Purslane (Portulaca oleracea L.) as a novel green-bioreactor for expression of human serum albumin (HSA) gene.

Transgenic plants showed high potential to become a valuable and safe source of bio-compounds that can be used as therapeutics without any require for pooled human blood products. Human serum albumin (HSA) is one of the best-selling pharmaceuticals in the world because it is utilized for treating several acute illnesses, including hypovolemia, burns, and hemorrhage. This work was aimed to investigate the production of recombinant HSA (rHSA) protein in a plant-based expression platform. For this, we used in-planta and tissue culture-based Agrobacterium-mediated transformation (TCBAT) procedures to insert HSA gene into purslane (Portulaca oleracea L.) genome. The purslane seeds and leaves were infected with A. tumefaciens strain LBA4404 containing the HSA gene on pBI121 plasmid, and then regenerated into transgenic plant on MS medium. The qRT-PCR, southern hybridization, western blotting, and ELISA analysis were accomplished to corroborate the insertion and expression of HSA gene in transgenic plantlets. The molecular asses indicated that HSA gene was successfully transferred and expressed in purslane plants using in-planta and TCBAT methods. The first attempt to express rHSA in purslane resulted in a low-level accumulation of the protein in the transgenic plant shoots. Therefore, we used a synthetic 5'UTR (synJ) to enhance HSA transcript stability and translation efficiency. The results suggested that the synJ caused pronounced enhancement of rHSA expression rate. The highest amount of rHSA protein was recorded in transgenic purslane generated by TCBAT method (33.92 ± 4.31 µg/g FW).

Modulatory effects of R10 fraction of garlic (Allium sativum L.) on hormonal levels, T cell polarization, and fertility-related genes in mice model of polycystic ovarian syndrome.

Polycystic ovary syndrome (PCOS) is an inflammatory endocrine-metabolic disorder related to reproductive system characterized by polycystic ovarian morphology, androgen excess, and chronic anovulation. Current treatments haven't been very successful in PCOS treatment and the problem still remains as a challenge. Therefore, new approaches should be applied to overcome the disease. Previous studies demonstrated immunomodulatory effects of R10 fraction of garlic in the treatment of inflammatory conditions such as cancer. Considering previous studies suggesting immunomodulatory therapy for PCOS, therapeutic effects of R10 fraction was evaluated in a mouse model of PCOS. To do so, PCOS was developed by intramuscular injection of estradiol valerate. Treatment with R10 fraction, isolated from garlic, was performed and the alterations in hormonal levels (estradiol, progesterone, and testosterone), T cell polarization markers (IFN-γ, IL-4, and IL-17), and expression of fertility-related genes (Gpx3 and Ptx3) were evaluated. The results showed that hormonal levels were elevated in PCOS model comparing to normal animals but were markedly modulated after treatment with R10 fraction. Moreover, a severe disturbance in T cell polarization with a significant reduction of fertility-related genes expression were detected in PCOS-induced ovaries. Treatment with R10 fraction also represented modulatory effects on T cell polarization by increasing IL-4 and decreasing IL-17 and IFN-γ levels. Accordingly, fertility-related genes were also modulated following treatment with R10 fraction in PCOS. Our study elucidated that R10 fraction of garlic possess immunomodulatory effects alleviating PCOS symptoms. This approach could be adjusted to give rise the optimum therapeutic results and considered as a candidate therapeutic approach for PCOS.

Correction to: Transient expression of human serum albumin (HSA) in tobacco leaves.

The article 'Transient expression of human serum albumin (HSA) in tobacco leaves' written by Behnam Sedaghati, Raheem Haddad, and Mojgan Bandehpour, was originally published online on 8th July 2020 with Open Access under a Creative Commons Attribution (CC BY) license 4.0. With the authors' decision to cancel Open Access the copyright of the article changed on 21st August 2020 to @Springer Nature B.V. 2020 with all rights reserved. The original article has been corrected.

