Abnormal cancer antioxidant capacity is considered as a potential mechanism of tumor malignancy. Modulation of oxidative stress status is emerging as an anti-cancer treatment. Our previous studies ...have found that Nestin-knockdown cells were more sensitive to oxidative stress in non-small cell lung cancer (NSCLC). However, the molecular mechanism by which Nestin protects cells from oxidative damage remains unclear. Here, we identify a feedback loop between Nestin and Nrf2 maintaining the redox homeostasis. Mechanistically, the ESGE motif of Nestin interacts with the Kelch domain of Keap1 and competes with Nrf2 for Keap1 binding, leading to Nrf2 escaping from Keap1-mediated degradation, subsequently promoting antioxidant enzyme generation. Interestingly, we also map that the antioxidant response elements (AREs) in the Nestin promoter are responsible for its induction via Nrf2. Taken together, our results indicate that the Nestin-Keap1-Nrf2 axis regulates cellular redox homeostasis and confers oxidative stress resistance in NSCLC.
Mortality from hepatitis B virus (HBV)–related acute‐on‐chronic liver failure (ACLF) is high due to limited treatment options. Preclinical and clinical investigations have proved that treatment with ...mesenchymal stromal cells (MSCs) is beneficial for recovery from liver injury. We hypothesized that the outcome of HBV‐related ACLF would be improved by MSC treatment. From 2010 to 2013, 110 patients with HBV‐related ACLF were enrolled in this open‐label, nonblinded randomized controlled study. The control group (n = 54) was treated with standard medical therapy (SMT) only. The experimental group (n = 56) was infused weekly for 4 weeks with 1.0 to 10 × 105 cells/kg allogeneic bone marrow–derived MSCs and then followed for 24 weeks. The cumulated survival rate of the MSC group was 73.2% (95% confidence interval 61.6%‐84.8%) versus 55.6% (95% confidence interval 42.3%‐68.9%) for the SMT group (P = 0.03). There were no infusion‐related side effects, but fever was more frequent in MSC compared to SMT patients during weeks 5‐24 of follow‐up. No carcinoma occurred in any trial patient in either group. Compared with the control group, allogeneic bone marrow–derived MSC treatment markedly improved clinical laboratory measurements, including serum total bilirubin and Model for End‐Stage Liver Disease scores. The incidence of severe infection in the MSC group was much lower than that in the SMT group (16.1% versus 33.3%, P = 0.04). Mortality from multiple organ failure and severe infection was higher in the SMT group than in the MSC group (37.0% versus 17.9%, P = 0.02). Conclusion: Peripheral infusion of allogeneic bone marrow–derived MSCs is safe and convenient for patients with HBV‐related ACLF and significantly increases the 24‐week survival rate by improving liver function and decreasing the incidence of severe infections. (Hepatology 2017;66:209–219).
Monkeys serve as important model species for studying human diseases and developing therapeutic strategies, yet the application of monkeys in biomedical researches has been significantly hindered by ...the difficulties in producing animals genetically modified at the desired target sites. Here, we first applied the CRISPR/Cas9 system, a versatile tool for editing the genes of different organisms, to target monkey genomes. By coinjection of Cas9 mRNA and sgRNAs into one-cell-stage embryos, we successfully achieve precise gene targeting in cynomolgus monkeys. We also show that this system enables simultaneous disruption of two target genes (Ppar-γ and Rag1) in one step, and no off-target mutagenesis was detected by comprehensive analysis. Thus, coinjection of one-cell-stage embryos with Cas9 mRNA and sgRNAs is an efficient and reliable approach for gene-modified cynomolgus monkey generation.
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•CRISPR/Cas9-mediated simultaneous targeting of multiple genes in monkey embryos•Demonstrates an efficient and reliable approach for genome modified monkey generation•Achieves Ppar-g and Rag1 double mutation in monkeys in one step
Simultaneous disruption of two target genes in one step has been achieved in cynomolgus monkeys by CRISPR technology.
