BMC Biotechnology最新文献

Background: Melia azedarach is known as a medicinal plant that has wide biological activities such as analgesic, antibacterial, and antifungal effects and is used to treat a wide range of diseases such as diarrhea, malaria, and various skin diseases. However, optimizing the extraction of valuable secondary metabolites of M. azedarach using alternative extraction methods has not been investigated. This research aims to develop an effective, fast, and environmentally friendly extraction method using Ultrasound-assisted extraction, methanol and temperature to optimize the extraction of two secondary metabolites, lupeol and stigmasterol, from young roots of M. azedarach using the response surface methodology.

Methods: Box-behnken design was applied to optimize different factors (solvent, temperature, and ultrasonication time). The amounts of lupeol and stigmasterol in the root of M. azedarach were detected by the HPLC-DAD. The required time for the analysis of each sample by the HPLC-DAD system was considered to be 8 min.

Results: The results indicated that the highest amount of lupeol (7.82 mg/g DW) and stigmasterol (6.76 mg/g DW) was obtained using 50% methanol at 45 °C and ultrasonication for 30 min, and 50% methanol in 35 °C, and ultrasonication for 30 min, respectively. Using the response surface methodology, the predicted conditions for lupeol and stigmasterol from root of M. azedarach were as follows; lupeol: 100% methanol, temperature 45 °C and ultrasonication time 40 min (14.540 mg/g DW) and stigmasterol 43.75% methanol, temperature 34.4 °C and ultrasonication time 25.3 min (5.832 mg/g DW).

Conclusions: The results showed that the amount of secondary metabolites lupeol and stigmasterol in the root of M. azedarach could be improved by optimizing the extraction process utilizing response surface methodology.

Background: This study compared the differences of microvesicles (MVs) and microvesicles-delivering Smad7 (Smad7-MVs) on macrophage M1 polarization and fibroblast differentiation in a model of Peyronie's disease (PD).

Methods: Overexpression of Smad7 in rat BMSCs was obtained by pCMV5-Smad7 transfection. MVs were collected from rat BMSCs using ultracentrifugation. In cells, 100 µg/mL of MVs or Smad7-MVs were used to treat the 100 ng/mL of lipopolysaccharide (LPS)-induced RAW264.7 cells or 10 ng/mL of recombinant transforming growth factor-β1 (TGF-β1)-induced fibroblasts. The pro-inflammatory cytokines and markers of M1 macrophages were measured in RAW264.7 cells, and the migration and markers of fibroblast differentiation were measured in fibroblasts. In rats, 50 µg of MVs or Smad7-MVs were used to treat the TGF-β1-induced animals. The pathology of tunica albuginea (TA), the markers of M1 macrophages and fibroblast differentiation in the TA were measured.

Results: The MVs or Smad7-MVs treatment suppressed the LPS-induced macrophage M1 polarization and TGF-β1-induced fibroblast differentiation. Moreover, the Smad7-MVs treatment decreased the fibroblast differentiation compared with the MVs treatment. In the TGF-β1-induced TA of rats, MVs or Smad7-MVs treatment ameliorated the TA fibrosis by suppressing the macrophage M1 polarization and fibroblast differentiation. There was no significance on the M1-polarized macrophages between the MVs treatment and the Smad7-MVs treatment. Meanwhile, the Smad7-MVs treatment had an edge in terms of suppressing the fibroblast differentiation in the TGF-β1-induced PD model compared with the MVs treatment.

Conclusions: This study demonstrated that Smad7-MVs treatment had advantages over MVs treatment in suppressing of fibroblast differentiation in a model of PD.

Background: As part of a publicly funded initiative to develop genetically engineered Brassicas (cabbage, cauliflower, and canola) expressing Bacillus thuringiensis Crystal (Cry)-encoded insecticidal (Bt) toxin for Indian and Australian farmers, we designed several constructs that drive high-level expression of modified Cry1B and Cry1C genes (referred to as Cry1B^M and Cry1C^M; with M indicating modified). The two main motivations for modifying the DNA sequences of these genes were to minimise any licensing cost associated with the commercial cultivation of transgenic crop plants expressing Cry^M genes, and to remove or alter sequences that might adversely affect their activity in plants.

