Cervical intramedullary schwannoma: a case report and review of the literature

Intramedullary schwannomas unrelated with neurofibromatosis are uncommon tumors, but if correctly diagnosed and properly treated they may have a good prognosis

Role of Acyl Chain Composition of Phosphatidylcholine in Tafazzin-Mediated Remodeling of Cardiolipin in Liposomes

Remodeling of the acyl chain compositions of cardiolipin (CL) species by the transacylase tafazzin is an important process for maintaining optimal mitochondrial functions. The results of mechanistic studies on the tafazzin-mediated transacylation from phosphatidylcholine (PC) to monolyso-CL (MLCL) in artificial lipid membranes are controversial. The present study investigated the role of the acyl chain composition of PC in the Saccharomyces cerevisiae tafazzin-mediated remodeling of CL by examining the structural factors responsible for the superior acyl donor ability of dipalmitoleoyl (16:1) PC over dipalmitoyl (16:0) PC. To this end, we synthesized systematic derivatives of dipalmitoleoyl PC; for example, the location of the <i>cis</i> double bond was migrated from the Δ9-position toward either end of the acyl chains (the Δ5- or Δ13-position), the <i>cis</i> double bond in the <i>sn</i>-1 or <i>sn</i>-2 position or both, was changed to a <i>trans</i> form, and palmitoleoyl and palmitoyl groups were exchanged in the <i>sn</i>-1 and <i>sn</i>-2 positions, maintaining similar PC fluidities. Analyses of the tafazzin-mediated transacylation from these PCs to <i>sn</i>-2′-MLCL­(18:1-18:1/18:1-OH) in the liposomal membrane revealed that tafazzin strictly discriminates the molecular configuration of the acyl chains of PCs, including their glycerol positions (<i>sn</i>-1 or <i>sn</i>-2); however, the effects of PC fluidity on the reaction may not be neglected. On the basis of the findings described herein, we discuss the relevance of the so-called thermodynamic remodeling hypothesis that presumes no acyl selectivity of tafazzin