Transient expression of human serum albumin (HSA) in tobacco leaves.

Today, recombinant human proteins make up a considerable part of FDA-approved biotechnological drugs. The selection of proper expression platform for manufacturing recombinant protein is a vital factor in achieving the optimal yield and quality of a biopharmaceutical in a timely fashion. This experiment was aimed to compare the transient expression level of human serum albumin gene in different tobacco genotype. For this, the Agrobacterium tumefaciens strains LB4404 and GV3101 harboring pBI121-HSA binary vector were infiltered in leaves of three tobacco genotypes, including Nicotiana benthamiana and N. tabacum cv Xanthi and Samsun. The qRT-PCR, SDS-PAGE, western blotting and ELISA analysis were performed to evaluate the expression of HSA gene in transgenic plantlets. Our results illustrated that the expression level of rHSA in tobacco leaves was highly dependent on Agrobacterium strains, plant genotypes and harvesting time. The highest production of recombinant HSA protein was obtained in Samsun leaves infected with A. tumefaciens strain GV3101 after 3 days of infiltration.

Fusion to elastin-like polypeptide increases production of bioactive human IFN-γ in tobacco.

The plant-based expression systems are now accredited as bioreactors for the high production of various biopharmaceuticals. However, low levels of agglomeration and the absence of effective procedures for purification of recombinant proteins have remained two essential obstacles in molecular farming. In this research, we have studied the production of human interferon gamma (hIFN-γ) in tobacco and analyzed the effects of elastin-like polypeptide (ELP) tag and subcellular localization on its accumulation. We report a remarkable enhancement of accumulation of the fusion proteins versus the corresponding unfused hIFN-γ proteins. Furthermore, the hIFN-γ (with and without ELP) accumulated to higher levels in the endoplasmic reticulum. The ELP fusion proteins were successfully recovered from total soluble protein with adding 2.75 M NaCl and three rounds of inverse transition cycling (ITC). The hIFN-γ was also separated from ELP with Enterokinase cleavage of the fusion protein and recovered by ITC. Inverse transition analysis indicated that the hIFN-γ-ELP variants aggregate above their inverse transition temperature and at high ionic strength. Investigation of glycosylation revealed that fused or unfused hIFN-γ proteins are N-glycosylated in different cellular locations. Moreover, N-glycosylation analysis and bioassay showed that fusion to ELP does not disturb glycosylation process and antiviral activity of hIFN-γ.

Production of bioactive human IFN-γ protein by agroinfiltration in tobacco.

In animals, interferon-γ (IFN-γ) is known as a cytokine involved in antiviral and anticancer activities with a higher biochemical activity in contrast to other IFNs. To produce recombinant human IFN-γ (hIFN-γ) protein in tobacco, factors influencing gene delivery were first evaluated for higher efficiency of transient expression by fluorometric measurement of GUS activity. Higher levels of transient expression were observed in leaves of Nicotiana tabacum cv. Samsun infiltrated with GV3101 strain (optical density equal to 1.0 at 600 nm) under treatment of 200 µM AS at 4 days post agroinfiltration (dpa). The Samsun cv. proved to be amenable with 1.4- and 1.5-fold higher levels of transient expression than Xanthi and N. benthamiana, respectively. In addition, the GV3101 remained the best strain for use in transient assays without any necrotic response in tobacco. The levels of transient hIFN-γ expression were also estimated in the Samsun cv. infiltrated with different Agrobacterium tumefaciens strains carrying various expression constructs. Higher levels of accumulation were obtained with targeting the hIFN-γ protein to endoplasmic reticulum (ER) or apoplastic space than those expressed into cytoplasm. Moreover, antiviral bioassay revealed that recombinant hIFN-γ protein produced in tobacco is biologically active and protects the Vero cells from infection generated by vesicular stomatitis virus (VSV).

Elastin-like polypeptide fusions for high-level expression and purification of human IFN-γ in Escherichia coli.

