Engineered Exosomes for Drug Delivery in Cancer Therapy: A promising approach and application.

A significant amount of research effort is currently focused on investigating the role of exosomes in various cancers. These tiny vesicles, apart from acting as biomarkers, also play a crucial role in tumor formation and development. Several studies have demonstrated that exosomes can be a drug delivery vehicle for cancer therapy. In this paper, we highlight the key advantages of exosomes as a drug delivery candidate, with a particular focus on their low immunogenicity, natural targeting ability and suitable mechanical properties. Furthermore, we propose that the selection of appropriate exosomes and drug loading methods based on therapeutic goals and product heterogeneity is essential for preparing engineered exosomes. We comprehensively analyzed the superiorities of current drug-loading methods to improve the creation of designed exosomes. Moreover, we systematically review the applications of engineered exosomes in various therapies such as immunotherapy, gene therapy, protein therapy, chemotherapy, indicating that engineered exosomes have the potential to be reliable and, safe drug carriers that can address the unmet needs in cancer clinical practice.

Facile and selective separation of anthraquinones by alizarin-modified iron oxide magnetic nanoparticles.

Anthraquinones are widely distributed in higher plants and possess broad biological activities. The conventional separation procedures for isolating anthraquinones from the plant crude extracts require multiple extraction, concentration, and column chromatography steps. In this study, we synthesized three alizarin (AZ)-modified Fe3O4 nanoparticles (Fe3O4@AZ, Fe3O4@SiO2-AZ, and Fe3O4@SiO2-PEI-AZ) by thermal solubilization method. Fe3O4@SiO2-PEI-AZ showed strong magnetic responsiveness, high methanol/water dispersion, good recyclability, and high loading capacity for anthraquinones. To evaluate the feasibility of using Fe3O4@SiO2-PEI-AZ for separating various aromatic compounds, we employed molecular dynamics simulations to predict the adsorption/desorption effects of PEI-AZ for various aromatic compounds in different methanol concentrations. The results showed that the anthraquinones could be efficiently separated from the monocyclic and bicyclic aromatic compounds by adjusting the methanol/water ratio. The Fe3O4@SiO2-PEI-AZ nanoparticles were then used to separate the anthraquinones from the rhubarb extract. At 5% methanol, all the anthraquinones were adsorbed by the nanoparticles, thus allowing their separation from other components in the crude extract. Compared with the conventional separation methods, this adsorption method has the advantages of high adsorption specificity, simple operation, and solvent saving. This method sheds light on the future application of functionalized Fe3O4 magnetic nanoparticles to selectively separate desired components from complex plant and microbial crude extracts.

Integrating the tumor-suppressive activity of Maspin with p53 in retuning the epithelial homeostasis: A working hypothesis and applicable prospects.

Epithelial malignant transformation and tumorous development were believed to be closely associated with the loss of its microenvironment integrity and homeostasis. The tumor-suppressive molecules Maspin and p53 were demonstrated to play a crucial role in body epithelial and immune homeostasis. Downregulation of Maspin and mutation of p53 were frequently associated with malignant transformation and poor prognosis in various human cancers. In this review, we focused on summarizing the progress of the molecular network of Maspin in studying epithelial tumorous development and its response to clinic treatment and try to clarify the underlying antitumor mechanism. Notably, Maspin expression was reported to be transcriptionally activated by p53, and the transcriptional activity of p53 was demonstrated to be enhanced by its acetylation through inhibition of HDAC1. As an endogenous inhibitor of HDAC1, Maspin possibly potentiates the transcriptional activity of p53 by acetylating the p53 protein. Hereby, it could form a "self-propelling" antitumor mechanism. Thus, we summarized that, upon stimulation of cellular stress and by integrating with p53, the aroused Maspin played the epigenetic surveillant role to prevent the epithelial digressional process and retune the epithelial homeostasis, which is involved in activating host immune surveillance, regulating the inflammatory factors, and fine-tuning its associated cell signaling pathways. Consequentially, in a normal physiological condition, activation of the above "self-propelling" antitumor mechanism of Maspin and p53 could reduce cellular stress (e.g., chronic infection/inflammation, oxidative stress, transformation) effectively and achieve cancer prevention. Meanwhile, designing a strategy of mimicking Maspin's epigenetic regulation activity with integrating p53 tumor-suppressive activity could enhance the chemotherapy efficacy theoretically in a pathological condition of cancer.

