Sci. Immunol. | 獨特的免疫促進細胞和脂肪產生基質成分協調脂肪組織的免疫和代謝進程

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Raul German Spallanzani, David Zemmour,Tianli Xiao, et al.

Sci. Immunol. 2019

Innate and adaptive immune system cells exert important positive or negative influences on the sterile inflammation of visceral adipose tissue (VAT) that shapes organismal metabolism. The authors relied on single-cell RNA sequencing and found that the major IL-33 producers in VATto be particular mesenchymal stromal cell subtypes, related to but distinct from adipocyte progenitor cells. The data showed that PDGFR+ Sca-1 + mSCs are not only the main source of IL-33 in eVAT, but also are biologically relevant IL-33 producers. Then it indicated that mSCs exhibit extensive transcriptional heterogeneity and mSC subtypes exhibit different functional properties. In addition, age strongly influences immunocyte-promoting VmSCs and thereby Treg accumulation. Furthermore, gender determines drastically distinct VmSC subtype distribution and VAT Treg abundance. An obvious question is how these observations relate to human adipose tissue. Human omVAT has a stromal cell population very similar to the PDGFR + IL-33–producing compartment in mice. Thus, it is likely that these observations will prove true in humans as well.

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 AkariIshikawa, Tsutomu Wada ID et al.

PLOS ONE.2020

Numerous biological phenomena exhibit distinctive traits due to sexual dimorphism. Immune and metabolic systems are representative because they are markedly affected by sex hormones. Resident Tregin visceral adipose tissue (VAT-Treg) decrease in male obese mice, which leads to the development of obesity-associated chronic inflammations and insulin resistance. Although gender differences in immune responses have been reported, the effects of the difference in a metabolic environment on VAT-Treg are unclear. The authors investigated the localization of VAT-Treg in female mice in comparison with that in male mice. Firstly, a sex difference in energy and glucose metabolism of diet-induced obesity was found. On a high-fat diet (HFD), VAT-Treg decreased in male mice but increased in female mice. The increase was abolished in ovariectomized and HFD-fed mice but was restored by estrogen supplementation. The IL33 receptor ST2, which is important for the localization and maturation of VAT-Treg in males, was reduced in CD4 + CD25 + T cells isolated from gonadal fat of obese mice of both genders, suggesting that a different system exists for VAT-Treg localization in females. Extensive analysis of chemokine expression in gonadal fat and adipose CD4 + CD25 + T cells revealed several chemokine signals related to female-specific VAT-Tregaccumulation such as CCL24, CCR6, and CXCR3. Taken together, the current study demonstrated sexual dimorphism in VAT-Treg localization in obese mice. Estrogen may attenuate obesity-associated chronic inflammation partly through altering chemokine-related VAT-Treg localization in females.