In this study, the ELP sequence was fused to human interferon-γ (hIFN-γ) and hIFN-γ-ELP fusion protein accumulated with high levels of yield and purity, compared with the corresponding unfused hIFN-γ protein. The hIFN-γ was exclusively produced in the form of insoluble inclusion bodies while the hIFN-γ was relatively soluble when expressed as an ELP fusion protein. The insoluble inclusion bodies were then solubilized under denaturing conditions, refolded in the presence of arginine and purified by single-step ion-exchange chromatography. The fusion to ELP signidficantly increased the accumulation of hIFN-γ by 10-fold with a stable expression on average of 46.85% of total soluble protein (TSP). Furthermore, three rounds of Inverse Transition Cycling (ITC) purification increased overall purity of the hIFN-γ-ELP to 98 ±â€¯5%. The recovery amount of the fusion protein found to be dependent on the NaCl concentration, with increase of NaCl concentration, a greater fraction of the hIFN-γ-ELP was aggregated. However, due to the presence of an aliphatic guest residue in ELP sequence, the high concentration of salt was necessary to trigger the inverse phase transition of hIFN-γ-ELP fusion protein. Moreover, recombinant hIFN-γ and hIFN-γ-ELP proteins purified from E. coli possessed a relatively similar bioactivity based on viral cytopathic assay.

In silico and in vivo analyses of the mutated human tissue plasminogen activator (mtPA) and the antithetical effects of P19 silencing suppressor on its expression in two Nicotiana species.

Human tissue-type plasminogen activator is one of the most important therapeutic proteins involved in the breakdown of blood clots following the stroke. A mutation was found at position 1541 bp (G514E) and the mutated form was cloned into the binary vector pTRAc-ERH. In silico analysis showed that this mutation might have no significant effect on the active site of the tissue plasminogen activator enzyme. Accordingly, zymography assay confirmed the serine protease activity of the mutated form and its derivatives. The expression of the mutated form was verified with/without co-agroinjection of the P19 gene silencing suppressor in both Nicotiana tabacum and N. benthamiana. The ELISA results showed that the concentration of the mutated form in the absence of P19 was 0.65% and 0.74% of total soluble protein versus 0.141% and 1.36% in the presence of P19 in N. benthamiana and N. tabacum, respectively. In N. tabacum, co-agroinjection of P19 had the synergistic effect and increased the mutated tissue plasminogen activator production two-fold higher. However, in N. benthamiana, the presence of P19 had the adverse effect of five-fold reduction in the concentration. Moreover, results showed that the activity of the mutated form and its derivatives was more than that of the purified commercial tissue plasminogen activator.

Isolation and functional characterization of two thioredoxin h isoforms from grape.

Thioredoxins (Trxs) are small ubiquitous proteins that participate in dithiol-disulfide exchange reactions. In contrast to animals and prokaryotes, plants possess different types of Trxs that play a vital role in a number of different cellular processes. Two full-length cDNAs encoding different Trx h isoforms, designated VvTrx h2 and VvTrx h3, were isolated and cloned from grape (Vitis vinifera L. cv. Askari) berry tissue by rapid amplification of cDNA ends (RACE) method. VvTrx h2 and VvTrx h3 were heterologously expressed in Escherichia coli and their activities were compared using DTT-dependent insulin reduction and 5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB) reduction activities. The NADPH-dependent DTNB reduction assay demonstrated that the both VvTrx h isoforms were reduced by NADPH-dependent thioredoxin reductase (NTR) from E. coli. Under heat shock treatment, the recombinant VvTrx h proteins formed the oligomeric structures at above 50 °C with a decrease in their disulfide reductase activities. The redox-dependent structural changes of VvTrx h2 and VvTrx h3 revealed that their oligomeric structures were changed into monomers and significantly increased their disulfide reductase activities. Furthermore, the both recombinant proteins were able to conserve a DTNB reduction activity even after 15 min heating at 99 °C.

