unique(microglia.unannotated$SCT_snn_res.0.6)
microglia.unannotated$cell_type <- microglia.unannotated$SCT_snn_res.0.6
DE.df <- data.frame()

for (i in cell_types) {
  print(i)
  cluster <- subset(microglia.unannotated, cell_type == i)
  Idents(cluster) <- cluster$treatment
  markers <- FindMarkers(object = cluster,
                         ident.1 = "LPS",
                         ident.2 = "Saline",
                         only.pos = FALSE, # default
                         min.pct = 0.10,  # default
                         test.use = "MAST",
                         verbose = TRUE,
                         assay = "RNA")
  if(nrow(markers) == 0) {
    next
  }
  markers$cluster <- i
  DE.df <- rbind(DE.df, markers)
}
## [1] "3"
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "4"
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "0"
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "2"
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
## [1] "1"
## 
## Done!
## Combining coefficients and standard errors
## Calculating log-fold changes
## Calculating likelihood ratio tests
## Refitting on reduced model...
## 
## Done!
# change column names
colnames(DE.df)[c(3,4)] <- c("percent_LPS","percent_Saline")
# add gene name column
DE.df$gene <- rownames(DE.df)
# change row names
rownames(DE.df) <- 1:nrow(DE.df)
# calculate percent difference
DE.df$percent_difference <- abs(DE.df$percent_LPS - DE.df$percent_Saline)
# reorder columns
DE.df <- DE.df[,c(6,7,1,5,2,3,4,8)]
# write table
write.table(DE.df, "../../results/recluster/microglia/LPS_vs_Saline_DEGs.tsv", sep = "\t",
            quote = FALSE, row.names = FALSE)

Shiny App

Cleanup object

metadata <- microglia.unannotated@meta.data
microglia.unannotated@meta.data <- metadata
microglia.unannotated@assays$SCT@meta.features <- metadata
microglia.unannotated@assays$RNA@meta.features <- metadata

Output folder

# load libraries
library(ShinyCell)

# make shiny folder
DefaultAssay(microglia.unannotated) <- "RNA"
Idents(microglia.unannotated) <- "merged_clusters"
sc.config <- createConfig(microglia.unannotated)
makeShinyApp(microglia.unannotated, sc.config, gene.mapping = TRUE,
             shiny.title = "recluster microglia")