Table 1.
Similarities and/or Differences between Peripheral Sample and CNS Samples
| Sampling | References | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Disease | Periphery | CNS | From Same Individuals |
Research Design/Focus |
Experimental Method | Findings | Similarities between CNS and Periphery |
Year, Journal | PMID |
| Genomics | |||||||||
| BPD | LCLs | Postmortem brain (DLPFC) |
No | An unbiased genome-wide |
DNA microarray | Differential expressions of PDLIM5 and HSPF1 both in blood and brain of BPD |
Two genes, out of 10 genes identified in postmortem, were replicated in LCLs |
2004, Mol Psychiatry |
14743183 |
| SZ | Blood | Postmortem brain (DLPFC) |
No | An unbiased genome-wide |
DNA microarray | Upregulation of SELENBP1 both in blood and brain of SZ |
Six genes, out of 177 genes identified in postmortem, were replicated in blood |
2005, Proc Natl Acad Sci U S A |
16223876 |
| Control | Blood | Postmortem brain (Multiple regions) |
No | An unbiased genome-wide |
DNA microarray | (1) Similarity of some signaling between blood/PFC (2) Half of SZ genes expressed both in blood/PFC |
Some signaling were similar |
2006, Am J Med Genet B Neuropsychiatr Genet |
16526044 |
| SZ/Control | Lymphocyte | Postmortem brain (PFC) |
No | HTR2A | RT-PCR | Disease associated SNP 102C is expressed lower than 102T in brains |
Lymphocyte: monoallelic, brain: biallelic expression |
2006, Biol Psychiatry |
17069769 |
| Control | Blood | Meta-analysis data | No | An unbiased genome-wide |
DNA microarray | Weak correlations between mean expression between brain and blood |
Only some signaling were similar |
2010, BMC Genomics |
20961428 |
| Control | Postmortem blood |
Postmortem brain (cerebellum) |
Yes | An unbiased genome-wide |
DNA microarray | 22% of total transcriptome expressed in both cerebellum and blood with high correlation (γ = .98). |
20% genes were expressed at similar level between blood and brain |
2010, Am J Med Genet B Neuropsychiatr Genet |
20127885 |
| SZ | Blood (discordant MZ twins) |
Postmortem brain | No | An unbiased methylome- wide |
Methylation microarray | Hypomethylation of ST6GALNAC1 both in blood and brain of SZ |
Brain DNA methylation were higher (~85%) than the blood (~40%) |
2011, Hum Mol Genet |
21908516 |
| BPD | LCLs | Postmortem brain (PFC) |
No | An unbiased promoter-wide |
Promoter tiling array and pyrosequencing |
Hypermethylation of SLC6A4 both in blood and brain of BPD |
2011, Transl Psychiatry |
22832526 | |
| BPD | Blood and sperm |
Postmortem brain | No | HCG9 | Bisulfite sequence | Hypomethylation of HCG9 in all tissues of BPD |
HCG9 methylation profiles were similar across tissues |
2012, Mol Psychiatry |
21647149 |
| Control | Blood (before death) |
Postmortem brain (multiple regions) |
Yes | An unbiased methylome- wide |
Methylated DNA immunoprecipitation |
Highly distinct patterns of DNA methylation between CNS and blood |
Methylation was generally tissue-specific, while that of CpG-rich promoter is largely similar |
2012, Genome Biol | 22703893 |
| SZ/Control | Blood | Postmortem brain | No | An unbiased methylome- wide |
Methylation microarray | Methylation levels were less variable than gene expression |
Moderate similarity of age- related CpG methylation (γ = .33) |
2012, Genome Biol |
23034122 |
| Proteomics/Metabolics | |||||||||
| Control (SIDS) |
Blood | Cortex, retina | Yes | Fatty acid composition |
Gas chromatography | Breast-fed infants had a higher DHA% both in brain and RBC |
Similar DHA% between brain/RBC (γ = .33) |
1994, Am J Clin Nutr |
7913291 |
| SZ/BPD/ Control |
RBC | Postmortem brain (DLPFC) |
