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

The manufacturing of allogeneic cell therapeutics based on human-induced pluripotent stem cells (hiPSCs) holds considerable potential to revolutionize the accessibility and affordability of modern healthcare. However,achieving the cell yields necessary to ensure robust production hinges on identifying suitable and scalable single-use (SU) bioreactor systems. While specific stirred SU bioreactor types have demonstrated proficiency in supporting hiPSC expansion at L -scale,others,notably instrumented SU multiplate and fixed-bed bioreactors,remain relatively unexplored. By characterizing these bioreactors using both computational fluid dynamics and experimental bioengineering methods,operating ranges were identified for the Xpansion ® 10 and Ascent™ 1 m 2 bioreactors in which satisfactory hiPSC expansion under serum-free conditions was achieved. These operating ranges were shown not only to effectively limit cell exposure to wall shear stress but also facilitated sufficient oxygen transfer and mixing. Through their application,almost 5 × 10 9 viable cells could be produced within 5 days,achieving expansion factors of up to 35 without discernable impact on cell viability,identity,or differentiation potential. Key Points • Bioengineering characterizations allowed the identification of operating ranges that supported satisfactory hiPSC expansion • Both the Xpansion ® 10 multiplate and Ascent™ 1 m 2 fixed-bed reactor accommodated the production of almost 5 × 10 9 viable cells within 5 days • Exposing the hiPSCs to a median wall shear stress of up to 8.2 × 10 −5 N cm −2 did not impair quality The online version contains supplementary material available at 10.1007/s00253-024-13373-2. View Publication

Trogocytosis is an underappreciated phenomenon that shapes the immune microenvironment surrounding many types of solid tumors. The consequences of membrane-bound proteins being deposited from a donor immune cell to a recipient cancer cell via trogocytosis are still unclear. Here,we report that human clear cell renal carcinoma tumors stably express the lymphoid markers CD45,CD56,CD14,and CD16. Flow cytometry performed on fresh kidney tumors revealed consistent CD45 expression on tumor cells,as well as varying levels of the other markers mentioned previously. These results were consistent with our immunofluorescent analysis,which also revealed colocalization of lymphoid markers with carbonic anhydrase 9,a standard kidney tumor marker. RNA analysis showed a significant upregulation of genes typically associated with immune cells by tumor cells. Finally,we show evidence of chromosomal DNA being transferred from immune cells to tumor cells through physical contact. This horizontal gene transfer has transcriptional consequences in the recipient tumor cell,resulting in a fusion phenotype that expresses both immune and cancer specific proteins. This work demonstrates a novel mechanism by which tumor cell protein expression is altered through the acquisition of surface membrane fragments and genomic DNA from infiltrating lymphocytes. These results alter the way in which we understand tumor-immune cell interactions and may reveal new insights into the mechanisms by which tumors develop. Additionally,further studies into trogocytosis and other mechanisms of contact-mediated cellular transfer will help push the field towards the next generation of immunotherapies and biomarkers for treating renal cell carcinoma and other cancers. View Publication

Circulating tumor cells (CTCs) hold significant promise for cancer diagnosis,prognosis,and treatment monitoring. We previously developed a technique for a single‐cell filtering device known as the microcavity array (MCA),specifically designed for the efficient recovery of CTCs from whole blood samples. Efficient enrichment and release of cells from the MCA remains challenging because of cell adhesion that occurs on the MCA surface during the enrichment phase. This study investigated the effects of surface modification with 2‐methacryloyloxyethyl phosphorylcholine (MPC) on the recovery efficiency of cancer cell lines from MCA. Scanning electron microscope (SEM) demonstrated reduced cell‐substrate interactions,leading to improved recovery efficiency. Comparative analyses showed that the MCA method provided superior recovery efficiency and reduced processing time compared to traditional methods such as density gradient centrifugation (DGC),while maintaining cell viability and proliferative capacity. CTCs were successfully detected in patients with gastric cancer,and short‐term cultures were achieved even when fewer than 20 CTCs per milliliter of blood were isolated. These findings emphasize the importance of surface modification for enhancing CTC isolation and the need for optimized culture conditions. The optimized MCA method offers a promising approach for rapid CTC recovery and potential integration with automated systems. Practical application : The Microcavity array (MCA) is a device specifically designed for efficient recovery of CTCs from whole blood. However cell adhesion on the MCA surface can limit release efficiency. This study demonstrated that surface modification with MPC signigicantly reduces cell‐substrate adhesion,improving recovery efficiency while maintaining cell viability and proliferative capacity. Compared to traditional density gradient centrifugation,the MPC‐modified MCA offers shorter processing time and better performance. CTCs were successfully detected in gastric cancer,and short‐term cultures were achieved even when fewer than 20 CTCs per mL of blood were isolated. The method supports downstearm applications such as cancer cell characterization and treatment monitoring. With potential for integration into automated system,the optimized MCA provides a practical,scalable solution for clinical liquid biopsy and personalized oncology. View Publication

