WALL-ASSOCIATED KINASE Like 14 regulates vascular tissue development in Arabidopsis and tomato

Initiation of plant vascular tissue is regulated by transcriptional networks during development and in response to environmental stimuli. The WALL-ASSOCIATED KINASES (WAKs) and WAK-likes (WAKLs) are cell surface receptors involved in cell expansion and defence in cells with primary walls, yet their roles in regulation of vascular tissue development that contain secondary walls remains unclear. In this study, we showed tomato (Solanum lycopersicum) SlWAKL2 and the orthologous gene in Arabidopsis thaliana, AtWAKL14, were specifically expressed in vascular tissues. SlWAKL2-RNAi tomato plants displayed smaller fruit size with fewer seeds and vascular bundles compared to wild-type (WT) and over-expression (OE) lines. RNA-seq data showed that SlWAKL2-RNAi fruits down-regulated transcript levels of genes related to vascular tissue development compared to WT. Histological analysis showed T-DNA insertion mutant wakl14-1 had reduced plant stem length with fewer number of xylem vessels and interfascicular fibres compared to WT, with no significant differences in cellulose and lignin content. Mutant wakl14-1 also showed reduced number of vascular bundles in fruit. A proWAKL14::mCherry-WAKL14 fusion protein was able to complement wakl14-1 phenotypes and showed mCherry-WAKL14 associated with the plasma membrane. In vitro binding assays showed both SlWAKL2 and AtWAKL14 can interact with pectin and oligogalacturonides. Our results reveal novel roles of WAKLs in regulating vascular tissue development.

Techno-functional properties of active film based on guar gum-propolis and its application for "Nanguo" pears preservation

Guar gum (GG) composite films, incorporating the ethanolic extract of propolis (EEP), were prepared and subjected to a comprehensive investigation of their functional characteristics. The addition of EEP resulted in a discernible enhancement in the opacity, moisture barrier capacity, and elongation at break. Incorporating EEP led to a noteworthy increase in the total phenolic and total flavonoid content of the films, resulting in superior antioxidant capacity upon GG-EEP films. Remarkably, the addition of 5 % EEP yielded noteworthy outcomes, manifesting in a DPPH radical scavenging rate of 47.60 % and the ABTS radical scavenging rate of 94.87 %, as well as FRAP and cupric reducing power of 331.98 mmol FeSO4-7H2O kg-1 and 56.95 μg TE mg-1, respectively. In addition, GG-EEP films demonstrated antifungal effect against Penicillium expansum and Aspergillus niger, along with a sustained antibacterial effect against Escherichia coli and Staphylococcus aureus. GG-EEP films had superior inhibitory ability against Gram-positive bacteria than Gram-negative bacteria. Crucially, GG-EEP composite films played a pivotal role in reducing both lesion diameter and depth, concurrently mitigating weight loss and firmness decline during the storage period of "Nanguo" pears. Therefore, GG-EEP composite films have the considerable potential to serve as advanced and effective active packaging materials for food preservation.

Dicer-like2b suppresses the wiry leaf phenotype in tomato induced by tobacco mosaic virus

Dicer-like (DCL) proteins are principal components of RNA silencing, a major defense mechanism against plant virus infections. However, their functions in suppressing virus-induced disease phenotypes remain largely unknown. Here, we identified a role for tomato (Solanum lycopersicum) DCL2b in regulating the wiry leaf phenotype during defense against tobacco mosaic virus (TMV). Knocking out SlyDCL2b promoted TMV accumulation in the leaf primordium, resulting in a wiry phenotype in distal leaves. Biochemical and bioinformatics analyses showed that 22-nt virus-derived small interfering RNAs (vsiRNAs) accumulated less abundantly in slydcl2b mutants than in wild-type plants, suggesting that SlyDCL2b-dependent 22-nt vsiRNAs are required to exclude virus from leaf primordia. Moreover, the wiry leaf phenotype was accompanied by upregulation of Auxin Response Factors (ARFs), resulting from a reduction in trans-acting siRNAs targeting ARFs (tasiARFs) in TMV-infected slydcl2b mutants. Loss of tasiARF production in the slydcl2b mutant was in turn caused by inhibition of miRNA390b function. Importantly, silencing SlyARF3 and SlyARF4 largely restored the wiry phenotype in TMV-infected slydcl2b mutants. Our work exemplifies the complex relationship between RNA viruses and the endogenous RNA silencing machinery, whereby SlyDCL2b protects the normal development of newly emerging organs by excluding virus from these regions and thus maintaining developmental silencing.

The axial and sagittal CT values of the 7th thoracic vertebrae in screening for osteoporosis and osteopenia

AIM

To evaluate the difference in computed tomography (CT) attenuation value of different planes of the 7th thoracic vertebra and investigate the efficacy of axial and sagittal vertebral CT measurements in predicting osteoporosis.

MATERIALS AND METHODS

Patients who underwent routine chest CT and dual-energy X-ray absorptiometry (DXA) within 1 month were included in this retrospective study. The CT attenuation values of different planes were compared. Logistic regression and receiver operating characteristic (ROC) were used to analyse the difference of each plane in the diagnosis of osteoporosis.

RESULTS

The study included 1,338 patients (mean age of 61.9±11.9; 54% female). The CT attenuation values decreased successively in the normal group, osteopenia group, and osteoporosis group. The paired t-test results showed that the mid-axial measurements were greater than mid-sagittal measurements, with a mean difference of 9 HU, the difference was statistically significant (p<0.001, 95% confidence interval [CI] = 7.8-10.1). For each one-unit reduction in mid-sagittal CT attenuation value, the risk of osteopenia or osteoporosis increased by 3.6%. To distinguish osteoporosis from non-osteoporosis (osteopenia + normal), the sensitivity was 90% and the specificity was 52.4% at the mid-sagittal threshold of 113.7 HU.

CONCLUSIONS

The CT attenuation values of mid-sagittal plane have higher diagnostic efficacy than axial planes in predicting osteoporosis. For patients with a sagittal CT attenuation value of <113.7 HU in the T7, further DXA examination is warranted.

