Strategies for exogenous RNA delivery in RNAi-mediated pest management / 生物工程学报

Plant diseases and insect pests threaten the safety of crop production greatly. Traditional methods for pest management are challenged by the problems such as environmental pollution, off-target effects, and resistance of pathogens and insects. New biotechnology-based strategies for pest control are expected to be developed. RNA interference (RNAi) is an endogenous process of gene regulation, which has been widely used to study the gene functions in various organisms. In recent years, RNAi-based pest management has received increasing attention. The effective delivery of the exogenous interference RNA into the targets is a key step in RNAi-mediated plant diseases and pest control. Considerable advances were made on the mechanism of RNAi, and various RNA delivery systems were developed for efficient pest control. Here we review the latest advances on mechanisms and influencing factors of RNA delivery, summarize the strategies of exogenous RNA delivery in RNAi-mediated pest control, and highlight the advantages of nanoparticle complexes in dsRNA delivery.

Opportunities and Challenges of RNA Interference Therapeutics in Oncology / 中国肺癌杂志

As the discovery of RNA interference (RNAi) and the gradual conquering of a series of technical issues, a few of RNAi therapeutics have been approved in the non-tumor field abroad. With the advantages of high specificity, long duration of efficacy, and high success rate of development, RNAi therapeutics have become the emerging field globally. There are no RNAi therapeutics approved in oncology so far, and people are hoping a breakthrough in the field. In the present article, the characteristics and potential anti-tumor mechanism of RNAi therapeutics, difficulties in delivery system and progress in oncology are described, and the potential reasons why their success in non-tumor field is difficult to be simply replicated in tumor field are analyzed, providing reference for research and clinical transformation of RNAi therapeutics in oncology.
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Pathways and mechanisms of RNA interference mediated by viral siRNA / 生物工程学报

RNA interference (RNAi) is one of the important mechanisms to regulate gene expression in eukaryotes. One of the original functions of RNAi is to facilitate the antiviral strategy of host. Early studies reveal that invertebrates can use RNAi to resist viruses. However, if this mechanism exists in mammals is still controversial. The latest studies confirm that mammals do have the RNAi-based immunity, and researchers believe that RNAi-based antiviral immunity is a brand-new immunological mechanism that was neglected in the past. It is worthy to note that virus can also use RNAi to enhance its infectivity and immune escape in host cells. This review introduces the research history of RNAi-based antiviral immunity in animals and summarizes the main findings in this field. Last but not least, we indicate a series of unresolved questions about RNAi-based antiviral immunity, and explore the relationship between RNAi-based antiviral immunity and other innate immunological pathways. The virus-mediated RNAi pathway in animal is not only an interesting basic biology question, but also has important guiding roles in the development of antiviral drugs.

Synergistic effect on biosynthesis of Panax notoginseng saponins by overexpressing a transcription factor PnbHLH and RNA interference of cycloartenol synthase gene / 中国中药杂志

This study cloned the transcription factor gene PnbHLH which held an open reading frame of 966 bp encoding 321 amino acids. This study constructed the overexpression vector of transcription factor PnbHLH of Panax notoginseng. The combination of PnbHLH overexpression and RNAi of the key enzyme gene PnCAS involved in the phytosterol biosynthesis was achieved in P. notoginseng cells, thus exploring the biosynthetic regulation of P. notoginseng saponins(PNS) by the synergistic effect of PnbHLH overexpression and PnCAS RNAi. The results showed that the PnbHLH transcription factor interacted with the promoters of key enzyme genes PnDS, PnSS and PnSE in the biosynthetic pathway of PNS, and then regulated the expression levels of key enzyme genes and affected the biosynthesis of saponins indirectly. Further study indicated that the synergistic effect of PnbHLH overexpression and PnCAS RNAi was a more effective approach to regulate the biosynthesis of saponins. Compared with the wild type and PnCAS RNAi cells of P. notoginseng, the contents of total saponins and monomeric saponins(Rd, Rb_1, Re, Rg_1 and R_1) were increased to some extent in the cell lines of PnbHLH overexpression and PnCAS RNAi. This indicated that the two ways of forward regulation and reverse regulation of saponin biosynthesis showed superposition effect. This study explored a more rational and efficient regulation strategy of PNS biosynthesis based on the advantages of multi-point regulation of transcription factors as well as the down-regulation of by-product synthesis of saponins.

