35 research outputs found
Macrophages maintain mammary stem cell activity and mammary homeostasis via TNF-α-PI3K-Cdk1/Cyclin B1 axis
No full textAbstract Adult stem cell niche is a special environment composed of a variety stromal cells and signals, which cooperatively regulate tissue development and homeostasis. It is of great interest to study the role of immune cells in niche. Here, we show that mammary resident macrophages regulate mammary epithelium cell division and mammary development through TNF-α-Cdk1/Cyclin B1 axis. In vivo, depletion of macrophages reduces the number of mammary basal cells and mammary stem cells (MaSCs), while increases mammary luminal cells. In vitro, we establish a three-dimensional culture system in which mammary basal cells are co-cultured with macrophages, and interestingly, macrophage co-culture promotes the formation of branched functional mammary organoids. Moreover, TNF-α produced by macrophages activates the intracellular PI3K/Cdk1/Cyclin B1 signaling in mammary cells, thereby maintaining the activity of MaSCs and the formation of mammary organoids. Together, these findings reveal the functional significance of macrophageal niche and intracellular PI3K/Cdk1/Cyclin B1 axis for maintaining MaSC activity and mammary homeostasis
Amphiregulin mediates the hormonal regulation on Rspondin-1 expression in the mammary gland
No full textThe steroid hormones are instrumental for the growth of mammary epithelial cells. Our previous study indicates that hormones regulate the expression of Rspondin-1 (Rspo1). Yet, the regulatory mechanism remains unknown. In the current study, we identify Amphiregulin (Areg) as a novel upstream regulator of Rspo1 expression mediating the hormonal influence. In response to hormonal signaling, Areg emanating from estrogen receptor (ER)-positive luminal cells, induce the expression of Rspo1 in ER-negative luminal cells. The paracrine action of Areg on Rspo1 expression is dependent on Egfr. Our data reveal a novel Estrogen-Areg-Rspo1 regulatory axis in the mammary gland, providing new evidence for the orchestrated action of systemic hormones and local growth factors.</p
A novel function of R-spondin1 in regulating estrogen receptor expression independent of Wnt/β-catenin signaling
No full textR-spondin1 (Rspo1) has been featured as a Wnt agonist, serving as a potent niche factor for stem cells in many tissues. Here we unveil a novel role of Rspo1 in promoting estrogen receptor alpha (Esr1) expression, hence regulating the output of steroid hormone signaling in the mouse mammary gland. This action of Rspo1 relies on the receptor Lgr4 and intracellular cAMP-PKA signaling, yet is independent of Wnt/b-catenin signaling. These mechanisms were reinforced by genetic evidence. Luminal cells-specific knockout of Rspo1 results in decreased Esr1 expression and reduced mammary side branches. In contrast, luminal cells-specific knockout of Wnt4, while attenuating basal cell Wnt/b-catenin signaling activities, enhances Esr1 expression. Our data reveal a novel Wnt-independent role of Rspo1, in which Rspo1 acts as a bona fide GPCR activator eliciting intracellular cAMP signaling. The identification of Rspo1-ERa signaling axis may have a broad implication in estrogen-associated diseases.</p
Identification of multipotent mammary stem cells by protein C receptor expression
No full textThe mammary gland is composed of multiple types of epithelial cells, which are generated by mammary stem cells (MaSCs) residing at the top of the hierarchy1,2. However, the existence of these multipotent MaSCs remains controversial and the nature of such cells is unknown 3,4. Here we demonstrate that protein C receptor (Procr), a novel Wnt target in the mammary gland, marks a unique population of multipotent mouse MaSCs. Procr-positive cells localize to the basal layer, exhibit epithelial-to-mesenchymal transition characteristics, and express low levels of basal keratins. Procr-expressing cells have a high regenerative capacity in transplantation assays and differentiate into all lineages of the mammary epitheliumby lineage tracing. These results define a novelmultipotentmammary stemcell population that could be important in the initiation of breast cancer.</p
Essential Roles of Cyclin Y-Like 1 and Cyclin Y in Dividing Wnt-Responsive Mammary Stem/Progenitor Cells.