Comparative transcriptomic analysis provides novel insights into the difference in textural alteration between mealy and crisp apple patterns

Mealiness is a common textural deterioration of several fruit after harvest. To unravel the underlying mechanism involved in mealiness, biochemical characterization and global transcriptomic profiling were comparatively performed between mealy 'Hongjiangjun' (HJJ) and crisp 'Fuji' apples. Sensory evaluation and SEM-based microstructure observation showed that HJJ apples appeared to be mealy in only 3 d at 23 ± 1 °C, while Fuji apples did not appear to be mealy even after 28 d of storage. Textural deterioration and ethylene burst occurred more sharply in HJJ apples than in Fuji apples during storage. The results obtained from the dimensional RNA-sequencing analysis showed that a much stronger upregulation of the transcription of genes encoding polygalacturonase (PG), pectin acetylesterase (PAE), pectinesterase (PE), β-galactosidase (GAL), α-l-arabinofuranase (AF), and expansin (EXP) was observed in the pair of mealy HJJ apples vs. harvest than in the pair of Fuji apples after 28 d vs. harvest. The gene expression of ethylene responsive factor (ERF) was found to be strongly upregulated in HJJ apples compared with Fuji apples, which may mediate the regulation of downstream genes encoding cell wall-modifying enzymes. Weighted gene co-expression network analysis showed that the transcription factors MdbHLH63 and MdERF-like, and a constructure gene of MdGAL had strong connectivity with mealiness. Validation by qRT-PCR further confirmed the main findings obtained by RNA-sequencing. The occurrence of apple mealiness involves altered expression patterns of cell wall-modifying enzymes as well as MdbHLH63 and MdERF-like, which are core genes regulating the mealiness process. The above findings provide global insight into the difference in textural alteration between mealy and crisp apple patterns.

Phytohormone ethylene mediates oligogalacturonic acid-induced growth inhibition in tomato etiolated seedlings

Plant growth and immunity are tightly interconnected. Oligogalacturonic acids (OGs) are pectic fragments and have been well investigated in plant immunity as a damage-associated molecular pattern. However, little is known regarding how OGs affect plant growth. Here, we reveal that OGs inhibit the growth of intact etiolated seedling by using the horticultural crop tomato as a model. This inhibitory effect is partially suppressed by the action of ethylene biosynthesis inhibitors, or the gene silencing of SlACS2, an essential rate-limiting enzyme for ethylene biosynthesis, suggesting that SlACS2-mediated ethylene production promotes OG-induced growth inhibition. Furthermore, OGs treatment elevates the SlACS2 protein phosphorylation, and its decrease by the kinase inhibitor K252a partially rescue OG-induced growth inhibition, indicating that SlACS2 phosphorylation involves in OG-induced growth inhibition. Moreover, the mitogen-activated protein kinase SlMPK3 could be activated by OGs treatment and can directly phosphorylate SlACS2 in vitro, and the bimolecular fluorescence complementation combining with the yeast two-hybrid assay shows that SlMPK3 interacts with SlACS2, indicating that SlMPK3 may participate in modulating the OG-induced SlACS2 phosphorylation and growth inhibition. Our results reveal a regulatory mechanism at both the transcriptional and post-transcriptional levels by which OGs inhibit the growth of intact plant seedlings.

SlRIP1b is a global organellar RNA editing factor, required for normal fruit development in tomato plants

RNA editing in plant organelles involves numerous C-U conversions, which often restore evolutionarily conserved codons and may generate new translation initiation and termination codons. These RNA maturation events rely on a subset of nuclear-encoded protein cofactors. Here, we provide evidence of the role of SlRIP1b on RNA editing of mitochondrial transcripts in tomato (Solanum lycopersicum) plants. SlRIP1b is a RIP/MORF protein that was originally identified as an interacting partner of the organellar editing factor SlORRM4. Mutants of SlRIP1b, obtained by CRISPR/Cas9 strategy, exhibited abnormal carpel development and grew into fruit with more locules. RNA-sequencing revealed that SlRIP1b affects the C-U editing of numerous mitochondrial pre-RNA transcripts and in particular altered RNA editing of various cytochrome c maturation (CCM)-related genes. The slrip1b mutants display increased H₂ O₂ and aberrant mitochondrial morphologies, which are associated with defects in cytochrome c biosynthesis and assembly of respiratory complex III. Taken together, our results indicate that SlRIP1b is a global editing factor that plays a key role in CCM and oxidative phosphorylation system biogenesis during fruit development in tomato plants. These data provide important insights into the molecular roles of organellar RNA editing factors during fruit development.

Glycine-rich RNA-binding cofactor RZ1AL is associated with tomato ripening and development

Tomato ripening is a complex and dynamic process coordinated by many regulatory elements, including plant hormones, transcription factors, and numerous ripening-related RNAs and proteins. Although recent studies have shown that some RNA-binding proteins are involved in the regulation of the ripening process, understanding of how RNA-binding proteins affect fruit ripening is still limited. Here, we report the analysis of a glycine-rich RNA-binding protein, RZ1A-Like (RZ1AL), which plays an important role in tomato ripening, especially fruit coloring. To analyze the functions of RZ1AL in fruit development and ripening, we generated knockout cr-rz1al mutant lines via the CRISPR/Cas9 gene-editing system. Knockout of RZ1AL reduced fruit lycopene content and weight in the cr-rz1al mutant plants. RZ1AL encodes a nucleus-localized protein that is associated with Cajal-related bodies. RNA-seq data demonstrated that the expression levels of genes that encode several key enzymes associated with carotenoid biosynthesis and metabolism were notably downregulated in cr-rz1al fruits. Proteomic analysis revealed that the levels of various ribosomal subunit proteins were reduced. This could affect the translation of ripening-related proteins such as ZDS. Collectively, our findings demonstrate that RZ1AL may participate in the regulation of carotenoid biosynthesis and metabolism and affect tomato development and fruit ripening.

SlRBP1 promotes translational efficiency via SleIF4A2 to maintain chloroplast function in tomato

Many glycine-rich RNA-binding proteins (GR-RBPs) have critical functions in RNA processing and metabolism. Here, we describe a role for the tomato (Solanum lycopersicum) GR-RBP SlRBP1 in regulating mRNA translation. We found that SlRBP1 knockdown mutants (slrbp1) displayed reduced accumulation of total chlorophyll and impaired chloroplast ultrastructure. These phenotypes were accompanied by deregulation of the levels of numerous key transcripts associated with chloroplast functions in slrbp1. Furthermore, native RNA immunoprecipitation-sequencing (nRIP-seq) recovered 61 SlRBP1-associated RNAs, most of which are involved in photosynthesis. SlRBP1 binding to selected target RNAs was validated by nRIP-qPCR. Intriguingly, the accumulation of proteins encoded by SlRBP1-bound transcripts, but not the mRNAs themselves, was reduced in slrbp1 mutants. Polysome profiling followed by RT-qPCR assays indicated that the polysome occupancy of target RNAs was lower in slrbp1 plants than in wild-type. Furthermore, SlRBP1 interacted with the eukaryotic translation initiation factor SleIF4A2. Silencing of SlRBP1 significantly reduced SleIF4A2 binding to SlRBP1-target RNAs. Taking these observations together, we propose that SlRBP1 binds to and channels RNAs onto the SleIF4A2 translation initiation complex and promotes the translation of its target RNAs to regulate chloroplast functions.

