搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Our previous studies showed that anti-β2M monoclonal antibodies (mAbs) at high doses have direct apoptotic effects on myeloma cells,suggesting that anti-β2M mAbs might be developed as a novel therapeutic agent. In this study,we investigated the ability of the mAbs at much lower concentrations to indirectly kill myeloma cells by utilizing immune effector cells or molecules. Our results showed that anti-β2M mAbs effectively lysed MM cells via antibody-dependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC),which were correlated with and dependent on the surface expression of β2M on MM cells. The presence of MM bone marrow stromal cells or addition of IL-6 did not attenuate anti-β2M mAb-induced ADCC and CDC activities against MM cells. Furthermore,anti-β2M mAbs only showed limited cytotoxicity toward normal B cells and nontumorous mesenchymal stem cells,indicating that the ADCC and CDC activities of the anti-β2M mAbs were more prone to the tumor cells. Lenalidomide potentiated in vitro ADCC activity against MM cells and in vivo tumor inhibition capacity induced by the anti-β2M mAbs by enhancing the activity of NK cells. These results support clinical development of anti-β2M mAbs,both as a monotherapy and in combination with lenalidomide,to improve MM patient outcome. View Publication

Background: Human pluripotent stem cells (hPSCs),including human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs),can undergo erythroid differentiation,offering a potentially invaluable resource for generating large quantities of erythroid cells. However,the majority of erythrocytes derived from hPSCs fail to enucleate compared with those derived from cord blood progenitors,with an unknown molecular basis for this difference. The expression of vimentin (VIM) is retained in erythroid cells differentiated from hPSCs but is absent in mature erythrocytes. Further exploration is required to ascertain whether VIM plays a critical role in enucleation and to elucidate the underlying mechanisms. Methods: In this study,we established a hESC line with reversible vimentin degradation (dTAG-VIM-H9) using the proteolysis-targeting chimera (PROTAC) platform. Various time-course studies,including erythropoiesis from CD34+ human umbilical cord blood and three-dimensional (3D) organoid culture from hESCs,morphological analysis,quantitative real-time PCR (qRT-PCR),western blotting,flow cytometry,karyotyping,cytospin,Benzidine-Giemsa staining,immunofluorescence assay,and high-speed cell imaging analysis,were conducted to examine and compare the characteristics of hESCs and those with vimentin degradation,as well as their differentiated erythroid cells. Results: Vimentin expression diminished during normal erythropoiesis in CD34+ cord blood cells,whereas it persisted in erythroid cells differentiated from hESC. Depletion of vimentin using the degradation tag (dTAG) system promotes erythroid enucleation in dTAG-VIM-H9 cells. Nuclear polarization of erythroblasts is elevated by elimination of vimentin. Conclusions: VIM disappear during the normal maturation of erythroid cells,whereas they are retained in erythroid cells differentiated from hPSCs. We found that retention of vimentin during erythropoiesis impairs erythroid enucleation from hPSCs. Using the PROTAC platform,we validated that vimentin degradation by dTAG accelerates the enucleation rate in dTAG-VIM-H9 cells by enhancing nuclear polarization. View Publication

Following activation through the TCR,CD4+ T cells can differentiate into three major subsets: Th1,Th2,and Th17 cells. IL-17-secreting Th17 cells play an important role in the pathogenesis of several autoimmune diseases and in immune responses to pathogens,but little is known about the regulation of apoptosis in Th17 cells. In this study,the sensitivity of in vitro-polarized Th1,Th2,and Th17 cells to Fas-mediated apoptosis was compared directly by different methods. The order of sensitivity of T cell subsets to Fas-mediated apoptosis is: Th1 textgreater Th17 textgreater Th2. The greater sensitivity of Th17 cells to Fas-mediated apoptosis compared with Th2 cells correlated with their higher expression of FasL and comparable expression of the antiapoptotic molecule FLIP. The decreased sensitivity of Th17 compared with Th1 cells correlated with the higher expression of FLIP by Th17 cells. Transgenic overexpression of FLIP in T cells protected all three subsets from Fas-mediated apoptosis. These findings provide new knowledge for understanding how survival of different subsets of T cells is regulated. View Publication

