Knockdown of H19 Inhibits the Pathogenesis of Acne Vulgaris by Targeting the miR-196a/TLR2/NF-κB Axis

Acne vulgaris (AV) is a chronic inflammatory disease of the pilosebaceous unit, and Propionibacterium acnes (P. acnes) has been implicated in acne inflammation. Numerous studies have shown that non-coding RNAs play important roles in regulating the pathophysiological processes of acne. In addition, the first imprinted long non-coding RNA (lncRNA) identified, H19, plays a critical role in inflammatory disease. However, the expression and role of H19 in AV remain unclear. In this study, we investigated the effects of H19 in keratinocytes and explored the regulatory mechanisms underlying these effects. H19 was upregulated in keratinocytes treated with P. acnes in a concentration-dependent manner. The phosphorylated forms of the nuclear factor (NF)-κB-related proteins IκBα (p-IκBα) and p65 (p-P65) were significantly upregulated after P. acnes treatment. Additionally, secretion of the proinflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 was upregulated in a concentration-dependent manner. Knockdown of H19 inhibited the expression of p-IκBα and p-P65 as well as the secretion of TNF-α, IL-6, and IL-8 in keratinocytes treated with P. acnes. Moreover, H19 was found to exert its proinflammatory effects by activating NF-κB. H19, which was localized mainly in the cytoplasm of keratinocytes, facilitated Toll-like receptor 2 (TLR2) expression by acting as a miR-196a sponge. H19 thus promoted the activation of NF-κB and the secretion of inflammatory cytokines through the miR-196a/TLR2 axis. These findings provide novel insight into the pathogenesis of AV.

A Validated Functional Analysis of Partner and Localizer of BRCA2 Missense Variants for Use in Clinical Variant Interpretation

Clinical genetic testing readily detects germline genetic variants. Yet, the rarity of individual variants limits the evidence available for variant classification, leading to many variants of uncertain significance (VUS). VUS cannot guide clinical decisions, complicating counseling and management. In hereditary breast cancer gene PALB2, approximately 50% of clinically identified germline variants are VUS and approximately 90% of VUS are missense. Truncating PALB2 variants have homologous recombination (HR) defects and rely on error-prone nonhomologous end-joining for DNA damage repair (DDR). Recent reports show that some missense PALB2 variants may also be damaging, but most functional studies have lacked benchmarking controls required for sufficient predictive power for clinical use. Here, variant-level DDR capacity in hereditary breast cancer genes was assessed using the Traffic Light Reporter (TLR) to quantify cellular HR/nonhomologous end-joining with fluorescent markers. First, using BRCA2 missense variants of known significance as benchmarks, the TLR distinguished between normal/abnormal HR function. The TLR was then validated for PALB2 and used to test 37 PALB2 variants. Based on the TLR's ability to correctly classify PALB2 validation controls, these functional data where applied in subsequent germline variant interpretations at a moderate level of evidence toward a pathogenic interpretation (PS3_moderate) for 8 variants with abnormal DDR, or a supporting level of evidence toward a benign interpretation (BS3_supporting) for 13 variants with normal DDR.

Cell-specific effects of Dyt1 knock-out on sensory processing, network-level connectivity, and motor deficits

DYT1 dystonia is a debilitating movement disorder characterized by repetitive, unintentional movements and postures. The disorder has been linked to mutation of the TOR1A/DYT1 gene encoding torsinA. Convergent evidence from studies in humans and animal models suggest that striatal medium spiny neurons and cholinergic neurons are important in DYT1 dystonia. What is not known is how torsinA dysfunction in these specific cell types contributes to the pathophysiology of DYT1 dystonia. In this study we sought to determine whether torsinA dysfunction in cholinergic neurons alone is sufficient to generate the sensorimotor dysfunction and brain changes associated with dystonia, or if torsinA dysfunction in a broader subset of cell types is needed. We generated two genetically modified mouse models, one with selective Dyt1 knock-out from dopamine-2 receptor expressing neurons (D2KO) and one where only cholinergic neurons are impacted (Ch2KO). We assessed motor deficits and performed in vivo 11.1 T functional MRI to assess sensory-evoked brain activation and connectivity, along with diffusion MRI to assess brain microstructure. We found that D2KO mice showed greater impairment than Ch2KO mice, including reduced sensory-evoked brain activity in key regions of the sensorimotor network, and altered functional connectivity of the striatum that correlated with motor deficits. These findings suggest that (1) the added impact of torsinA dysfunction in medium spiny and dopaminergic neurons of the basal ganglia generate more profound deficits than the dysfunction of cholinergic neurons alone, and (2) that sensory network impairments are linked to motor deficits in DYT1 dystonia.