Deciphering Precise Gene Transcriptional Expression Using gwINTACT in Tomato

Functional gene transcription mainly occurs in the nucleus and has a significant role in plant physiology. The isolation of nuclei tagged in specific cell type (INTACT) technique provides an efficient and stable nucleus purification method to investigate the dynamic changes of nuclear gene transcriptional expression. However, the application of traditional INTACT in plants is still limited to seedlings or root cells because of severe chloroplast pollution. In this study, we proposed a newly designed and simplified INTACT based on mas-enhanced GFP (eGFP)-SlWIP2 (gwINTACT) for nuclear purification in tomato (Solanum lycopersicum) leaves, flowers, and fruits for the first time. The yield of the nucleus purified using gwINTACT from transgenic tomato leaves was doubled compared with using a traditional INTACT procedure, accompanied by more than 95% removal of chloroplasts. Relative gene expression of ethylene-related genes with ethylene treatment was reevaluated in gwINTACT leaves to reveal more different results from the traditional gene expression assay based on total RNA. Therefore, establishing the gwINTACT system in this study facilitates the precise deciphering of the transcriptional status in various tomato tissues, which lays the foundation for the further experimental study of nucleus-related molecular regulation on fruit ripening, such as ChIP-seq and ATAC-seq.

A tomato receptor-like cytoplasmic kinase, SlZRK1, acts as a negative regulator in wound-induced jasmonic acid accumulation and insect resistance

Jasmonates accumulate rapidly and act as key regulators in response to mechanical wounding, but few studies have linked receptor-like cytoplasmic kinases (RLCKs) to wound-induced jasmonic acid (JA) signaling cascades. Here, we identified a novel wounding-induced RLCK-XII-2 subfamily member (SlZRK1) in tomato (Solanum lycopersicum) that was closely related to Arabidopsis HOPZ-ETI-DEFICIENT 1 (ZED1)-related kinases 1 based on phylogenetic analysis. SlZRK1 was targeted to the plasma membrane of tobacco mesophyll protoplasts as determined by transient co-expression with the plasma membrane marker mCherry-H+-ATPase. Catalytic residue sequence analysis and an in vitro kinase assay indicated that SlZRK1 may act as a pseudokinase. To further analyse the function of SlZRK1, we developed two stable knock-out mutants by CRISPR/Cas9. Loss of SlZRK1 significantly altered the expression of genes involved in JA biosynthesis, salicylic acid biosynthesis, and ethylene response. Furthermore, after mechanical wounding treatment, slzrk1 mutants increased transcription of early wound-inducible genes involved in JA biosynthesis and signaling. In addition, JA accumulation after wounding and plant resistance to herbivorous insects also were enhanced. Our findings expand plant regulatory networks in the wound-induced JA production by adding RLCKs as a new component in the wound signal transduction pathway.

Genome-Wide Identification, Classification, Characterization, and Expression Analysis of the Wall-Associated Kinase Family during Fruit Development and under Wound Stress in Tomato (Solanum lycopersicum L.)

The wall-associated kinase (WAK) and wall-associated kinase like (WAKL) is a subfamily of receptor-like kinases associated with the cell wall, which have been suggested as sensors of the extracellular environment and triggers of intracellular signals. However, these proteins have not yet been comprehensively analyzed in tomato (Solanum lycopersicum L.). In this study, 11 SlWAK and 18 SlWAKL genes were identified in an uneven distribution in 9 of 12 chromosomes. GUB-WAK-bind (wall-associated receptor kinase galacturonan-binding) and epidermal growth factor (EGF) domains appear more often in SlWAK proteins. However, more SlWAKLs (wall-associated kinase like) have a WAK-assoc (wall-associated receptor kinase C-terminal) domain. Based on their phylogenetic relationships, 29 SlWAK-RLKs (wall associated kinase-receptor like kinases) were clustered into three distinct categories analogous to those in Arabidopsis thaliana. High similarities were found in conserved motifs of the genes within each group. Cis-elements in the promoter region of these 29 genes were found mainly in response to methyl jasmonate (MeJA), abscisic acid (ABA), salicylic acid (SA), anaerobic, light, wound, and MYB transcription factors. Public tomato genome RNA-seq data indicates that multiple SlWAK-RLKs showed different expression patterns under developmental and ripening stages of fruits, such as SlWAK4, SlWAKL11, SlWAKL9, SlWAKL15, SlWAKL14, and SlWAKL1, their RPKM (Reads Per Kilo bases per Million reads) value constantly increases during the fruit expansion period, and decreases as the fruit matures. In tomato leaves, our RNA-seq data showed that nine SlWAK-RLKs transcripts (SlWAK3, SlWAK4, SlWAK10,SlWAKL1, SlWAKL2, SlWAKL3, SlWAKL5, SlWAKL14, and SlWAKL18) were significantly induced (p < 0.001), and three transcripts (SlWAK2, SlWAK5, and SlWAKL15) were significantly inhibited (p < 0.001) under mechanical wounding. The qRT-PCR (Quantitative reverse transcription polymerase chain reaction) of SlWAKL1 and SlWAKL6 verify these results.

Molecular and functional diversity of organelle RNA editing mediated by RNA recognition motif-containing protein ORRM4 in tomato

Plant organellar RNA editing is a distinct type of post-transcriptional RNA modification that is critical for plant development. We showed previously that the RNA editing factor SlORRM4 is required for mitochondrial function and fruit ripening in tomato (Solanum lycopersicum). However, a comprehensive atlas of the RNA editing mediated by SlORRM4 is lacking. We observed that SlORRM4 is targeted to both chloroplasts and mitochondria, and its knockout results in pale-green leaves and delayed fruit ripening. Using high-throughput sequencing, we identified 12 chloroplast editing sites and 336 mitochondrial editing sites controlled by SlORRM4, accounting for 23% of chloroplast sites in leaves and 61% of mitochondrial sites in fruits, respectively. Analysis of native RNA immunoprecipitation sequencing revealed that SlORRM4 binds to 31 RNA targets; 19 of these targets contain SlORRM4-dependent editing sites. Large-scale analysis of putative SlORRM4-interacting proteins identified SlRIP1b, a RIP/MORF protein. Moreover, functional characterization demonstrated that SlRIP1b is involved in tomato fruit ripening. Our results indicate that SlORRM4 binds to RNA targets and interacts with SlRIP1b to broadly affect RNA editing in tomato organelles. These results provide insights into the molecular and functional diversity of RNA editing factors in higher plants.