The ability to identify and isolate lineage-specific stem cells from adult tissues could facilitate cell replacement therapy. Leydig cells （LCs） are the primary source of androgen in the mammalian ...testis, and the prospective iden- tification of stem Leydig cells （SLCs） may offer new opportunities for treating testosterone deficiency. Here, in a transgenic mouse model expressing GFP driven by the Nestin （Nes） promoter, we observed Nes-GFP~ cells located in the testicular interstitial compartment where SLCs normally reside. We showed that these Nes-GFP~ cells expressed LIFR and PDGFR-e, but not LC lineage markers. We further observed that these cells were capable of clonogenic self-renewal and extensive proliferation in vitro and could differentiate into neural or mesenchymal cell lineages, as well as LCs, with the ability to produce testosterone, under defined conditions. Moreover, when transplanted into the testes of LC-disrupted or aging models, the Nes-GFP＋ cells colonized the interstitium and partially increased testosterone production, and then accelerated meiotic and post-meiotic germ cell recovery. In addition, we further demonstrated that CD51 might be a putative cell surface marker for SLCs, similar with Nestin. Taken together, these results suggest that Nes-GFP~ cells from the testis have the characteristics of SLCs, and our study would shed new light on developing stem cell replacement therapy for testosterone deficiency.
Abstract Introducing concentration gradients of nerve growth factor (NGF) into conduits for repairing of peripheral nerve injury is crucial for nerve regeneration and guidance. Herein, combining ...differential adsorption of NGF/silk fibroin (SF) coating, the gradient of NGF-immobilized membranes (G-Ms) and nanofibrous nerve conduits (G-nNCs) were successfully fabricated. The efficacy of NGF gradients was confirmed by a quantitative comparison of dorsal root ganglia (DRG) neurite outgrowth on the G-Ms or uniform NGF-immobilized membranes (U-Ms). Significantly, the neurite turning ratio was 0.48 ± 0.11 for G-M group, but it was close to zero for U-M group. The neurite length of DRGs in the middle of the G-Ms was significantly longer than that of U-M group, even though the average NGF concentration was approximated. Furthermore, 12 weeks after implantation in rats with a 14 mm gap of sciatic nerve injury, G-nNCs achieved satisfying outcomes of nerve regeneration associated with morphological and functional improvements, which was superior to that of the uniform NGF-immobilized nNCs (U-nNCs). Sciatic function index (SFI), compound muscle action potentials (CMAPs), total number of myelinated nerve fibers, thickness of myelin sheath were similar for the G-nNCs and autografts, with the G-nNCs having a higher density of axons than the autografts. Our results demonstrated the significant role of introducing NGF gradients into scaffolds in promoting nerve regeneration.
Despite the high cure rate of T cell acute lymphoblastic leukemia (T-ALL), drug resistance to chemotherapy remains a significant clinical problem. Bone marrow mesenchymal stem cells (MSCs) protect ...leukemic cells from chemotherapy, but the underlying mechanisms are poorly understood. In this study, we aimed to uncover the mechanism of MSC-induced chemoresistance in T-ALL cells, thus providing a promising clinical therapy target.
Cell viability was determined using the viability assay kit CCK-8. The mitochondrial ROS levels were detected using the fluorescent probe MitoSOX™ Red, and fluorescence intensity was measured by flow cytometry. In vitro, MSCs and Jurkat cells were cocultured. MSCs were labeled with green fluorescent protein (GFP), and Jurkat cells were labeled with the mitochondria-specific dye MitoTracker Red. Bidirectional mitochondrial transfer was detected by flow cytometry and confocal microscopy. The mechanism of mitochondria transfer was analyzed by inhibitor assays. Transcripts related to Jurkat cell/MSC adhesion in the coculture system were assessed by qRT-PCR. After treatment with a neutralizing antibody against a key adhesion molecule, mitochondria transfer from Jurkat cells to MSCs was again detected by flow cytometry and confocal microscopy. Finally, we verified our findings using human primary T-ALL cells cocultured with MSCs.
Chemotherapeutic drugs caused intracellular oxidative stress in Jurkat cells. Jurkat cells transfer mitochondria to MSCs but receive few mitochondria from MSCs, resulting in chemoresistance. This process of mitochondria transfer is mediated by tunneling nanotubes, which are protrusions that extend from the cell membrane . Moreover, we found that most Jurkat cells adhered to MSCs in the coculture system, which was mediated by the adhesion molecule ICAM-1. Treatment with a neutralizing antibody against ICAM-1 led to a decreased number of adhering Jurkat cells, decreased mitochondria transfer, and increased chemotherapy-induced cell death.
We show evidence that mitochondria transfer from Jurkat cells to MSCs, which is mediated by cell adhesion, may be a potential therapeutic target for T-ALL treatment.