Establishment of RNA interfered hairy root system of two CYP450 genes in Arnebia euchroma and its influence / 中国中药杂志

In this study, based on the transcriptome database of suspension cells of Arnebia euchroma, we explored two candidate cytochrome P450 enzyme genes that might relate to the shikonin biosynthesis downstream pathway when CYP76B74 sequence was referenced. We constructed interference-type hairy roots of candidate genes and cultured them. We measured the fresh weight, dry weight, total naphthoquinone content, shikonin and its derivatives content and expression levels of key enzyme genes involved in shikonin biosynthesis pathway. The effects of candidate genes on the growth and shikonin production of A. euchroma hairy roots were discussed, and the possible regulatory mechanisms that candidate genes affected shikonin synthesis were discussed. Through local Blast and phylogenetic analysis, two candidate CYP450 genes(CYP76B75 and CYP76B100) with high homology to CYP76B74 in A. euchroma were screened, and corresponding interference hairy roots were constructed. Compared with the control(RNAi-control), the fresh weight of CYP76B75 interfered hairy root(RNAi-CYP76B75) and CYP76B100 interfered hairy root(RNAi-CYP76B100) were significantly reduced, while dry weight were not affected, so the dry rate increased significantly. Except for β-acetoxyisovalerylalkannin, which is high in three groups of hairy roots, the contents of shikonin, deoxyshikonin, acetylshikonin, β,β'-dimethacrylicalkannin, β-hydroxyisovalerylshikonin,β-hydroxyisovalerylshikonin, isobutyrylshikonin and total naphthoquinones showed a consistent pattern: RNAi-CYP76B75>RNAi-CYP76B100>RNAi-control. Among them, the synthesis of β-hydroxyisovalerylshikonin was most significantly promoted by interfering with the expression of CYP76B75. The content of β-hydroxyisovalerylshikonin in RNAi-CYP76B75 was 11.7 times that of RNAi-control. RESULTS:: of real-time qPCR analysis showed that compared to RNAi-control, the expression levels of AePGT gene in RNAi-CYP76B75 and RNAi-CYP76B100 were not changed significantly, and the expression levels of CYP76B74 and AeHMGR were up-regulated. In addition, the expression level of CYP76B100 in RNAi-CYP76B75 was down-regulated, whereas in RNAi-CYP76B100, the expression of CYP76B75 was significantly up-regulated. Therefore, this study confirmed that when the expression of CYP76B75 and CYP76B100 were interrupted, the growth of hairy roots were suppressed, but the synthesis of shikonin were promoted. They might increase the shikonin biosynthesis by up-regulating the expression of CYP76B74 in the hairy roots of A. euchroma.

Lrrc34 Is Highly Expressed in SSCs and Is Necessary for SSC Expansion In Vitro / 中国医学科学杂志(英文版)

Objective To discover critical genes contributing to the stemness and maintenance of spermatogonial stem cells (SSCs) and provide new insights into the function of the leucine-rich repeat (LRR) family member Lrrc34 (leucine-rich repeat-containing 34) in SSCs from mice. Methods Bioinformatic methods, including differentially expressed gene (DEG), gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, were used to uncover latent pluripotency-related genes. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence analyses were utilized to verify the mRNA and protein expression levels, respectively. RNA interference of Lrrc34 using siRNA was performed to detect its transient impact on SSCs. Results Eight DEGs between ID4-EGFP+ (G) and ID4-EGFP+/TSPAN8High (TH), eight DEGs between G and ID4-EGFP+/TSPAN8Low (TL) and eleven DEGs between TH and TL were discovered, and eleven protein-protein interaction (PPI) modules were found to be significant in the PPI network of DEGs. One of the DEGs, Lrrc34, was selected as a potential pluripotency-related gene due to its differential expression among ID4-EGFP+ spermatogonia subsets and its interaction with fibroblast growth factor 2 in the fifth module. Immunofluorescence experiments exhibited specific expression of Lrrc34 in a subpopulation of undifferentiated spermatogonia marked by LIN28A, and RT-PCR experiments confirmed the high expression of Lrrc34 in SSCs from P7 and adult mice. The transient knockdown of Lrrc34 in SSCs resulted in reduced colony sizes and significant changes in the transcriptome and apoptotic pathways. Conclusion Lrrc34 is highly expressed in mouse SSCs and is required for SSC proliferation in vitro through effects on transcriptome and signaling transduction pathways.

