Corrigendum: Genome-Wide Identification and Expression Profiling of Germin-Like Proteins Reveal Their Role in Regulating Abiotic Stress Response in Potato.

[This corrects the article DOI: 10.3389/fpls.2021.831140.].

Expression profiling of pathogenesis-related Protein-1 (PR-1) genes from Solanum tuberosum reveals its critical role in phytophthora infestans infection.

Pathogen-related (PR) proteins are an integral part of plants' defense mechanisms against various types of biotic and abiotic stresses. A little is known about the importance of these PR proteins in potato defense mechanisms. In the current study, a total of 22 pathogenesis-related 1 genes were identified in the potato genome. All identified proteins possessed the CAP superfamily domain with some other motifs. The cis-acting elements analysis identified several stress-responsive elements, including MYB, ABRE, and MeJRE. The gene duplication events demonstrated purifying and positive selection pressure. Expression profiling showed high transcripts level in root compared to other tissues; however, some genes have tissue-specific expression. Furthermore, the PR-1-5 gene is transcriptionally induced under Phytophthora infestans stress and hormonal (ABA and IAA) treatments. The Real-Time qPCR analysis also validated the RNA-seq data results of genes with maximum expression in roots compared to leaves and stems. The current study results provided basic data for functional characterization and can also use as a reference study for other important crops.

Intelligent photothermal dendritic cells restart the cancer immunity cycle through enhanced immunogenic cell death.

Dendritic cells (DCs) play a pivotal role in initiating antigen-specific tumor immunity. However, the abnormal function of DCs owing to the immunosuppressive tumor microenvironment (TME) and the insufficient number of tumor infiltrating DCs could promote immune tolerance and tumor immune escape. Thus, there is great potential to employ DCs to induce efficient antitumor immunity. In this paper, we developed intelligent DCs (iDCs), which consist of nanoparticles loaded with photothermal agents (IR-797) and coated with a mature DC membrane. The DC cell membrane on the surface of iDCs preserves the ability to present antigens and prime T cells. The iDCs can also enter the lymph node and stimulate T cells. The activated T cells reduced the expression of heat shock proteins (HSPs) in tumor cells, rendering them more sensitive to heat stress. Subsequently, we used mild photothermal therapy (42-45 °C) to induce immunogenic cell death and contribute to a synergistic antitumor effect. iDCs as a refined and precise system in combination with DC-based immunotherapy and thermal therapy can be stored long-term and on a large scale, so they can be applied in many patients.

Genome-Wide Identification and Expression Profiling of Germin-Like Proteins Reveal Their Role in Regulating Abiotic Stress Response in Potato.

Germin and germin-like proteins (GLPs) perform a significant role in plants against biotic and abiotic stress. To understand the role of GLPs in potato, a comprehensive genome-wide analysis was performed in the potato genome. This study identified a total of 70 StGLPs genes in the potato genome, distributed among 11 chromosomes. Phylogenetic analysis exhibited that StGLPs were categorized into six groups with high bootstrap values. StGLPs gene structure and motifs analysis showed a relatively well-maintained intron-exon and motif formation within the cognate group. Additionally, several cis-elements in the promoter regions of GLPs were hormones, and stress-responsive and different families of miRNAs target StGLPs. Gene duplication under selection pressure also exhibited positive and purifying selections in StGLPs. In our results, the StGLP5 gene showed the highest expression in response to salt stress among all expressed StGLPs. Totally 19 StGLPs genes were expressed in response to heat stress. Moreover, three genes, StGLP30, StGLP17, and StGLP14, exhibited a relatively higher expression level in the potato after heat treatment. In total, 22 genes expressed in response to abscisic acid (ABA) treatment indicated that ABA performed an essential role in the plant defense or tolerance mechanism to environmental stress. RNA-Seq data validated by RT-qPCR also confirm that the StGLP5 gene showed maximum expression among selected genes under salt stress. Concisely, our results provide a platform for further functional exploration of the StGLPs against salt and heat stress conditions.

Genome-Wide Identification and Expression Profiling of DUF221 Gene Family Provides New Insights Into Abiotic Stress Responses in Potato.

