Using reverse transcription--(RT-) PCR arrays, they showed that human bone marrow MSC-derived EVs contain mRNAs involved in transcription (e.g., CLOCK, IRF6, and LHX6), immune regulation (e.g., CRLF1, IL1RN, and MT1X), cell cycle regulation (e.g., SENP2
, RBL1, and CDC14B), DNA/RNA binding (e.g., HMGN4, TOPORS, and ESF1), actin cytoskeleton regulation (e.g., DDN, MSN, and CTNNA1), and extracellular matrix remodeling (e.g., COL4A2, IBSP) as well as cell differentiation into neuron (e.g., RAX2, OR11H12), bone (e.g., NIN, BMP15), endothelium/epithelium (e.g., MAGED2, CEACAM5), and hematopoietin (e.g., HK3, EPX).
Other PTMs, such as acetylation (HDAC6) and SUMOylation (P1AS2[beta], TRIM38, and SENP2
), or direct association of cellular proteins with RIG-I to disrupt its interaction with MAVS (NLRC5, NLRX1), have also been shown to contribute to RIG-I activation or repression.
First author Joshua Bernstock and his colleagues examined whether any of over 4,000 molecules from the NCATS small molecule collections could boost SUMOylation by blocking a SENP called SENP2, which would theoretically protect cells from a shortage of life-sustaining substances.
The researchers first used an automated process to examine whether the compounds prevented SENP2 from severing the connection between a tiny metal bead and an artificial SUMO protein created in the lab of Wei Yang, Ph.D., the study's other senior author and an associate professor at Duke University in Durham, NC.
miRNA Target Partial target genes numbers miR-2070-3p 1352 SH3D21, BCL7C, ACTR3B, EPC1 miR-222 624 RGS6, HMG20A, RBM15, NFE2 miR-502-3p 462 CRTC1, FGD1, CCL8, STARD8 miR-6238 391 Mcph1, PDZK1 miR-7446-3p 414 KLF13, SIAH2, TUB miR-7475-5p 517 LDB1, DVL3, PEG3, LRP1, LATS2, EFHD2 miR-125a-5p 2246 ESRRa, SENP2
, BCL2L12, SREBP-1, ABCA2, NNMT miR-126 2438 TNKS2, PTPRU, RGS14, NAP1L5 miR-378e 1044 IGF1R, CACNB2, RASIP1, API5, SCD5, SLC25A29 miR-7930-3p 1793 CABIN1, PCDHA2, PLXNA4
It was demonstrated that the mRNAs present in EVs are associated with the mesenchymal phenotype and with several cell functions related to the control of cell differentiation (RAX2, OR11H12, OR2M3, DDN, and GRIN3A), transcription (CLOCK, IRF6, RAX2, TCFP2, and BCL6B), proliferation (SENP2
, RBL1, CDC14B, and S100A13), cytoskeleton (DDN, MSN, and CTNNA1), metabolism (ADAM15, FUT3, ADM2, LTA4H, BDH2, and RAB5A) , and cell immune regulation (CRLF1, IL1RN, and MT1X) (Table 2).
The second, Sentrin/SUMO-specific protease 2, or SENP2, snips SUMO off of proteins (de-SUMOylation).
The researchers held on to this line of research after knocking SENP2 out of mouse DNA and found that the embryos died at about day 10.
In early development, SENP2 works as a switch to turn on Gata4 and Gata6.
The researchers have discovered a link between the key placental gene, SENP2 and well-known p53 protein, which is defective in 50 percent of all cancers.
"What we discovered was an unexpected interaction between an old player, p53, and a new player, SENP2," said lead author Wei Hsu, Ph.D., associate professor of Biomedical Genetics and Oncology, of the James P.
SENP2 (SUMO-specific protease 2) is highly expressed in trophoblast cells, which are the stem cells required to form the placenta.