Cell Reports
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2020
·
IF 8.109
Lidia Wrobel,Farah H. Siddiqi,Sandra M. Hill,Sung Min Son,Cansu Karabiyik,Hyunjeong Kim,David C. Rubinsztein
Summary The mechanistic target of rapamycin complex 2 (mTORC2) controls cell metabolism and survival in response to environmental inputs. Dysregulation of mTORC2 signaling has been linked to diverse human diseases, including cancer and metabolic disorders, highlighting the importance of a tightly controlled mTORC2. While mTORC2 assembly is a critical determinant of its activity, the factors regulating this event are not well understood, and it is unclear whether this process is regulated by growth factors. Here, we present data, from human cell lines and mice, describing a mechanism by which growth factors regulate ubiquitin-specific protease 9X (USP9X) deubiquitinase to stimulate mTORC2 assembly and activity. USP9X removes Lys63-linked ubiquitin from RICTOR to promote its interaction with mTOR, thereby facilitating mTORC2 signaling. As mTORC2 is central for cellular homeostasis, understanding the mechanisms regulating mTORC2 activation toward its downstream targets is vital for our understanding of physiological processes and for developing new therapeutic strategies in pathology.
研究领域:
细胞生物学
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分子生物学
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癌症研究
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代谢研究
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DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Huan Wu,Yuexin Wei,Yu Zhou,Chunlan Long,Yifan Hong,Yan Fu,Tianxin Zhao,Junke Wang,Yuhao Wu,Shengde Wu,Lianju Shen,Guanghui Wei
Bisphenol S (BPS) is now used as an alternative of bisphenol A (BPA), but has been implicated in male reproductive dysfunction—including diminished sperm number and quality and altered hormonal concentrations. However, the mechanisms of action subserving these effects remains unclear. In the present study, BPS at doses of 50 mg/kg bw and 100 mg/kg bw caused defects in the integrity of the blood-testis barrier (BTB) and apical ectoplasmic specialization (ES), and we also delineated an underlying molecular mechanism of action. BPS induced F-actin and α-tubulin disorganization in seminiferous tubules, which in turn led to the truncation of actin filaments and microtubules. Additionally, BPS was found to perturb the expression of the actin-binding proteins Arp3 and Eps8, which are critical for the organization of the actin filaments. mTORC1 and mTORC2 manifest opposing roles in Sertoli cell junctional function, and we demonstrated that mTORC1/rpS6/Akt/MMP9 signaling was increased and that mTORC2/rictor activity was also attenuated. In summary, we showed that BPS-induced disruption of the BTB and apical ES perturbed normal spermatogenic function that was mediated by mTORC1 and mTORC2. The imbalance in mTORC1 and mTORC2, in turn, altered the expression of actin-binding proteins, resulting in the impairment of F-actin and MT organization, and inhibited the expression of junctional proteins at the BTB and apical ES.
研究领域:
毒理学
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生殖生物学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
Cell Death & Disease
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2022
·Vol. 13
·期 4
·1-12
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IF 9.685
Liu Qihui,Yang Quanli,Wu Zengfeng,Chen Yanfang,Xu Miaomiao,Zhang Hua,Zhao Jiliang,Liu Zonghua,Guan Zerong,Luo Jing,Li Zhi-yong,Sun Guodong,Wen Qiong,Xu Yan,Li Zhenhua,Chen Kebing,Ben Xiaosong,He Wanchun,Li Xueshi,Yin Zhinan,Hao Jianlei,Lu Ligong
Liver fibrosis represents a severe stage of liver damage, with hallmarks of inflammation, hepatic stellate cell activation, and extracellular matrix accumulation. Although previous studies demonstrated γδ T cells are involved in liver fibrosis, the precise role and mechanisms of γδ T cells migrating to fibrotic liver have not been elucidated. Here, we aim to investigate the functional subsets of γδ T cells in hepatic fibrosis and to further explore the underlying causes and drivers of migration. In this study, we observed that γδ T cells accumulate in fibrotic liver. Adoptive transfer of γδ T, especially Vγ4 γδ T subset, can significantly alleviate liver fibrosis. In addition, CCl 4 treatment also leads to activation of mTOR signaling in γδ T cells. Genetic deletion of the Rictor gene, but not Raptor, in γδ T cells markedly exacerbated liver fibrosis. Mechanistically, CCl 4 -induced liver injury causes macrophage accumulation in the liver, and IL-1β produced by macrophages promotes mTORC2 signaling activation in γδ T cells, which upregulates T-bet expression and eventually promotes CXCR3 transcription to drive γδ T cell migration. Moreover, hepatic γδ T cells ameliorated liver fibrosis by cytotoxicity against activated hepatic stellate cells in FasL-dependent manner, and secrete IFN-γ to inhibit the differentiation of pro-fibrotic Th17 cells. Thus, IL-1β-activated mTORC2 signaling in γδ T cells upregulates CXCR3 expression, which is critical for IFN-γ + γδ T cells migration into the liver and amelioration of liver fibrosis. Our findings indicate that targeting the mTORC2 or CXCR3 in γδ T cells could be considered as a promising approach for γδ T cell immunotherapy against liver fibrosis.
研究领域:
免疫学
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肝病学
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细胞生物学
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分子生物学
✓ 已验证
DOI
PubMed
高影响因子
CELL AND TISSUE RESEARCH
·
2022
·Vol. 390
·期 2
·293-313
·
IF 4.051
Li Zhen-Fang,Hao Shuang-Li,Wang Lan-Min,Qi Hong-Yu,Wang Jia-Ming,Tan Fu-Qing,Yang Wan-Xi
Spermatogenesis is a finely regulated process of germ cell proliferation and differentiation that leads to the production of sperm in seminiferous tubules. Although the mammalian target of rapamycin (mTOR) signaling pathway is crucial for spermatogenesis in mammals, its functions and molecular mechanisms in spermatogenesis remain largely unknown in nonmammalian species, particularly in Crustacea. In this study, we first identified es-Raptor (the core component of mTOR complex 1) and es-Rictor (the core component of mTOR complex 2) from the testis of Eriocheir sinensis . Dynamic localization of es-Raptor and es-Rictor implied that these proteins were indispensable for the spermatogenesis of E. sinensis. Furthermore, es-Raptor and es-Rictor knockdown results showed that the mature sperm failed to be released, causing almost empty lumens in the testis. We investigated the reasons for these effects and found that the actin-based cytoskeleton was disrupted in the knockdown groups. In addition, the integrity of the testis barrier (similar to the blood-testis barrier in mammals) was impaired and affected the expression of cell junction proteins. Further study revealed that es-Raptor and es-Rictor may regulate spermatogenesis via both mTORC1- and mTORC2-dependent mechanisms that involve es-rpS6 and es-Akt/es-PKC, respectively. Moreover, to explore the testis barrier in E. sinensis , we established a cadmium chloride (CdCl 2 )–induced testis barrier damage model as a positive control. Morphological and immunofluorescence results were similar to those of the es-Raptor and es-Rictor knockdown groups. Altogether, es-Raptor and es-Rictor were important for spermatogenesis through maintenance of the actin filament network and cell junctions in E. sinensis.
研究领域:
分子生物学
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生殖生物学
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甲壳动物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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