Smad1/5 signal transduction regulates the ameloblastic differentiation of induced pluripotent stem cells

Abstract Induced pluripotent stem (iPS) cells could be induced into ameloblast-like cells by ameloblasts serum-free conditioned medium (ASF-CM), and bone morphogenetic proteins (BMPs) might be essential during the regulation of this process. The present study investigates the signal transduction that regulates the ameloblastic differentiation of iPS cells induced by ASF-CM. Mouse iPS cells were characterized and then cultured for 14 days in epithelial cell medium (control) or ASF-CM. Bone morphogenetic protein receptor II (BMPR-II) siRNA, inhibitor of Smad1/5 phosphorylation activated by activin receptor-like kinase (ALK) receptors, and inhibitors of mitogen-activated protein kinases (MAPKs) phosphorylation were used to treat the iPS cells in combination with ASF-CM. Real-time PCR, western blotting, and immunofluorescent staining were used to evaluate the expressions of ameloblast markers ameloblastin, enamelin, and cytokeratin-14. BMPR-II gene and protein levels increased markedly in ASF-CM-treated iPS cells compared with the controls, while the mRNA levels of Bmpr-Ia and Bmpr-Ib were similar between the ASF-CM and control groups. ASF-CM stimulation significantly increased the gene and protein expression of ameloblastin, enamelin and cytokeratin-14, and phosphorylated SMAD1/5, p38 MAPK, and ERK1/2 MAPK compared with the controls. Knockdown of BMPR-II and inhibition of Smad1/5 phosphorylation both could significantly reverse the increased expression of ameloblastin, enamelin, and cytokeratin-14 induced by ASF-CM, while neither inhibition of p38 nor ERK1/2 phosphorylation had significant reversing effects. We conclude that smad1/5 signaling transduction, activated by ALK receptors, regulates the ameloblastic differentiation of iPS cells induced by ameloblast-conditioned medium.

Smad1/5 signal transduction regulates the ameloblastic differentiation of induced pluripotent stem cells

Abstract Induced pluripotent stem (iPS) cells could be induced into ameloblast-like cells by ameloblasts serum-free conditioned medium (ASF-CM), and bone morphogenetic proteins (BMPs) might be essential during the regulation of this process. The present study investigates the signal transduction that regulates the ameloblastic differentiation of iPS cells induced by ASF-CM. Mouse iPS cells were characterized and then cultured for 14 days in epithelial cell medium (control) or ASF-CM. Bone morphogenetic protein receptor II (BMPR-II) siRNA, inhibitor of Smad1/5 phosphorylation activated by activin receptor-like kinase (ALK) receptors, and inhibitors of mitogen-activated protein kinases (MAPKs) phosphorylation were used to treat the iPS cells in combination with ASF-CM. Real-time PCR, western blotting, and immunofluorescent staining were used to evaluate the expressions of ameloblast markers ameloblastin, enamelin, and cytokeratin-14. BMPR-II gene and protein levels increased markedly in ASF-CM-treated iPS cells compared with the controls, while the mRNA levels of Bmpr-Ia and Bmpr-Ib were similar between the ASF-CM and control groups. ASF-CM stimulation significantly increased the gene and protein expression of ameloblastin, enamelin and cytokeratin-14, and phosphorylated SMAD1/5, p38 MAPK, and ERK1/2 MAPK compared with the controls. Knockdown of BMPR-II and inhibition of Smad1/5 phosphorylation both could significantly reverse the increased expression of ameloblastin, enamelin, and cytokeratin-14 induced by ASF-CM, while neither inhibition of p38 nor ERK1/2 phosphorylation had significant reversing effects. We conclude that smad1/5 signaling transduction, activated by ALK receptors, regulates the ameloblastic differentiation of iPS cells induced by ameloblast-conditioned medium.

Relationship between PI3K/mTOR/RhoA pathway-regulated cytoskeletal rearrangements and phagocytic capacity of macrophages