Historically,it has been difficult to propagate cells in vitro that are derived directly from human tumors or healthy tissue. However,in vitro preclinical models are essential tools for both the study of basic cancer biology and the promotion of translational research,including drug discovery and drug target identification. This protocol describes conditional reprogramming (CR),which involves coculture of irradiated mouse fibroblast feeder cells with normal and tumor human epithelial cells in the presence of a Rho kinase inhibitor (Y-27632). CR cells can be used for various applications,including regenerative medicine,drug sensitivity testing,gene expression profiling and xenograft studies. The method requires a pathologist to differentiate healthy tissue from tumor tissue,and basic tissue culture skills. The protocol can be used with cells derived from both fresh and cryopreserved tissue samples. As approximately 1 million cells can be generated in 7 d,the technique is directly applicable to diagnostic and predictive medicine. Moreover,the epithelial cells can be propagated indefinitely in vitro,yet retain the capacity to become fully differentiated when placed into conditions that mimic their natural environment. View Publication

Recent studies suggest that forced activation of AMP-activated protein kinase (AMPK) could inhibit melanoma cell proliferation. In this report,we evaluated the anti-melanoma cell activity by a novel small-molecular AMPK activator,GSK621. Treatment of GSK621 decreased survival and proliferation of human melanoma cells (A375,WM-115 and SK-Mel-2 lines),which was accompanied by activation of caspase-3/-9 and apoptosis. Reversely,caspase inhibitors attenuated GSK621-induced cytotoxicity against melanoma cells. Significantly,GSK621 was more potent than other AMPK activators (A769662,Compound 13 and AICAR) in inhibiting melanoma cells. Intriguingly,same GSK621 treatment was non-cytotoxic or pro-apoptotic against human melanocytes. Molecularly,we showed that activation of AMPK mediated GSK621's activity against melanoma cells. AMPK$\alpha$1 shRNA knockdown or dominant negative mutation (T172A) dramatically attenuated GSK621-induced melanoma cell lethality. Further studies revealed that MEK-ERK activation might be the primary resistance factor of GSK621. MEK-ERK inhibition,either genetically or pharmacologically,significantly sensitized melanoma cells to GSK-621. Remarkably,intraperitoneal (i.p.) injection of GSK621 inhibited A375 tumor growth in SCID mice. Co-administration of MEK-ERK inhibitor MEK162 further sensitized GSK621-induced anti-A375 tumor activity in vivo. Together,the results imply that targeted activation of AMPK by GSK621 inhibits melanoma cell survival and proliferation. MEK-ERK inhibition may further sensitize GSK621's anti-melanoma cell activity in vitro and in vivo. View Publication

Manganese ions block apoptosis of phagocytes induced by various agents. The prevention of apoptosis was attributed to the activation of manganous superoxide dismutase (Mn-SOD) and to the antioxidant function of free Mn2+ cations. However,the effect of Mn2+ on B cell apoptosis is not documented. In this study,we investigated the effects of Mn2+ on the apoptotic process in human B cells. We observed that Mn2+ but not Mg2+ or Ca2+,inhibited cell growth and induced apoptosis of activated tonsilar B cells,Epstein Barr virus (EBV)-negative Burkitt's lymphoma cell lines (BL-CL) and EBV-transformed B cell lines (EBV-BCL). In the same conditions,no apoptosis was observed in U937,a monoblastic cell line. Induction of B cell apoptosis by Mn2+ was time- and dose-dependent. The cell permeable tripeptide inhibitor of ICE family cysteine proteases,zVAD-fmk,suppressed Mn2+-induced apoptosis. Furthermore,Mn2+ triggered the activation of interleukin-1beta converting enzyme (ICE/caspase 1),followed by the activation of CPP32/Yama/Apopain/caspase-3. In addition,poly-(ADP-ribose) polymerase (PARP),a cellular substrate for CPP32 protease was degraded to generate apoptotic fragments in Mn2+-treated B cell lines. The inhibitor,zVAD-fmk suppressed Mn2+-triggered CPP32 activation and PARP cleavage and apoptosis. These results indicate that the activation of caspase family proteases is required for the apoptotic process induced by Mn2+ treatment of B cells. While the caspase-1 inhibitor YVAD was unable to block apoptosis,the caspase-3 specific inhibitor DEVD-cmk,partially inhibited Mn2+-induced CPP32 activation,PARP cleavage and apoptosis of cells. Moreover,Bcl-2 overexpression in BL-CL effectively protected cells from apoptosis and cell death induced by manganese. This is the first report showing the involvement of Mn2+ in the regulation of B lymphocyte death presumably via a caspase-dependent process with a death-protective effect of Bcl-2. View Publication