No | Lipid composition | Mass spectrometry | Alterations in the free fatty acids and ceramide both in blood and brain of SZ and BPD group |
Closely correlated but quantitatively different between brain and RBC |
2008, J Proteome Res |
18778095 |
| SZ | RBC, serum, and liver |
Postmortem brain, CSF |
Partially Yes |
Proteomic profiling |
Mass spectroscopy and 2D-DIGE |
Downregulation of ApoA1 in all 5 tissues of SZ |
No correlation of CSF and serum apoA1 levels from the same subjects |
2008, Mol Psychiatry |
17938634 |
| SZ | Serum | Postmortem brain (BA 10) |
No | Proteomic/ metabolic profiling |
Multiplex immunoassay panel (187 molecules) |
21 analytes were altered in SZ postmortem brain |
5 analytes showed same directional change both tissues |
2012, PLoS One | 23118852 |
| Functional Cellular Assay | |||||||||
| SZ | Skin fibroblast | Multiple regions | Yes | Comparison of tyrosine kinetics |
▪ Uptake of tyrosine (fibroblast) ▪ Tyrosine transport across BBB (PET) |
Utilization of tyrosine was lower in the SZ (PET), and tyrosine transport was decreased in the fibroblast |
Similar tyrosine kinetics between tissues |
1991, J Nucl Med; 1994, Schizophr Res |
1941137 7841139 |
| MDD | Platelet | CSF | Yes | Comparison of 5-HT indexes |
▪ 5-HT index (platelet) ▪ 5-HT (CSF) |
No correlation between platelet and CSF for 5-HT indexes |
No support for the use of platelet for CSF 5-HT monitoring |
1992, Arch Gen Psychiatry |
1376106 |
| SZ (first episode, drug naïve) |
RBC | Living brain | Yes | Comparison of lipid metabolism |
▪ Fatty acids (RBC) ▪ 31P-MRS (brain) |
A parallel decrease in RBC phospholipid fatty acids and phospholipid metabolism in the PFC of SZ individuals |
Similarity between RBC and PFC lipid metabolism (γ= .56) |
2002, Biol Psychiatry |
12372654 |
| Control | Plasma | mPFC | Yes | Monitoring the brain Glu by plasma |
▪ HPLC (plasma) ▪ 1H-MRS (brain) |
No correlation between plasma and mPFC for Glu and Glx (Glu + Gln) concentration |
No support for the use of blood for CNS Glu monitoring |
2006, J Psychiatry Neurosci |
17136218 |
| SZ | Platelet | Living brain | Yes | Platelet as a predictor of CNS function |
▪ Mitochondrial complex I (platelet) ▪ FDG-PET (brain) |
Complex I activity in platelet was correlated with PANSS and cerebral glucose metabolism |
Similarity between peripheral and cerebral energy metabolism |
2007, Prog Neuropsycho Biol Psychiatry |
17329000 |
| MDD/BPD | Plasma | Living brain | Yes | Monitoring the brain PUFAs level by plasma |
▪ PUFA (plasma) ▪ FDG-PET (brain) |
Temporoparietal glucose usage correlated positively with both DHA% and AA% |
Similar PUFA ratio between plasma and cortex (γ = .77) |
2009,Prostaglandins Leukot Essent Fatty Acids |
19128951 |
2D-DIGE, two-dimensional difference gel electrophoresis; 5-HT, serotonin; AA, arachidonic acid; BA, Brodmann area; BBB, blood-brain barrier; BPD, bipolar disorder; CNS, central nervous system; CSF, cerebrospinal fluid; DHA, docosahexaenoic acid; DLPFC, dorsolateral prefrontal cortex; FDG, fluorodeoxyglucose; Gln, glutamine; Glu, glutamate; Glx, glutamate + glutamine; HPLC, high-pressure liquid chromatography; LCLs, lymphoblastoid cell lines; mPFC, medial prefrontal cortex; MDD, major depressive disorder; MRS, magnetic resonance spectroscopy; MZ, monozygotic; PANSS, Positive and Negative Syndrome Scale; PBMC, peripheral blood mononuclear cell; PET, positron emission tomography; PFC, prefrontal cortex; PMID, PubMed identifier; PUFA, polyunsaturated fatty acids; RBC, red blood cells; RT-PCR, reverse transcriptase polymerase chain reaction; SIDS, sudden infant death syndrome; SZ, schizophrenia.