The objective of this study was to investigate the relationship between PI3K/mTOR/RhoA signaling regulated cytoskeletal rearrangements and phagocytic capacity of macrophages. RAW264.7 macrophages were divided into four groups; blank control, negative control, PI3K-RNAi, and mTOR-RNAi. The cytoskeletal changes in the macrophages were observed. Furthermore, the phagocytic capacity of macrophages against Escherichia coli is reported as mean fluorescence intensity (MFI) and percent phagocytosis. Transfection yielded 82.1 and 81.5% gene-silencing efficiencies against PI3K and mTOR, respectively. The PI3K-RNAi group had lower mRNA and protein expression levels of PI3K, mTOR, and RhoA than the blank and negative control groups (Р<0.01). The mTOR-RNAi group had lower mRNA and protein levels of mTOR and RhoA than the blank and the negative control groups (Р<0.01). Macrophages in the PI3K-RNAi group exhibited stiff and inflexible morphology with short, disorganized filopodia and reduced number of stress fibers. Macrophages in the mTOR-RNAi group displayed pronounced cellular deformations with long, dense filopodia and an increased number of stress fibers. The PI3K-RNAi group exhibited lower MFI and percent phagocytosis than blank and negative control groups, whereas the mTOR-RNAi group displayed higher MFI and percent phagocytosis than the blank and negative controls (Р<0.01). Before and after transfection, the mRNA and protein levels of PI3K were both positively correlated with mTOR and RhoA (Р<0.05), but the mRNA and protein levels of mTOR were negatively correlated with those of RhoA (Р<0.05). Changes in the phagocytic capacity of macrophages were associated with cytoskeletal rearrangements and were regulated by the PI3K/mTOR/RhoA signaling pathway.

C-Type Natriuretic Peptide/Natriuretic Peptide Receptor 2 Is Involved in Cell Proliferation and Testosterone Production in Mouse Leydig Cells

PURPOSE: This study investigated the role of natriuretic peptide receptor 2 (NPR2) on cell proliferation and testosterone secretion in mouse Leydig cells. MATERIALS AND METHODS: Mouse testis of different postnatal stages was isolated to detect the expression C-type natriuretic peptide (CNP) and its receptor NPR2 by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Leydig cells isolated from mouse testis were cultured and treated with shNPR2 lentiviruses or CNP. And then the cyclic guanosine monophosphate production, testosterone secretion, cell proliferation, cell cycle and cell apoptosis in mouse Leydig cells were analyzed by ELISA, RT-qPCR, Cell Counting Kit-8, and flow cytometry. Moreover, the expression of NPR2, cell cycle, apoptosis proliferation and cell cycle related gene were detected by RT-qPCR and Western blot. RESULTS: Knockdown of NPR2 by RNAi resulted in S phase cell cycle arrest, cell apoptosis, and decreased testosterone secretion in mouse Leydig cells. CONCLUSIONS: Our study provides more evidences to better understand the function of CNP/NPR2 pathway in male reproduction, which may help us to treat male infertility.

AcuD Gene Knockout Attenuates the Virulence of Talaromyces marneffei in a Zebrafish Model

Talaromyces marneffei is the only dimorphic species in its genus and causes a fatal systemic mycosis named talaromycosis. Our previous study indicated that knockdown of AcuD gene (encodes isocitrate lyase of glyoxylate bypass) of T. marneffei by RNA interference approach attenuated the virulence of T. marneffei, while the virulence of the AcuD knockout strains was not studied. In this study, T. marneffei-zebrafish infection model was successfully established through hindbrain microinjection with different amounts of T. marneffei yeast cells. After co-incubated at 28°C, the increasing T. marneffei inoculum doses result in greater larval mortality; and hyphae generation might be one virulence factor involved in T. marneffei-zebrafish infection. Moreover, the results demonstrated that the virulence of the ΔAcuD was significantly attenuated in this Zebrafish infection model.

Silencing Calreticulin Expression Inhibits Invasion Ability of SNK6 Cells in Vitro via Down-Regulating Expression of VEGF and MMP2/9 / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of steadily down-regulating the expression of calreticulin (CALR) on the invasion of natural killer/T-cell lymphoma SNK6 cells, and explore its possible mechanism.@*METHODS@#The sequences of specific short hairpin RNA (shRNA) targeting on human CALR were designed, and were inserted into pLKO.1-puro lentivirus vector, and the reconbinant lentivirus vector was obtained; the lentivirus particles were backed by three-plasmid system and transfected into SNK6 cells, the SNK6 cells stably down-regulating the CALR expression were sercened by puromytain, the CALR-silencing effect was verified by real-time PCR and Western blot. CCK-8 assay was used to evaluate the cell viability, The transwell invasion assays was used to analyse invasion of SNK6 cells. The mRNA expression of Calreticulin, MMP2, MMP9 and VEGF was determined by real time PCR, the protein expression of Calreticulin and GAPDH was analyzed by Western blot.@*RESULTS@#The recombinant lentiviral vector pLKO.1-puro-shCALR was successfully constructed, packed into the lentivirus, then the SNK6 cells stably down-regulating Calreticulin expression was obtained. When Calreticulin was down-rengulated in SNK6 cells, the proliferation rate was reduced and the invasion ability was decreased; the mRNA levels of VEGF and MMP-2/9 also were reduced.@*CONCLUSION@#The stable down-regnlation of CALR expression in SNK6 cells can attenuate the imvasiveness of SNK6 cells, which maybe related with transcriptional decrease of MMP2, MMP9 and VEGF.