Recombinant lactobacillin PlnK adjusts the gut microbiome distribution in broilers

1. The heterologous expression and biological function of the Lactobacillus bacteriocin plantaricin K (PlnK) remain largely unknown. 2. In this study, PlnK was efficiently expressed in competent E. coli BL21 (used in transformation and protein expression) after 12 h, at 37°C and in 0.4 mmol/l isopropyl β- d-1-thiogalactopyranoside (IPTG). 3. The inhibitory bacterial spectrum of recombinant PlnK was investigated and indicated that levels of PlnK above 0.10 mg/ml produced an obvious inhibitory effect on gram-positive bacteria and gram-negative bacteria in vitro. 4. The effects of PlnK on intestinal immune function and the gut microbiome distribution in broilers were studied. The results revealed that, after consuming 2.50 × 10^-3 mg/ml of PlnK in water for one week, at the phylum level, the abundance of Firmicutes was increased and the abundance of Bacleroidetes was decreased. At the family level, the abundance of Lachnospiraceae, Ruminococcaceae and Streptococcaceae were significantly improved, but the abundance of Bacteroidaceae was reduced. At the genus level, the abundances of Lachnoclostridium, Streptococcus and Ruminococcaceae-UCG-013, were significantly up-regulated, and the abundance of Bacteroides was down-regulated. 5. After oral liquid intake of PlnK for one week, levels of secretory immunoglobulin A (sIgA) in the duodenal mucus were not significantly increased, but the mRNA levels of TLR3, MDA5, IFN-α, IFN-β, IFITM3 and IFITM10 in the duodenum were significantly reduced. 6. This study demonstrated that the recombinant PlnK could adjust the intestinal microbiome distribution and downregulate the IFN pathway.

Association between caregivers' anxiety and depression symptoms and feeding difficulties of preschool children: A cross-sectional study in rural China

PURPOSE

To investigate the prevalence of feeding difficulties in preschool children and explore the association between caregivers' anxiety and depression symptoms and preschool children's feeding difficulties.

METHODS

This cross-sectional study was conducted between June 2017 and January 2018 in rural areas of Anhui province, China. A total of 2231 preschool children and their caregivers were interviewed. Feeding difficulties of preschool children were reported by caregivers using the adapted Identification and Management of Feeding Difficulties (IMFeD) tool. Anxiety and depression symptoms of caregivers were evaluated via the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS).

RESULTS

In total, 54.1% of preschool children were reported to have feeding difficulties by their caregivers. Among all children, when the caregivers had symptoms of anxiety or depression, the children had a higher risk of feeding difficulties. Specifically, for caregivers' anxiety symptoms, the odds ratios (ORs) of feeding difficulties in all children, left-behind children (LBC), and non-LBC were 1.91 (95% confidence interval [CI]: 1.42-2.57), 2.04 (95% CI: 1.34-3.09), and 1.86 (95% CI: 1.21-2.87), respectively; for caregivers' depression symptoms, the ORs of feeding difficulties in all children, LBC, and non-LBC were 1.86 (95% CI: 1.46-2.39), 1.76 (95% CI: 1.24-2.51), and 2.08 (95% CI: 1.45-2.97), respectively. In addition, when caregivers who were parents or grandparents had anxiety or depression symptoms, their children had a higher risk of feeding difficulties. Specifically, for parents and grandparents with anxiety symptoms, the ORs of feeding difficulties were 1.84 (95% CI: 1.14-2.98) and 2.17 (95% CI: 1.46-3.22), respectively; for parents and grandparents with depression symptoms, the ORs of feeding difficulties were 2.03 (95% CI: 1.40-2.95) and 1.93 (95% CI: 1.37-2.73), respectively.

CONCLUSION

Caregivers' anxiety or depression symptoms are positively associated with feeding difficulties in children.

Diversity and redundancy of the ripening regulatory networks revealed by the fruitENCODE and the new CRISPR/Cas9 CNR and NOR mutants

Tomato is considered as the genetic model for climacteric fruits, in which three major players control the fruit ripening process: ethylene, ripening transcription factors, and DNA methylation. The fruitENCODE project has now shown that there are multiple transcriptional circuits regulating fruit ripening in different species, and H3K27me3, instead of DNA methylation, plays a conserved role in restricting these ripening pathways. In addition, the function of the core tomato ripening transcription factors is now being questioned. We have employed CRISPR/Cas9 genome editing to mutate the SBP-CNR and NAC-NOR transcription factors, both of which are considered as master regulators in the current tomato ripening model. These plants only displayed delayed or partial non-ripening phenotypes, distinct from the original mutant plants, which categorically failed to ripen, suggesting that they might be gain-of-function mutants. Besides increased DNA methylation genome-wide, the original mutants also have hyper-H3K27me3 in ripening gene loci such as ACS2, RIN, and TDR4. It is most likely that multiple genetic and epigenetic factors have contributed to their strong non-ripening phenotypes. Hence, we propose that the field should move beyond these linear and two-dimensional models and embrace the fact that important biological processes such as ripening are often regulated by highly redundant network with inputs from multiple levels.

Delayed response to cold stress is characterized by successive metabolic shifts culminating in apple fruit peel necrosis

BACKGROUND

Superficial scald is a physiological disorder of apple fruit characterized by sunken, necrotic lesions appearing after prolonged cold storage, although initial injury occurs much earlier in the storage period. To determine the degree to which the transition to cell death is an active process and specific metabolism involved, untargeted metabolic and transcriptomic profiling was used to follow metabolism of peel tissue over 180 d of cold storage.

RESULTS

The metabolome and transcriptome of peel destined to develop scald began to diverge from peel where scald was controlled using antioxidant (diphenylamine; DPA) or rendered insensitive to ethylene using 1-methylcyclopropene (1-MCP) beginning between 30 and 60 days of storage. Overall metabolic and transcriptomic shifts, representing multiple pathways and processes, occurred alongside α-farnesene oxidation and, later, methanol production alongside symptom development.

CONCLUSIONS

Results indicate this form of peel necrosis is a product of an active metabolic transition involving multiple pathways triggered by chilling temperatures at cold storage inception rather than physical injury. Among multiple other pathways, enhanced methanol and methyl ester levels alongside upregulated pectin methylesterases are unique to peel that is developing scald symptoms similar to injury resulting from mechanical stress and herbivory in other plants.

Oligogalacturonic acids promote tomato fruit ripening through the regulation of 1-aminocyclopropane-1-carboxylic acid synthesis at the transcriptional and post-translational levels

BACKGROUND

Oligogalacturonic acids (OGs) are oligomers of alpha-1,4-linked galacturonosyl residues that are released from cell walls by the hydrolysis of polygalacturonic acids upon fruit ripening and under abiotic/biotic stress. OGs may induce ethylene production and fruit ripening, however, the mechanism(s) behind these processes is unknown.

RESULTS

Tomato cultivar 'Ailsa Craig' (AC) and mutant Neverripe, ripening inhibitor, non-ripening, and colorless non-ripening fruits were treated with OGs at different stages. Only AC fruits at mature green stage 1 showed an advanced ripening phenomenon, although transient ethylene production was detected in all of the tomato fruits. Ethylene synthesis genes LeACS2 and LeACO1 were rapidly up-regulated, and the phosphorylated LeACS2 protein was detected after OGs treatment. Protein kinase/phosphatase inhibitors significantly affected the ripening process induced by the OGs. As a potential receptor of OGs, LeWAKL2 was also up-regulated in their presence.

