The Power of mRNA in Anucleate Platelets

Platelets are the smallest cell in the bloodstream, and one of the few anucleate cells (i.e., cells that circulate without a nucleus). Because of their small size and anucleate stature, platelets have historically been conceived of as "sacs of glue" that function solely to stop bleeding. Andrew Weyrich, MD, and his group made the seminal discovery that anucleate human platelets transform messenger RNA (mRNA) into mature products that code for protein. More recently, his group found that a specific type of microRNAs (Dicer1-dependent) and their precursors (megakaryocytes) modulate the expression of target mRNAs important for cellular function. These observations revolutionized the field of hematology, leading to an explosion of studies that use mRNA profiling to identify previously-unrecognized functions of megakaryocytes and platelets that regulate thrombosis and inflammation (i.e., thromboinflammation). This work has also advanced scientific understanding of non-traditional functions of platelets that regulate the course of numerous diseases, including cardiovascular disease, diabetes, and infectious syndromes.