Bacterial Lipopolysaccharide Augmented Malignant Transformation and Promoted the Stemness in Prostate Cancer Epithelial Cells.

PURPOSE: To study bacterial lipopolysaccharide (LPS)-induced cancer stem-like transformation and to investigate the inhibitory effect of Trichostatin A (TSA) on the malignant transformation through targeting p-Stat3 signaling. METHODS: 2D, 3D, and serum-free suspension culture system were used to study LPS-induced malignant transformation in series malignant grade of prostate cancer (PCa) epithelial cells. Flow cytometry assay and RT-PCR were utilized to evaluate the CD44+CD133+ stem cell population, the expression of inflammatory cytokines and series tumor stemness biomarkers. Meanwhile, Western blot was used to analyze the alteration of cell signaling associated-molecules by treatment with TSA, an original antifungal antibiotic and a panel inhibitor of histone deacetylase. RESULTS: Our study found that LPS promoted the migration, invasion and stem-like tumoroshpere forming in multiple PCa cell lines including DU145, PC3, 22RV1, LNCaP. LPS also enriched CD44+CD133+ stem cell population and increased the expression of series tumor stemness biomarkers (e.g., CD44, CD133, SOX-2, α-intergrin, Nestin, etc.). TSA was found to prevent tumor cell migration, invasion and tumorosphere forming in DU145 and PC3 cells with increasing tumor suppressive Maspin and reducing both phosphorylation of Stat3 (p-Stat3) and pro-oncogene c-Myc expression in LPS-treated DU145 cells. Furthermore, blocking Stat3 signaling pathway by treatment with TSA and/or small molecule compound Stattic of an p-Stat3 inhibitor effectively abrogated LPS-induced tumorosphere forming with decrease of IL-6, IL-8 and stemness biomarkers CD44, SOX-2 expression. CONCLUSION: Our data demonstrated that the inflammatory agent of bacterial LPS augmented malignant transformation and promoted the cancerous stemness in PCa epithelial cells. TSA could prevent, at least in part, the LPS-induced malignant transformation by targeting p-Stat3/c-Myc signaling pathway and reducing inflammatory IL-6, IL-8. In addition, the assay of LPS-induced tumorosphere forming could serve as a simple and an easy handling method for targeting cancer stem cells drug screening in vitro in clinical practice.

Relationship Between Social Anxiety and Internet Addiction in Chinese College Students Controlling for the Effects of Physical Exercise, Demographic, and Academic Variables.

This study aims to identify the relationship between social anxiety (SA) and internet addiction (IA) in a group of Chinese college students by controlling for the effects of physical exercise (PE), demographic, and academic variables. A sample of 4,677 students from five major regions of China participated in this survey. The findings revealed that: (1) SA had a direct effect on IA; (2) regular and active participation in physical exercise can relieve SA and IA effectively; (3) the level of SA and IA is strongly linked to sex; (4) the levels of SA and IA are different among students of different majors; (5) students in the middle phase of their academic career are more likely to have IA than those in the starting phase. The study is significant because few existing studies discuss the role of PE on SA and IA. Additionally, the study found that college students with more PE would have a lower level of SA and a lower probability of IA.

The Differential Antitumor Activity of 5-Aza-2'-deoxycytidine in Prostate Cancer DU145, 22RV1, and LNCaP Cells.