Improved transient silencing of gene expression in the mosquito female Aedes aegypti

Gene silencing using RNA interference (RNAi) has become a widely used genetic technique to study gene function in many organisms. In insects, this technique is often applied through the delivery of dsRNA. In the adult female Aedes aegypti, a main vector of human-infecting arboviruses, efficiency of gene silencing following dsRNA injection varies greatly according to targeted genes. Difficult knockdowns using dsRNA can thus hamper gene function analysis. Here, by analysing silencing of three different genes in female Ae. aegypti (p400, ago2 and E75), we show that gene silencing can indeed be dsRNA sequence dependent but different efficiencies do not correlate with dsRNA length. Our findings suggest that silencing is likely also gene dependent, probably due to gene-specific tissue expression and/or feedback mechanisms. We demonstrate that use of high doses of dsRNA can improve knockdown efficiency, and injection of a transfection reagent along with dsRNA reduces the variability in efficiency between replicates. Finally, we show that gene silencing cannot be achieved using siRNA injection in Ae. aegypti adult females. Overall, this work should help future gene function analyses using RNAi in adult females Ae. aegypti, leading toward a better understanding of physiological and infectious processes.

CircANKRD36 Knockdown Suppressed Cell Viability and Migration of LPS-Stimulated RAW264.7 Cells by Sponging MiR-330

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an independent risk factor for mortality in patients with sepsis. In this study, we attempt to investigate the molecular mechanism of circANKRD36 underlying sepsis-induced ALI/ARDS in vitro. We first detected the altered circRNAs in serums of patients with sepsis-induced ARDS using circRNAs microarray. CircANKRD36 expression in serums and LPS-stimulated RAW264.7 cells was measured using qRT-PCR. CCK-8, cell migration, ELISA, and qRT-PCR were applied to the evaluation of cell biological behavior and inflammation reaction. The results showed that circANKRD36 expression was significantly elevated in serum of patients with sepsis-induced ARDS. Knockdown of circANKRD36 inhibited cell viability and migration and alleviated inflammation of lipopolysaccharide-stimulated (LPS-stimulated) RAW264.7 cells. Bioinformatic analysis demonstrated that circANKRD36 serves as a sponge for miR-330 and ROCK1 was directly targeted by miR-330. Furthermore, knockdown of circANKRD36 repressed ROCK1 expression by targeting miR-330. In short, circANKRD36 knockdown suppressed cell viability and migration of LPS-stimulated RAW264.7 cells in vitro via sponging miR-330, which may provide new ideas for the treatment of sepsis-induced ARDS.

The upregulation of miR-204-3p in LPS-induced acute lung injury aggravated pulmonary endothelial cells apoptosis via targeting sulfatase 2

Acute lung injury (ALI) results from the injury of alveolar epithelial cells and pulmonary capillary endothelial cells, with a high mortality rate ranging from 29% to 42%. Therefore, more efficient therapeutic strategies for ALI are necessary. Numerous studies revealed that miRNAs play a role in the regulation of ALI. Lipopolysaccharide (LPS) can induce an inflammatory response and has been widely applied in the establishment of the mouse ALI model. Here, we reported that miR-204-3p expression was upregulated by LPS treatment with increased cytokine secretion. LPS treatment promoted cell apoptosis, accompanied by abnormal cell structure and unobvious alveolar structure. These effects could be prevented by down-regulation of miR-204-3p, and promoted by miR-204-3p overexpression. Sulfatase 2 (SULF2) appeared to be the target of miR-204-3p predicted by TargetScan. Downregulation of miR-204-3p enhanced the protein level of SULF2, indicating that SULF2 was a target of miR-204-3p, which could negatively regulate the expression of SULF2. Thus, targeting miR-204-3p may be a potential therapeutic strategy for ALI.

