Lectin microarrays have emerged as a novel platform for glycan analysis during recent years. Here, we have combined surface plasmon resonance imaging (SPRi) with the lectin microarray for rapid and label-free profiling of stem cells. In this direction, 40 lectins from seven different glyco-binding motifs and three different cell lines—mouse embryonic stem cells (mESCs), mouse-induced pluripotent stem cells (miPSCs), and mouse embryonic fibroblast stem cells (MEFs)—were used. Pluripotent mouse stem cells were clearly distinguished from non-pluripotent stem cells. Eight lectins—DBA, MAL, PHA_E, PHA_L, EEL, AAL, PNA, and SNA—generated maximal value to define pluripotency of mouse stem cells in our experiments. The discriminant function based on lectin reactivities was highly accurate for the determination of stem cell pluripotency. These results suggested that glycomic analysis of stem cells leads to a novel comprehensive approach for quality control in cell-based therapy and regenerative medicine. 相似文献
Eight swainsonine (SW)-degrading bacteria were isolated from the soil where locoweed was buried for 6 months and one of the
strains (YLZZ-1) was selected for further study. Based on morphology, physiologic tests, 16S rRNA gene sequence, and phylogenetic
characteristics, the strain showed the greatest similarity to members of the order Acinetobacters and within the order to members of the Acinetobacter calcoaceticus group. The ability of the strain for degrading SW, as sole carbon source, was investigated under different culture conditions.
The preferential temperature and initial pH for the strain were 25–35°C and 6–9, respectively. The optimal temperature for
the strain was 30°C and the optimal pH was 7.0. There was a positive correlation between degradation rate and inoculation
amount. The concentration of SW affected the degradation ability. When the concentration of SW was lower than 100 mg/l, SW
decreased immediately after incubation, and when the concentration of SW was 200 mg/l, there was an inhibiting effect for
bacteria growth and SW degradation. The strain could degrade SW completely within 14 h when the concentration of SW was 50 mg/l.
These results highlight the potential of this bacterium to be used in detoxifying of SW in livestock consuming locoweed. 相似文献
In both humans and mice, a deficiency of surfactant protein B (SP-B) is associated with a decreased concentration of mature SP-C and accumulation of a larger SP-C peptide, denoted SP-C(i), which is not observed under normal conditions. Isolation of hydrophobic polypeptides from the lungs of children who died with two different SP-B mutations yielded pure SP-C(i) and showed only trace amounts of mature SP-C. Determination of the SP-C(i) covalent structure revealed a 12-residue N-terminal peptide segment, followed by a 35-residue segment that is identical to mature SP-C. The SP-C(i) structure determined herein is similar to that of a proposed late intermediate in the processing of proSP-C, suggesting that SP-C(i) is the immediate precursor of SP-C. In bronchoalveolar lavage fluid from transgenic mice with a focal deficiency of SP-B, SP-C(i) was detected in the biophysically active, large aggregate fraction and was associated with membrane structures that are typical for a large aggregate surfactant. However, unlike SP-C, SP-C(i) exhibited a very poor ability to promote phospholipid adsorption, gave high surface tension during cyclic film compression, and did not bind lipopolysaccharide in vitro. SP-C(i) is thus capable of associating with surfactant lipids, but its N-terminal dodecapeptide segment must be proteolytically removed to generate a biologically functional peptide. The results of this study indicate that the early postnatal fatal respiratory distress seen in SP-B-deficient children is combined with the near absence of active variants of SP-C. 相似文献
Although
green light is not considered to contribute to the photosynthesis of plants, the photosynthesis of ginger, a dual-purpose vegetable used as a medicine and food, is affected by the green wave band. In this study, the supplementary green band of sunlight (SG) increased the net photosynthetic rate (Pn), maximal photochemical efficiency of PSII (Fv/Fm), and actual photochemical efficiency of PSII (Y(II)) compared with the sunlight treatment (S). The Pn and Fv/Fm of the SG treatment were higher than those of the white light (W) treatment, while the Pn and Fv/Fm of the green light (G) treatment alone were lower than those of the W treatment. Further analysis found that the minimal fluorescence (Fo) of the S treatment increased, especially at noon, while the Fo of the SG treatment decreased. Similarly, the Fo of the W treatment increased significantly, while the Fo of the white–green mixed light (WG) treatment decreased. The relative fluorescence values of the K-J-I bands in the SG and WG treatments were lower than those in the S and W treatments, respectively. The photochemical quenching (qP) of the WG treatment was higher than that of the W treatment, while the primary thermal losses corresponded to the sum of nonregulated heat dissipation and fluorescence emission (Y(NO)) of the WG treatment was lower than that of the W treatment. The SG treatment reduced the accumulation of plastoglobules but increased the accumulation of starch granules and leaf thickness. Moreover, the green band supplemented with white light significantly increased the biomass of the aboveground plant parts and promoted the active growth of the aboveground parts. Supplementing green light plays a regulatory role in ginger based on the following four points. First, it effectively promotes the transfer of electrons between the acceptor side of photosystem II; second, it optimizes ginger photosynthesis; third, it alleviates strong light stress by reducing the accumulation of reactive oxygen species; and fourth, it promotes heat dissipation and reduces the rapid burst of active oxygen in the chloroplast caused by excess energy. In summary, green light can significantly optimize the photosynthetic characteristics of ginger.
