Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
Sci Rep. 2021 May 27;11(1):11153. doi: 10.1038/s41598-021-90600-0.
The perivascular adipose tissue (PVAT) differs from other fat depots and exerts a paracrine action on the vasculature. The spleen has an important role in the immune response, and it was observed to have either a protective role or a contribution to obesity-related diseases. However, the relation between spleen and PVAT is elusive in obesity. We investigated the role of spleen in the inflammatory profile of the mesenteric PVAT (mPVAT) from mice fed a high-fat diet (HFD) for 16 weeks. Male C57Bl/6 mice were sham-operated or splenectomized (SPX) and fed a HFD for 16 weeks. mPVAT morphology was evaluated by hematoxylin and eosin staining, infiltrated immune cells were evaluated by flow cytometry, inflammatory cytokines were evaluated by ELISA and the splenic cell chemotaxis mediated by mPVAT was evaluated using a transwell assay. In SPX mice, HFD induced adipocyte hypertrophy and increased immune cell infiltration and proinflammatory cytokine levels in mPVAT. However, none of these effects were observed in mPVAT from sham-operated mice. Spleen from HFD fed mice presented reduced total leukocytes and increased inflammatory markers when compared to the spleen from control mice. Chemotaxis of spleen cells mediated by mPVAT of HFD fed mice was reduced in relation to standard diet fed mice. The spleen protects mPVAT against the effects of 16-week HFD. This information was missing, and it is important because PVAT is different from other fat depots and data cannot be extrapolated from any type of adipose tissue to PVAT.
血管周脂肪组织（PVAT）与其他脂肪组织不同，对血管发挥旁分泌作用。脾脏在免疫反应中具有重要作用，它具有保护作用或有助于肥胖相关疾病。然而，肥胖症中脾脏与 PVAT 之间的关系尚不清楚。我们研究了高脂饮食（HFD）喂养 16 周的小鼠肠系膜 PVAT（mPVAT）中脾脏的作用。雄性 C57Bl/6 小鼠接受假手术或脾切除术（SPX），并接受 HFD 喂养 16 周。通过苏木精和伊红染色评估 mPVAT 形态，通过流式细胞术评估浸润的免疫细胞，通过 ELISA 评估炎症细胞因子，通过 Transwell 测定评估 mPVAT 介导的脾细胞趋化性。在 SPX 小鼠中，HFD 诱导脂肪细胞肥大，并增加 mPVAT 中的免疫细胞浸润和促炎细胞因子水平。然而，在假手术小鼠的 mPVAT 中并未观察到这些作用。与对照小鼠相比，HFD 喂养小鼠的脾脏总白细胞减少，炎症标志物增加。与标准饮食喂养小鼠相比，HFD 喂养小鼠的 mPVAT 介导的脾细胞趋化性降低。脾脏可保护 mPVAT 免受 16 周 HFD 的影响。这方面的信息是缺失的，而且非常重要，因为 PVAT 与其他脂肪组织不同，不能从任何类型的脂肪组织推断出关于 PVAT 的数据。
