RNA sequencing of mesenchymal stem cells reveals a blocking of differentiation and immunomodulatory activities under inflammatory conditions in rheumatoid arthritis patients.

Introduction: Mesenchymal stem cells (MSCs) have the ability to differentiate into different types of cells of the mesenchymal lineage, such as osteocytes, chondrocytes, and adipocytes. It is also known that under inflammatory stimuli or in the appropriate experimental conditions, they can also act as regulators of inflammation. Thus, in addition to their regenerating potential, their interest has been extended to their possible use in cell therapy strategies for treatment of immune disorders.

Objective: To analyze, by RNA-seq analysis, the transcriptome profiling of allogenic MSCs under RA lymphocyte activation.

Methods: We identified the differentially expressed genes in bone marrow mesenchymal stem cells after exposure to an inflammatory environment. The transcriptome profiling was evaluated by means of the precise measurement of transcripts provided by the RNA-Seq technology.

Results: Our results evidenced the existence of blocking of both regenerative (differentiation) and immunomodulatory phenotypes under inflammatory conditions characterized by an upregulation of genes involved in immune processes and a simultaneous downregulation of genes mainly involved in regenerative or cell differentiation functions.

Conclusions: We conclude that the two main functions of MSCs (immunomodulation and differentiation) are blocked, at least while the inflammation is being resolved. Inflammation, at least partially mediated by gamma-interferon, drives MSCs to a cellular distress adopting a defensive state. This knowledge could be of particular interest in cases where the damage to be repaired has an important immune-mediated component.