Suppressor of Variegation 3–9 Homolog 2, a Novel Binding Protein of Translationally Controlled Tumor Protein, Regulates Cancer Cell Proliferation

Suppressor of Variegation 3–9 Homolog 2 (SUV39H2) methylates the lysine 9 residue of histone H3 and induces heterochromatin formation, resulting in transcriptional repression or silencing of target genes. SUV39H1 and SUV39H2 have a role in embryonic development, and SUV39H1 was shown to suppress cell cycle progression associated with Rb. However, the function of human SUV39H2 has not been extensively studied. We observed that forced expression of SUV39H2 decreased cell proliferation by inducing G1 cell cycle arrest. In addition, SUV39H2 was degraded through the ubiquitin-proteasomal pathway. Using yeast two-hybrid screening to address the degradation mechanism and function of SUV39H2, we identified translationally controlled tumor protein (TCTP) as an SUV39H2-interacting molecule. Mapping of the interacting regions indicated that the N-terminal 60 amino acids (aa) of full-length SUV39H2 and the C-terminus of TCTP (120–172 aa) were critical for binding. The interaction of SUV39H2 and TCTP was further confirmed by co-immunoprecipitation and immunofluorescence staining for colocalization. Moreover, depletion of TCTP by RNAi led to up-regulation of SUV39H2 protein, while TCTP overexpression reduced SUV39H2 protein level. The half-life of SUV39H2 protein was significantly extended upon TCTP depletion. These results clearly indicate that TCTP negatively regulates the expression of SUV39H2 post-translationally. Furthermore, SUV39H2 induced apoptotic cell death in TCTP-knockdown cells. Taken together, we identified SUV39H2, as a novel target protein of TCTP and demonstrated that SUV39H2 regulates cell proliferation of lung cancer cells.

Effects of silencing Rce1 in vitro on the invasion and migration of tongue carcinoma / 华西口腔医学杂志

OBJECTIVE@#This study aimed to explore the influence of Rce1 on invasion and migration of tongue squamous cell carcinoma cells by silencing the Rce1 gene with RNA interference.@*METHODS@#The tongue squamous cell carcinoma Cal-27 and SCC-4 cells were cultured in vitro. The small interfering RNA (siRNA) of the Rce1 gene was designed, and the Rcel gene expression was silenced vialiposome transfection. According to the siRNA transfected by liposome, the experimental group was divided into three groups, namely, Rce1-siRNA-1, Rce1-siRNA-2, and Rce1-siRNA-3 groups. Negative control group was transfected by siCON, and the blank control group was untransfected by siRNA. The Rce1, RhoA, and K-Ras gene expression levels in each group were analyzed by real-time quantitative polymerase chain reaction. The Rce1, RhoA, K-Ras, MMP-2, and MMP-9 protein expression levels were analyzed by Western blot. The invasiveness of tongue cancer cell Cal-27 and SCC-4 were determined by Transwell invasion assay, and cell migration assay was performed by cell scratch assay.@*RESULTS@#Real-time quantitative polymerase chain reaction and Western blot results showed that compared with the negative and blank control groups, the Rce1 gene and protein expression levels in three experimental groups decreased (P0.05). Meanwhile, the MMP-2 and MMP-9 expression levels decreased (P<0.05). Transwell invasion assay results showed that the total number of cells in the PET film of the experimental groups was significantly decreased compared with the control group (P<0.05). The cell scratch test showed that the cell closure time of the scratch in the interference group was significantly longer than those in the control and blank groups (P<0.05).@*CONCLUSIONS@#Silencing Rce1 in vitro can effectively downregulate its expression in tongue squamous cell carcinoma cells Cal-27 and SCC-4 and reduce the migration and invasion abilities of these cells.

