The DnaJ proteins DJA6 and DJA5 are essential for chloroplast iron-sulfur cluster biogenesis.

Fe-S clusters are ancient, ubiquitous and highly essential prosthetic groups for numerous fundamental processes of life. The biogenesis of Fe-S clusters is a multistep process including iron acquisition, sulfur mobilization, and cluster formation. Extensive studies have provided deep insights into the mechanism of the latter two assembly steps. However, the mechanism of iron utilization during chloroplast Fe-S cluster biogenesis is still unknown. Here we identified two Arabidopsis DnaJ proteins, DJA6 and DJA5, that can bind iron through their conserved cysteine residues and facilitate iron incorporation into Fe-S clusters by interactions with the SUF (sulfur utilization factor) apparatus through their J domain. Loss of these two proteins causes severe defects in the accumulation of chloroplast Fe-S proteins, a dysfunction of photosynthesis, and a significant intracellular iron overload. Evolutionary analyses revealed that DJA6 and DJA5 are highly conserved in photosynthetic organisms ranging from cyanobacteria to higher plants and share a strong evolutionary relationship with SUFE1, SUFC, and SUFD throughout the green lineage. Thus, our work uncovers a conserved mechanism of iron utilization for chloroplast Fe-S cluster biogenesis.

AtNusG, a chloroplast nucleoid protein of bacterial origin linking chloroplast transcriptional and translational machineries, is required for proper chloroplast gene expression in Arabidopsis thaliana.

In Escherichia coli, transcription-translation coupling is mediated by NusG. Although chloroplasts are descendants of endosymbiotic prokaryotes, the mechanism underlying this coupling in chloroplasts remains unclear. Here, we report transcription-translation coupling through AtNusG in chloroplasts. AtNusG is localized in chloroplast nucleoids and is closely associated with the chloroplast PEP complex by interacting with its essential component PAP9. It also comigrates with chloroplast ribosomes and interacts with their two components PRPS5 (uS5c) and PRPS10 (uS10c). These data suggest that the transcription and translation machineries are coupled in chloroplasts. In the atnusg mutant, the accumulation of chloroplast-encoded photosynthetic gene transcripts, such as psbA, psbB, psbC and psbD, was not obviously changed, but that of their proteins was clearly decreased. Chloroplast polysomic analysis indicated that the decrease in these proteins was due to the reduced efficiency of their translation in this mutant, leading to reduced photosynthetic efficiency and enhanced sensitivity to cold stress. These data indicate that AtNusG-mediated coupling between transcription and translation in chloroplasts ensures the rapid establishment of photosynthetic capacity for plant growth and the response to environmental changes. Therefore, our study reveals a conserved mechanism of transcription-translation coupling between chloroplasts and E. coli, which perhaps represents a regulatory mechanism of chloroplast gene expression. This study provides insights into the underlying mechanisms of chloroplast gene expression in higher plants.

mTERF8, a Member of the Mitochondrial Transcription Termination Factor Family, Is Involved in the Transcription Termination of Chloroplast Gene psbJ.

Members of the mitochondrial transcription terminator factor (mTERF) family, originally identified in vertebrate mitochondria, are involved in the termination of organellular transcription. In plants, mTERF proteins are mainly localized in chloroplasts and mitochondria. In Arabidopsis (Arabidopsis thaliana), mTERF8/pTAC15 was identified in the plastid-encoded RNA polymerase (PEP) complex, the major RNA polymerase of chloroplasts. In this work, we demonstrate that mTERF8 is associated with the PEP complex. An mTERF8 knockout line displayed a wild-type-like phenotype under standard growth conditions, but showed impaired efficiency of photosystem II electron flow. Transcription of most chloroplast genes was not substantially affected in the mterf8 mutant; however, the level of the psbJ transcript from the psbEFLJ polycistron was increased. RNA blot analysis showed that a larger transcript accumulates in mterf8 than in the wild type. Thus, abnormal transcription and/or RNA processing occur for the psbEFLJ polycistron. Circular reverse transcription PCR and sequence analysis showed that the psbJ transcript terminates 95 nucleotides downstream of the translation stop codon in the wild type, whereas its termination is aberrant in mterf8 Both electrophoresis mobility shift assays and chloroplast chromatin immunoprecipitation analysis showed that mTERF8 specifically binds to the 3' terminal region of psbJ Transcription analysis using the in vitro T7 RNA polymerase system showed that mTERF8 terminates psbJ transcription. Together, these results suggest that mTERF8 is specifically involved in the transcription termination of the chloroplast gene psbJ.