DNA methylation is a DNA methyltransferase-mediated epigenetic modification affecting gene expression. This process is involved in the initiation and development of malignant disease. 5-Aza-2'-deoxycytidine (5-Aza), a classic DNA methyltransferase inhibitor, possesses antitumor proliferation activity. However, whether 5-Aza induces cytotoxicity in solid tumors warrants further investigated. In this study, human prostate cancer (CaP) cells were treated with 5-Aza and subjected to cell viability and cytotoxicity analysis. Reverse transcription-polymerase chain reaction and methylation-specific polymerase chain reaction assay were utilized to test the gene expression and methylation status of the p53 and p21 gene promoters. The results showed that 5-Aza differentially inhibited spontaneous proliferation, arrested the cell cycle at S phase in DU145, at G1 phase in 22RV1 and LNCaP cells, and G2 phase in normal RWPE-1 cells, as well as induced the expression of phospho-H2A.X and tumor suppressive mammary serine protease inhibitor (maspin) in all three types of CaP cells. 5-Aza also increased p53 and p21 transcription through promoter demethylation, and decreased the expression of oncogene c-Myc in 22RV1 and LNCaP cells. Western blotting analysis showed that the poly (ADP-ribose) polymerase cleavage was detected in DU145 and 22RV1 cells. Moreover, there were no significant changes in p53, p21 and c-Myc expression in DU145 cells following treatment with 5-Aza. Thus, in responsible for its apoptotic induction and DNA damage, the mechanism of the antitumor activities of 5-Aza may involve in an increase of tumor suppressive maspin, upregulation of wild type p53-mediated p21 expression and a decrease of oncogene c-Myc level in 22RV1 and LNCaP cells, and enhancing the tumor suppressive maspin expression in DU145 cells. These results enriched our understanding of the multifaceted antitumor activity of 5-Aza, and provided the expression basis of biomarkers for its possible clinical application in prostate cancer.

Tumor Suppressive Maspin-Sensitized Prostate Cancer to Drug Treatment Through Negative Regulating Androgen Receptor Expression.

Overactivation of androgen receptor (AR)-mediated signal has been extensively implicated in prostate cancer (CaP) development, progression, and recurrence, which makes it an attractive therapeutic target. Meanwhile, as an endogenous inhibitor of histone deacetylase 1 (HDAC 1), tumor-suppressive mammary serine protease inhibitor (maspin) was reported to sensitize drug-induced apoptosis with a better therapeutic outcome in CaP, but the relationship between AR and maspin remains unclear. In the current study, treatment of 5'-Aza or MS-275/enzalutamide induced poly (ADP-ribose) polymerase (PARP) cleavage and p-H2A.X in CaP cells with an increase of maspin expression but a decrease of AR. Then, treatment with protease inhibitor MG132 did not rescue the above drug-induced loss of AR. In addition, modulation of maspin expression by gene recombinant or siRNA technology showed an inverse correlation between expression of maspin and AR, consequently affecting the AR-regulated downstream gene transcription (e.g., NKX3.1 and TMPRSS2). Bioinformatics analysis of the data extracted from the National Center for Biotechnology Information Gene Expression Omnibus (NCBI GEO) database also revealed an inverse correlation between low maspin expression and high AR level in advanced CaP. Furthermore, chromatin immunoprecipitation (ChIP) assay using anti-maspin antibody identified that a portion of AR promoter sequence was co-precipitated and presented in the immunoprecipitated complex. Finally, maspin-mediated repression of AR was induced by treatment of MS-275, which promoted enzalutamide treatment efficacy with decrease of prostate-specific antigen (PSA) expression in LNCaP and 22RV1 cells. Taken together, the data not only demonstrated maspin-mediated repression of AR to augment drug anti-tumor activity but also provided in-depth support for combination of HDAC inhibitors with AR antagonist in CaP therapy.

Investigation of a Progressive Relaxation Training Intervention on Precompetition Anxiety and Sports Performance Among Collegiate Student Athletes.