PURPOSE: The existence of cancer stem cells (CSCs) in breast cancer has profound implications for cancer prevention. In this study,we evaluated sulforaphane,a natural compound derived from broccoli/broccoli sprouts,for its efficacy to inhibit breast CSCs and its potential mechanism. EXPERIMENTAL DESIGN: Aldefluor assay and mammosphere formation assay were used to evaluate the effect of sulforaphane on breast CSCs in vitro. A nonobese diabetic/severe combined immunodeficient xenograft model was used to determine whether sulforaphane could target breast CSCs in vivo,as assessed by Aldefluor assay,and tumor growth upon cell reimplantation in secondary mice. The potential mechanism was investigated using Western blotting analysis and beta-catenin reporter assay. RESULTS: Sulforaphane (1-5 micromol/L) decreased aldehyde dehydrogenase-positive cell population by 65% to 80% in human breast cancer cells (P textless 0.01) and reduced the size and number of primary mammospheres by 8- to 125-fold and 45% to 75% (P textless 0.01),respectively. Daily injection with 50 mg/kg sulforaphane for 2 weeks reduced aldehyde dehydrogenase-positive cells by textgreater50% in nonobese diabetic/severe combined immunodeficient xenograft tumors (P = 0.003). Sulforaphane eliminated breast CSCs in vivo,thereby abrogating tumor growth after the reimplantation of primary tumor cells into the secondary mice (P textless 0.01). Western blotting analysis and beta-catenin reporter assay showed that sulforaphane downregulated the Wnt/beta-catenin self-renewal pathway. CONCLUSIONS: Sulforaphane inhibits breast CSCs and downregulates the Wnt/beta-catenin self-renewal pathway. These findings support the use of sulforaphane for the chemoprevention of breast cancer stem cells and warrant further clinical evaluation. View Publication

Here we demonstrate,both in vivo and in vitro,that growth hormone (GH) mediates precursor cell activation in the subventricular zone (SVZ) of the aged (12-month-old) brain following exercise,and that GH signaling stimulates precursor activation to a similar extent to exercise. Our results reveal that both addition of GH in culture and direct intracerebroventricular infusion of GH stimulate neural precursor cells in the aged brain. In contrast,no increase in neurosphere numbers was observed in GH receptor null animals following exercise. Continuous infusion of a GH antagonist into the lateral ventricle of wild-type animals completely abolished the exercise-induced increase in neural precursor cell number. Given that the aged brain does not recover well after injury,we investigated the direct effect of exercise and GH on neural precursor cell activation following irradiation. This revealed that physical exercise as well as infusion of GH promoted repopulation of neural precursor cells in irradiated aged animals. Conversely,infusion of a GH antagonist during exercise prevented recovery of precursor cells in the SVZ following irradiation. View Publication

Tuberculosis is a leading cause of death in mankind due to infectious agents,and Mycobacterium tuberculosis (Mtb) infects and survives in macrophages (MФs). Although MФs are a major niche,myeloid-derived suppressor cells (MDSCs) are an alternative site for pathogen persistence. Both MФs and MDSCs express varying levels of leukocyte immunoglobulin-like receptor B (LILRB),which regulate the myeloid cell suppressive function. Herein,we demonstrate that antagonism of LILRB2 by a monoclonal antibody (mab) induced a switch of human MDSCs towards an M1-macrophage phenotype,increasing the killing of intracellular Mtb. Mab-mediated antagonism of LILRB2 alone and its combination with a pharmacological blockade of SHP1/2 phosphatase increased proinflammatory cytokine responses and phosphorylation of ERK1/2,p38 MAPK,and NF-kB in Mtb-infected MDSCs. LILRB2 antagonism also upregulated anti-mycobacterial iNOS gene expression and an increase in both nitric oxide and reactive oxygen species synthesis. Because genes associated with the anti-mycobacterial function of M1-MФs were enhanced in MDSCs following mab treatment,we propose that LILRB2 antagonism reprograms MDSCs from an immunosuppressive state towards a pro-inflammatory phenotype that kills Mtb. LILRB2 is therefore a novel therapeutic target for eradicating Mtb in MDSCs. View Publication

Nuclear reprogramming of somatic tissue enables derivation of induced pluripotent stem (iPS) cells from an autologous,non-embryonic origin. The purpose of this study was to establish efficient protocols for lineage specification of human iPS cells into functional glucose-responsive,insulin-producing progeny. We generated human iPS cells,which were then guided with recombinant growth factors that mimic the essential signaling for pancreatic development. Reprogrammed with four stemness factors,human fibroblasts were here converted into authentic iPS cells. Under feeder-free conditions,fate specification was initiated with activin A and Wnt3a that triggered engagement into definitive endoderm,followed by priming with fibroblast growth factor 10 (FGF10) and KAAD-cyclopamine. Addition of retinoic acid,boosted by the pancreatic endoderm inducer indolactam V (ILV),yielded pancreatic progenitors expressing pancreatic and duodenal homeobox 1 (PDX1),neurogenin 3 (NGN3) and neurogenic differentiation 1 (NEUROD1) markers. Further guidance,under insulin-like growth factor 1 (IGF-1),hepatocyte growth factor (HGF) and N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT),was enhanced by glucagon-like peptide-1 (GLP-1) to generate islet-like cells that expressed pancreas-specific markers including insulin and glucagon. Derived progeny demonstrated sustained expression of PDX1,and functional responsiveness to glucose challenge secreting up to 230 pM of C-peptide. A pancreatogenic cocktail enriched with ILV/GLP-1 offers a proficient means to specify human iPS cells into glucose-responsive hormone-producing progeny,refining the development of a personalized platform for islet-like cell generation. View Publication

