Question

Biology of Stem Cells:Thanks!

1a: A miRNA regulates its target mRNA by degradation. Let’s assume miRNA-199 targets Blimp1. Which progenitor population in the developing embryo will be affected?

1b:How does this affect your ability to isolate this progenitor pool?

Answer 1

The miR-199 microRNA precursor is a small non-coding RNA gene, which is involved in gene regulation.

miR-199a-3p is highly expressed in hair follicles and in some tumor cells, that proposes its possible involvement in tumor progression.

BLIMP1 is a bona fide tumor suppressor gene in ABC-DLBCL( Diffuse Large B cell Lymphoma). It is a type of Non Hodgkin's lymphoma. BLIMP1 acts as inactivation in lymphomagenesis to block the terminal differentiation and to change the expression of genes involved in cell cycle progression. In response to viral infection, naive CD8(+) T cells multiply and differentiate into cytotoxic and cytokine-producing effector cells. Here the transcription factor Blimp-1 is a essential regulator of plasma cell differentiation. It is required for CD8(+) T cells to differentiate into functional killer T cells in response to influenza virus.

So, if miRNA-199 targets Blimp1 then the Lymphogenesis would be affected. There will be decreased expression of the Blimp-1 protein in B lymphocytes, T lymphocytes, NK cell and other key immune system effector cells , which lead to decreased immune response by the process of proliferation and differentiation of antibody secreting plasma cells.

Also, Blimp-1 is an important regulator of the terminal differentiation of B cells into antibody-secreting plasma cells. Therefore, no such differentiation would occur. Also, the naive T cells won't differentiate into the cytotoxic and cytokine-producing effector cells.

Therefore, B- lymphocyte presursor cells would be chiefly affected.