This study aims to investigate whether simple and convenient progressive relaxation training (PRT) is effective in enhancing collegiate student athletes' mental health and sports performance. An experimental group of 14 (6 female) and a control group of 10 (5 female) collegiate student athletes were recruited from among track and field athletes who were preparing for provincial competition. The experimental group was exposed to a PRT intervention in 30-min sessions conducted twice per week for a duration of one month. At baseline, the Competitive State Anxiety Inventory-2 (CSAI-2), State-Trait Anxiety Inventory (STAI), and Eysenck Personality Questionnaire-Revised Short Scale for Chinese (EPQ-RSC) were completed, while only the CSAI-2 was reassessed at one, two, and three weeks after initiation of the intervention. Additionally, within half a day after completing all one's individual competition events, the CSAI-2 was again assessed in the two groups recalling their memory of their precompetition state anxiety. Then, the differences in the three dimensions of the CSAI-2 between the two groups at the five time points introduced above were compared. This study also explored whether PRT affected sports performance, defined by the athletes reaching their best records or not, by logistic regressive analysis. This study found significant between-group differences in the self-confidence dimension score at the second and third time points. Through logistic regression analysis, a positive effect of PRT was found for the enhancement of sports performance. In sum, PRT showed positive effects on precompetition state self-confidence and enhanced sports performance among collegiate student athletes.

Polydatin Increases Radiosensitivity by Inducing Apoptosis of Stem Cells in Colorectal Cancer.

This study aimed to investigate the radiosensitizing effect of polydatin (PD) on colorectal cancer (CRC) and its underlying mechanism. The C57BL/6 mouse model of CRC was induced by treatment with azoxymethane (AOM)/dextran sodium sulfate (DSS) and then divided into four groups: control, PD alone, IR alone, and combination of PD and IR. Radiation therapy (200 cGy/min, 10Gy) was performed in mice in the experimental groups for once a week with a total of four times. Thirty minutes before IR, mice were intraperitoneally injected with PD at the dose of 25mg/kg. The number and volume of CRC xenografts were calculated. Immunohistochemical staining was performed to detect the expression of Ki67 and cleaved caspase-3 in tumor tissues samples. The effects of PD on proliferation and apoptosis were evaluated in CT26 and HCT116 colon tumor cells. Leucine-rich repeat-containing G-protein coupled receptor 5 positive (Lgr5+) cancer stem cells (CSCs) were sorted from CT26 cells and the effects of PD on their proliferation and apoptosis were observed to elucidate the radiosensitizing mechanism of PD in CRC cells. Combined therapy with PD and IR significantly decreased tumor volume, inhibited proliferation and induced apoptosis of tumor cells in the mouse model of CRC compared to other three groups. Compared to the IR group, in vitro assay showed that PD combined with IR inhibited proliferation and promoted apoptosis of CT26 and HCT116 colon tumor cells as well as Lgr5+ CSCs. However, addition of the bone morphogenetic protein (BMP) type I receptor inhibitor K02288 (6.4nM) dramatically increased proliferation of Lgr5+ CSCs and abolished the cytotoxic effect of PD combined with IR on Lgr5+ CSCs. The in vivo and in vitro experiments demonstrated that IR combined treatment with PD could inhibit proliferation and promote apoptosis of CRC cells and Lgr5+ CSCs, and BMP signaling pathway was involved in the radiosensitizing effect of PD.

Exosomal miR-7 Mediates Bystander Autophagy in Lung after Focal Brain Irradiation in Mice.

This study investigated whether exosomal microRNA-7 (miR-7) mediates lung bystander autophagy after focal brain irradiation in mice. After 10 Gy or sham irradiation of mice brains, lung tissues were extracted for the detection of autophagy markers by immunohistochemistry, western blotting, and quantitative real-time reverse transcription PCR (qRT-PCR), meanwhile the brains were dissociated, the neuron/astrocyte/microglia/oligodendrocyte were isolated, and the miR-7 expression in each population were detected, respectively. A dual-luciferase reporter assay was developed to identify whether Bcl-2 is a target gene of miR-7. After 10 Gy or sham irradiation of astrocytes, exosomes were extracted, stained with Dil (1,1'-Dioctadecyl-3,3,3',3'-Tetramethylindocarbocyanine Perchlorate), and added into non-irradiated astrocytes. Meanwhile, Dil-stained exosomes released from 10 Gy or sham irradiated astrocytes were injected into LC3B-GFP mice via the tail vein. Lung tissues were then extracted for western blotting and qRT-PCR. Irradiation of mouse brains increased the LC3B-II/I ratio, Beclin-1 and miR-7 levels, while decreased the Bcl-2 level in non-irradiated lung tissue. Interestingly, brain irradiation remarkably increased the miR-7 expression in astrocyte and oligodendrocyte. MiR-7 significantly inhibited the luciferase activity of the wild-type Bcl-2-3'-untranslated regions (UTR) reporter vector, but not that of the Bcl-2-3'-UTR mutant vector, indicating that Bcl-2 is directly targeted by miR-7. In in vitro study, the addition of irradiated astrocyte-secreted exosomes increased the LC3B-II/I ratio, Beclin-1 and miR-7 levels, while decreased the Bcl-2 level in non-irradiated astrocytes. Further, the injection of irradiated astrocyte-secreted exosomes through the tail vein increased the lung LC3B-II/I ratio, Beclin-1 and miR-7 level, but decreased the Bcl-2 level in vivo. We concluded that exosomal miR-7 targets Bcl-2 to mediate distant bystander autophagy in the lungs after brain irradiation.