Identification of Key mRNAs and Pathways in Colorectal Cancer.

Colorectal cancer (CRC) is the third most cancer-related death worldwide. This work aimed to identify potential hub genes and dysregulated pathways in the CRC by bioinformatics analysis. Three gene expression datasets were collected from GEO datasets, including tumor sample (N = 242) and adjacent nontumor tissue sample (N = 59). RankProd was used to discover the differential expressed genes between tumor and adjacent nontumor tissues for datasets generated by different laboratories. The gene set enrichment analysis conducted on the DE genes, followed by the protein-protein interaction (PPI) network. In total, 2,007 significant differential expression (DE) genes between tumor and adjacent nontumor tissues, include 1,090 upregulated genes and 917 downregulated genes in the tumor. The DE mRNAs are involved in cancer-related pathways. We comprehensively identified the CRC-related key mRNAs. Our data demonstrated combined different resources of transcriptomes will promote the understanding of the molecular mechanisms underlying CRC development and may be useful in discovering candidate molecular biomarkers for diagnosing, prognosis, and treating of CRC.

Influence of Vitamin A deficiency on the transcriptomic profile of rat meibomian glands.

PURPOSE: Vitamin A deficiency (VAD) is associated with chalazion in young children. However, the underlying molecular mechanism remains unclear. In the present study, transcriptome data from rat meibomian glands (MGs) were analyzed to reveal specific molecular responses to VAD. METHODS: Total RNA was extracted and purified for library preparation and transcriptome sequencing. Differentially expressed genes (DEGs) between vitamin A normal (VAN) and VAD rats were analyzed using DESeq software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of DEGs were performed using the GO seq R package and KOBAS software. Real-time quantitative reverse transcription polymerase chain reaction was used to validate the RNA sequencing results. RESULTS: The number of DEGs in the VAD group compared to the VAN group was 3129 (1531 upregulated and 1598 downregulated) in the rat MGs. VAD upregulated a large number of lipid metabolism-related genes. GO analysis showed that the most enriched and meaningful terms were related to lipid metabolism (e.g., "oxidation-reduction process, GO: 0,055,114," "lipid metabolic process, GO: 000,662"). KEGG pathway analysis showed that most of the enriched signaling pathways were involved in lipid metabolism, including the PPAR signaling pathway associated with retinoic acid (RA)-mediated nuclear receptors. CONCLUSION: These findings demonstrate that VAD regulates the expression of numerous genes in the rat MG and that many of these genes are involved in lipid metabolic pathways.

[Expression Level of FLRG in Colon Cancer Tissue and Its Clinical Significance].

OBJECTIVE: To investigate the expression of follistatin related gene ( FLRG) in colon cancer and its relationship with clinicopathological features of colon cancer. METHODS: The cancer tissue, paracancerous tissue and normal tissue were collected from 80 patients with colon cancer who underwent radical operation from December 2018 to December 2019. Immunohistochemistry and Real-time PCR were carried out to examine the expression of FLRG and the clinical implications of FLRG was further analyzed. RESULTS: The expression of FLRG in colon cancer tissues was significantly higher than that in paracancerous tissues and normal tissues ( P<0.05), and the expression of FLRG in paracancerous tissues was significantly higher than that in normal tissues ( P<0.05). There was no significant difference in the expression of FLRG among colon cancer patients with different sex, age, tumor growth location and differentiation degree ( P>0.05). The expression level of FLRG in patients with distant metastasis was higher than that in patients without distant metastasis ( P<0.05), and the expression level of FLRG in patients with late clinical stage (stage Ⅲ and Ⅳ) was higher than that in patients with earlier clinical stage (stage Ⅰ and Ⅱ) ( P<0.05). CONCLUSION: FLRG is up-regulated in colon cancer tissue, which may be involved in the regulation of tumor development. FLRG may be a potential prognostic target.