No full textCyclin Y family can enhance Wnt/β-catenin signaling in mitosis. Their physiological roles in mammalian development are yet unknown. Here we show that Cyclin Y-like 1 (Ccnyl1) and Cyclin Y (Ccny) have overlapping function and are crucial for mouse embryonic development and mammary stem/progenitor cell functions. Double knockout of Ccnys results in embryonic lethality at E16.5. In pubertal development, mammary terminal end buds robustly express Ccnyl1. Depletion of Ccnys leads to reduction of Lrp6 phosphorylation, hampering β-catenin activities and abolishing mammary stem/progenitor cell expansion in vitro. In lineage tracing experiments, Ccnys-deficient mammary cells lose their competitiveness and cease to contribute to mammary development. In transplantation assays, Ccnys-deficient mammary cells fail to reconstitute, whereas constitutively active β-catenin restores their regeneration abilities. Together, our results demonstrate the physiological significance of Ccnys-mediated mitotic Wnt signaling in embryonic development and mammary stem/progenitor cells, and reveal insights in the molecular mechanisms orchestrating cell cycle progression and maintenance of stem cell properties
Efficient generation of induced pluripotent stem cell lines from healthy donors’ peripheral blood mononuclear cells of different genders
No full textPeripheral blood mononuclear cell (PBMC) are recognized as a conveniently collected reprogramming resource. Several methods are available in academia to reprogram PBMC into induced pluripotent stem cells (iPSC). In this research, we reprogrammed PBMC of different genders by using non-integrative non-viral liposome electrotransfer containing the reprogramming factors OCT4, SOX2, KLF4, and c-MYC. The three obtained iPSC cell lines were karyotypically normal and showed significant tritiated differentiation potential in vitro and in vivo. Our study provided an efficient procedure for reprogramming PBMC into iPSC and obtained three well-functioning iPSC, that may contribute to advance personalized cell therapy in the future
CDK14 inhibition reduces mammary stem cell activity and suppresses triple negative breast cancer progression
No full textThe Wnt/β-catenin signaling pathway plays an important role in regulating mammary organogenesis and oncogenesis. However, therapeutic methods targeting the Wnt pathway against breast cancer have been limited. To address this challenge, we investigate the function of cyclin-dependent kinase 14 (CDK14), a member of the Wnt signaling pathway, in mammary development and breast cancer progression. We show that CDK14 is expressed in the mammary basal layer and elevated in triple negative breast cancer (TNBC). CDK14 knockdown reduces the colony-formation ability and regeneration capacity of mammary basal cells and inhibits the progression of murine MMTV-Wnt-1 basal-like mammary tumor. CDK14 knockdown or pharmacological inhibition by FMF-04-159-2 suppresses the progression and metastasis of TNBC. Mechanistically, CDK14 inhibition inhibits mammary regeneration and TNBC progression by attenuating Wnt/β-catenin signaling. These findings highlight the significance of CDK14 in mammary development and TNBC progression, shedding light on CDK14 as a promising therapeutic target for TNBC.</p
R-spondin1 is a novel hormone mediator for mammary stem cell self-renewal
No full textSignals from the niche play pivotal roles in regulating adult stem cell self-renewal. Previous studies indicated that the steroid hormones can expand mammary stem cells (MaSCs) in vivo. However, the facilitating local niche factors that directly contribute to the MaSC expansion remain unclear. Here we identify R-spondin1 (Rspo1) as a novel hormonal mediator in the mammary gland. Pregnancy and hormonal treatment up-regulate Rspo1 expression. Rspo1 cooperates with another hormonal mediator, Wnt4, to promote MaSC self-renewal through Wnt/b-catenin signaling. Knockdown of Rspo1 and Wnt4 simultaneously abolishes the stem cell reconstitution ability. In culture, hormonal treatment that stimulates the expression of both Rspo1 and Wnt4 can completely substitute for exogenous Wnt proteins, potently expand MaSCs, and maintain their full development potential in transplantation. Our data unveil the intriguing concept that hormones induce a collaborative local niche environment for stem cells.</p