Dear Editor,
Non-human primates （NHPs） are genetically, physiologically and psychologically more similar to humans than other model organisms, providing an important model for human development and ...diseases 1, 2. Precise genome modification in non-human primates （NHPs） holds great promise for biomedical researches. However, owing to the long sexual maturation time and low reproduction rate of NHPs, it is very challenging to generate biallelic mutant NHPs for loss-of-function studies through breeding. Recently, the site-specific nucleases, namely TALENs （transcription activator-like effector nucleases） and CRISPR （clustered regularly interspaced short palindromic repeat）/Cas （CRISPR-associated） system, make it feasible to generate NHPs with precise genome modifications, yet the resulting transgenic animals exhibited mosaic mutations accompanied by the presence of wild type allele in different tissues 3, 4. Thus, the feasibility of obtaining biallelic mutations in monkeys remains an open question. Here we report that by systematically optimizing the mutagenesis effi- ciency of the CRISPR/Cas-based method in monkeys, we have successfully obtained the first live p53 biallelic mutant monkey, and achieved homology directed repair （HDR）-driven gene editing with nucleotide-level preci- sion in monkey embryos.
Mesenchymal stromal cells (MSCs) can modulate inflammation and contribute to tissue regeneration and, thus, have emerged as a promising option for cell-based therapy. However, the ability of MSCs to ...migrate to injured tissues still needs to be improved. In this study, we investigated whether genetically engineered MSCs could exhibit increased migratory properties and improved therapeutic efficacy. Using a mouse model of contact hypersensitivity (CHS), chemokine gene expression screening revealed that CXCL13 changed most significantly in injured tissue. Unfortunately, MSCs hardly express the corresponding receptor, CXCR5. Thus, CXCR5-overexpressing MSCs (MSCCXCR5) were generated that retained their abilities of proliferation, differentiation, and immunomodulation. Furthermore, MSCCXCR5 showed significantly increased migrating ability toward CXCL13. Importantly, systemic infusion of MSCCXCR5 dramatically suppressed CHS in mice, as evidenced by decreased levels of inflammatory cell infiltration and pro-inflammatory cytokine production. Numerous MSCCXCR5 migrated into inflamed ears, localized with T cells, inhibited T cell proliferation, promoted T cell apoptosis, and suppressed the production of T cell-derived pro-inflammatory factors. Collectively, these findings demonstrate that CXCR5 overexpression increases the ability of MSCs to respond to migratory stimuli and highly intensifies their immunomodulatory effects in vivo. This strategy for enhancing targeted stem/progenitor cell homing may improve the efficacy of MSC-based therapies.
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Xiang et al. describe that genetically engineered MSCs with CXCR5 significantly increase their migration to diseased organs/tissues and improve therapeutic efficacy in a mouse model of contact hypersensitivity. This strategy for enhancing targeted stem/progenitor cell homing may provide a potential strategy to improve the efficacy of MSC-based therapeutics.
Mesenchymal stromal cells (MSCs) are known to be widespread in many tissues and possess a broad spectrum of immunoregulatory properties. They have been used in the treatment of a variety of ...inflammatory diseases; however, the therapeutic effects are still inconsistent owing to their heterogeneity. Spleen stromal cells have evolved to regulate the immune response at many levels as they are bathed in a complex inflammatory milieu during infection. Therefore, it is unknown whether they have stronger immunomodulatory effects than their counterparts derived from other tissues. Here, using a transgenic mouse model expressing GFP driven by the Nestin (Nes) promoter, Nes-GFP+ cells from bone marrow and spleen were collected. Artificial lymphoid reconstruction in vivo was performed. Cell phenotype, inhibition of T cell inflammatory cytokines, and in vivo therapeutic effects were assessed. We observed Nes-GFP+ cells colocalized with splenic stromal cells and further demonstrated that these Nes-GFP+ cells had the ability to establish ectopic lymphoid-like structures in vivo. Moreover, we showed that the Nes-GFP+ cells possessed the characteristics of MSCs. Spleen-derived Nes-GFP+ cells exhibited greater immunomodulatory ability in vitro and more remarkable therapeutic efficacy in inflammatory diseases, especially inflammatory bowel disease (IBD) than bone marrow-derived Nes-GFP+ cells. Overall, our data showed that Nes-GFP+ cells contributed to subsets of spleen stromal populations and possessed the biological characteristics of MSCs with a stronger immunoregulatory function and therapeutic potential than bone marrow-derived Nes-GFP+ cells.
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