Upregulation of miR-1266-5p serves as a prognostic biomarker of hepatocellular carcinoma and facilitates tumor cell proliferation, migration and invasion

OBJECTIVE

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. This study aimed to analyze the prognostic value of microRNA-1266-5p (miR-1266-5p) in HCC patients and investigate its biological function in HCC progression.

METHODS

The expression of miR-1266-5p in tissues and cells was measured by quantitative real-time PCR (qRT-PCR). Cell counting kit-8 (CCK-8) assay was used to detect HCC cell proliferation. Transwell assay was performed to evaluate the migration and invasion of HCC cells. Kaplan-Meier methods and Cox regression analysis were used to assess the prognostic value of miR-1266-5p in HCC patients. The relationship between miR-1266-5p and DAB2IP was evaluated by luciferase reporter assay.

RESULTS

Relative expression of miR-1266-5p in tumor tissues, tissues from patients with advanced TNM stage (III-IV) and HCC cells was increased compared with that in corresponding control group. MiR-1266-5p expression was significantly associated with tumor size and TNM stage in HCC patients. Elevated expression of miR-1266-5p was associated with poor prognosis of HCC patients and served as an independent prognostic factor for HCC patients. Overexpression of miR-1266-5p significantly promoted, while miR-1266-5p knockdown significantly inhibited the proliferation, migration and invasion of HCC cells. DAB2IP could directly bind to the miR-1266-5p.

CONCLUSION

Our findings indicated that elevated expression of miR-1266-5p can predict the poor prognosis of HCC patients, and promotes the proliferation, migration and invasion of HCC cells. Therefore, we predict that miR-1266-5p may be a novel biomarker and therapeutic target for the treatment of HCC.

miR-19a-3p inhibition alleviates sepsis-induced lung injury via enhancing USP13 expression

Sepsis is a systemic inflammatory response syndrome caused by various pathogenic microorganisms or toxins. Lung damage is one of the causes of death in patients with sepsis. This study aimed to investigate the role of miR-19a-3p and its regulation mechanism in sepsis-induced lung injury. MH-S cells were treated with lipopolysaccharide (LPS) to establish sepsis-induced lung injury cell model. C57BL/6 mice were injected with miR-19a-3p antagomiR and LPS to construct animal model. LPS-treated and control cells were transfected with miR-19a-3p mimic, miR-19a-3p inhibitor or USP13 expression vector . The expression levels of miR-19a-3p and USP13 were examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The concentration of inflammatory cytokines was measured with enzyme-linked immunosorbent assay (ELISA). The relationship of miR-19a-3p and USP13 was validated using dual-luciferase reporter assay. The lung damage was assessed with hematoxylin-eosin staining (HE). The results showed that LPS treatment increased the concentration of TNF-α, IL-6 and IL-1β in MH-S cells. In LPS treated MH-S cells, the level of miR-19a-3p gradually increased over time. Both miR-19a-3p knockdown and USP13 overexpression in MH-S cells inhibited the LPS-induced production of TNF-α, IL-6 and IL-1β. Moreover, miR-19a-3p negatively regulated the expression of USP13 in MH-S cells. Furthermore, miR-19a-3p inhibitor suppressed lung damage in sepsis model mice. In conclusion, miR-19a-3p knockdown could alleviate sepsis-induced lung injury through enhancing USP13 expression.