Combined therapy of CAR-IL-15/IL-15Rα-T cells and GLIPR1 knockdown in cancer cells enhanced anti-tumor effect against gastric cancer
No full textAbstract Background Chimeric antigen receptor (CAR) T cell therapy has shown remarkable responses in hematological malignancies with several approved products, but not in solid tumors. Patients suffer from limited response and tumor relapse due to low efficacy of CAR-T cells in the complicated and immunosuppressive tumor microenvironment. This clinical challenge has called for better CAR designs and combined strategies to improve CAR-T cell therapy against tumor changes. Methods In this study, IL-15/IL-15Rα was inserted into the extracellular region of CAR targeting mesothelin. In-vitro cytotoxicity and cytokine production were detected by bioluminescence-based killing and ELISA respectively. In-vivo xenograft mice model was used to evaluate the anti-tumor effect of CAR-T cells. RNA-sequencing and online database analysis were used to identify new targets in residual gastric cancer cells after cytotoxicity assay. CAR-T cell functions were detected in vitro and in vivo after GLI Pathogenesis Related 1 (GLIPR1) knockdown in gastric cancer cells. Cell proliferation and migration of gastric cancer cells were detected by CCK-8 and scratch assay respectively after GLIPR1 were overexpressed or down-regulated. Results CAR-T cells constructed with IL-15/IL-15Rα (CAR-ss-T) showed significantly improved CAR-T cell expansion, cytokine production and cytotoxicity, and resulted in superior tumor control compared to conventional CAR-T cells in gastric cancer. GLIPR1 was up-regulated after CAR-T treatment and survival was decreased in gastric cancer patients with high GLIPR1 expression. Overexpression of GLIPR1 inhibited cytotoxicity of conventional CAR-T but not CAR-ss-T cells. CAR-T treatment combined with GLIPR1 knockdown increased anti-tumor efficacy in vitro and in vivo. Conclusions Our data demonstrated for the first time that this CAR structure design combined with GLIPR1 knockdown in gastric cancer improved CAR-T cell-mediated anti-tumor response
Image_5_Programmed Cell Death Ligand 1 Is Enriched in Mammary Stem Cells and Promotes Mammary Development and Regeneration.TIF
No full textProgrammed cell death ligand 1 (PD-L1) is widely expressed in a variety of human tumors, and inhibition of the PD-L1/PD-1 pathway represents one of the most promising therapy for many types of cancer. However, the physiological function of PD-L1 in tissue development is still unclear, although PD-L1 mRNA is abundant in many tissues. To address this puzzle, we investigated the function of PD-L1 in mammary gland development. Interestingly, we found that PD-L1 is enriched in protein C receptor (Procr)-expressing mammary stem cells (MaSCs), and PD-L1-expressing mammary basal cells (PD-L1+ basal cells) exhibit robust mammary regeneration capacity in transplantation assay. The lineage tracing experiment showed that PD-L1+ cells can differentiate into all lineages of mammary epithelium cells, suggesting that PD-L1+ basal cells have the activities of MaSCs. Furthermore, PD-L1 deficiency significantly impairs mammary development and reduces mammary regeneration capacity of mammary basal cells, suggesting that PD-L1 is not only enriched in MaSCs but also improves activities of MaSCs. In summary, these results demonstrated that PD-L1 is enriched in MaSCs and promotes mammary gland development and regeneration. Mechanistically, our data indicated that PD-L1 expression is induced by continuous activation of Wnt/ß-catenin signaling. In conclusion, these results demonstrated that PD-L1 is a marker of MaSCs, and PD-L1 is essential for mammary development. Our study provides novel insight into the physiological functions of PD-L1 in tissue development.</p
