Sympathetic neurons express and secrete MMP-2 and MT1-MMP to control nerve sprouting via pro-NGF conversion.
Recently, we have shown that high frequency electrical field stimulation (HFES) of sympathetic neurons (SN) induces nerve sprouting by up-regulation of nerve growth factor (NGF) which targets the tyrosine kinase A receptor (TrkA) in an autocrine/paracrine manner. There is increasing evidence that matrix metalloproteinase-2 (MMP-2) is not only involved in extracellular matrix (ECM) turnover but may also exert beneficial effects during neuronal growth. Therefore, this study aimed to investigate the regulation and function of MMP-2 and its major activator membrane type 1-matrix metalloproteinase (MT1-MMP) as well its inhibitor TIMP-1 in SN under conditions of HFES. Moreover, we analyzed molecular mechanisms of the beneficial effect of losartan, an angiotensin II type I receptor (AT-1)blocker on HFES-induced nerve sprouting. Cell cultures of SN from the superior cervical ganglia (SCG) of neonatal rats were electrically stimulated for 48 h with a frequency of 5 or 50 Hz. HFES increased MMP-2 and MT1-MMP mRNA and protein expression, whereas TIMP-1 expression remained unchanged. Under conditions of HFES, we observed a shift from pro- to active-MMP-2 indicating an increase in MMP-2 enzyme activity. Specific pharmacological MMP-2 inhibition contributed to an increase in pro-NGF amount in the cell culture supernatant and significantly reduced HFES-induced neurite outgrowth. Losartan abolished HFES-induced nerve sprouting in a significant manner by preventing HFES-induced NGF, MMP-2, and MT1-MMP up-regulation. In summary, specific MMP-2 blockade prevents sympathetic nerve sprouting (SNS) by inhibition of pro-NGF conversion while losartan abolishes HFES-induced SNS by reducing total NGF, MMP-2 and MT1-MMP expression.
Saygili
Erol
E
Department of Cardiology, Medical Clinic I, RWTH Aachen University, Germany. esaygili@ukaachen.de
Schauerte
Patrick
P
Pekassa
Maimouna
M
Saygili
Esra
E
Rackauskas
Gediminas
G
Schwinger
Robert H G
RH
Weis
Joachim
J
Weber
Christian
C
Marx
Nikolaus
N
Rana
Obaida R
OR
D057911:Angiotensin Receptor Antagonists / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004558:Electric Stimulation / Q000379:methods; D019808:Losartan / Q000494:pharmacology; D053511:Matrix Metalloproteinase 14 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009414:Nerve Growth Factors / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013564:Sympathetic Nervous System / Q000378:metabolism* / Q000502:physiology
D057911:Angiotensin Receptor Antagonists; D009414:Nerve Growth Factors; D011498:Protein Precursors; C514218:pro-nerve growth factor, rat; D020778:Matrix Metalloproteinase 2; D053511:Matrix Metalloproteinase 14; D019808:Losartan