Expression of Neuroserpin, an Inhibitor of Tissue Plasminogen Activator, in the Developing and Adult Nervous System of the Mouse

Abstract

Neuroserpin is a serine protease inhibitor of the serpin family that has been identified as an axonally secreted glycoprotein in neuronal cultures of chicken dorsal root ganglia. To obtain an indication for possible functions of neuroserpin, we analyzed its expression in the developing and the adult CNS of the mouse. In the adult CNS, neuroserpin was most strongly expressed in the neocortex, the hippocampal formation, the olfactory bulb, and the amygdala. In contrast, most thalamic nuclei, the caudate putamen, and the cerebellar granule cells were devoid of neuroserpin mRNA. During embryonic development, neuroserpin mRNA was not detectable in neuroepithelia, but it was expressed in the differentiating fields of most CNS regions concurrent with their appearance. In the cerebellum, the granule cells and a subgroup of Purkinje cells were neuroserpin-positive during postnatal development. As a further step toward the elucidation of neuroserpin function, we performed a study to identify potential target proteases. In vitro, neuroserpin formed SDS-stable complexes and inhibited the amidolytic activity of tissue plasminogen activator, urokinase, and plasmin. In contrast, no complex formation with or inhibition of thrombin was found. Expression pattern and inhibitory specificity implicate neuroserpin as a candidate regulator of plasminogen activators, which have been suggested to participate in the modulation or reorganization of synaptic connections in the adult. During development, neuroserpin may attenuate extracellular proteolysis related to processes such as neuronal migration, axogenesis, or the formation of mature synaptic connections.

Mutant Neuroserpin (S49P) That Causes Familial Encephalopathy with Neuroserpin Inclusion Bodies Is a Poor Proteinase Inhibitor and Readily Forms Polymers in Vitro

“…However, there is evidence that cleaved NS could result from dissociation of the complex. Osterwalder and colleagues (13,19) have shown the dissociation of the complex between tPA and chicken neuroserpin, which has Ͼ80% homology to human neuroserpin and an identical reactive center loop. Our investigations show conclusively that the generation of the reactive center loop-cleaved species of NS was mainly because of the dissociation of the NS⅐tPA complex.…”

“…Neuroserpin is an axonally secreted member of the serine proteinase inhibitor or serpin superfamily (11)(12)(13)(14)(15). Members of this family share a similar molecular architecture based on a dominant ␤-sheet A and a mobile inhibitory reactive center loop (16).…”

“…Following docking, the reactive loop is cleaved, and the proteinase is inhibited by translocation over 70 Å to the lower pole of the inhibitor (16,17). The most probable target for neuroserpin is tissue plasminogen activator (tPA) (13,18,19), and it has been suggested that neuroserpintPA interactions play an important role in regulating neuronal and synaptic plasticity and memory (20 -27).…”

The serine protease inhibitor neuroserpin is required for normal synaptic plasticity and regulates learning and social behavior

“…Expression is particularly high throughout the CNS at late stages of neuronal development, during neuronal migration, axogenesis, synaptogenesis, and refinement of synaptic connections (Krueger et al 1997). In contrast, in adults, neuroserpin expression is restricted to regions of high plasticity, where synaptic changes are associated with learning and memory (neocortex, hippocampus, amygdala, and olfactory bulb).…”

Identification of genes regulating sensory neuron genesis and differentiation in the avian dorsal root ganglia

“…The bottom row is a series of control amplicons, and the lower right arrow points out the subtraction of the glyceraldehyde 3-phosphodehydrogenase (G3PDH) amplicon in both subtracted probe sets, while strong signals are seen in both unsubtracted probe sets, indicative of the success of SSH-PCR. The amplicon in the lower left corner (left arrow) is a random clone picked from the E8.5 subtracted library as a reverse control, showing that it was significantly enriched by the reverse experiment and, interestingly, was later identified as Neuroserpin, a gene known to be involved in later stages of neural differentiation (Osterwalder et al, 1996;Krueger et al, 1997). Amplicons with signal intensities similar to that of the clone identified later as NELL2 were selected for sequencing analysis.…”