The long non-coding RNA Meg3 is dispensable for hematopoietic stem cells

Area of Science:

• Genetics
• Molecular Biology
• Hematopoiesis

Background:

• The long non-coding RNA (lncRNA) Maternally Expressed Gene 3 (Meg3) is encoded by the imprinted Dlk1-Meg3 locus and is maternally expressed.
• Meg3 functions as a tumor suppressor and regulates cellular proliferation.
• Meg3 is highly expressed in adult hematopoietic stem cells (HSCs) but downregulated in early progenitors.

Purpose of the Study:

• To investigate the functional role of Meg3 in HSCs during homeostasis and stress.
• To determine if Meg3 is essential for maintaining the hematopoietic system.

Main Methods:

• Conditional deletion of Meg3 in adult mouse bone marrow using MxCre.
• Analysis of hematopoietic stem and progenitor cells in Meg3-deficient mice under homeostatic and stress conditions.
• In vitro and in vivo functional assays, including serial transplantation and response to interferon stimulation.
• Analysis of Meg3 deletion in the embryonic hematopoietic system using VavCre.

Main Results:

• Meg3 deficiency did not impair hematopoiesis in adult mice under homeostatic conditions.
• Meg3-deficient HSCs showed normal function upon serial transplantation.
• Deletion of Meg3 in the embryonic hematopoietic system did not result in hematopoietic defects.
• Meg3-deficient HSCs responded similarly to controls upon interferon-mediated stimulation.

Conclusions:

• The imprinted lncRNA Meg3 is dispensable for HSC function during homeostasis.
• Meg3 is not required for hematopoietic reconstitution in vivo.
• Meg3 does not play a critical role in HSC response to stress mediators like interferon.