Close homologue of adhesion molecule L1 promotes survival of Purkinje and granule cells and granule cell migration during murine cerebellar development

Abstract

Several L1-related adhesion molecules, expressed in a well-coordinated temporospatial pattern during development, are important for fine tuning of specific cerebellar circuitries. We tested the hypothesis that CHL1, the close homologue of L1, abundantly expressed in the developing and adult cerebellum, is also required for normal cerebellar histogenesis. We found that constitutive ablation of CHL1 in mice caused significant loss (20-23%) of Purkinje and granule cells in the mature 2-month-old cerebellum. The ratio of stellate/basket interneurons to Purkinje cells was abnormally high (+38%) in CHL1-deficient (CHL1-/-) mice compared with wild-type (CHL1+/+) littermates, but the gamma-aminobutyric acid (GABA)ergic synaptic inputs to Purkinje cell bodies and dendrites were normal, as were numbers of Golgi interneurons, microglia, astrocytes, and Bergmann glia. Purkinje cell loss occurred before the first postnatal week and was associated with enhanced apoptosis, presumably as a consequence of CHL1 deficiency in afferent axons. In contrast, generation of granule cells, as indicated by in vivo analyses of cell proliferation and death, was unaffected in 1-week-old CHL1-/- mice, but numbers of migrating granule cells in the molecular layer were increased. This increase was likely related to retarded cell migration because CHL1-/- granule cells migrated more slowly than CHL1+/+ cells in vitro, and Bergmann glial processes guiding migration in vivo expressed CHL1 in wild-type mice. Granule cell deficiency in adult CHL1-/- mice appeared to result from decreased precursor cell proliferation after the first postnatal week. Our results indicate that CHL1 promotes Purkinje and granule cell survival and granule cell migration during cerebellar development.

Cellular Form of Prion Protein Inhibits Reelin-Mediated Shedding of Caspr from the Neuronal Cell Surface to Potentiate Caspr-Mediated Inhibition of Neurite Outgrowth

“…Tissue preparation and immunohistochemistry on cerebella of young C57BL/6 mice was done as described previously (Jakovcevski et al, 2009).…”

Interaction of the Cell Adhesion Molecule CHL1 with Vitronectin, Integrins, and the Plasminogen Activator Inhibitor-2 Promotes CHL1-Induced Neurite Outgrowth and Neuronal Migration

“…ELISA and label-free binding assay have been described (Schmidt et al, 2008; Loers et al, 2012). For quantitative assessment of the CHL1 and vitronectin interaction, a bead aggregation assay was performed (Jakovcevski et al, 2007). Briefly, a 10 l suspension of protein A-coupled magnetic beads (Dynabeads, Invitrogen) was incubated in PBS, pH 7.4, overnight at 4°C with 37.5 nM CHL1-Fc, L1-Fc, or NCAMFc.…”

“…Cell adhesion molecule close homolog of L1 (CHL1) is important for neural cell proliferation, migration, differentiation, and survival, as well as in neuritogenesis, synaptogenesis, synaptic plasticity, and regeneration after injury (Holm et al, 1996;Hillenbrand et al, 1999;Jakovcevski et al, 2007;Maness and Schachner, 2007). In humans, CHL1 is linked to mental retardation, schizophrenia, major depression, epilepsy, and autism spectrum disorders (Angeloni et al, 1999a,b;Sakurai et al, 2002;Frints et al, 2003;Chu and Liu, 2010;Tam et al, 2010;Cuoco et al, 2011;Morag et al, 2011;Salyakina et al, 2011;Shoukier et al, 2013).…”

“…In humans, CHL1 is linked to mental retardation, schizophrenia, major depression, epilepsy, and autism spectrum disorders (Angeloni et al, 1999a,b;Sakurai et al, 2002;Frints et al, 2003;Chu and Liu, 2010;Tam et al, 2010;Cuoco et al, 2011;Morag et al, 2011;Salyakina et al, 2011;Shoukier et al, 2013). CHL1-deficient mice show alterations in social and exploratory behavior, reactivity to novelty, ability to gate sensorimotor information, and working memory (Montag-Sallaz et al, 2002;Pratte et al, 2003;Irintchev et al, 2004;Morellini et al, 2007;Kolata et al, 2008;Pratte and Jamon, 2009) Wright et al, 2007;Andreyeva et al, 2010). In the cerebellum of constitutively CHL1-deficient mice, increased numbers of migrating cells were observed at the end of the first postnatal week, while a loss of Purkinje and granule cells was observed in adult mice (Jakovcevski et al, 2009), indicating that CHL1 plays a role not only in early postnatal mouse cerebellar development, but also in the adult.…”

“…Function-triggering CHL1 antibodies enhanced neuritogenesis (Chen et al, 1999), whereas homophilic CHL1 interactions studied with cells from constitutively CHL1-deficient mice showed that CHL1 is inhibitory for neuritogenesis in vitro and in vivo: CHL1-deficient mice recover better after spinal cord injury than their wild-type littermates, CHL1-deficient neurons grow better on CHL1-expressing astrocytes than wild-type neurons, and CHL1-expressing neurons grow better on CHL1-negative astrocytes (Jakovcevski et al, 2007). These observations led to the conclusion that homophilic (CHL1-CHL1) interactions block the neurite outgrowth-promoting functions of CHL1, whereas heterophilic CHL1 interactions with, for instance, integrins in cis-and trans-configurations are conducive (Hillenbrand et al, 1999;Buhusi et al, 2003;Demyanenko et al, 2004;Jakovcevski et al, 2007Jakovcevski et al, , 2009). …”