Results: To assess the insecticidal efficacy of the Cry1B^M/Cry1C^M genes, constructs were introduced into the model Brassica Arabidopsis thaliana in which Cry1B^M/Cry1C^M expression was directed from either single (S4/S7) or double (S4S4/S7S7) subterranean clover stunt virus (SCSV) promoters. The resulting transgenic plants displayed a high-level of Cry1B^M/Cry1C^M expression. Protein accumulation for Cry1C^M ranged from 5.18 to 176.88 µg Cry1C^M/g dry weight of leaves. Contrary to previous work on stunt promoters, we found no correlation between the use of either single or double stunt promoters and the expression levels of Cry1B^M/Cry1C^M genes, with a similar range of Cry1C^M transcript abundance and protein content observed from both constructs. First instar Diamondback moth (Plutella xylostella) larvae fed on transgenic Arabidopsis leaves expressing the Cry1B^M/Cry1C^M genes showed 100% mortality, with a mean leaf damage score on a scale of zero to five of 0.125 for transgenic leaves and 4.2 for wild-type leaves.

Conclusions: Our work indicates that the modified Cry1 genes are suitable for the development of insect resistant GM crops. Except for the PAT gene in the USA, our assessment of the intellectual property landscape of components presents within the constructs described here suggest that they can be used without the need for further licensing. This has the capacity to significantly reduce the cost of developing and using these Cry1^M genes in GM crop plants in the future.

Background: Antibiotic-containing carrier systems are one option that offers the advantage of releasing active ingredients over a longer period of time. In vitro sustained drug release from a carrier system consisting of microporous β-TCP ceramic and alginate has been reported in previous works. Alginate dialdehyde (ADA) gelatin gel showed both better mechanical properties when loaded into a β-TCP ceramic and higher biodegradability than pure alginate.

Methods: Dual release of daptomycin and BMP-2 was measured on days 1, 2, 3, 6, 9, 14, 21, and 28 by HPLC and ELISA. After release, the microbial efficacy of the daptomycin was verified and the biocompatibility of the composite was tested in cell culture.

Results: Daptomycin and the model compound FITC protein A (n = 30) were released from the composite over 28 days. A Daptomycin release above the minimum inhibitory concentration (MIC) by day 9 and a burst release of 71.7 ± 5.9% were observed in the loaded ceramics. Low concentrations of BMP-2 were released from the loaded ceramics over 28 days.

Fusarium head blight (FHB) is a devastating fungal disease affecting different cereals, particularly wheat, and poses a serious threat to global wheat production. Chitinases and β-glucanases are two important proteins involved in lysing fungal cell walls by targeting essential macromolecular components, including chitin and β-glucan micro fibrils. In our experiment, a transgenic wheat (Triticum aestivum) was generated by introducing chitinase and glucanase genes using Biolistic technique and Recombinant pBI121 plasmid (pBI-ChiGlu (-)). This plasmid contained chitinase and glucanase genes as well as nptII gene as a selectable marker. The expression of chitinase and glucanase was individually controlled by CaMV35S promoter and Nos terminator. Immature embryo explants from five Iranian cultivars (Arta, Moghan, Sisun, Gascogen and A-Line) were excised from seeds and cultured on callus induction medium to generate embryonic calluses. Embryogenic calluses with light cream color and brittle texture were selected and bombarded using gold nanoparticles coated with the recombinant pBI-ChiGlu plasmid. Bombarded calluses initially were transferred to selective callus induction medium, and later, they were transfferd to selective regeneration medium. The selective agent was kanamycin at a concentration of 25 mg/l in both media. Among five studied cultivars, A-Line showed the highest transformation percentage (4.8%), followed by the Sisun, Gascogen and Arta in descending order. PCR and Southern blot analysis confirmed the integration of genes into the genome of wheat cultivars. Furthermore, in an in-vitro assay, the growth of Fusarium graminearum was significantly inhibited by using 200 μg of leaf protein extract from transgenic plants. According to our results, the transgenic plants (T₁) showed the resistance against Fusarium when were compared to the non-transgenic plants. All transgenic plants showed normal fertility and no abnormal response was observed in their growth and development.