C-Myc regulates radiation-induced G2/M cell cycle arrest and cell death in human cervical cancer cells.

AIM: The study was conducted to investigate the role of c-Myc in the regulation of ionizing radiation-induced cell cycle arrest and cell death in human cervical cancer cells. METHODS: Control and c-Myc-silenced Hela cells were collected at different time points after 60 Co γ-ray radiation. Flow cytometry was used to measure cell cycle distribution and apoptosis. Immunofluorescence was applied to determine the percentage of cells in M phase. Transmission electron microscopy and immunoblotting were used to detect the induction of autophagy after radiation. Immunoblotting was also used to measure the expression levels of apoptosis-related proteins. RESULTS: In c-Myc-silenced cells, radiation induced delayed but long-lasting G2/M arrest and an abnormal M phase compared with the control. In addition, c-Myc knockdown significantly inhibited apoptotic cell death induced by radiation. Meanwhile, radiation-induced autophagy appeared stronger in c-Myc-silenced cells. Mechanically, we found that Caspase 8 and survivin expression was decreased in c-Myc-silenced Hela-630 cells. CONCLUSIONS: These data showed that c-Myc serves as a co-regulator in radiation-induced G2/M cell cycle arrest and cell death in human cervical cancer cells.

MCPIP1 suppresses hepatitis C virus replication and negatively regulates virus-induced proinflammatory cytokine responses.

Human MCP-1-induced protein 1 (MCPIP1, also known as ZC3H12A and Regnase-1) plays important roles in negatively regulating the cellular inflammatory response. Recently, we found that as an RNase, MCPIP1 has broad-spectrum antiviral effects by targeting viral RNA. In this study, we demonstrated that MCPIP1 expression was induced by hepatitis C virus (HCV) infection in Huh7.5 hepatoma cells. MCPIP1 expression was higher in liver tissue from patients with chronic HCV infection compared with those without chronic HCV infection. Knockdown of MCPIP1 increased HCV replication and HCV-mediated expression of proinflammatory cytokines, such as TNF-α, IL-6, and MCP-1. However, overexpression of MCPIP1 significantly inhibited HCV replication and HCV-mediated expression of proinflammatory cytokines. Various mutants of functional domains of MCPIP1 showed disruption of the RNA binding and oligomerization abilities, as well as RNase activity, but not deubiquitinase activity, which impaired the inhibitory activity against HCV replication. On immunocytochemistry, MCPIP1 colocalized with HCV RNA. Use of a replication-defective HCV John Cunningham 1/AAG mutant and in vitro RNA cleavage assay demonstrated that MCPIP1 could directly degrade HCV RNA. MCPIP1 may suppress HCV replication and HCV-mediated proinflammatory responses with infection, which might contribute to the regulation of host defense against the infection and virus-induced inflammation.

Direct labeling of hMSC with SPIO: the long-term influence on toxicity, chondrogenic differentiation capacity, and intracellular distribution.