Effect of Down-Regulating the CD59 by RNAi Lentivirus on the Expression of Acute T-lineage Leukemia Jurkat Cell Line / 中国实验血液学杂志

OBJECTIVE@#To analyze the effect of down-regulating the CD59 gene expression by RNAi lentivirus as vector on Jurkat cell line of acute T-lineage leukemia.@*METHODS@#The expression of CD59 in Jurkat cell line of acute T-line leukemia was induced to decrease by RNAi lentivirus as vector. The transfection of RNA lentivirus and the localization of CD59 molecule were analyzed by laser confocal technique. The relative expression of CD59 gene in blank control, negative control and RNAi lentivirus transfected group was detected by real-time fluorescence quantitative PCR, and the enzyme-linked immunosorbent assay was used to detect the expression of TNF-β and IL-3 in supernatants of cultured cells in 3 groups. The expression levels of apoptosis-related molecules including Caspase-3, Survivin, BCL-2 and BCL-2-associated X protein (BAX) were measured by Western blot.@*RESULTS@#The transfection efficiency for Jurkat cells was higher than 90%. CD59 was mainly located on the cell membrane. Compared with the blank control group and the negative control group, the expression level of CD59 mRNA and protein in the RNAi lentivirus transfected group significantly decreased (P<0.05). Compared with the blank control group and the negative control group, the expression of TNF-β and IL-3 in the RNAi lentivirus transfected group were significantly higher and lower (P<0.05) respectively. The expression levels of Survivin and BCL-2 in the RNAi lentivirus transfected group were significantly lower than those in the blank control group and the negative control group, while the expression levels of Caspase-3 and BAX in the RNAi lentivirus transfected group were significantly higher than those in the blank control group and the negative control group (P< 0.05).@*CONCLUSION@#The down-regulation of CD59 gene expression induced by RNAi lenti-virus can decrease the expression of proliferation and differentiation-promoting molecule such as IL-3 and increase the expression of TNF-related factor in Jurkat cell line of acute T-lineage leukemia, which also can increase the expression of apoptosis-related proteins such as Caspase-3 and BAX, and decrease the expression of anti-apoptosis-related proteins such as Survivin and BCL-2.

Neurogenesis and gliogenesis modulation in cerebral ischemia by CDK5 RNAi-based therapy / Modulación de la neurogénesis y la gliogénesis en la isquemia cerebral mediante una terapia basada en la interferencia de CDK5

Abstract Introduction: Cerebral ischemia is the third cause of death risk in Colombia and the first cause of physical disability worldwide. Different studies on the silencing of the cyclin-dependent kinase 5 (CDK5) have shown that reducing its activity is beneficial in ischemic contexts. However, its effect on neural cell production after cerebral ischemia has not been well studied yet. Objective: To evaluate CDK5 silencing on the production of neurons and astrocytes after a focal cerebral ischemia in rats. Materials and methods: We used 40 eight-week-old male Wistar rats. Both sham and ischemia groups were transduced at CA1 hippocampal region with an adeno-associated viral vector using a noninterfering (shSCRmiR) and an interfering sequence for CDK5 (shCDK5miR). We injected 50 mg/kg of bromodeoxyuridine intraperitoneally from hour 24 to day 7 post-ischemia. We assessed the neurological abilities during the next 15 days and we measured the immunoreactivity of bromodeoxyuridine (BrdU), doublecortin (DCX), NeuN, and glial fibrillary acid protein (GFAP) from day 15 to day 30 post-ischemia. Results: Our findings showed that CDK5miR-treated ischemic animals improved their neurological score and presented increased BrdU+ cells 15 days after ischemia, which correlated with higher DCX and lower GFAP fluorescence intensities, and, although mature neurons populations did not change, GFAP immunoreactivity was still significantly reduced at 30 days post-ischemia in comparison with untreated ischemic groups. Conclusion: CDK5miR therapy generated the neurological recovery of ischemic rats associated with the induction of immature neurons proliferation and the reduction of GFAP reactivity at short and longterm post-ischemia.