Genome-Wide Network-Based Analysis of Colorectal Cancer Identifies Novel Prognostic Factors and an Integrative Prognostic Index.

BACKGROUND/AIMS: Colorectal cancer (CRC) is one of leading cancers in both incidence and mortality rate. The 5-year survival rate varies considerably depending on the pathological stage of the tumor. Although prominent progress has been made through screening for survival-associated factors from a certain type of genetic or epigenetic modifications, few attempts have been made to apply a network-based approach in prognostic factor identification, which could prove valuable for a complex, multi-faceted disease such as CRC. METHODS: In this study, a TCGA dataset of 379 CRC patients was subjected to a network-based analysis strategy consisting of multivariate regression, co-expression network and gene regulatory network analyses, and survival analyses. Both genetic and epigenetic aberrations, including those in gene expression and DNA methylation at specific sites, were screened for significant association with patient survival. A prognostic index (PI) integrating all potential prognostic factors was subsequently validated for its prognostic value. RESULTS: A collection of six miRNAs, eleven mRNAs, and nine DNA methylation sites were identified as potential prognostic factors. The low- and high-risk patient groups assigned based on PI level showed significant difference in overall survival (hazard ratio = 1.32, 95% confidence interval 1.29-1.36, p < 0.0001). Patients in the low- and high-risk groups can be further divided into a total of four subgroups, based on pathological staging. In the two high-risk subgroups (PI > 0), there was significant different (Cox p < 0.0001) in OS between the earlier (stages I/II) and later stages (stages III/IV). However, in the two low-risk subgroups (PI < 0), earlier (stages I/II) and later stages (stages III/IV) showed no significant difference in OS (Cox p = 0.185). On the other hand, there were significant differences in OS between the low- and high-risk subgroups when both subgroups were of earlier stages (Cox p < 0.001) or of later stages (Cox p < 0.0001). CONCLUSION: The novel network-based, integrative analysis adopted in this study was efficient in screening for prognostic predictors. Along with PI, the set of 6 miRNAs, 11 mRNAs, and 9 DNA methylation sites could serve as the basis for improved prognosis estimation for CRC patients in future clinical practice.

Chitosan inhibits inflammation and adipogenesis of orbital fibroblasts in Graves ophthalmopathy.

Purpose: The aim of this study was to investigate the roles of chitosan in inflammation and adipogenesis of primary cultured orbital fibroblasts in Graves ophthalmopathy (GO). Methods: Cell viability, apoptosis, and cell cycle were determined with the Cell Counting Kit-8 (CCK-8), the Annexin V-FITC/PI kit, and flow cytometry, respectively. Inflammation of orbital fibroblasts was stimulated by interleukin-1 beta (IL-1ß). The levels of IL-6 and prostaglandin E-2 (PGE-2) were measured using an enzyme-linked immunosorbent assay (ELISA). The expression of cyclooxygenase-2 (COX-2) was measured with real-time PCR and western blot assay. Phosphorylation of c-Jun N-terminal kinase (JNK) was evaluated with western blot assay. An inhibitor of JNK was used to investigate the signal transduction pathway of cytokine production. Orbital fibroblasts differentiated to adipose cells in differentiation medium. Adipose cells were dyed with Oil Red O. FABP4, adiponectin, C/EBPα, PPAR-γ, and phosphorylation of AKT were evaluated with western blot assay. Results: The results showed that IL-1ß statistically significantly increased the expression of IL-6, PGE-2, and COX-2 in orbital fibroblasts. Phosphorylation of JNK was promoted by IL-1ß. IL-6 and PGE-2 were modulated by the JNK signaling pathway as determined with the inhibition experiments. Chitosan downregulated expression of IL-1ß-stimulated IL-6, COX-2, and PGE-2 and downregulated phosphorylation of JNK. Chitosan inhibited the production of adipose cells dyed by Oil Red O. Chitosan statistically significantly decreased the protein levels of FABP4, adiponectin, C/EBPα, and PPAR-γ with downregulation of AKT phosphorylation during adipocyte differentiation. Conclusions: Chitosan statistically significantly inhibits inflammation and adipogenesis, as well as related signaling pathways, of orbital fibroblasts in GO. This indicates a possible therapeutic effect of chitosan on Graves ophthalmopathy.