The generation of iPSC-derived hepatocyte-like cells (HLCs) is a powerful tool for studying liver diseases,their therapy as well as drug development. iPSC-derived disease models benefit from their diverse origin of patients,enabling the study of disease-associated mutations and,when considering more than one iPSC line to reflect a more diverse genetic background compared to immortalized cell lines. Unfortunately,the use of iPSC-derived HLCs is limited due to their lack of maturity and a rather fetal phenotype. Commercial kits and complicated 3D-protocols are cost- and time-intensive and hardly useable for smaller working groups. In this study,we optimized our previously published protocol by fine-tuning the initial cell number,exchanging antibiotics and basal medium composition and introducing the small molecule forskolin during the HLC maturation step. We thereby contribute to the liver research field by providing a simple,cost- and time-effective 2D differentiation protocol. We generate functional HLCs with significantly increased HLC hallmark gene (ALB,HNF4?,and CYP3A4) and protein (ALB) expression,as well as significantly elevated inducible CYP3A4 activity. Graphical Abstract View Publication

Ovarian cancer remains the most lethal gynaecological malignancy,with tumour recurrence and chemoresistance posing significant therapeutic challenges. Emerging evidence suggests that cancer stem cells (CSCs),a rare subpopulation within tumours with self‐renewal and differentiation capacities,contribute to these hurdles. Therefore,elucidating the mechanisms that sustain CSCs is critical for improving treatment strategies. Mitophagy,a selective process for eliminating damaged mitochondria,plays a key role in maintaining cellular homeostasis,including CSC survival. Our study demonstrates that ovarian CSCs exhibit enhanced mitophagy,accompanied by elevated expression of the mitochondrial outer membrane receptors BNIP3 and BNIP3L. Knockdown of BNIP3 or BNIP3L significantly reduces mitophagy and impairs CSC self‐renewal,indicating that receptor‐mediated mitophagy is essential for CSC maintenance. Mechanistically,we identify that hyperactivated NF‐κB signalling drives the upregulation of BNIP3 and BNIP3L in ovarian CSCs. Inhibition of NF‐κB signalling,either via p65 knockdown or pharmacological inhibitors,effectively suppresses mitophagy. Furthermore,we demonstrate that elevated DNA‐PK expression contributes to the constitutive activation of NF‐κB signalling,thereby promoting mitophagy in ovarian CSCs. In summary,our findings establish that BNIP3/BNIP3L‐mediated mitophagy,driven by DNA‐PK‐dependent NF‐κB hyperactivation,is essential for CSC maintenance. Targeting the DNA‐PK/NF‐κB/BNIP3L‐BNIP3 axis to disrupt mitochondrial quality control in CSCs represents a promising therapeutic strategy to prevent ovarian cancer recurrence and metastasis. View Publication

Definitive erythropoiesis occurs in islands composed of a central macrophage in contact with differentiating erythroblasts. Erythroid maturation including enucleation can also occur in the absence of macrophages both in vivo and in vitro. We reported previously that loss of Rb induces cell-autonomous defects in red cell maturation under stress conditions,while other reports have suggested that the failure of Rb-null erythroblasts to enucleate is due to defects in associated macrophages. Here we show that erythropoietic islands are disrupted by hypoxic stress,such as occurs in the Rb-null fetal liver,that Rb(-/-) macrophages are competent for erythropoietic island formation in the absence of exogenous stress and that enucleation defects persist in Rb-null erythroblasts irrespective of macrophage function. View Publication

Haematopoietic stem cells (HSCs) regenerate blood cells throughout the lifespan of an organism. With age,the functional quality of HSCs declines,partly owing to the accumulation of damaged DNA. However,the factors that damage DNA and the protective mechanisms that operate in these cells are poorly understood. We have recently shown that the Fanconi anaemia DNA-repair pathway counteracts the genotoxic effects of reactive aldehydes. Mice with combined inactivation of aldehyde catabolism (through Aldh2 knockout) and the Fanconi anaemia DNA-repair pathway (Fancd2 knockout) display developmental defects,a predisposition to leukaemia,and are susceptible to the toxic effects of ethanol-an exogenous source of acetaldehyde. Here we report that aged Aldh2(-/-) Fancd2(-/-) mutant mice that do not develop leukaemia spontaneously develop aplastic anaemia,with the concomitant accumulation of damaged DNA within the haematopoietic stem and progenitor cell (HSPC) pool. Unexpectedly,we find that only HSPCs,and not more mature blood precursors,require Aldh2 for protection against acetaldehyde toxicity. Additionally,the aldehyde-oxidizing activity of HSPCs,as measured by Aldefluor stain,is due to Aldh2 and correlates with this protection. Finally,there is more than a 600-fold reduction in the HSC pool of mice deficient in both Fanconi anaemia pathway-mediated DNA repair and acetaldehyde detoxification. Therefore,the emergence of bone marrow failure in Fanconi anaemia is probably due to aldehyde-mediated genotoxicity restricted to the HSPC pool. These findings identify a new link between endogenous reactive metabolites and DNA damage in HSCs,and define the protective mechanisms that counteract this threat. View Publication