Phytoplanktons and DNA barcoding: Characterization and molecular analysis of phytoplanktons on the Persian Gulf.

BACKGROUND AND OBJECTIVES: Phytoplanktons are organisms with a very high diversities and global distribution in different habitats. The high distribution of phytoplankton is due to ecological flexibility and their ability to tolerate different climatic conditions and environmental stress. Phytoplankton is the most sensitive biological indicators of water resources. The purpose of this study was to identify the phytoplankton species with emphasis on DNA bar-coding method. The study of phytoplankton variation and the identification of their species composition can provide useful information about the water quality. MATERIALS AND METHODS: In this research project, a clone library of the ribosomal small subunit RNA gene (18S rDNA) in the nuclear genome was constructed by PCR using A and SSU-inR1 primers, and then, after examining the clones, selected clones were sequenced. RESULTS: Eleven analyzed sequences were identified correctly and characterized by a similarity search of the GenBank database using BLAST (NCBI). In this study, we revealed a wide range of taxonomic groups in the Alveolata (Ciliphora and Dinophyceae), Stramenopiles (Bacillariophyta and Bicosoecida), Rhodophyta and Haptophyceae. Moreover, we found species of fungi and Metazoa (Arthropoda). Most of the sequences were previously unknown but could still be assigned to important marine phyla. CONCLUSION: Clone library of 18S rDNA is an accurate method to identify marine specimens and it is recommended as an efficient method for phylogenic studies in marine environments. There seems to be a high diversity and abundance of small eukaryotes in the marine regions of Persian Gulf.

Identification of Chlorophyceae based on 18S rDNA sequences from Persian Gulf.

BACKGROUND AND OBJECTIVES: Chlorophyceae are important constituents of marine phytoplankton. The taxonomy of Chlorophyceae was traditionally based solely on morphological characteristics. In the present research project, genetic diversity was investigated to analyze five species of Chlorophyceae from waters of the Persian Gulf. MATERIALS AND METHODS: A clone library of the ribosomal small subunit RNA gene (18S rDNA) in the nuclear genome was constructed by PCR, and then, after examining the clones, selected clones were sequenced. The determined clone sequences were analyzed by a similarity search of the NCBI GenBank database using BLAST. RESULTS AND CONCLUSION: Eleven sequences were identified correctly and used for phylogenetic analysis. We identified species of Chlorophyta (Chlorella sorokiniana, Chlamydomonas sp., Neochloris aquatic, Picochlorum sp. and Nannochloris atomus) without the need to conduct extensive colony isolation techniques. Therefore, this improved molecular method can be used to generate a robust database describing the species diversity of environmental samples.

Cloning, identification and expression analysis of ACC oxidase gene involved in ethylene production pathway.

1-aminocyclopropane-1-carboxylic acid oxidase (ACO) enzyme is a member of the Fe II-dependent family of oxidases/oxygenases which require Fe(2+) as a cofactor, ascorbate as a cosubstrate and CO(2) as an activator. This enzyme catalyses the terminal step in the plant signaling of ethylene biosynthetic pathway. A 948 bp fragment of the ACO1 gene cDNA sequence was cloned from tomato (Lycopersicon esculentum) fruit tissues by using reverse transcriptase-polymerase chain reaction (RT-PCR) with two PCR primers designed according to the sequence of a tomato cDNA clone (X58273). The BLAST search showed a high level of similarity (77-98 %) between ACO1 and ACO genes of other plants. The calculated molecular mass and predicted isoelectric point of LeACO1 were 35.8 kDa and 5.13, respectively. The three-dimensional structure studies illustrated that the LeACO1 protein folds into a compact jelly-roll motif comprised of 8 α-helices, 12 ß-strands and several long loops. The cosubstrate was located in a cofactor-binding pocket referred to as a 2-His-1-carboxylate facial triad. Semi-quantitative RT-PCR analysis of gene expression revealed that the LeACO1 was expressed in fruit tissues at different ripening stages.

