Palestini Paola, Botto Laura, Rivolta Ilaria, Miserocchi Giuseppe
Department of Experimental Medicine, University of Milano-Bicocca, 48 Via Cadore, 20052 Monza, Italy.
J Lipids. 2011;2011:695369. doi: 10.1155/2011/695369. Epub 2011 Jul 13.
Membrane rafts (MRs) are clusters of lipids, organized in a "quasicrystalline" liquid-order phase, organized on the cell surface and whose pattern of molecules and physicochemical properties are distinct from those of the surrounding plasma membrane. MRs may be considered an efficient and fairly rapid cell-activated mechanism to express or mask surface receptors aimed at triggering specific response pathways. This paper reports observations concerning the role of MRs in the control of lung extravascular water that ought to be kept at minimum to assure gas diffusion, supporting the hypothesis that MRs expression is a potential mechanism of sensing minor changes in the volume of extravascular water. We present the evidence that MRs expression specifically relates to signal-transduction processes evoked by mechanical stimuli arising in the interstitial lung compartment when a small increase in extravascular volume occurs. We further hypothesize that a differential expression of MRs might also reflect the damage to precise components of the extracellular matrix caused by the perturbation in water balance and thus can trigger a molecule-oriented specific matrix remodelling.
膜筏（MRs）是脂质簇，以“准晶态”液态有序相组织，位于细胞表面，其分子模式和物理化学性质与周围质膜不同。膜筏可被视为一种高效且相当快速的细胞激活机制，用于表达或掩盖旨在触发特定反应途径的表面受体。本文报道了关于膜筏在控制肺血管外水分方面作用的观察结果，肺血管外水分应保持在最低水平以确保气体扩散，支持了膜筏表达是感知血管外水分体积微小变化的潜在机制这一假说。我们提供的证据表明，当血管外体积出现小幅增加时，膜筏表达与肺间质中机械刺激引发的信号转导过程具体相关。我们进一步推测，膜筏的差异表达也可能反映了水平衡扰动对细胞外基质精确成分造成的损伤，从而可触发面向分子的特定基质重塑。