CONCLUSIONS

We demonstrated that OGs promoted tomato fruit ripening by inducing ethylene synthesis through the regulation of LeACS2 at transcriptional and post-translational levels.

Role of Glycol Chitosan-incorporated Ursolic Acid Nanoparticles in the Treatment of Osteosarcoma

Purpose: To investigate the effect of ursolic acid (UA)-incorporated glycol chitosan (GC) nanoparticles on inhibition of human osteosarcoma.Methods: U2OS and Saos-2 osteosarcoma cells were transfected with ursolic acid (UA) incorporated glycol chitosan (GC) nanoparticles. Ultraviolet (UV)  spectrophotometry was used to measure drug contents in nanoparticles at 365 nm with empty GC vehicles as blank. Bicinchoninic acid assay (BCA) method was employed to determine protein concentration. Identification of apoptosis and necrosis in osteosarcoma cells was performed by propidium iodide and FITC-annexin V reagents, respectively. FAC Scan flow cytometry was used to analyse apoptotic cells.Results: Among the range of UA concentrations tested, the minimum effective concentration was 10 μM with half inhibitory concentration IC50 of 25 μM. In U2OS cells, treatment with 10 and 25 μM UAinduced apoptosis in 5.89 ± 3.90 and 60.54 ± 5.40 % cells, respectively, compared to 2.05 ± 1.01 % cells for control. In Saos-2 cells, exposure to 10 and 25 μM UA induced apoptosis in 9.86 ± 8.89 and 47.54 ± 14.5 % cells, respectively, compared to 1.79 ± 0.23 % for control cells. Western blot analysis revealed  translocation of Bax and Bcl-2 proteins from mitochondria to cell cytosol. Increase in UA concentration  from 10 μM to 25 μM led to increase in the proportion of cells in G0/G1 phase and decrease in the number of cells in S and G2/M phases. These results confirm that UA transfection arrests cell cycle in G0/G1 phase in human osteosarcoma cell lines.Conclusion: UA transfection resulted in the inhibition of cell proliferation, Ezh2 expression inhibition, and apoptosis via mitochondrial pathway due to decrease in membrane potential and release of cytochrome C, as well as cell cycle arrest in G0/G1 phase.Keywords: Osteosarcoma, Cell cycle arrest, Palliation, Glycol chitosan, Ursolic acid

SRNAome parsing yields insights into tomato fruit ripening control

Small RNAs have emerged as critical regulators in the expression and function of eukaryotic genomes at the post-transcriptional level. To elucidate the functions of microRNA (miRNAs) and endogenous small-interfering RNAs (siRNAs) in tomato fruit ripening process, the deep sequencing and bioinformatics methods were combined to parse the small RNAs landscape in three fruit-ripening stages (mature green, breaker and red-ripe) on a whole genome. Two species-specific miRNAs and two members of TAS3 family were identified, 590 putative phased small RNAs and 125 cis-natural antisense (nat-siRNAs) were also found in our results which enriched the tomato small RNAs repository and all of them showed differential expression patterns during fruit ripening. A large amount of the targets of the small RNAs were predicted to be involved in fruit ripening and ethylene pathway. Furthermore, the promoters of the conserved and novel miRNAs were found to contain the conserved motifs of TATA-box and CT microsatellites which were also found in Arabidopsis and rice, and several species-specific motifs were found in parallel.

Chitinase III in pomegranate seeds (Punica granatum Linn.): a high-capacity calcium-binding protein in amyloplasts

Chitinases are a class of ubiquitous proteins that are widely distributed in plants. Defense is the major natural role for chitinases, primarily against fungal pathogens. Little is known regarding their non-defensive roles in seeds. In this study, a new class III chitinase from pomegranate seeds (pomegranate seed chitinase, PSC) was isolated and purified to homogeneity. The native state of PSC is a monomer with a molecular weight of approximately 30 kDa. This chitinase naturally binds calcium ions with high capacity and low affinity, suggesting that PSC is a calcium storage protein. Consistent with this idea, its amino acid sequence (inferred from cDNA) is rich in acidic amino acid residues, especially Asp, similar to reported calcium storage proteins. The presence of calcium considerably improves the stability of the protein but has little effect on its enzymatic activity. Transmission electron microscopy analyses indicate that, similar to phytoferritin, this enzyme is widely distributed in the stroma of amyloplasts of the embryonic cells, suggesting that amyloplasts in seeds could serve as an alternative plastid for calcium storage. Indeed, the transmission electron microscopy results showed that, within the embryonic cells, calcium ions are mainly distributed in the stroma of the amyloplasts, consistent with a role for PSC in calcium storage. Thus, the plant appears to have evolved a new plastid for calcium storage in seeds. During seed germination, the content of this enzyme decreases with time, suggesting that it is involved in the germination process.

Soil quality indicators response to application of hydrophilic polymers to a soil from a sulfide mine

In soils impacted by mining activities a vegetal cover is required to protect the site from the erosive forces of water and wind. The success of this objective depends on plant establishment and canopy closure. Polyacryalate polymers aid the growth of crops and indigenous plants in soils from sulfide mines. Soil characteristics change as a consequence of polymer application, but indicators that pinpoint these changes have not been identified yet. Our objectives were to (1) identify the sensitive indicators of changes in soil quality following polymer application, (2) relate these with assessment based on plant growth and soil cover. A mine soil was left unamended or received a characterized polyacrylate, a polyacrylate removed from diapers, or shredded diapers. Biomass of Spergularia purpurea was measured and proportion of soil cover evaluated. Soil enzymes, microbial activity, and respiration were analyzed. Availability of potentially toxic trace elements was estimated by their concentration in shoots. Factor analysis identified three factors that accounted for 94% of the variation in parameters, and the scores separated the four treatments. The indicators with greatest communality were correlated with plant growth and soil cover. The best soil quality indicators were As and Zn in shoots, protease, β-glucosidase, and fructose-induced respiration. It seems that the most important indicators to be used to assess the restoration of sulfide mine soils are those related with bioavailability of trace elements and soil enzymatic activities.

Use of hydrophilic polymers from diapers to aid the establishment of Spergularia purpurea in a mine soil

We used hydrophilic polymers from diapers to aid the establishment of an indigenous plant (Spergularia purpurea (Persoon) G. Don fil.) in a soil from a pyrite mine. Lysimeters were filled with the mine soil with no amendment (control), with a polyacrylate polymer, with a polymer removed from diapers, and with shredded diapers. The establishment of a plant cover was faster in soil amended with polymer from diapers, and 85 days after sowing the soil was completely covered in all treatments except control. The concentrations of trace elements in plant shoots decreased in amended soil. The activities of soil acid phosphatase, beta-glucosidase, protease and cellulase were greatest in soil amended with the polyacrylate polymer or with polymer removed from diapers, while the application of shredded diapers leads to values that were in general intermediate between these treatments and unamended control. Basal- and substrate-induced respirations, and dehydrogenase were greatest in soil amended with polymers, but the presence of a plastic film and fibrous materials from shredded diapers prevented any improvement in these parameters compared with unamended soil. In the second experiment, we evaluated the risk of downward movement of polymers in columns of a sandy soil. Polymer from diapers, with or without Cu, was placed at a 10 cm-depth. Five leaching cycles with artificial rain took place and leachates were analyzed for organic matter and Cu. At the end of the experiment, the soil columns were sliced and each layer was analyzed separately. Some repacking of soil and polymer particles took place, but there was no indication that polymers moved to any great depth in soil columns.

