Expression patterns in alternative splicing forms of prosaposin mRNA in the rat facial nerve nucleus after facial nerve transection.

Publisher: Elsevier Country of Publication: Ireland NLM ID: 8500749 Publication Model: Print-Electronic Cited Medium: Print ISSN: 0168-0102 (Print) Linking ISSN: 01680102 NLM ISO Abbreviation: Neurosci Res Subsets: MEDLINE

Publication: Limerick : Elsevier
Original Publication: [Shannon : Elsevier Scientific Publishers Ireland, c1984-

Alternative Splicing/*genetics ; Facial Nerve/*metabolism ; Facial Nerve Injuries/*metabolism ; Motor Neurons/*metabolism ; Rhombencephalon/*metabolism ; Saposins/*genetics; Animals ; Denervation ; Facial Nerve/physiopathology ; Facial Nerve Injuries/genetics ; Facial Nerve Injuries/physiopathology ; Gene Expression Regulation/physiology ; Male ; Microglia/metabolism ; Nerve Regeneration/genetics ; Protein Isoforms/genetics ; Protein Isoforms/metabolism ; Protein Structure, Tertiary/physiology ; RNA, Messenger/analysis ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; Rats ; Rats, Wistar ; Recovery of Function/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Rhombencephalon/physiopathology ; Saposins/biosynthesis ; Saposins/chemistry ; Up-Regulation/genetics

Prosaposin acts as a neurotrophic factor, in addition to its role as the precursor protein for saposins A, B, C, and D, which are activators for specific sphingolipid hydrolases in lysosomes. In rats, the prosaposin gene generates two alternative splicing forms of mRNA: Pro+9 containing a 9-base insertion and Pro+0 without. The expression of these mRNAs changes after brain injury. We examined the expression patterns of the alternative splicing forms of prosaposin mRNA in the rat facial nerve nucleus for 52 days following facial nerve transection. Pro+0 mRNA increased within 3 days of transection, peaked after 5-10 days, and remained significantly elevated for 21 days. In contrast, the expression of Pro+9 mRNA was constant throughout the regenerative period. Prosaposin mRNA expression increased not only in facial motoneurons, but also in microglia during facial nerve regeneration. Our findings indicate that the saposin B domain of prosaposin, which is the domain affected by alternative splicing, plays an important role in both neurons and microglia during neuroregeneration.

0 (Protein Isoforms)
0 (Psap protein, rat)
0 (RNA, Messenger)
0 (Saposins)

Date Created: 20071121 Date Completed: 20080411 Latest Revision: 20080107

20250114

10.1016/j.neures.2007.09.010

18022721