Inhibition of GPR4 attenuates SH-SY5Y cell injury in cerebral ischemia/reperfusion via anti-apoptotic pathways

Cerebral ischemia/reperfusion injury (CIRI) can lead to increased vascular endothelial permeability and blood-brain barrier damage in patients with stroke. G protein-coupled receptor 4 (GPR4) is a functional pH sensor that plays a key role in renal ischemia-reperfusion-induced apoptosis. However, whether GPR4 has a role in cerebral ischemia remains to be further studied. Our study found that after oxygen-glucose deprivation/reoxygenation (OGD/R) treatment, the levels of GPR4 and CHOP in SH-SY5Y cells were significantly increased, which was accompanied by a decrease in cell viability, and an increase in LDH release and apoptosis. After knockdown of GPR4 using shRNA, CHOP levels in SH-SY5Y cells were also decreased, which unexpectedly increased cell activity and decreased LDH release and apoptosis rate. Interestingly, CHOP overexpression reversed the effect of GPR4 knockdown, suggesting that OGD/R-induced CIRI may involve endoplasmic reticulum stress-related apoptosis. In conclusion, our study provided a basis for further research on the mechanism of CIRI.

Mycobacterial infection-induced miR-206 inhibits protective neutrophil recruitment via the CXCL12/CXCR4 signalling axis

Pathogenic mycobacteria actively dysregulate protective host immune signalling pathways during infection to drive the formation of permissive granuloma microenvironments. Dynamic regulation of host microRNA (miRNA) expression is a conserved feature of mycobacterial infections across host-pathogen pairings. Here we examine the role of miR-206 in the zebrafish model of Mycobacterium marinum infection, which allows investigation of the early stages of granuloma formation. We find miR-206 is upregulated following infection by pathogenic M. marinum and that antagomir-mediated knockdown of miR-206 is protective against infection. We observed striking upregulation of cxcl12a and cxcr4b in infected miR-206 knockdown zebrafish embryos and live imaging revealed enhanced recruitment of neutrophils to sites of infection. We used CRISPR/Cas9-mediated knockdown of cxcl12a and cxcr4b expression and AMD3100 inhibition of Cxcr4 to show that the enhanced neutrophil response and reduced bacterial burden caused by miR-206 knockdown was dependent on the Cxcl12/Cxcr4 signalling axis. Together, our data illustrate a pathway through which pathogenic mycobacteria induce host miR-206 expression to suppress Cxcl12/Cxcr4 signalling and prevent protective neutrophil recruitment to granulomas.

The role of Notch ligand Jagged1 in osteosarcoma proliferation, metastasis, and recurrence

BACKGROUND

Osteosarcoma is the most common primary bone cancer occurring in young adults and the 5-year survival rate of patients with metastatic osteosarcoma is less than 30% due to high metastatic recurrence and drug resistance. Notch is a highly conserved cell to cell signaling pathway in evolution, and Jagged1 is an important ligand of Notch. Although some studies have found that Notch receptors and ligands including Jagged1 were highly expressed in osteosarcoma tissues and osteosarcoma cells, the role of Jagged1 in osteosarcoma progression and metastasis are still not clear.

METHODS

Tumor tissues were collected from 68 patients and immunohistochemical staining was employed to group these patients by expression of Jagged1. Real-time quantitative PCR and Western blotting were used to detect the expression of Jagged1. We used siRNA to knockdown the expression of Jagged1 in F5M2 cells. Colony formation assay and MTT were employed to detect and analyze the proliferation of F5M2 cells with or without knockdown of Jagged1. Transwell assay were used to detect the migration and invasion of F5M2 cells.

RESULTS

In this study, we found that the high expression of Jagged1 is closely related to the metastasis and recurrence of osteosarcoma in 68 clinical specimens. The expression of Jagged1 in F5M2 cells with high metastasis was significantly higher than that in F4 cells with low metastasis. Knockdown of Jagged1 led to lower ability of proliferation, migration, and invasion in F5M2 cells.