Use of insoluble polyacrylate polymers to aid phytostabilization of mine soils: effects on plant growth and soil characteristics

We evaluated the use of polyacrylate polymers to aid phytostabilization of mine soils. In a pot experiment, perennial ryegrass was grown in a mine soil and in uncontaminated soil. Growth was stimulated in the polymer-amended mine soil compared with an unamended control, and water-extractable levels of soil Cu and Zn decreased after polymer application. In an experiment performed in six 60-cm-diameter cylinders filled with fertilized mine soil, polymers were applied to three cylinders, with the remainder used as unamended control. Total biomass produced by indigenous plant species sown in polymer-amended soil was 1.8 (Spring-Summer) or 2.4 times (Fall-Winter) greater than that of plants from unamended soil. The application of polymers to the mine soil led to the greatest activity of soil enzymes. Soil pH, biomass of Spergularia purpurea and Chaetopogon fasciculatus, and activities of protease and cellulase had large loadings on principal component (PC)1, whereas growth of Briza maxima and the activities of urease, acid phosphatase, and beta-glucosidase had large loadings on PC2. The treatments corresponding to controls were located on the negative side of PC1 and PC2. Amended treatments were on the positive side of PC2 (Spring-Summer) or on the positive side of PC1 (Fall-Winter), demonstrating differential responses of plants and soil parameters in the two growth cycles.

The osteogenic potential of pseudoarthrosis tissue and bone from human scaphoid non-unions

Scaphoid fractures have the highest prevalence of non-union in the human body, but little is known about the osteogenic potential of cells at the pseudoarthrosis. It was our goal to determine whether cells isolated from non-unions could be stimulated to differentiate into osteoblasts and produce bone in vitro. Fifteen human scaphoid non-unions were excised during surgery and bone from either side of the non-union and the fibrocartilagenous central regions were harvested. Osteoblastic populations were subcultured from these. The number of bone nodules (colonies of osteoblast cells that produced bone) from all three regions was similar to the number of nodules derived from iliac bone cultures from the same patients. Treatment of cells with rhBMP-2 resulted in a 3- to 10-fold increase in bone nodule formation in vitro from cells derived from the non-unions. These data demonstrate that cells at the pseudoarthrosis have osteogenic capability and can be stimulated by rhBMP-2, possibly increasing the ability to heal.

Structure-activity relationships of saponins from Gleditsia sinensis in cytotoxicity and induction of apoptosis

Thirteen compounds were isolated from the anomalous fruits of Gleditsia sinensis on the basis of bioassay-guided fractionation. These saponins together with six analogues or related compounds were tested for their cytotoxicities against six tumor cell lines by the MTT method. The induction of apoptosis in HL-60 cells by these compounds was determined through flow cytometric analysis. Some structure-activity relationships in cytotoxicity and induction of apoptosis were identified. The evaluation of the cytotoxicity and the ability to induce apoptosis revealed that some important structural features are required for activity. A valuable model which enables prediction of their activities was established and may be employed for the drug design of new Gleditsia saponin analogues.

Novel cytotoxic bufadienolides derived from bufalin by microbial hydroxylation and their structure-activity relationships

Microbial transformation was used to prepare novel cytotoxic bufadienolides. Twelve products (3-14) were obtained from bufalin (1) by the fungus Mucor spinosus. Their structures were elucidated by high-resolution mass spectroscopy (HR-MS) and extensive NMR techniques, including 1H NMR, 13C NMR, DEPT, 1H-1H correlation spectroscopy (COSY), two dimensional nuclear Overhauser effect correlation spectroscopy (NOESY), heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple bond coherence (HMBC). Compounds 3, 4, 9 and 11-14 are new mono- or dihydroxylated derivatives of bufalin with novel oxyfunctionalities at C-1beta, C-7beta, C-11beta, C-12beta and C-16alpha positions. The in vitro cytotoxic activities against human cancer cell lines of 3-14, together with 16 biotransformed products derived from cinobufagin (15-30) were determined by the MTT method, and their structure-activity relationships (SAR) were discussed.

Specific 12 beta-hydroxylation of cinobufagin by filamentous fungi

Biotransformation of natural products has great potential for producing new drugs and could provide in vitro models of mammalian metabolism. Microbial transformation of the cytotoxic steroid cinobufagin was investigated. Cinobufagin could be specifically hydroxylated at the 12 beta-position by the fungus Alternaria alternata. Six products from a scaled-up fermentation were obtained by silica gel column chromatography and reversed-phase liquid chromatography and were identified as 12 beta-hydroxyl cinobufagin, 12 beta-hydroxyl desacetylcinobufagin, 3-oxo-12 beta-hydroxyl cinobufagin, 3-oxo-12 beta-hydroxyl desacetylcinobufagin, 12-oxo-cinobufagin, and 3-oxo-12 alpha-hydroxyl cinobufagin. The last five products are new compounds. 12 beta-Hydroxylation of cinobufagin by A. alternata is a fast catalytic reaction and was complete within 8 h of growth with the substrate. This reaction was followed by dehydrogenation of the 3-hydroxyl group and then deacetylation at C-16. Hydroxylation at C-12 beta also was the first step in the metabolism of cinobufagin by a variety of fungal strains. In vitro cytotoxicity assays suggest that 12 beta-hydroxyl cinobufagin and 3-oxo-12 alpha-hydroxyl cinobufagin exhibit somewhat decreased but still significant cytotoxic activities. The 12 beta-hydroxylated bufadienolides produced by microbial transformation are difficult to obtain by chemical synthesis.

Cytotoxic biotransformed products from triptonide by Aspergillus niger

The diterpenoid triepoxides are the major active constituents of Tripterygium wilfordii with potent antitumor and immune activities. But the strong toxicity of these compounds has restricted their application to a great extent. In order to find more effective compounds with less toxicity, structural modifications of triptonide (1) by Aspergillus niger (AS 3.739) were investigated and four biotransformed products were obtained. Based on their chemical and spectral data, their structures were elucidated as 5alpha-hydroxytriptonide (2), triptolide (3), 17-hydroxytriptonide (4), and 16-hydroxytriptonide (5), among which 2, 4 and 5 are new compounds. All the three new transformed products showed cytotoxic activities against the majority of the human tumor cell lines tested, however, they are found to possess less cytotoxic activity when compared with 1. Both compounds 4 and 5 showed similar cytotoxic activity and their IC (50) values were 5-15 fold less than 1, while 2 is about 100 times less active than 1.