OBJECTIVE: Abnormal expression of the hepatic gluconeogenic genes (glucose-6-phosphatase [G6Pase] and PEPCK) contributes to hyperglycemia. These genes are repressed by insulin,but this process is defective in diabetic subjects. Protein kinase B (PKB) is implicated in this action of insulin. An inhibitor of PKB,Akt inhibitor (Akti)-1/2,was recently reported; however,the specificity and efficacy against insulin-induced PKB was not reported. Our aim was to characterize the specificity and efficacy of Akti-1/2 in cells exposed to insulin and then establish whether inhibition of PKB is sufficient to prevent regulation of hepatic gene expression by insulin. RESEARCH DESIGN AND METHODS: Akti-1/2 was assayed against 70 kinases in vitro and its ability to block PKB activation in cells exposed to insulin fully characterized. RESULTS: Akti-1/2 exhibits high selectivity toward PKBalpha and PKBbeta. Complete inhibition of PKB activity is achieved in liver cells incubated with 1-10 mumol/l Akti-1/2,and this blocks insulin regulation of PEPCK and G6Pase expression. Our data demonstrate that only 5-10% of maximal insulin-induced PKB is required to fully repress PEPCK and G6Pase expression. Finally,we demonstrate reduced insulin sensitivity of these gene promoters in cells exposed to submaximal concentrations of Akti-1/2; however,full repression of the genes can still be achieved by high concentrations of insulin. CONCLUSIONS: This work establishes the requirement for PKB activity in the insulin regulation of PEPCK,G6Pase,and a third insulin-regulated gene,IGF-binding protein-1 (IGFBP1); suggests a high degree of functional reserve; and identifies Akti-1/2 as a useful tool to delineate PKB function in the liver. View Publication

BACKGROUND: The enhancement of circulating endothelial progenitor cells (EPCs) obtained by exercise training can be beneficial to patients with cardiac disease. Changes in the levels and differentiation of CD34(pos)/KDR(pos) EPCs,as well as the plasma concentration of vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1 EPC-mobilizing cytokines,were evaluated in patients with chronic heart failure after 8 weeks of supervised aerobic training (SAT) and 8 weeks of subsequent discontinued SAT (DSAT). METHODS AND RESULTS: The levels of circulating EPC and EPC differentiation potential of 22 patients who underwent SAT were studied by fluorescence-activated cell sorter analysis and colony forming-unit assay,respectively. The plasma levels of VEGF and SDF-1 were measured by enzyme-linked immunosorbent assay. In response to SAT,the levels of both EPC and VEGF/SDF-1 markedly increased (P textless .001 vs baseline) but returned to the baseline levels after DSAT. A similar change was observed with the EPC clonogenic potential,but on DSAT the baseline level was incompletely attained. CONCLUSIONS: In response to SAT,patients with chronic heart failure show enhanced EPC levels and clonogenic potential that is mirrored by increased plasma VEGF and SDF-1 levels. DSAT can interfere with the maintenance of training-acquired VEGF/SDF-1-related EPC levels and clonogenic potential. View Publication

