The CRISPR-Cas9 System Is Used to Edit the Autoimmune Regulator Gene in Vitro and in Vivo.

Although mutations in the AIRE gene in patients with autoimmune polyendocrine syndrome type 1 (APS-1) syndrome are associated with the onset of this autoimmune disease, much of what is known about its mechanisms has been obtained through studies with Aire mutant Mus musculus mouse model or with Aire mutant medullary thymic epithelial cells (mTEC) cultured in vitro. The in vivo murine model was soon established, and ten mutant strains are currently described. Most Aire mutant mice were obtained through homologous recombination, which generated Aire knockout (KO) animals.

The Thymus as a Mirror of the Body's Gene Expression.

The thymus, a complex organ formed by different cell types that establish close interaction, serves a unique function of significant interest. The role played by the thymic stroma is not only a connective tissue or a support structure, but it also involves the stromal thymic epithelial cells (TECs) establishing physical and functional interaction with developing thymocytes. This interaction culminates in the induction of central tolerance, a function that sets this organ apart.

The single-cell transcriptome of mTECs and CD4 thymocytes under adhesion revealed heterogeneity of mTECs and a network controlled by and lncRNAs.

To further understand the impact of deficiency of the autoimmune regulator () gene during the adhesion of medullary thymic epithelial cells (mTECs) to thymocytes, we sequenced single-cell libraries (scRNA-seq) obtained from wild-type (WT) ( ) or -deficient ( ) mTECs cocultured with WT single-positive (SP) CD4 thymocytes. Although the libraries differed in their mRNA and long noncoding RNA (lncRNA) profiles, indicating that mTECs were heterogeneous in terms of their transcriptome, UMAP clustering revealed that both mTEC lines expressed their specific markers, i.e.

miR-155 exerts posttranscriptional control of autoimmune regulator (Aire) and tissue-restricted antigen genes in medullary thymic epithelial cells.

Background: The autoimmune regulator (Aire) gene is critical for the appropriate establishment of central immune tolerance. As one of the main controllers of promiscuous gene expression in the thymus, Aire promotes the expression of thousands of downstream tissue-restricted antigen (TRA) genes, cell adhesion genes and transcription factor genes in medullary thymic epithelial cells (mTECs). Despite the increasing knowledge about the role of Aire as an upstream transcriptional controller, little is known about the mechanisms by which this gene could be regulated.

Autoimmune regulator act in synergism with thymocyte adhesion in the control of lncRNAs in medullary thymic epithelial cells.

The autoimmune regulator (Aire) gene in medullary thymic epithelial cells (mTECs) encodes the AIRE protein, which interacts with its partners within the nucleus. This "Aire complex" induces stalled RNA Pol II on chromatin to proceed with transcription elongation of a large set of messenger RNAs and microRNAs. Considering that RNA Pol II also transcribes long noncoding RNAs (lncRNAs), we hypothesized that Aire might be implicated in the upstream control of this RNA species.

Aire Gene Influences the Length of the 3' UTR of mRNAs in Medullary Thymic Epithelial Cells.

Aire is a transcriptional controller in medullary thymic epithelial cells (mTECs) modulating a set of peripheral tissue antigens (PTAs) and non-PTA mRNAs as well as miRNAs. Even miRNAs exerting posttranscriptional control of mRNAs in mTECs, the composition of miRNA-mRNA networks may differ. Under reduction in Aire expression, networks exhibited greater miRNA diversity controlling mRNAs.

Effect of cell source and osteoblast differentiation on gene expression profiles of mesenchymal stem cells derived from bone marrow or adipose tissue.

Mesenchymal stem cells (MSCs) have been used in therapies for bone tissue healing. The aim of this study was to investigate the effect of cell source and osteoblast differentiation on gene expression profiles of MSCs from bone marrow (BM-MSCs) or adipose tissue (AT-MSCs) to contribute for selecting a suitable cell population to be used in cell-based strategies for bone regeneration. BM-MSCs and AT-MSCs were cultured in growth medium to keep MSCs characteristics or in osteogenic medium to induce osteoblast differentiation (BM-OBs and AT-OBs).