Scaling-up production of recombinant AAV vectors for clinical applications

Recombinant adeno-associated virus (AAV)-based vectors capable of expressing therapeutic gene products in vivo have shown significant promise for human gene therapy. A major challenge for these applications is the development of processes to enable production of large quantities of AAV vectors and purification of material that is well characterized and appropriate for parenteral administration. Several cell culture systems have been developed for AAV vector production, and a limited number of these demonstrate the potential to generate AAV vectors at concentrations compatible with cost-effective large-scale production. Vector purification protocols, in particular those based on the use of scalable column chromatography, have concurrently been developed that demonstrate the potential to provide highly purified AAV vector preparations with high yield. These advances support the potential for AAV vectors as therapeutic agents for gene therapy.

Purification of recombinant adeno-associated virus vectors by column chromatography and its performance in vivo

Recombinant adeno-associated virus (AAV) holds much promise for human gene therapy. While evidence indicates that AAV mediates long-term gene transfer in several different tissues, difficulty in preparing and purifying this viral vector in large quantities remains a major obstacle for evaluating AAV vectors in clinical trials. The current method of purification, based on sedimentation through cesium chloride, is not scaleable and yields product of insufficient quality. In this article we report a new technique for purifying AAV, using a fully closed two-column chromatography system. Yields of AAV vectors purified by this method are high, potency is increased, and the purity of column-purified preparations is substantially improved. We previously reported a novel method to generate AAV based on an AAV Rep/Cap-containing cell line (B50) and an Ad-AAV hybrid virus, which is amenable to scale-up in bioreactors. By combining the new, fully scaleable purification process we report here with the B50/hybrid production method, it would be feasible to prepare AAV vectors to the scale and purity required for clinical and potential commercial applications.

Vibrational spectroscopic studies on ion solvation of lithium perchlorate in propylene carbonate + N,N-dimethylformamide mixtures

The infrared (IR) and Raman spectra are reported for solutions of lithium perchlorate in propylene carbonate (PC), N,N-dimethylformamide (DMF) and PC + DMF mixtures. The band splittings of symmetric ring deformation for PC and O=CN deformation for DMF suggest that there is a strong interaction between lithium cations and solvent molecules. The solvent molecules have been assigned to two types, the free and complexed molecules. By a comparison of the intensity for the corresponding bands, it has been concluded that Li+ cations are preferentially solvated by DMF molecules in the LiClO4/PC-DMF solutions. This has been explained by the difference in values of donor number.

[Effect of nitrogen on water use efficiency of apple tree]

This paper studied the effect of nitrogen fertilizer on water use efficiency(WUE) and relevant parameters of two years old potted apple trees(Starkrimson/Malus hupenensis) under different soil moisture condition. The results showed that under adequate soil moisture, WUE was decreased with increasing application of nitrogen fertilizer. Nitrogen fertilizer application resulted in an increase of stomatal conductane. Consequently, the transpiration rate was increased more than photosynthetic rate did. Under soil drought, the WUE of plants applied with nitrogen fertilizer was apparently higher than that of control. The WUE value was in the order of high N > medium N > low N. The improvement of WUE was due to the increase of mesophyll capacity, which led to the promotion of photosynthesis.

Recombinant adeno-associated virus-mediated correction of lysosomal storage within the central nervous system of the adult mucopolysaccharidosis type VII mouse

The central nervous system (CNS) is a predominant site of involvement in several lysosomal storage diseases (LSDs); and for many patients, these diseases are diagnosed only after the onset of symptoms related to the progressive accumulation of macromolecules within lysosomes. The mucopolysaccharidosis type VII (MPS VII) mice are deficient for the lysosomal enzyme beta-glucuronidase and, by early adulthood, develop a significant degree of glycosaminoglycan storage within neuronal, glial, and leptomeningeal cells. Using this animal model, we investigated whether gene transfer mediated by a recombinant adeno-associated virus (rAAV) vector is capable of reversing the progression of storage lesions within the CNS. Adult MPS VII mice received intracerebral injections of 4 X 10(7) infectious units of a rAAV vector carrying the murine beta-glucuronidase (gus-s(a)) cDNA under the transcriptional direction of the cytomegalovirus immediate-early promoter and enhancer. By 1 month after vector administration, transgene-derived beta-glucuronidase was present surrounding the injection site. Enzyme levels were between 50 and 240% of that found in wild-type mice. This level of beta-glucuronidase activity was sufficient to reduce the degree of lysosomal storage. Moreover, the reduction in storage was maintained for at least 3 months post-rAAV administration. These data demonstrate that rAAV vectors can transduce the diseased CNS of MPS VII mice and mediate levels of transgene expression necessary for a therapeutic response. Thus, rAAV vectors are potential tools in the treatment of the mucopolysaccharidoses and other lysosomal storage diseases.

Gene transfer into the CNS using recombinant adeno-associated virus: analysis of vector DNA forms resulting in sustained expression

Recombinant adeno-associated virus (rAAV) vectors have shown significant promise as vehicles for in vivo gene transfer, particularly for transduction of organs composed primarily of non-dividing cells (i.e., muscle, CNS, and liver). However, the mechanistic basis for this desirable property remains unclear. To investigate the fate of rAAV genomes in mouse brain, we stereotactically injected an rAAV vector carrying the E. coli lacZ gene into the caudate of BALB/c mice and demonstrate efficient transduction of mouse brain cells that possess cellular morphology consistent with post-mitotic neurons. We observed a significant increase in beta-galactosidase expression from 5 to 56 days after injection that paralleled the disappearance of single-stranded DNA input genomes. Analysis of in vivo viral DNA forms over time out to 5 months after inoculation revealed that rAAV genomes associated with high molecular weight mouse chromosomal DNA by 14 days after injection and persisted for the length of this study. The pattern of Southern hybridization was consistent with random viral integration in predominantly head-to-tail concatameric arrays. Importantly, we also documented an additional DNA species that appears to be a monomeric episomal circular form based on nuclease sensitivity assays. These data are the first to document the existence of multiple vector DNA forms present within the adult murine brain following direct rAAV inoculation and therefore, provide insight into the molecular events that ultimately result in long-term rAAV mediated transgene expression.