Production of different molecular weight glycosaminoglycans with microbial cell factories.

Glycosaminoglycans (GAGs) are naturally occurring acidic polysaccharides with wide applications in pharmaceuticals, cosmetics, and health foods. The diverse biological activities and physiological functions of GAGs are closely associated with their molecular weights and sulfation patterns. Except for the non-sulfated hyaluronan which can be synthesized naturally by group A Streptococcus, all the other GAGs such as heparin and chondroitin sulfate are mainly acquired from animal tissues. Microbial cell factories provide a more effective platform for the production of structurally homogeneous GAGs. Enhancing the production efficiency of polysaccharides, accurately regulating the GAGs molecular weight, and effectively controlling the sulfation degree of GAGs represent the major challenges of developing GAGs microbial cell factories. Several enzymatic, metabolic engineering, and synthetic biology strategies have been developed to tackle these obstacles and push forward the industrialization of biotechnologically produced GAGs. This review summarizes the recent advances in the construction of GAGs synthesis cell factories, regulation of GAG molecular weight, and modification of GAGs chains. Furthermore, the challenges and prospects for future research in this field are also discussed.

Advances and challenges in biotechnological production of chondroitin sulfate and its oligosaccharides.

Chondroitin sulfate (CS) is a member of glycosaminoglycans (GAGs) and has critical physiological functions. CS is widely applied in medical and clinical fields. Currently, the supply of CS relies on traditional animal tissue extraction methods. From the perspective of medical applications, the biggest drawback of animal-derived CS is its uncontrollable molecular weight and sulfonated patterns, which are key factors affecting CS activities. The advances of cell-free enzyme catalyzed systems and de novo biosynthesis strategies have paved the way to rationally regulate CS sulfonated pattern and molecular weight. In this review, we first present a general overview of biosynthesized CS and its oligosaccharides. Then, the advances in chondroitin biosynthesis, 3'-phosphoadenosine-5'-phosphosulfate (PAPS) synthesis and regeneration, and CS biosynthesis catalyzed by sulfotransferases are discussed. Moreover, the progress of mining and expression of chondroitin depolymerizing enzymes for preparation of CS oligosaccharides is also summarized. Finally, we analyze and discuss the challenges faced in synthesizing CS and its oligosaccharides using microbial and enzymatic methods. In summary, the biotechnological production of CS and its oligosaccharides is a promising method in addressing the drawbacks associated with animal-derived CS and enabling the production of CS oligosaccharides with defined structures.

The DELLA-ABI4-HY5 module integrates light and gibberellin signals to regulate hypocotyl elongation.

Plant growth is coordinately controlled by various environmental and hormonal signals, of which light and gibberellin (GA) signals are two critical factors with opposite effects on hypocotyl elongation. Although interactions between the light and GA signaling pathways have been studied extensively, the detailed regulatory mechanism of their direct crosstalk in hypocotyl elongation remains to be fully clarified. Previously, we reported that ABA INSENSITIVE 4 (ABI4) controls hypocotyl elongation through its regulation of cell-elongation-related genes, but whether it is also involved in GA signaling to promote hypocotyl elongation is unknown. In this study, we show that promotion of hypocotyl elongation by GA is dependent on ABI4 activation. DELLAs interact directly with ABI4 and inhibit its DNA-binding activity. In turn, ABI4 combined with ELONGATED HYPOCOTYL 5 (HY5), a key positive factor in light signaling, feedback regulates the expression of the GA2ox GA catabolism genes and thus modulates GA levels. Taken together, our results suggest that the DELLA-ABI4-HY5 module may serve as a molecular link that integrates GA and light signals to control hypocotyl elongation.

Downregulation of miR-211-5p Promotes Carboplatin Resistance in Human Retinoblastoma Y79 Cells by Affecting the GDNF-LIF Interaction.