PURPOSE: The purpose of this study was to evaluate the long-term cellular toxicity, labeling efficiency, chondrogenic differentiation capacity, and intracellular distribution following direct superparamagnetic iron oxide (SPIO) nanoparticle labeling of human mesenchymal stem cells (hMSCs) in the absence of transfection agents. PROCEDURES: hMSCs were incubated with a SPIO, Ferucarbotran, at concentrations of 0, 1, 10, and 100 µg Fe/ml for 24 or 72 h. The cell granularity and size change, reactive oxygen species generation, and mitochondria membrane potential were measured by flow cytometry. The differentiation capacity of the cells into chondrocytes was determined by Alcian blue and Safranin-O staining, immunocytochemical analysis, and reverse transcription polymerase chain reaction. RESULTS: The intracellular distribution of the internalized particles was visualized via confocal microscopy. No significant difference was found in the toxicity of labeled cells relative to controls. Successful chondrogenesis of Ferucarbotran-labeled hMSCs was confirmed. The intracellular SPIO nanoparticles were located within the lysosomes. CONCLUSIONS: In conclusion, we have demonstrated the feasibility of direct labeling with Ferucarbotran without impairment of cellular function, toxicity, or inhibition of differentiation capacity. Furthermore, lysosomal metabolism takes place after intracellular uptake of Ferucarbotran.

Effects of flow rate on delivery of bubble continuous positive airway pressure in an in vitro model.

BACKGROUND: There has been concern over the effect of vigorous bubbling on the delivery pressure during the operation of the bubble nasal continuous positive airway pressure (CPAP) system. We investigated the relationship between intra-tubing pressure changes and flow rates in a closed bubble CPAP system in vitro. METHODS: Using an experimental (in vitro) model, the distal connecting tube of the CPAP system was immersed under the water seal to a depth of 5 cm. Sixteen different flow rates, ranging from 2 L/min to 20 L/min, were tested. The procedure was repeated 10 times at each flow rate, and the intra-tubing pressure was recorded. RESULTS: The intra-tubing pressure within the model increased as the air flow rates were adjusted from 2 L/min to 20 L/min. The relationship was represented by the following equation, pressure (cmH(2)O) = 5.37 + 0.15 x flow rate (L/min) (R(2) = 0.826, p < 0.001). CONCLUSION: These results demonstrated that the intra-tubing pressure in a bubble CPAP system was highly correlated with flow rate in vitro.

Molecular analysis of an actin gene, CarACT1, from chickpea (Cicer arietinum L.).

Actins are ubiquitous and highly conserved proteins that play key roles in cell formation and cellular activities. In this study, an actin gene was isolated from chickpea for the first time and designated as CarACT1 (for Cicer arietinum L. actin gene 1; Genbank accession no. EU529707). It encoded a putative protein with 377 amino acids and contained five exons and four introns within genomic DNA sequence. CarACT1 was localized in cytoplasm and showed high similarity to other well known actins from various species. Reverse transcription-polymerase chain reaction (RT-PCR) assay proved that CarACT1 transcripts were ubiquitously accumulated in all major organs, such as seedling roots, stems, leaves, flowers, young pods, and seeds, as well as in diverse developmental stages, such as leaf senescence, seed development and germination. Our results suggested that CarACT1 is an actin gene with physiological functions and may be served as a potential reference gene for transcription level of interesting genes in chickpea.

Cloning and characterization of a novel NAC family gene CarNAC1 from chickpea (Cicer arietinum L.).

The plant-specific NAC (for NAM, ATAF1,2 and CUC2) proteins have been found to play important roles in plant development and stress responses. In this study, a NAC gene CarNAC1 (for Cicer arietinum L. NAC gene 1) was isolated from a cDNA library constructed with chickpea seedling leaves treated by polyethylene glycol. CarNAC1 encoded a putative protein with 239 amino acids and contained 3 exons and 2 introns within genomic DNA sequence. CarNAC1 had a conserved NAC domain in the N-terminus and the CarNAC1:GFP (green fluorescent protein) fusion protein was localized in the nucleus of onion epidermal cells. Additionally, CarNAC1 exhibited the trans-activation activity which was mapped to the C-terminus. The CarNAC1 transcript was detected in many chickpea organs including seedling leaves, stems, roots, flowers, and young pods, but less accumulated in young seeds. CarNAC1 was induced by leaf age and showed changes in expression during seed development and germination. Furthermore, the expression of CarNAC1 was strongly induced by drought, salt, cold, wounding, H(2)O(2), ethephon, salicylic acid, indole-3-acetic acid, and gibberellin. Our results suggest that CarNAC1 encodes a novel NAC-domain protein and may be a transcriptional activator involved in plant development and various stress responses.