CONCLUSION

The high expression of Jagged1 is closely related to the metastasis and recurrence of osteosarcoma. Knockdown of Jagged1 significantly reduced the proliferation, migration, and invasion of osteosarcoma cells. Our results suggested that knockdown of Jagged1 may be a potentially effective treatment for metastatic osteosarcoma.

Aquaporin 3 promotes human extravillous trophoblast migration and invasion

PROBLEM

Does aquaporin 3 (AQP3) affect the migration and invasion of human extravillous trophoblast (HTR8/Svneo) cells?

METHOD OF STUDY

A lentivirus infection system was used to construct stable cell lines with either AQP3 knockdown or overexpression. RT-PCR and western blotting were used to verify the efficiencies of AQP3 knockdown or overexpression in HTR8/Svneo cells at mRNA and protein levels, respectively. Cell Counting Kit-8 and flow cytometry assays were used to detect the influence of AQP3 knockdown or overexpression on proliferation and apoptosis of HTR8/Svneo cells. In addition, wound healing and Transwell invasion assays were used to detect the effects of AQP3 knockdown or overexpression on migration and invasion capabilities of HTR8/Svneo cells. An Agilent gene chip was used to screen for significant differentially expressed genes after AQP3 knockdown. Finally, mechanisms by which AQP3 influences the migration and invasion of HTR8/Svneo cells were explored using bioinformatic analysis.

RESULTS

Compared with controls, migration and invasion capabilities of HTR8/Svneo cells were significantly reduced after AQP3 knockdown, and significantly increased after AQP3 overexpression. Subsequent bioinformatic analysis of gene chip expression profiles indicated downregulation of genes related to adhesion such as PDGF-B, as well as signaling pathways (such as PIK3/AKT, NF-κB, and TNF) after AQP3 knockdown.

CONCLUSIONS

AQP3 could significantly promote migration and invasion capabilities of human extravillous trophoblasts, it may mediate embryo invasion and adhesion to endometrium by regulating PDGF-B, PIK3/AKT signaling pathways, although this requires further verification.

Alpha-actinin-4 is essential for maintaining normal trophoblast proliferation and differentiation during early pregnancy

BACKGROUND

Proper differentiation of trophoblasts in the human placenta is essential for a successful pregnancy, whereas abnormal regulation of this process may lead to adverse pregnancy outcomes, especially preeclampsia (PE). However, the underlying mechanism of trophoblast differentiation remains unclear. Previous studies have reported the involvement of alpha-actinin-4 (ACTN4) in the actin cytoskeleton dynamics and motility. Hence, we hypothesized that ACTN4 may act as an important regulator in the normal proliferation and differentiation of trophoblasts during early pregnancy.

METHOD

To test this hypothesis, we collected villous tissues from women undergoing a legal pregnancy termination during 6-10 weeks of gestation and explanted them for cell culture and siRNA transfection. We also obtained placental tissues from PE patients and healthy pregnant women and isolated the primary cytotrophoblast (CTB) cells. The expression of ACTN4 in the CTBs of placental villi and during the differentiation of CTBs into STBs was detected by immunofluorescence, immunohistochemistry (IHC), and EdU proliferation assays. Besides, villous explant, Matrigel invasion, transwell migration assay, and Wound-healing assay were performed to identify the possible role of ACTN4 in the outgrowth of explants and the invasion, migration, and proliferation of cell column trophoblasts (CCTs). Western blot analysis was carried out to compare the protein expression level of AKT, Snail activities, and epithelial-to-mesenchymal transition (EMT) in the villi or HTR8/SVneo cells with ACTN4 knockdown.

RESULTS

ACTN4 was highly expressed in CTB cells and interstitial extravillous trophoblast (iEVT) cells but not found in the syncytiotrophoblast (STB) cells in the first trimester villi. Downregulation of ACTN4 led to reduced trophoblast proliferation and explant outgrowth ex vivo, as well as iEVT invasion and migration in vitro due to disrupt of actin filaments organization. Such ACTN4 inhibition also decreased AKT and Snail activities and further impeded the EMT process. In addition, ACTN4 expression was found to be downregulated in the iEVTs from preeclamptic placentas.

