Big data differential analysis of microglial cell responses in neurodegenerative diseases

TRIM5 Promotes Systemic Lupus Erythematosus Through CD4(+) T Cells and Macrophage

Purpose

Systemic lupus erythematosus (SLE) is a typical autoimmune disease characterized by the involvement of multiple organs and the production of antinuclear antibodies. This study aimed to investigate the molecular mechanism of SLE.

Patients and Methods

We retrieved genome-wide gene expression levels from five public datasets with relatively large sample sizes from the Gene Expression Omnibus (GEO), and we compared the expression profiles of peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy controls (HCs). The expression of seven target genes in PBMCs from 25 cases and 3 HCs was further validated by reverse-transcription quantitative PCR (RT‒qPCR). Flow cytometry was used for verifying the proportion of naive CD4(+) T cells and M2 macrophages in PBMCs from 5 cases and 4 HCs.

Results

We found 14 genes (TRIM5, FAM8A1, SHFL, LHFPL2, PARP14, IFIT5, PARP12, DDX60, IRF7, IF144, OAS1, OAS3, RHBDF2, and RSAD2) that were differentially expressed among all five datasets. The heterogeneity test under the fixed effect model showed no obvious heterogeneity of TRIM5, FAM8A1, and SHFL across different populations. TRIM5 was positively correlated with the remaining 13 genes. By separating patient samples into TRIM5-high and TRIM5-low groups, we found that up-regulated genes in the TRIM5-high group were mainly enriched in virus-related pathways. Immune cell proportion analysis and flow cytometry revealed that naive CD4(+) T cells were significantly decreased while M2 macrophages were increased in the SLE group. TRIM5 expression levels were negatively correlated with naive CD4(+) T cells but positively correlated with M2 macrophages.

Conclusion

Our data indicated that TRIM5 might be a key factor that modulates SLE etiology, possibly through naive CD4(+) T cells and M2 macrophages.

Camillo Golgi (1843-1926): scientist extraordinaire and pioneer figure of modern neurology

Camillo Golgi was an extraordinary scientist whose contributions in the domain of neuroanatomy proved to be critical for emergence of neuroscience as a sovereign scientific discipline. Golgi's invention of the Black Reaction (La reazione nera) was a watershed event as it allowed remarkable visualization of the organizational pattern of elements of nervous system among complex puzzle of close knit interconnections. Till this time thin filamentary extensions of neural cells (axon and dendrites) could not be visualized with available staining techniques because of their slender and transparent nature. However invention of Black Reaction and its subsequent application demystified the basic architecture of brain tissue which was now visible to the scholars in all its complexity in microscopic studies. Golgi is also credited with the discovery of two types of sensory receptors in muscle tendons: Golgi tendon organ and Golgi-Mazzoni corpuscles. Golgi was the first to be successful in staining myelin component of axon, which he used to discover the myelin annular apparatus. He identified the complete life cycle of Plasmodium (malarial parasite) in human erythrocytes. His research on histological details of human kidney highlighted the existence of juxtaglomerular apparatus. Later on Spanish scientist Santiago Ramón y Cajal, based on the use of Golgi's Staining (Black Reaction) documented the morphologic details of nervous system in a more refined manner, which eventually led to the emergence of Neuron Doctrine. In recognition of their exemplary contributions in neuroscience Golgi and Cajal were jointly awarded the Nobel Prize for Physiology or Medicine in 1906.