The domain of the unknown function 221 proteins regulate several processes in plants, including development, growth, hormone transduction mechanism, and abiotic stress response. Therefore, a comprehensive analysis of the potato genome was conducted to identify the deafness-dystonia peptide (DDP) proteins' role in potatoes. In the present study, we performed a genome-wide analysis of the potato domain of the unknown function 221 (DUF221) genes, including phylogenetic inferences, chromosomal locations, gene duplications, gene structures, and expression analysis. In our results, we identified 10 DDP genes in the potato genome. The phylogenetic analysis results indicated that StDDPs genes were distributed in all four clades, and clade IV was the largest clade. The gene duplication under selection pressure analysis indicated various positive and purifying selections in StDDP genes. The putative stu-miRNAs from different families targeting StDDPs were also predicted in the present study. Promoter regions of StDDP genes contain different cis-acting components involved in multiple stress responses, such as phytohormones and abiotic stress-responsive factors. The analysis of the tissue-specific expression profiling indicated the StDDPs gene expression in stem, root, and leaf tissues. We subsequently observed that StDDP4, StDDP5, and StDDP8 showed higher expressions in roots, stems, and leaves. StDDP5 exhibited high expression against heat stress response, and StDDP7 showed high transcript abundance against salt stress in potatoes. Under abscisic acid (ABA) and indole acetic acid (IAA) treatments, seven StDDP genes' expressions indicated that ABA and IAA performed important roles in immunity response. The expression profiling and real-time qPCR of stems, roots, and leaves revealed StDDPs' significant role in growth and development. These expression results of DDPs are primary functional analysis and present basic information for other economically important crops.

Small Peptide-Doxorubicin Co-Assembly for Synergistic Cancer Therapy.

Design of elaborated nanomaterials to improve the therapeutic efficacy and mitigate the side effects of chemotherapeutic anticancer drugs, such as Doxorubicin (Dox), is significant for cancer treatment. Here, we describe a co-assembled strategy, where amphiphile short peptides are co-assembled with Doxorubicin to form nanoscale particles for enhanced delivery of Dox. Two kinds of short peptides, Fmoc-FK (FK) and Fmoc-FKK (FKK), are synthesized. Through adjusting the component ratio of peptide and Dox, we obtain two kinds of co-assembled nanoparticles with homogeneous size distributions. These nanoparticles show several distinct characteristics. First, they are pH-responsive as they are stable in alkaline and neutral conditions, however, de-assembly at acidic pH enables selective Dox release in malignant cancer cells. Second, the nanoparticles show an average size of 50-100 nm with positive charges, making them effective for uptake by tumor cells. Moreover, the side effects of Dox on healthy cells are mitigated due to decreased exposure of free-Dox to normal cells. To conclude, the co-assembled peptide-Dox nanoparticles exhibit increased cellular uptake compared to free-Dox, therefore causing significant cancer cell death. Further apoptosis and cell cycle analysis indicates that there is a synergistic effect between the peptide and Doxorubicin.

Noninvasive monitoring of intracellular pH change induced by drug stimulation using silica nanoparticle sensors.

We have synthesized and applied a nanoparticle-based pH sensor for noninvasive monitoring of intracellular pH changes induced by drug stimulation. The pH sensor is a two-fluorophore-doped nanoparticle sensor (2DFNS) that contains a pH-sensitive indicator (fluorescein isothiocyanate, FITC) and a reference dye (tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate, RuBPY). The nanoparticles have an average diameter of 42 +/- 3 nm and can easily be taken up by cells for noninvasive intracellular pH measurement. The 2DFNS exhibited excellent pH sensitivity, reversibility, and a dynamic range of pH 4-7 for biological studies. We have used 2DFNS to monitor pH changes in living cells by drug stimulation. Both lysosomal pH changes in murine macrophages stimulated by chloroquine and intracellular acidification in apoptotic cancer cells were monitored in real time and with high pH sensitivity. Hela cells underwent intracellular acidification with a drop in pH from 7.2 to 6.5 after 8 h of treatment with 2 mumol/L dexamethasone, and this intracellular pH drop in the apoptotic cells was not influenced by the addition of zinc ions. The application of 2DFNS to intracellular pH measurements yields some important advantages: excellent pH sensitivity, little environmental effect on the pH dye, excellent quantification, high stability and excellent reversibility.

Identification of live liver cancer cells in a mixed cell system using galactose-conjugated fluorescent nanoparticles.

Bio-functioned fluorescent silica nanoparticles have been synthesized for cell labeling and cell differentiation and have shown great promise as novel fluorescent probes. The galactose-conjugated fluorescent nanoparticles (GCFNPs) have been obtained by the conjugation of amino-modified fluorescent silica nanoparticles with lactobionic acid (LA) through EDAC linkage. The GCFNPs retain excellent biological activity and can be used in bioanalysis as an immunofluorescence assay. The specific identification of target cells from the background cells have been directly demonstrated in a simple model system by a laser confocal scanning microscope, because the specific and non-specific labeling can simultaneously visualized in a given microscopic field of view. The flow cytometric analysis has proved that GCFNPs can effectively recognize target cells in the mixed cell system. The demonstration of precise identification of few liver cancer cells in the blood confirmed the excellent capability of GCFNPs in identifying specific cells in a large host cell background. The nanoparticle's excellent photostability, good biocompatibility and significant signal amplification make them well-suited for the identification of individual cells sensitively for a variety of biomedical studies such as cancer metastasis and stem cell progeny in vivo.