Leukemia stem cells (LSCs) have critical functions in acute leukemia (AL) pathogenesis, participating in its initiation and relapse. Thus, identifying new molecules to eradicate LSCs represents a high priority for AL management. This work identified E35, a novel Emodin derivative, which strongly inhibited growth and enhanced apoptosis of AL stem cell lines, and primary stem and progenitor cells from AL cases, while sparing normal hematopoietic cells. Furthermore, functional assays in cultured cells and animals suggested that E35 preferentially ablated primitive leukemia cell populations without impairing their normal counterparts. Moreover, molecular studies showed that E35 remarkably downregulated drug-resistant gene and dramatically inhibited the Akt/mammalian target of rapamycin signaling pathway. Notably, the in vivo anti-LSC activity of E35 was further confirmed in murine xenotransplantation models. Collectively, these findings indicate E35 constitutes a novel therapeutic candidate for AL, potentially targeting leukemia stem and progenitor cells. 相似文献
Glycerol stabilizes the triple-helical structure of solubilized calf skin collagen. The equilibrium melting temperature of the protein increased linearly from 38.0 degrees C in AS buffer (0.01 M NaOAc and 0.02 M NaCl, pH 4.0) to 43.0 degrees C in AS and 6 M glycerol buffer. To understand the thermodynamic basis of this effect on the equilibrium melting temperature and the glycerol inhibition of collagen self-association, the preferential interactions of native and denatured calf skin collagens in AS buffer containing 1.5, 3, and 4.5 M glycerol were measured with a precision densimeter. The results indicated that native collagen binds glycerol preferentially whereas denatured collagen neither binds nor repels glycerol. The preferential binding of glycerol by native collagen, when interpreted in terms of the three-component solution thermodynamics, suggests that the surface interaction of native collagen with glycerol is energetically more favorable than its interaction with water. By use of the Wyman linked function, the negative chemical potential change of collagen derived from its preferential binding of glycerol can account for both the glycerol stabilization of the triple-helical structure of collagen and the inhibition of in vitro self-association of monomers into fibrils. 相似文献
Recently cloned leukotactin-1 (Lkn-1) that belongs to CC chemokine family has not been characterized. To understand the intracellular events following Lkn-1 binding to CCR1, we investigated the activities of signaling molecules in response to Lkn-1 in human osteogenic sarcoma cells expressing CCR1. Lkn-1-stimulated cells showed elevated phosphorylation of extracellular signal-related kinases (ERK1/2) with a distinct time course. ERK activation was peaked in 30 min and 12 h showing biphasic activation of ERK. Pertussis toxin, an inhibitor of G(i)/G(o) protein, and phospholipase C (PLC) inhibitor blocked Lkn-1-induced activation of ERK. Protein kinase C delta (PKC delta) specific inhibitor rottlerin inhibited ERK activation in Lkn-1-stimulated cells. The activities of PLC and PKC delta were also enhanced by Lkn-1 stimulation. Dominant negative Ras inhibited activation of ERK. Immediate early response genes such as c-fos and c-myc were induced by Lkn-1 stimulation. Lkn-1 affected the cell cycle progression by cyclin D(3) induction. These results suggest that Lkn-1 activates the ERK pathway by transducing the signal through G(i)/G(o) protein, PLC, PKC delta and Ras, and it may play a role for cell proliferation, differentiation, and regulation of gene expression for other cellular processes. 相似文献