Purpose: To investigate the role of the miR-211-5p-GDNF signaling pathway in carboplatin resistance of retinoblastoma Y79 cells and what factors it may be affected by. Methods: A carboplatin-resistant retinoblastoma cell line (Y79R) was established in vitro. RNA-seq and microRNA-seq were constructed between Y79 and Y79R cells. RNA interference, RT-PCR, Western blot (WB), and flow cytometry were used to verify the expression of genes and proteins between the two cell lines. The TargetScan database was used to predict the microRNAs that regulate the target genes. STING sites and Co-Immunoprecipitation (COIP) were used to study protein-protein interactions. Results: GDNF was speculated to be the top changed gene in the drug resistance in Y79R cell lines. Moreover, the speculation was verified by subsequent RT-PCR and WB results. When the expression of GDNF was knocked down, the IC50 of the Y79R cell line significantly reduced. GDNF was found to be the target gene of miR-211-5p. Downregulation of miR-211-5p promotes carboplatin resistance in human retinoblastoma Y79 cells. MiR-211-5p can regulate the expression of GDNF. Our further research also found that GDNF can bind to LIF which is also a secreted protein. Conclusion: Our results suggest that downregulation of miR-211-5p promotes carboplatin resistance in human retinoblastoma Y79 cells, and this process can be affected by GDNF-LIF interaction. These results can provide evidence for the reversal of drug resistance of RB.

Characterization and Bioactive Potential of Carotenoid Lutein from Gordonia rubripertncta GH-1 Isolated from Traditional Pixian Douban.

The characterization and bioactive properties of carotenoid produced by Gordonia rubripertincta GH-1 originating from Pixian Douban (PXDB), the Chinese traditional condiment, was investigated. The produced and purified yellow pigment was characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier transformed infrared (FTIR), nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS), and was identified as carotenoid lutein. Additionally, the bioactive activity of lutein from G. rubripertincta GH-1 was evaluated by measuring the free radical scavenging capacity in vitro and feeding zebrafish lutein through aqueous solution. The results showed that the carotenoid lutein had strong antioxidant capacity and a protective effect on zebrafish eye cells, which could inhibit the apoptosis of eye cells in a concentration dependent manner. The results suggested that carotenoid lutein from G. rubripertincta GH-1 could be utilized as a potential source of natural antioxidants or functional additives for food/pharmaceutical industries.

AtRsmD Is Required for Chloroplast Development and Chloroplast Function in Arabidopsis thaliana.

AtRsmD was recently demonstrated to be a chloroplast 16S rRNA methyltransferase (MTase) for the m2G915 modification in Arabidopsis. Here, its function of AtRsmD for chloroplast development and photosynthesis was further analyzed. The AtRsmD gene is highly expressed in green photosynthetic tissues. AtRsmD is associated with the thylakoid in chloroplasts. The atrsmd-2 mutant exhibited impaired photosynthetic efficiency in emerging leaves under normal growth conditions. A few thylakoid lamellas could be observed in the chloroplast from the atrsmd-2 mutant, and these thylakoids were loosely organized. Knockout of the AtRsmD gene had minor effects on chloroplast ribosome biogenesis and RNA loading on chloroplast ribosomes, but it reduced the amounts of chloroplast-encoded photosynthesis-related proteins in the emerging leaves, for example, D1, D2, CP43, and CP47, which reduced the accumulation of the photosynthetic complex. Nevertheless, knockout of the AtRsmD gene did not cause a general reduction in chloroplast-encoded proteins in Arabidopsis grown under normal growth conditions. Additionally, the atrsmd-2 mutant exhibited more sensitivity to lincomycin, which specifically inhibits the elongation of nascent polypeptide chains. Cold stress exacerbated the effect on chloroplast ribosome biogenesis in the atrsmd-2 mutant. All these data suggest that the AtRsmD protein plays distinct regulatory roles in chloroplast translation, which is required for chloroplast development and chloroplast function.

Protein Targeting Into the Thylakoid Membrane Through Different Pathways.