An antisense oligonucleotide carrier based on amino silica nanoparticles for antisense inhibition of cancer cells.

Antisense oligonucleotides (anti-ODNs), which are able to interfere with gene expression at the mRNA level, have potential activity in the treatment of viral infections or cancer. However, the application of therapies based on anti-ODNs is hampered by their instability to cellular nuclease and their weak intracellular penetration. Among the many efforts to increase their stability and cellular penetration have been modifications of ODNs and introduction of particulate carriers. Here we report an anti-ODNs carrier based on amino silica nanoparticles (NH(2)SiNPs) and its preliminary applications in cancer cells. The positively charged NH(2)SiNPs were synthesized by a water-in-oil microemulsion method. The NH(2)SiNP-ODN complexes were formed by electrostatic interaction, and their cellular uptake was visualized by using fluorescein isothiocyanate (FITC)-labeled ODNs and NH(2)SiNPs doped with rhodamine 6G isothiocyanate (RITC) as fluorescent signal indicators. The antisense inhibition efficiency of anti-ODNs delivered by NH(2)SiNPs was evaluated using MTT (3,4,5-dimethylthiazol-2,5-diphenyl tetrazolium bromide) assay and western blot analysis. Uniform NH(2)SiNPs with an average diameter of 25 nm were obtained and could combine with anti-ODNs to form a bioconjugate favorable for cellular uptake. The NH(2)SiNPs were able to protect anti-ODNs from degradation by DNase I. In vitro experiments showed that the NH(2)SiNPs could greatly improve the inhibition efficiency of anti-ODNs for the proliferation and survivin expression in Hela cells and A549 cells. Compared with liposomes, the NH(2)SiNPs presented a better biocompatibility and had almost no cytotoxicity at the concentrations required for efficient transfection. Our results suggest that the NH(2)SiNPs may be a promising carrier for delivery of anti-ODNs.

Uptake of silica-coated nanoparticles by HeLa cells.

Nanoparticles have seen wide applications in cellular research and development. One major issue that is unclear is the uptake of nanoparticles by cells. In this study, we have investigated the uptake of silica-coated nanoparticles by HeLa cells, employing rhoadime 6G isothiocyanate (RITC)-doped nanoparticles as a synchronous fluorescent signal indicator. These nanoparticles were synthesized with reverse microemulsion. A few factors, such as nanoparticle concentration, incubation time and temperature, and serum and inhibitors in culture medium were assessed on the nanoparticle's cellular uptake. The experimental results demonstrated that uptake was maximum after a 6 h incubation and was higher at 37 degrees C than that at 4 degrees C. Nanoparticle uptake depended on the nanoparticle concentration and was inhibited by hyperosmolarity, K+ depletion. In addition, serum in culture medium decreased the cellular uptake of nanoparticles. The results indicated that the uptake of silica-coated nanoparticles by HeLa cells was a concentration-, time-, and energy-dependent endocytic process. Silica-coated nanoparticles could be transported into HeLa cells in part through adsorptive endocytosis and in part through fluid-phase endocytosis.

Influence of anions on the formation and properties of chitosan-DNA nanoparticles.

Chitosan-DNA nanoparticles were prepared by using different anions (such as chloride, sulfate, citrate, and tripolyphosphate) as mediation agents. The research suggested that the formation and morphological characteristics of chitosan-DNA nanoparticles largely depended on concentration, molecular size, charge number, and chemical structure of anions, as well as chitosan/DNA ratio. The observation by atom force microscopy showed that chitosan-DNA nanoparticles mediated by four anions (in their appropriate range of concentration) had a spherical shape, narrow size distribution, and good monodispersivity. Especially, nanoparticles mediated by sulfate and TPP had a size distribution of 40-50 nm. Additionally, the nanoparticles presented high encapsulation efficiency and good protection of DNA from DNasel digestion. The zeta-potential of nanoparticles could be adjusted moderately by adding different anions and controlling their concentrations, and DNA encapsulation efficiency was not influenced, which would reduce nonspecific interactions with the cell membrane and nanoparticle toxicity. Smaller size and lower zeta-potential will be beneficial for improving gene therapy. In addition, the anion mediation method has potential for the preparation of cationic polymer nanoparticles as drug or gene vectors.