Background: Signal peptide (SP) engineering has proven able to improve production of many proteins yet is a laborious process that still relies on trial and error. mRNA structure around the translational start site is important in translation initiation and has rarely been considered in this context, with recent improvements in in silico mRNA structure potentially rendering it a useful predictive tool for SP selection. Here we attempt to create a method to systematically screen candidate signal peptide sequences in silico based on both their nucleotide and amino acid sequences. Several recently released computational tools were used to predict signal peptide activity (SignalP), localization target (DeepLoc) and predicted mRNA structure (MXFold2). The method was tested with Bone Morphogenetic Protein 2 (BMP2), an osteogenic growth factor used clinically for bone regeneration. It was hoped more effective BMP2 SPs could improve BMP2-based gene therapies and reduce the cost of recombinant BMP2 production.

Results: Amino acid sequence analysis indicated 2,611 SPs from the TGF-β superfamily were predicted to function when attached to BMP2. mRNA structure prediction indicated structures at the translational start site were likely highly variable. The five sequences with the most accessible translational start sites, a codon optimized BMP2 SP variant and the well-established hIL2 SP sequence were taken forward to in vitro testing. The top five candidates showed non-significant improvements in BMP2 secretion in HEK293T cells. All showed reductions in secretion versus the native sequence in C2C12 cells, with several showing large and significant decreases. None of the tested sequences were able to increase alkaline phosphatase activity above background in C2C12s. The codon optimized control sequence and hIL2 SP showed reasonable activity in HEK293T but very poor activity in C2C12.

Conclusions: These results support the use of peptide sequence based in silico tools for basic predictions around signal peptide activity in a synthetic biology context. However, mRNA structure prediction requires improvement before it can produce reliable predictions for this application. The poor activity of the codon optimized BMP2 SP variant in C2C12 emphasizes the importance of codon choice, mRNA structure, and cellular context for SP activity.

Pasta assortments fortified with high quality foods are a modern nutritional trends. This study, explored the effects of fortification with linseed flour (LF) and linseed oil (LO) on durum wheat pasta characteristics. Wheat flour semolina was replaced with 5%, 10% and 15% of LF or 1%, 2.5% and 5% of LO. Control pasta CP (without LF or LO addition), LF-enriched pasta LFP 5%, LFP 10% and LFP 15% and LO-enriched pasta LOP 1%, LOP 2.5% and LOP 5% was compared for the proteins, fat and phenolic contents and fatty acids (FA) profile. Impact on lipid oxidation and sensory evaluation were also determined. Fortification of pasta with LF improved significantly (p < 0.05) the contents of protein, fat and phenolic compared to CP whereas the enrichment of pasta with LO resulted in a significant increase (p < 0.05) in the content of fat and a significant decrease in protein and phenolic contents. All the formulations decreased the saturated FA percent and increased the polyunsaturated FA percent with enhancement of omega-3 FA content. Antioxidant activity measured by FRAP and DPPH assays was improved after the fortification. For lipid oxidation, the replacement of semolina by LF or LO promoted an increase (p < 0.05) on TBARS values in level-dependent manner. Regarding sensory evaluation, the two types of fortification did not affect the taste; flavor and aroma of cooked pasta, but LOP 5% showed the highest score of the overall acceptability. The results recommended the possibility of producing pasta supplemented with LF or LO (even at a level of 15% and 5% respectively) as a functional food.

β-TCP ceramics are versatile bone substitute materials and show many interactions with cells of the monocyte-macrophage-lineage. The possibility of monocytes entering microporous β-TCP ceramics has however not yet been researched. In this study, we used a model approach to investigate whether monocytes might enter β-TCP, providing a possible explanation for the origin of CD68-positive osteoclast-like giant cells found in earlier works.We used flow chambers to unidirectionally load BC, PRP, or PPP into slice models of either 2 mm or 6 mm β-TCP. Immunofluorescence for CD68 and live/dead staining was performed after the loading process.Our results show that monocytes were present in a relevant number of PRP and BC slices representing the inside of our 2 mm slice model and also present on the actual inside of our 6 mm model. For PPP, monocytes were not found beyond the surface in either model.Our results indicate the possibility of a new and so far neglected constituent in β-TCP degradation, perhaps causing the process of ceramic degradation also starting from inside the ceramics as opposed to the current understanding. We also demonstrated flow chambers as a possible new in vitro model for interactions between blood and β-TCP.