In higher plants, chloroplasts are essential semi-autonomous organelles with complex compartments. As part of these sub-organellar compartments, the sheet-like thylakoid membranes contain abundant light-absorbing chlorophylls bound to the light-harvesting proteins and to some of the reaction center proteins. About half of the thylakoid membrane proteins are encoded by nuclear genes and synthesized in the cytosol as precursors before being imported into the chloroplast. After translocation across the chloroplast envelope by the Toc/Tic system, these proteins are subsequently inserted into or translocated across the thylakoid membranes through distinct pathways. The other half of thylakoid proteins are encoded by the chloroplast genome, synthesized in the stroma and integrated into the thylakoid through a cotranslational process. Much progress has been made in identification and functional characterization of new factors involved in protein targeting into the thylakoids, and new insights into this process have been gained. In this review, we introduce the distinct transport systems mediating the translocation of substrate proteins from chloroplast stroma to the thylakoid membrane, and present the recent advances in the identification of novel components mediating these pathways. Finally, we raise some unanswered questions involved in the targeting of chloroplast proteins into the thylakoid membrane, along with perspectives for future research.

Effect of fed-batch and chemostat cultivation processes of C. glutamicum CP for L-leucine production.

Most of the current industrial processes for L-leucine production are based on fermentation, usually in fed-batch operation mode. Although the culture technology has advanced in recent decades, the process still has significant drawbacks. To solve these problems, we investigated the effects of chemostat culture conditions on the production of L-leucine by Corynebacterium glutamicum CP. The dilution rate, the nitrogen source, and the carbon-nitrogen ratio of the medium were optimized. With the addition of ammonium acetate to the chemostat medium, the initial C/N ratio was adjusted to 57.6, and the L-leucine titer reached the highest level at the optimal dilution rate of 0.04 h-1. Compared with fed-batch culture, the L-leucine titer was reduced (from 53.0 to 24.8 g L-1), but the yield from glucose was increased by 10.0% (from 0.30 to 0.33 mol mol-1) and productivity was increased by 58.3% (from 1.2 to 1.9 g L-1 h-1). Moreover, the titer of the by-product L-alanine was significantly reduced (from 8.9 to 0.8 g L-1). In addition, gene expression levels and activity of key enzymes in the synthesis of L-leucine and L-alanine were analyzed to explain the difference of production performance between chemostat culture and fed-batch culture. The results indicate that chemostat culture has great potential to increase the industrial production of L-leucine compared to current fed-batch approaches.

Effect of sodium dodecyl sulfate on the production of L-isoleucine by the fermentation of Corynebacterium glutamicum.

Corynebacterium glutamicum is a safe and popular industrial microorganism that it is gram-positive bacteria with thick cell walls, which hinder the extracellular secretion of products. Surfactant has good surface or interface activity and can destroy the cell membrane of microorganisms. In this study, the surfactant SDS was used to artificially destroy the cell membrane of Corynebacterium glutamicum, increase the permeability of the cell membrane, and increase the ability of the strain to secrete L-isoleucine. This is the first time that surfactants have been applied to the fermentation of Corynebacterium glutamicum. Results indicated that after optimization, the output of L-isoleucine reached 43.67 g/L, which was 13.01% higher than that without sodium dodecyl sulfate. The yield of the by-products, such as valine, leucine, and alanine, was reduced by 72.30%, 64.30%, 71.70%, respectively. This method can promote the production of L-isoleucine while minimizing the damage of SDS to the strain.

QTL mapping and candidate gene analysis of cadmium accumulation in polished rice by genome-wide association study.

Cadmium (Cd) accumulation in rice is a serious threat to food safety and human health. Breeding rice varieties with low Cd accumulation is one of the most effective approaches to reducing health risks from Cd-polluted rice. However, the genetic basis of Cd accumulation in grains, especially in indica rice varieties, has not been fully elucidated. The evaluation of Cd-accumulation capacity was conducted among 338 diverse rice accessions grown in Cd-contaminated soils with different Cd contents. Thirteen rice lines with relatively low Cd accumulation, including six indica rice lines, were identified. Then, 35 QTLs significantly associated with Cd accumulation were identified through sequencing-based SNP discovery and a genome-wide association study (GWAS) in the two experimental years, and only qCd8-1 was detected in both years. Among of them, nine QTLs were co-localized with identified genes or QTLs. A novel QTL, qCd1-3, with the lowest P value was selected for further LD decay analysis and candidate gene prediction. We found differential expression of OsABCB24 between high-Cd-accumulative and low-Cd-accumulative accessions, suggesting it may be a candidate gene for qCd1-3 associated with low Cd accumulation. These results may be helpful for further exploiting novel functional genes related to Cd accumulation and developing rice variety with low Cd accumulation through marker-assisted breeding.