CONCLUSIONS

Our findings suggest that ACTN4 may act as an important regulator of trophoblast proliferation and differentiation during early pregnancy, and dysregulation of this protein may contribute to preeclampsia pathogenesis.

MiR-1179 is downregulated in cervical cancer and its overexpression suppresses cancer cells invasion by targeting CHAF1A/ZEB1

The anticancer effect of miR-1179 has been extensively studied in many tumors. The mechanism of miR-1179 action in cervical cancer, however, remains largely unknown. In the present study, miR-1179 was downregulated in both cervical cancer cell lines and cancer tissues. In addition, miR-1179 mimic suppressed cancer cells invasion and epithelial-mesenchymal transition (EMT) in cervical cancer SiHa and Caski cells. We found that chromatin assembly factor 1 subunit A (CHAF1A) might be a direct target of miR-1179 and could be regulated by miR-1179. Furthermore, CHAF1A shRNA suppressed the cervical cancer cells invasion and the expression of EMT-promoted proteins. Reversely, CHAF1A overexpression not only promoted cervical cancer cells invasion but also upregulated the level of Zinc finger E-box binding protein 1 (ZEB1), an EMT-related protein. The induction of ZEB1 could be counteracted by miR-1179 overexpression. It was observed that in cervical cancer patients' tissues, miR-1179 was downregulated while the pathway of CHAF1A/ZEB1 was upregulated. In summary, our research indicated that the miR-1179 might regulate CHAF1A/ZEB1 axis and inhibit the invasion of cervical cancer cells.

Non-Target Effects of dsRNA Molecules in Hemipteran Insects

Insect pest control by RNA interference (RNAi)-mediated gene expression knockdown can be undermined by many factors, including small sequence differences between double-stranded RNA (dsRNA) and the target gene. It can also be compromised by effects that are independent of the dsRNA sequence on non-target organisms (known as sequence-non-specific effects). This study investigated the species-specificity of RNAi in plant sap-feeding hemipteran pests. We first demonstrated sequence-non-specific suppression of aphid feeding by dsRNA at dietary concentrations ≥0.5 µg µL⁻¹. Then we quantified the expression of NUC (nuclease) genes in insects administered homologous dsRNA (with perfect sequence identity to the target species) or heterologous dsRNA (generated against a related gene of non-identical sequence in a different insect species). For the aphids Acyrthosiphon pisum and Myzus persicae, significantly reduced NUC expression was obtained with the homologous but not heterologous dsRNA at 0.2 µg µL⁻¹, despite high dsNUC sequence identity. Follow-up experiments demonstrated significantly reduced expression of NUC genes in the whitefly Bemisia tabaci and mealybug Planococcus maritimus administered homologous dsNUCs, but not heterologous aphid dsNUCs. Our demonstration of inefficient expression knockdown by heterologous dsRNA in these insects suggests that maximal dsRNA sequence identity is required for RNAi targeting of related pest species, and that heterologous dsRNAs at appropriate concentrations may not be a major risk to non-target sap-feeding hemipterans.

Knockdown of Nuclear lncRNAs by Locked Nucleic Acid (LNA) Gapmers in Nephron Progenitor Cells

Despite recent advance in our understanding on the role of long noncoding RNAs (lncRNAs), the function of the vast majority of lncRNAs remains poorly understood. To characterize the function of lncRNAs, knockdown studies are essential. However, the conventional silencing methods for mRNA, such as RNA interference (RNAi), may not be as efficient against lncRNAs, partly due to the mismatch of the localization of lncRNAs and RNAi machinery. To circumvent such limitation, a new technique has recently been developed, i.e., locked nucleic acid (LNA) gapmers. This system utilizes RNase H that distributes evenly in both nucleus and cytoplasm and is expected to knock down lncRNAs of interest more consistently regardless of their localization in the cell. In this chapter, we describe the procedure with tips to silence lncRNAs by LNA gapmers, by using mouse nephron progenitor cells as an example.