Isolation, identification and sequence analysis of a thioredoxin h gene, a member of subgroup III of h-type Trxs from grape (Vitis vinifera L. cv. Askari).

Thioredoxins (Trxs) are small ubiquitous proteins which play a regulatory role in a variety of cellular processes. In contrast to other organisms, plants have a great number of Trx types, consisting of six well-defined groups: f, m, x, and y in chloroplasts, o in mitochondria, and h mainly in cytosol. A full-length cDNA, designated VvCxxS2, encoding Trx h polypeptide was isolated and cloned from grape (Vitis vinifera L. cv. Askari) berries organ by reverse transcription polymerase chain reaction (RT-PCR). The cDNA was 381 bp nucleotides in length with a deduced amino acid of 126 residues, possessing a WCIPS active site, which belongs to the subgroup III of h-type Trxs based on phylogenetic analysis. The calculated molecular mass and the predicted isoelectric point of the deduced polypeptide are 14.25 kDa and 4.68, respectively. Nucleotide sequence analysis of genomic DNA fragment of VvCxxS2 gene revealed that this gene possesses two introns at positions identical to the previously sequenced Trx h genes. A modeling analysis indicated that VvCxxS2 shares a common structure with other Trxs, and is preferably reduced by Grx rather than NADPH-dependent thioredoxin reductase (NTR). The deduced protein sequence showed a high similarity to Trx h from other plants, in particular from castor bean (Ricinus communis), Betula pendula and sweet orange (Citrus sinensis). Semiquantitative RT-PCR experiments indicated that the transcripts of VvCxxS2 gene are present in all plant organs and different developmental stages. In addition, the higher expression of the VvCxxS2 gene was observed in berry organ as compared to the other organs.

Rapid and efficient isolation of high quality nucleic acids from plant tissues rich in polyphenols and polysaccharides.

Isolation of high quality nucleic acids from plant tissues rich in polysaccharides and polyphenols is often difficult. The presence of these substances can affect the quality and/or quantity of the nucleic acids isolated. Here, we describe a rapid and efficient nucleic acids extraction protocol that in contrast to other methods tested, effectively purify high quality nucleic acids from plant tissues rich in polysaccharides and polyphenolic compounds such as different grape tissues and fruit tissue of fruit trees. The nucleic acids isolated with this protocol were successfully used for many functional genomic based experiments including polymerase chain reaction, reverse transcription polymerase chain reaction (RT-PCR), cloning, and semiquantitative RT-PCR.

In vitro propagation of Lilium longiflorum var. ceb-dazzle through direct somatic embryogenesis.

Experiments were carried out to investigate the effects of various concentrations of Picloram (0, 1, 2, 3, 6 and 9 mg L(-1)), TDZ (0, 0.5, 1, 1.5 and 2 mg L(-1)), NAA (1.5 mg L(-1)) in combination with TDZ (0.08, 0.2 and 0.4 mg L(-1)), 2,4-D (2.5, 5 and 10 mg L(-1)) combined with BAP (0.25 mg L(-1)) and different types of explants (basal, central and distal part of the bulb scale) on direct somatic embryogenesis induction of Lilium longiflorum var. Ceb-Dazzle. The explants were surface sterilized and cultured on MS medium supplemented with 3% sucrose, 0.3% Phytagel and various concentrations of mentioned growth regulators. It was found that Picloram at a concentration of 2 mg L-' was the most effective treatment for induction of direct somatic embryogenesis and gave the highest number of embryos (18.6) on each explant. The explants from basal part of the bulb scale showed the best responses (19.9 embryos/explant). TDZ alone or combined with NAA in various concentrations was not able to induce somatic embryogenesis, but gave direct bulblet regeneration. Similar results were obtained for 2, 4-D and BAP combination treatments. Induced somatic embryos were transferred to MS medium without growth regulators for maturation and matured plantlets were successfully acclimatized and transferred to in vivo conditions.