Resumen Introducción. La isquemia cerebral es la tercera causa de riesgo de muerte en Colombia y la primera causa de discapacidad física en el mundo. En diversos estudios en los que se silenció la cinasa 5 dependiente de la ciclina (CDK5) se ha demostrado que la reducción de su actividad es beneficiosa frente a la isquemia. Sin embargo, su efecto sobre la neurogénesis después de la isquemia no se ha dilucidado suficientemente. Objetivo. Evaluar el silenciamiento de la CDK5 en la neurogénesis y la gliogénesis después de la isquemia cerebral focal en ratas. Materiales y métodos. Se usaron 40 machos de rata Wistar de ocho semanas de edad. Los grupos de control y los isquémicos sometidos a transducción en la región del hipocampo CA1, se inyectaron intraperitonealmente por estereotaxia con 50 mg/kg de bromodesoxiuridina (BrdU) a partir de las 24 horas y hasta el día 7 después de la isquemia, con un vector viral asociado a adenovirus usando una secuencia no interferente (SCRmiR) y una interferente (CDK5miR). Se evaluó la capacidad neurológica durante los quince días siguientes y se detectó la capacidad de inmunorreacción para la BrdU, la proteína doblecortina (DCX), los núcleos neuronales (NeuN), y la proteína fibrilar acídica de la glía (Glial Fibrillary Acidic Protein, GFAP) a los 15 y 30 días de la isquemia. Resultados. Los animales isquémicos tratados con CDK5miR mejoraron su puntuación neurológica y presentaron un incremento de la BrdU+ a los 15 días de la isquemia, lo cual se correlacionó con una mayor intensidad de la DCX+ y una menor de la GFAP+. No hubo modificación de los NeuN+, pero sí una reducción significativa de la GFAP+ a los 30 días de la isquemia en los animales tratados comparados con los animales isquémicos no tratados. Conclusión. La terapia con CDK5miR generó la recuperación neurológica de ratas isquémicas asociada con la inducción de la neurogénesis y el control de la capacidad de reacción de la proteína GFAP a corto y largo plazo después de la isquemia.

Downregulation of OsAGO17 by artificial microRNA causes pollen abortion resulting in the reduction of grain yield in rice

Background: Pollen development is an important reproductive process that directly affects pollen fertility and grain yield in rice. Argonaute (AGO) proteins, the core effectors of RNA-mediated silencing, play important roles in regulating plant growth and development. However, few AGO proteins in rice were reported to be involved in pollen development. In this study, artificial microRNA technology was used to assess the function of OsAGO17 in pollen development. Results: In this study, OsAGO17, a rice-specific gene, was specifically expressed in rice pollen grains, with the highest expression in uninucleate microspores. Downregulation of OsAGO17 by artificial microRNA technology based on the endogenous osa-miRNA319a precursor was successfully achieved. It is found that downregulation of OsAGO17 could significantly affect pollen fertility and cause pollen abortion, thus suggesting that OsAGO17 functions in rice pollen development. In addition, the downregulation of OsAGO17 mainly caused a low seed-setting rate, thereby resulting in the reduction of grain yield, whereas the downregulation of OsAGO17 did not significantly affect rice vegetative growth and other agricultural traits including number of florets per panicle, number of primary branch per panicle, and 100-grain weight. Furthermore, the result of subcellular localization analysis indicated that the OsAGO17 protein was localized to both the nucleus and the cytoplasm. Conclusion: These results represent the first report of the biological function for OsAGO17 in rice and indicate that OsAGO17 may possibly play crucial regulatory roles in rice pollen development. It helps us to better understand the mechanism of pollen development in rice.

Effect of RNA Interference Targeting Gene Combined with Ultrasonic Irradiation and SonoVue Microbubbles on Proliferation and Apoptosis in Keratinocytes of Psoriatic Lesions / 中华医学杂志(英文版)