TRPV1 Induced Apoptosis of Colorectal Cancer Cells by Activating Calcineurin-NFAT2-p53 Signaling Pathway.

BACKGROUND/AIMS: TRPV1 is a nonselective Ca2+ channel which has recently been observed in many cancers, while its effect on cell proliferation, apoptosis, metabolism, and cancer development in colorectal cancer (CRC) is still unclear. In this study, we hypothesized that TRPV1 is a tumor suppressor in CRC development as well as the underlying mechanism. METHODS: Immunohistochemistry assay was applied to detect the expression of TRPV1 protein in CRC tissues. HCT116 cell proliferation and apoptosis were measured by CCK-8 and flow cytometry, respectively. Cellular Ca2+ concentration was measured by Fluo-4/AM-based flow cytometer. Apoptosis-related proteins were measured by Western blotting. RESULTS: In this study, we found that TRPV1 expression was significantly decreased in CRC tissues, compared with CRC-adjacent tissues and normal tissues, respectively. Then, we found that the TRVP1 agonist capsaicin treatment inhibited CRC growth and induced apoptosis by activating P53. Subsequent mechanistic study revealed that the TRPV1 induced cytosolic Ca2+ influx to regulate cell apoptosis and p53 activation through calcineurin. CONCLUSIONS: This study suggests that TRPV1 served as a tumor suppressor in CRC and contributed to the development of novel therapy of CRC.

A laser-activated multifunctional targeted nanoagent for imaging and gene therapy in a mouse xenograft model with retinoblastoma Y79 cells.

Retinoblastoma (RB) is the most common intraocular malignancy of childhood that urgently needs early detection and effective therapy methods. The use of nanosized gene delivery systems is appealing because of their highly adjustable structure to carry both therapeutic and imaging agents. Herein, we report a folic acid (FA)-modified phase-changeable cationic nanoparticle encapsulating liquid perfluoropentane (PFP) and indocyanine green (ICG) (FA-CN-PFP-ICG, FCNPI) with good plasmid DNA (pDNA) carrying capacity, favorable biocompatibility, excellent photoacoustic (PA) and ultrasound (US) contrast, enhanced gene transfection efficiency and therapeutic effect. The liquid-gas phase transition of the FCNPI upon laser irradiation has provided splendid contrasts for US/PA dual-modality imaging in vitro as well as in vivo. More importantly, laser-mediated gene transfection with targeted cationic FCNPI nanoparticles demonstrated the best therapeutic effect compared with untargeted cationic nanoparticle (CN-PFP-ICG, CNPI) and neutral nanoparticle (NN-PFP-ICG, NNPI), both in vitro and in vivo. Such a multifunctional nanoagent is expected to combine dual-mode guided imaging with fewer side effects and proper therapeutic efficacy. These results establish an experimental foundation for the clinical detection of and therapy for RB. STATEMENT OF SIGNIFICANCE: We successfully constructed a multifunctional targeted cationic nanoparticle (FCNPI) and meticulously compared the variations in the plasmid loading capacity and binding to Y79 cells with NNPI, CNPI, and FCNPI. FCNPI exhibited favorable plasmid loading capability, splendid ability for targeting and only it could provide optimal US and PA contrast to background during a considerable long time. The FCNPI/pDNA + Laser system also exhibited the best therapeutic effect in vivo; this finding proposes a potential strategy for the evaluation of an efficient gene delivery nanocarrier for gene targeting therapy of RB tumor. Our study showed that there are great advantages of targeting FCNPI to provide PA/US imaging and to enlighten laser-mediated gene transfection. FCNPI is a very helpful multifunctional agent with potential.