ARID1A knockdown in human endothelial cells directly induces angiogenesis by regulating angiopoietin-2 secretion and endothelial cell activity

AT-rich interactive domain 1A (ARID1A) is a novel tumor suppressor gene found in several human cells and its loss/defect is commonly observed in many cancers. However, its roles in angiogenesis, which is one of the hallmarks for tumor progression, remained unclear. Herein, we demonstrated the direct effects of ARID1A knockdown in human endothelial cells by lentivirus-based short-hairpin RNA (shRNA) (shARID1A) on angiogenesis. Functional assays revealed that shARID1A significantly enhanced cell proliferation and migration/invasion and endothelial tube formation compared with the control cells transfected with scramble shRNA (shControl). Additionally, the shARID1A-transfected cells had significantly increased podosome formation and secretion of angiopoietin-2 (ANG2), a key angiogenic factor. Moreover, neutralization of ANG2 with monoclonal anti-ANG2 antibody strongly reduced cell proliferation and migration/invasion and endothelial tube formation in the shARID1A-transfected cells. These findings indicate that down-regulation of ARID1A in human endothelial cells directly induces angiogenesis by regulating angiopoietin-2 secretion and endothelial cell activity.

Collapsin response mediator protein 5 (CRMP5) modulates susceptibility to chronic social defeat stress in mice

Collapsin response mediator protein 5 (CRMP5), a member of the CRMP family, is expressed in the brain, particularly in the hippocampus, an area of the brain that can modulate stress responses. Social stress has a well-known detrimental effect on health and can lead to depression, but not all individuals are equally sensitive to stress. To date, researchers have not conclusively determined how social stress increases the susceptibility of the brain to depression. Here, we used the chronic social defeat stress (CSDS) model and observed higher hippocampal CRMP5 expression in stress-susceptible (SS) mice than in control and stress-resilient (RES) mice. A negative correlation was observed between the expression levels of CRMP5 and the social interaction (SI) ratio. Reduced hippocampal CRMP5 expression increased the SI ratio in SS mice, whereas CRMP5 overexpression was sufficient to induce social avoidance behaviors in control mice following exposure to subthreshold social stress induced by lentivirus-based overexpression and inducible tetracycline-on strategies to upregulate CRMP5. Interestingly, increased CRMP5 expression in SS and lenti-CRMP5-treated mice also caused serum corticosterone concentrations to increase. These findings improve our understanding of the potential mechanism by which CRMP5 triggers susceptibility to social stress, and they support the further development of therapeutic agents for the treatment of stress disorders in humans.

Knockdown of AURKA sensitizes the efficacy of radiation in human colorectal cancer

AIMS

Abnormally amplified expression of AURKA (aurora kinase A) is closely related to chemo-resistance in human colorectal cancer, lung cancer and leukemia. However, the biological role of AURKA in response to radio-sensitivity in human colorectal cancer is still unknown. Therefore, we evaluated the radio-sensitize ability of perturbation AURKA in human colorectal cancer.

MAIN METHODS

The knockdown effect of shAURKA was determined by western blot and qRT-PCR, respectively. Cell growth was determined by CCK-8 and clonogenic assay. Cell migration and metastasis was measured by wound healing assay and transwell invasive assay, respectively. Cell cycle and apoptosis was analyzed by flow cytometry. The alteration of down-stream targets was determined by western blot analysis.

KEY FINDINGS

We observed that high-level of AURKA expression is associated with poor prognosis in CRC patients receiving radiotherapy. Knockdown of AURKA significantly sensitizes the efficacy of radiation on the proliferation of HCT116 and HT-29 cells. The combination of AURKA inhibition and radiation could effectively suppress the ability of cell migration and metastasis, but also synergistically induce cellular apoptosis and arrest cell cycle at G2/M phase. Further studies demonstrated that knockdown AURKA markedly enhanced the efficacy of radiation through elevated PARP cleavage and induced AURKA-mediated pro-apoptosis factor BIM. Meanwhile, knockdown of AURKA in combination with radiation synergistically suppressed the regulator in blockage of G2/M phase, CDK2.