Satellite DNA hypomethylation vs. overall genomic hypomethylation in ovarian epithelial tumors of different malignant potential

Rearrangements in heterochromatin in the vicinity of the centromeres of chromosomes 1 and 16 are frequent in many types of cancer, including ovarian epithelial carcinomas. Satellite 2 DNA is the main sequence in the unusually long heterochromatin region adjacent to the centromere of each of these chromosomes. Rearrangements in these regions and hypomethylation of satellite 2 DNA are a characteristic feature of patients with a rare recessive genetic disease, ICF (immunodeficiency, centromeric region instability, and facial anomalies). In all normal tissues of postnatal somatic origin, satellite 2 DNA is highly methylated. We examined satellite 2 DNA methylation in ovarian tumors of different malignant potential, namely, ovarian cystadenomas, low malignant potential (LMP) tumors, and epithelial carcinomas. Most of the carcinomas and LMP tumors exhibited hypomethylation in satellite 2 DNA of both chromosomes 1 and 16. A comparison of methylation of these sequences in the three types of ovarian neoplasms demonstrated that there was a statistically significant correlation between the extent of this satellite DNA hypomethylation and the degree of malignancy (P<0.01). Also, there was a statistically significant association (P<0.005) between genome-wide hypomethylation and undermethylation of satellite 2 DNA among these 17 tumors. In addition, we found abnormal hypomethylation of satellite alpha DNA in the centromere of chromosome 1 in many of these tumors. Our findings are consistent with the hypothesis that one of the ways that genome-wide hypomethylation facilitates tumor development is that it often includes satellite hypomethylation which might predispose cells to structural and numerical chromosomal aberrations. Several of the proteins that bind to pericentromeric heterochromatin are known to be sensitive to the methylation status of their target sequences and so could be among the sensors for detecting abnormal demethylation and mediating effects on chromosome structure and stability.

Adeno-associated virus-mediated gene transfer to the brain: duration and modulation of expression

Adeno-associated virus (AAV) is a promising vector for central nervous system (CNS) gene transfer, but a number of issues must be addressed if AAV is to be used for widespread delivery throughout the CNS. Our aim was to test the effect of dose, route of delivery, and hydroxyurea treatment on brain expression of beta-galactosidase activity after cerebral inoculation with an rAAV-lacZ vector (rAAV-beta-gal). We also wished to test whether an immune response appeared against the vector and the transgene product. We found in BALB/c mice that beta-Gal expression increased during the first 2 months after inoculation, then decreased slightly by 4 months, and continued out to 6, 12, and 15 months in single animals. Cerebral injection produced localized beta-Gal expression that did not diffuse to other regions despite a fivefold increase in injection volume. Intraventricular injection resulted in negligible transduction. Antibodies to AAV capsid protein and beta-Gal appeared at low levels at 2 and 4 months, but correlated poorly with beta-Gal expression and did not prevent readministration of rAAV-beta-gal. Hydroxyurea treatment did not result in increased transduction in vivo. We conclude that our study confirms rAAV vectors as having considerable potential for CNS gene transfer; however, several important problems must be addressed if this vector system is to be used for long-term transduction of the entire brain. Sustained, regulatable expression will be needed if rAAV is to be used in the treatment of chronic CNS disease. The difficulty in delivering AAV to diverse regions of the brain is an important problem that must be overcome if these vectors are to be used for anything beyond localized transduction.

[Relationship between urinary albumin excretion and blood vessel lesion in non-insulin-dependent diabetics]

To search the relationships between urinary albumin excretion and blood vessel lesion in non-insulin-dependent diabetics, we compared the differences of blood-lipid, blood pressure, coronary heart disease and retina disease between 58 patients. The group with microalbuminuria had significantly lower concentration of apolipoprotein A, and apolipoprotein A1/apolipoprotein B100 than that of the group with normal albuminuria, but there was no significant change in concentrations of trigly cerides, total cholesterol, high density lipoprotein, and apolipoprotein B100. Coronary heart disease and retina disease were significantly increased in group with microalbuminuria. There was negative correlation with apolipoprotein A1 and value of apolipoprotein A1/apolipoprotein B100, but positive correlation with systolic blood pressure by linear regression analysis for urinary albumin excretion.

High-titer adeno-associated viral vectors from a Rep/Cap cell line and hybrid shuttle virus

Adeno-associated virus (AAV) is a potential vector for in vivo gene therapy. A critical analysis of its utility has been hampered by methods of production that are inefficient, difficult to scale up, and that often generate substantial quantities of replication-competent AAV. We describe a novel method for producing AAV that addresses these problems. A cell line, called B50, was created by stably transfecting into HeLa cells a rep/cap-containing plasmid utilizing endogenous AAV promoters. Production of AAV occurs in a two-step process. B50 is infected with an adenovirus defective in E2b, to induce Rep and Cap expression and provide helper functions, followed by a hybrid virus in which the AAV vector is cloned in the E1 region of a replication-defective adenovirus. This results in a 100-fold amplification and rescue of the AAV genome, leading to a high yield of recombinant AAV that is free of replication-competent AAV. Intramuscular injection of vector encoding erythropoietin into skeletal muscle of mice resulted in supraphysiologic levels of hormone in serum that was sustained and caused polycythemia. This method of AAV production should be useful in scaling up for studies in large animals, including humans.

Separate and variably shaped chromosome arm domains are disclosed by chromosome arm painting in human cell nuclei

Fluorescence in situ hybridization (FISH) with microdissection probes from human chromosomes 3 and 6 was applied to visualize arm and subregional band domains in human amniotic fluid cell nuclei. Confocal laser scanning microscopy and quantitative three-dimensional image analysis showed a pronounced variability of p- and q-arm domain arrangements and shapes. Apparent intermingling of neighbouring arm domains was limited to the domain surface. Three-dimensional distance measurements with pter and qter probes supported a high variability of chromosome territory folding.

Actin isoform utilization during differentiation and remodeling of BC3H1 myogenic cells

Mouse BC3H1 myogenic cells and a bi-functional chemical cross linking reagent were utilized to investigate the polymerization of newly-synthesized vascular smooth muscle (alpha-actin) and non-muscle (beta- and gamma-actin) actin monomers into native F-actin filament structures during myogenesis. Two actin dimer species were identified by SDS-PAGE analysis of phenylenebismaleimide-cross linked fractions of BC3H1 myoblasts and myocytes. P-dimer was derived from the F-actin-enriched, detergent-insoluble cytoskeleton. Pulse-chase analysis revealed that D-dimer initially was associated with the cytoskeleton but then accumulated in the soluble fraction of lysed muscle cells that contained a non-filamentous or aggregated actin pool. Immunoblot analysis indicated that non-muscle and smooth muscle actins were capable of forming both types of dimer. However, induction of smooth muscle alpha-actin in developing myoblasts coincided with an increase in D-dimer level which may facilitate actin stress fiber assembly. Smooth muscle alpha-actin was rapidly utilized in differentiating myoblasts to assemble extraction-resistant F-actin filaments in the cytoskeleton whereas non-muscle beta- and gamma-actin filaments were more readily dissociated from the cytoskeleton by an extraction buffer containing ATP and EGTA. The data indicate that cytoarchitectural remodeling in developing BC3H1 myogenic cells is accompanied by selective actin isoform utilization that effectively segregates multiple isoactins into different sub-cellular domains and/or supramolecular entities.