BACKGROUND/AIMS: Tuberous sclerosis complex 1 (Tsc1) has been shown to regulate M1/M2 polarization of macrophages, but the precise roles of Tsc1 in the function and stability of macrophages are not fully understood. Here we show that Tsc1 is required for regulating the survival, migration and phagocytosis of macrophages. METHODS: Mice with Tsc1 homozygous deletion in myeloid cells (LysMCreTsc1(flox/flox); Tsc1 KO) were obtained by crossing Tsc1(flox/flox) mice with mice expressing Cre recombinase under the control of Lysozyme promoter (LysMCre). The apoptosis and growth of macrophages were determined by flow cytometry and Real-time PCR (RT-PCR). The phagocytosis was determined using a Vybrant™ phagocytosis assay kit. The migration of macrophages was determined using transwell migration assay. RESULTS: Peritoneal macrophages of Tsc1 KO mice exhibited increased apoptosis and enlarged cell size. Both M1 and M2 phenotypes in Tsc1-deficient macrophages were elevated in steady-state as well as in inflammatory conditions. Tsc1-deficient macrophages demonstrated impaired migration and reduced expression of chemokine receptors including CCR2 and CCR5. Phagocytosis activity and ROS production were enhanced in Tsc1-deficient macrophages. Furthermore, pharmacological inhibition of the mammalian target of rapamycin complex 1 (mTORC1) partially reversed the aberrance of Tsc1-deficient macrophages. CONCLUSION: Tsc1 plays a critical role in regulating macrophage survival, function and polarization via inhibition of mTORC1 activity.
BACKGROUND/AIMS: Tuberous sclerosis complex 1 (Tsc1) has been shown to regulate M1/M2 polarization of macrophages, but the precise roles of Tsc1 in the function and stability of macrophages are not fully understood. Here we show that Tsc1 is required for regulating the survival, migration and phagocytosis of macrophages. METHODS:Mice with Tsc1 homozygous deletion in myeloid cells (LysMCreTsc1(flox/flox); Tsc1 KO) were obtained by crossing Tsc1(flox/flox) mice with mice expressing Cre recombinase under the control of Lysozyme promoter (LysMCre). The apoptosis and growth of macrophages were determined by flow cytometry and Real-time PCR (RT-PCR). The phagocytosis was determined using a Vybrant™ phagocytosis assay kit. The migration of macrophages was determined using transwell migration assay. RESULTS: Peritoneal macrophages of Tsc1 KO mice exhibited increased apoptosis and enlarged cell size. Both M1 and M2 phenotypes in Tsc1-deficient macrophages were elevated in steady-state as well as in inflammatory conditions. Tsc1-deficient macrophages demonstrated impaired migration and reduced expression of chemokine receptors including CCR2 and CCR5. Phagocytosis activity and ROS production were enhanced in Tsc1-deficient macrophages. Furthermore, pharmacological inhibition of the mammalian target of rapamycin complex 1 (mTORC1) partially reversed the aberrance of Tsc1-deficient macrophages. CONCLUSION:Tsc1 plays a critical role in regulating macrophage survival, function and polarization via inhibition of mTORC1 activity.
Authors: R W Hallowell; S L Collins; J M Craig; Y Zhang; M Oh; P B Illei; Y Chan-Li; C L Vigeland; W Mitzner; A L Scott; J D Powell; M R Horton Journal: Nat Commun Date: 2017-01-27 Impact factor: 14.919
Authors: Monika Linke; Ha Thi Thanh Pham; Karl Katholnig; Thomas Schnöller; Anne Miller; Florian Demel; Birgit Schütz; Margit Rosner; Boris Kovacic; Nyamdelger Sukhbaatar; Birgit Niederreiter; Stephan Blüml; Peter Kuess; Veronika Sexl; Mathias Müller; Mario Mikula; Wolfram Weckwerth; Arvand Haschemi; Martin Susani; Markus Hengstschläger; Michael J Gambello; Thomas Weichhart Journal: Nat Immunol Date: 2017-01-16 Impact factor: 25.606
Authors: Alex S Yamashita; Thiago Belchior; Fábio S Lira; Nicolette C Bishop; Barbara Wessner; José C Rosa; William T Festuccia Journal: Mediators Inflamm Date: 2018-07-04 Impact factor: 4.711