Context: Meningeal abnormalities such as dural ectasia are seen in Marfan syndrome, but spinal meningeal cysts are rarely seen. These cysts usually asymptomatic and often found incidentally on magnetic resonance imaging, large cysts may cause neurological deficits and pain secondary to nerve root compression. Design: Case reports. Findings: Two patients with Marfan syndrome presented with urinary symptoms secondary to dural ectasia and sacral cysts. Patient 1 had a history of low back pain, erectile dysfunction, and occasional urinary incontinence and groin pain with recent symptom worsening. He underwent L5 partial laminectomy and S1-S2 laminectomy with sacral cyst decompression. Nine weeks later, he underwent drainage of a sacral pseudomeningocele. Pain and urinary symptoms resolved, and he remains neurologically normal 2 years after surgery. Patient 2 presented after a fall on his tailbone, complaining of low back pain and difficulty urinating. Physical therapy was implemented, but after 4 weeks, urinary retention had not improved. He then underwent resection of the sacral cyst and S1-S3 laminectomy. Pain and paresthesias resolved and bowel function returned to normal. Other than needing intermittent self-catheterization, all other neurologic findings were normal 30 months after surgery. Conclusion/clinical relevance: Surgical goals for sacral cysts include resection as well as closure of the dura, which can be challenging due to thinning from ectasia. Neurosurgical intervention in Marfan syndrome is associated with a high risk of dural tears and osseous complications, and should be performed only when symptoms are severe.

Evidence suggests that regulated ubiquitination of proteins plays a critical role in the development and plasticity of the central nervous system. We have previously identified the ubiquitin ligase Praja1 as a gene product induced during fear memory consolidation. However, the neuronal function of this enzyme still needs to be clarified. Here, we investigate its involvement in the nerve growth factor (NGF)-induced differentiation of rat pheochromocytoma (PC12) cells. Praja1 co-localizes with cytoskeleton components and the neurotrophin receptor interacting MAGE homologue (NRAGE). We observed an enhanced expression of Praja1 after 3 days of NGF treatment and a suppression of neurite formation upon Praja1 overexpression in stably transfected PC12 cell lines, which was associated with a proteasome-dependent reduction of NRAGE levels. Our data suggest that Praja1, through ubiquitination and degradation of NRAGE, inhibits neuronal differentiation. The two murine isoforms, Praja1.1 and Praja1.2, appear to be functionally homologous in this respect.

No abstract

Integrin-mediated cell adhesion and signaling is of critical importance for neuronal differentiation. Recent evidence suggests that an “inside-out” activation of β1-integrin, similar to that observed in hematopoietic cells, contributes to the growth and branching of dendrites. In this study, we investigated the role of the hematopoietic adaptor protein adhesion and degranulation promoting adapter protein (ADAP) in these processes. We demonstrate the expression of ADAP in the developing and adult nervous hippocampus, and in outgrowing dendrites of primary hippocampal neurons. We further show that ADAP occurs in a complex with another adaptor protein signal-transducing kinase-associated phosphoprotein-homolog (SKAP-HOM), with the Rap1 effector protein RAPL and the Hippo kinase macrophage-stimulating 1 (MST1), resembling an ADAP/SKAP module that has been previously described in T-cells and is critically involved in “inside-out” activation of integrins. Knock down of ADAP resulted in reduced expression of activated β1-integrin on dendrites. It furthermore reduced the differentiation of developing neurons, as indicated by reduced dendrite growth and decreased expression of the dendritic marker microtubule-associated protein 2 (MAP2). Our data suggest that an ADAP-dependent integrin-activation similar to that described in hematopoietic cells contributes to the differentiation of neuronal cells.