Background@#Signal transducer and activator of transcription 3 (STAT3) was strongly expressed and activated in psoriatic keratinocytes (KCs) and correlated with the severity of psoriasis. The study aimed to investigate the effects of STAT3 small interfering RNA (siRNA) combined with ultrasonic irradiation and SonoVue microbubbles on the proliferation and apoptosis in KCs of psoriatic lesions and the relative mechanisms.@*Methods@#Psoriatic KCs were transfected under four experimental conditions: (1) STAT3 siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (LUS group); (2) STAT3 siRNA only carried by Lipofectamine 3000 (L group); (3) the negative control of siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (siRNA-NC); (4) not treated as Blank. Cell Counting Kit-8 assay was used to evaluate the cell proliferation. Cell cycle analysis was detected with cycle test Plus DNA reagent kit associated with flow cytometer. FITC Annexin V apoptosis detection kit associated with flow cytometer was applied for apoptosis analysis. Fluo calcium indicator associated with flow cytometer was used to analyze intracellular free calcium concentration ([Ca]). The expressions of cyclin D1 and Bcl-xL were detected both at the mRNA level by real-time reverse transcription-polymerase chain reaction (RT-PCR) and at the protein level by Western blotting. The obtained data were statistically evaluated by two-way analysis of variance.@*Results@#STAT3 siRNA inhibited the growth of KCs in a time-dependent manner showing the highest proliferation inhibition in LUS group with proliferation ratio of 45.38% ± 5.85% at 72h (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced an altered cell cycle distribution of KCs showing the highest increases in G2/M-phase population up to 18.06% ± 0.36% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced late apoptosis of KCs with the highest late apoptosis percentage of 22.87% ± 1.28% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the elevation of [Ca]of KCs with the highest calcium fluorescence intensity mean of 1213.67 ± 60.51 in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the downregulation of cyclin D1 and Bcl-xL expressions of KCs at mRNA and protein levels with the lowest expressions in LUS group with cyclin D1 expression of 51.81% ± 9.58% and 70.17% ± 4.22% at mRNA level and at protein level, respectively, and with Bcl-xL expression of 37.58% ± 4.92% and 64.06% ± 7.78% at mRNA level and at protein level, respectively (P < 0.05 vs. L group, siRNA-NC, or Blank).@*Conclusions@#STAT3 siRNA inhibited the growth and induced the apoptosis in psoriatic KCs likely partly through altering cell cycle distribution, elevating [Ca], and downregulating cyclin D1 and Bcl-xL expressions. Silencing the target gene STAT3 in psoriatic KCs with siRNA combined with ultrasonic irradiation and microbubbles would contribute to a significant innovation as a new clinical therapy for psoriasis.

Effects of MnSOD silence on in vitro tumorigenicity in NCI-H446 cells / 中南大学学报(医学版)

To investigate the effect of manganese superoxide dismutase (MnSOD) silence on the in vitro tumorigenicity in human small cell lung cancer NCI-H446 cells and the underlying mechanisms.
 Methods: Sphere formation cells from NCI-H446 cells were obtained by suspension culture, while the expression of MnSOD and urokinase type plasminogen activator (uPAR) was analyzed by Western blot. Silence of MnSOD was performed by adenovirus infection in the second passage formation cells, and the effect of MnSOD silence on tumorigenicity in NCI-H446 cells was evaluated by sphere formation assay and soft-agar colony formation assay, while the expression of uPAR was analyzed by Western blot.
 Results: Compared with NCI-H446 cells, the sphere formation rate, colony formation rate, and the expression of MnSOD and uPAR were significantly increased in the second passage sphere formation cells in NCI-H446 cells (P<0.05). Silence of MnSOD inhibited the sphere formation rate, colony formation rate, and the expression level of uPAR in the second passage sphere formation cells in NCI-H446 cells.
 Conclusion: MnSOD may promote tumorigenicity in NCI-H446 cells by up-regulation of uPAR expression in vitro.

CCR6 Is a Predicting Biomarker of Radiosensitivity and Potential Target of Radiosensitization in Rectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study aimed to explore the functions and mechanisms of C-C motif chemokine receptor 6 (CCR6), a gene associated with progression and metastasis of colorectal cancer (CRC), in radiosensitivity of rectal cancer (RC). MATERIALS AND METHODS: RNA sequencing and immunohistochemical analysis on CCR6 expression were performed in pretreatment tissues of RC patients exhibiting different therapeutic effects of radiotherapy. Colonogenic survival assay was conducted in different CRC cell lines to assess their radiosensitivity. And the impact of CCR6 expression on radiosensitivity was validated through RNA interference. The DNA damage repair (DDR) abilities of cell lines with different CCR6 expression were evaluated through immunofluorescence-based γH2AX quantification. RESULTS: The CCR6 mRNA level was higher in patients without pathologic complete remission (pCR) than in those with pCR (fold changed, 2.11; p=0.004). High-level expression of CCR6 protein was more common in the bad responders than in the good responders (76.3% vs. 37.5%, p < 0.001). The CRC cell lines with higher CCR6 expression (LoVo and sw480) appeared to be more radioresistant, compared with the sw620 cell line which had lower CCR6 expression. CCR6 knockdown made the LoVo cells more sensitive to ionizing radiation (sensitization enhancement ratio, 1.738; p < 0.001), and decreased their DDR efficiency. CONCLUSION: CCR6 might affect the RC radiosensitivity through DDR process. These findings supported CCR6 as a predicting biomarker of radiosensitivity and a potential target of radiosensitization for RC patients.