BACKGROUND Adiponectin is a key mediator of the metabolic syndrome that is caused by visceral fat accumulation. Adiponectin and its receptors are known to be expressed in osteoblasts,but their actions with regard to bone metabolism are still unclear. In this study,we investigated the effects of adiponectin on the proliferation,differentiation,and mineralization of osteoblastic MC3T3-E1 cells. RESULTS Adiponectin receptor type 1 (AdipoR1) mRNA was detected in the cells by RT-PCR. The adenosine monophosphate-activated protein kinase (AMP kinase) was phosphorylated by both adiponectin and a pharmacological AMP kinase activator,5-amino-imidazole-4-carboxamide-riboside (AICAR),in the cells. AdipoR1 small interfering RNA (siRNA) transfection potently knocked down the receptor mRNA,and the effect of this knockdown persisted for as long as 10 days after the transfection. The transfected cells showed decreased expressions of type I collagen and osteocalcin mRNA,as determined by real-time PCR,and reduced ALP activity and mineralization,as determined by von Kossa and Alizarin red stainings. In contrast,AMP kinase activation by AICAR (0.01-0.5 mM) in wild-type MC3T3-E1 cells augmented their proliferation,differentiation,and mineralization. BrdU assay showed that the addition of adiponectin (0.01-1.0 mug/ml) also promoted their proliferation. Osterix,but not Runx-2,appeared to be involved in these processes because AdipoR1 siRNA transfection and AICAR treatments suppressed and enhanced osterix mRNA expression,respectively. CONCLUSION Taken together,this study suggests that adiponectin stimulates the proliferation,differentiation,and mineralization of osteoblasts via the AdipoR1 and AMP kinase signaling pathways in autocrine and/or paracrine fashions. View Publication

OBJECTIVES: Our objective was to develop and assess a novel endogenous progenitor cell (EPC) assay based on aldehyde dehydrogenase (ALDH) activity,and to define the relationship of ALDH-bright (ALDH(br)) cells with previously defined EPCs,patient age,and extent of coronary artery disease. BACKGROUND: Accurate assessment of circulating EPCs is of significant interest,yet current assays have limitations. Progenitor cells display high levels of ALDH activity. An assay based on ALDH activity may offer a simple means for enumerating EPCs. METHODS: We simultaneously determined the numbers of EPCs based on ALDH activity and cell surface expression of CD133,CD34,and vascular endothelial growth factor receptor-2 in 110 patients undergoing cardiac catheterization. We assessed the reproducibility of these estimates,correlation among EPC assays,and the association of ALDH(br) numbers with age and disease severity. RESULTS: Aldehyde dehydrogenase-bright cells were easily identified in nonmobilized peripheral blood with median and mean frequencies of 0.041% and 0.074%,respectively. Aldehyde dehydrogenase-bright cells expressed CD34 or CD133 cell surface markers (57.0% and 27.1%,respectively),correlated closely with CD133+CD34+ cells (r = 0.72; p textless 0.001),and differentiated into endothelial cells with greater efficiency than CD133+CD34+ cells. Aldehyde dehydrogenase-bright cell numbers were inversely associated with patient age and coronary disease severity. CONCLUSIONS: Aldehyde dehydrogenase activity represents a novel simplified method for quantifying EPCs. The correlation of ALDH(br) cells with clinical factors and outcomes warrants further study. View Publication

BACKGROUND: Excessive maturation of hematopoietic cells leads to a reduction of long-term proliferative capability during cord blood (CB) expansion. In this study,we report the effects of anit-CD52 (Alemtuzumab,Campath) on both short- and long-term ex vivo expansion of CB hematopoietic stem cells (HSC) by evaluating the potential role of Alemtuzumab in preserving the repopulating capability in CB HSC and nonlymphoid progenitors. METHODS: Ex vivo expansion experiments were carried out using freshly purified CB CD34(+)cells in StemSpantrade mark SFEM medium in the presence of stem cell factor,Flt3-Ligand and thrombopoietin at 50 ng/ml. Alemtuzumab (10 microg/ml) was used to deplete CD52(+) cells during the cultures. Flow cytometry was used to monitor CB HSC and their differentiation. Colony forming unit (CFU) assays and long term culture-initiating cell (LTC-IC) assays were performed on cells obtained from day 0 (before culture) and day 14 after cultures. Secondary cultures was performed using CD34(+) cells isolated at 35 days from primary cultures and further cultured in StemSpantrade mark SFEM medium for another 14 days to confirm the long term effect of alemtuzumab in liquid cultures. RESULTS: Compared to cytokines alone,addition of alemtuzumab resulted in a significant increase in total nucleated cells,absolute CD34(+) cells,myeloid and megakaryocytic progenitors,multi-lineage and myeloid CFU and LTC-IC. CONCLUSION: The results from current study suggested that the use of alemtuzumab for ex vivo expansion of CBHSC maybe advantageous. Our findings may improve current technologies for CBHSC expansion and increase the availability of CB units for transplantation. However,in vivo studies using animal models are likely needed in further studies to test the hematopoietic effects using such expanded CB products. View Publication