RNAi pathway is functional in peripheral nerve axons.
Recent observations demonstrated that translation of mRNAs may occur in axonal processes at sites that are long distances away from the neuronal perikaria. While axonal protein synthesis has been documented in several studies, the mechanism of its regulation remains unclear. The aim of this study was to investigate whether RNA interference (RNAi) may be one of the pathways that control local protein synthesis in axons. Here we show that sciatic nerve contains Argonaute2 nuclease, fragile X mental retardation protein, p100 nuclease, and Gemin3 helicase-components of the RNA-induced silencing complex (RISC). Application of short-interfering RNAs against neuronal beta-tubulin to the sciatic nerve initiated RISC formation, causing a decrease in levels of neuronal beta-tubulin III mRNA and corresponding protein, as well as a significant reduction in retrograde labeling of lumbar motor neurons. Our observations indicate that RNAi is functional in peripheral mammalian axons and is independent from the neuronal cell body or Schwann cells. We introduce a concept of local regulation of axonal translation via RNAi.
Murashov
Alexander K
AK
Department of Physiology, Brody School of Medicine, East Carolina University, 600 Moye Blvd., Greenville, NC 27834, USA. murashoval@ecu.edu
Chintalgattu
Vishnu
V
Islamov
Rustem R
RR
Lever
Teresa E
TE
Pak
Elena S
ES
Sierpinski
Paulina L
PL
Katwa
Laxmansa C
LC
Van Scott
Michael R
MR
D000818:Animals; D001369:Axons / Q000378:metabolism*; D055541:DEAD Box Protein 20; D053487:DEAD-box RNA Helicases / Q000378:metabolism; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010525:Peripheral Nerves / Q000166:cytology*; D011506:Proteins / Q000378:metabolism*; D034622:RNA Interference / Q000502:physiology*; D034741:RNA, Small Interfering / Q000378:metabolism / Q000494:pharmacology; D012584:Sciatic Nerve / Q000187:drug effects / Q000378:metabolism; D014404:Tubulin / Q000187:drug effects / Q000235:genetics / Q000378:metabolism
D055541:DEAD Box Protein 20; D053487:DEAD-box RNA Helicases; D051860:Fragile X Messenger Ribonucleoprotein 1; D011506:Proteins; D034741:RNA, Small Interfering; D014404:Tubulin; C485624:Ddx20 protein, mouse