Characterization of a chickpea (Cicer arietinum L.) NAC family gene, CarNAC5, which is both developmentally- and stress-regulated.

It has been documented that the plant-specific NAC (for NAM, ATAF1,2 and CUC2) transcription factors play an important role in plant development and stress responses. In this study, a chickpea NAC gene CarNAC5 (for Cicer arietinum L. NAC gene 5) was isolated from a cDNA library from chickpea leaves treated by polyethylene glycol (PEG). CarNAC5, as a single/low copy gene, contained three exons and two introns within genomic DNA sequence and encoded a polypeptide with 291 amino acids. CarNAC5 protein had a conserved NAC domain in the N-terminus and showed high similarity to other NACs, especially ATAF subgroup members. The CarNAC5:GFP fusion protein was localized in the nucleus of onion epidermal cells. Furthermore, CarNAC5 protein activated the reporter genes LacZ and HIS3 in yeast. The transactivation activity was mapped to the C-terminal region. The transcripts of CarNAC5 appeared in many chickpea tissues including seedling leaves, stems, roots, flowers, seeds and pods, but mostly accumulated in flowers. Meanwhile, CarNAC5 was strongly expressed during seed maturation and in embryos of the early germinating seeds. It was also significantly induced by drought, heat, wounding, salicylic acid (SA), and indole-3-acetic acid (IAA) treatments. Our results suggest that CarNAC5 encodes a novel NAC-domain protein and acts as a transcriptional activator involved in plant developmental regulation and various stress responses.

A NAC transcription factor gene of Chickpea (Cicer arietinum), CarNAC3, is involved in drought stress response and various developmental processes.

NAC transcription factors have been found to play important roles in plant development and responses to environmental stresses. Based on two cDNA libraries constructed from the PEG-treated and -nontreated seedling leaves of chickpea, a NAC gene, CarNAC3, was isolated and characterized. The results indicated that CarNAC3 contained 285 amino acids and had a conserved NAC domain. It was localized in the nucleus and possessed trans-activation activity in the C-terminus. Phylogenetic analysis showed that CarNAC3 belonged to the NAP (NAC-like, activated by APETALA3/PISTILLATA) subgroup of the NAC protein family. CarNAC3 exhibited organ-specific expression and its induction was strongly dependent on leaf age. CarNAC3 showed differential expression patterns during seed development and germination, and could be significantly induced by drought stress, abscisic acid (ABA), ethephon (Et) and indole-3-acetic acid (IAA), but was inhibited by N-6-benzyl-adenine (6-BA). Our data suggest that CarNAC3 may be a transcriptional activator involved in drought stress response and various developmental processes.

The promotion of human mesenchymal stem cell proliferation by superparamagnetic iron oxide nanoparticles.

Superparamagnetic iron oxide (SPIO) nanoparticles are very useful in cell imaging; meanwhile, however, biosafety concerns associated with their use, especially on therapeutic stem cells, have arisen. Most studies of biosafety issues focus on whether the nanoparticles have deleterious effects. Here, we report that Ferucarbotran, an ionic SPIO, is not toxic to human mesenchymal stem cells (hMSCs) under the conditions of these experiments but instead increases cell growth. Ferucarbotran-promoted cell growth is due to its ability to diminish intracellular H2O2 through intrinsic peroxidase-like activity. Also, Ferucarbotran can accelerate cell cycle progression, which may be mediated by the free iron (Fe) released from lysosomal degradation and involves the alteration of Fe on the expression of the protein regulators of the cell cycle.