Cavin1 Deficiency Alters Lung macrophage homeostasis in Mouse

Caveolae are cell membrane invaginations that are highly abundant in adipose tissue, endothelial cells and lung and are present at lower levels in other tissues. The formation of caveolae is dependent of the expression of various structural proteins that serve as scaffolding for these membrane invaginations. Cavin1 is a newly identified structural protein whose deficiency leads to absence of caveolae formation and to the development of a lipodystrophic phenotype. In this study we show Cavin1 expression is critical for regulating macrophage number and gene-expression (phenotype) in the lung. We used microarrays to detail the global programme of gene expression in alveolar macrophage in a Cavin1 knock-out mouse and identified distinct classes of dysregulated genes during this process. Bronchoalveolar Lavage performed though a 22-gauge needle tied in place to trachea with PBS containing 0.5 mM ethylenediaminetetraacetic acid (EDTA). Aliquots of 0.5 to 1 ml were instilled into the lungs under direct observation to ensure that all segments of lung were inflated, and aspirated back into the syringe. This was repeated five times per mouse. RNA was extracted from extracted alveolar macrophages and hybridized to Affymetrix microarrays for gene expression analysis.

胞膜窖（Caveolae）是一类细胞膜内陷结构，在脂肪组织、内皮细胞与肺组织中丰度极高，在其余组织中则呈低水平分布。胞膜窖的形成依赖于多种结构蛋白的表达，这些蛋白可作为该类膜内陷结构的支架。Cavin1（Cavin1）是新近鉴定出的结构蛋白，其缺失会导致胞膜窖形成完全丧失，并诱发脂肪营养不良表型。本研究证实，Cavin1的表达对肺内巨噬细胞的数量及基因表达（表型）调控至关重要。我们采用基因芯片（microarrays）解析了Cavin1敲除小鼠肺泡巨噬细胞的全局基因表达谱，并鉴定出该过程中多类显著失调的差异表达基因。本研究通过将22号针头固定于气管，使用含0.5 mM乙二胺四乙酸（EDTA）的磷酸盐缓冲液（PBS）实施支气管肺泡灌洗：每次向肺内滴注0.5至1 ml灌洗液，操作中通过直视确保肺脏所有节段均充盈，随后将灌洗液抽吸回注射器。每只小鼠重复该操作五次。从提取得到的肺泡巨噬细胞中提取RNA，将其与Affymetrix公司的基因芯片进行杂交以开展基因表达分析。