SIGNIFICANCE

Taken together, our results provide the evidence that targeted inhibition of AURKA could be a promising strategy for enhancing the efficacy of radiation for the treatment of human colorectal cancer.

CRISPR/Cas9 System to Knockdown MicroRNA In Vitro and In Vivo

MicroRNAs (miRNAs) are a class of small noncoding single-stranded RNA molecules containing 18-22 nucleotides that play an important role in the regulation of gene expression at the post-transcriptional and translational levels. Loss-of-function studies are the fundamental strategy to examine miRNA function and target genes in cellular and molecular biology. Traditional methods for miRNA loss-of-function studies include miRNA-specific antisense inhibitors, miRNA sponges, and genetic knockout. However, efficiency, specificity, and stability of these methods are not adequate. Our study suggests that CRISPR/Cas9 is an economic, convenient, and innovative strategy with high efficiency, specificity, and stability for the modulation of miRNA expression. Herein, we describe a detailed protocol for knocking out miRNA genes in vitro and in vivo with the CRISPR/Cas9 system.

Genome-Scale Perturbation of Long Noncoding RNA Expression Using CRISPR Interference

CRISPR-mediated interference (CRISPRi), a robust and specific system for programmably repressing transcription, provides a versatile tool for systematically characterizing the function of long noncoding RNAs (lncRNAs). When used with highly parallel, lentiviral pooled screening approaches, CRISPRi enables the targeted knockdown of tens of thousands of lncRNA-expressing loci in a single screen. Here we describe the use of CRISPRi to target lncRNA loci in a pooled screen, using cell growth and proliferation as an example of a phenotypic readout. Considerations for custom lncRNA-targeting libraries, alternative phenotypic readouts, and orthogonal validation approaches are also discussed.

MnFtz-f1 Is Required for Molting and Ovulation of the Oriental River Prawn Macrobrachium nipponense

Molting and ovulation are the basic processes responsible for the growth and reproduction of Macrobrachium nipponense; however, the molecular mechanisms of molting and ovulation in M. nipponense are poorly understood. The present study aimed to use MnFtz-f1 as the starting point to study the molting and ovulation phenomena in M. nipponense at the molecular level. The full-length MnFtz-f1 cDNA sequence was 2,198 base pairs (bp) in length with an open reading frame of 1,899 bp encoding 632 amino acids. Quantitative real-time PCR analysis showed that MnFtz-f1 was highly expressed in the ovary at the cleavage stage and on the fifth day after hatching. In vivo administration of 20-hydroxyecdysone (20E) showed that 20E effectively inhibited the expression of the MnFtz-f1 gene, and the silencing of the MnFtz-f1 gene reduced the content of 20E in the ovary. In situ hybridization (ISH) analysis revealed the localization of MnFtz-f1 in the ovary. Silencing of MnFtz-f1 by RNA interference (RNAi) resulted in significant inhibition of the expression of the vitellogenin (Vg), Spook, and Phantom genes, thus confirming that MnFtz-f1 had a mutual regulatory relationship with Vg, Spook, and Phantom. After RNAi, the molting frequency and ovulation number of M. nipponense decreased significantly, which demonstrated that MnFtz-f1 played a pivotal role in the process of molting and ovulation.

Enhancer II-targeted dsRNA decreases GDNF expression via histone H3K9 trimethylation to inhibit glioblastoma progression

BACKGROUND

Glial cell line-derived neurotrophic factor (GDNF) is expressed in both astrocytes and glioblastoma (GBM) cells. GDNF expression is significantly increased in GBM, and inhibiting its expression can retard GBM progression. However, there is no known method for specific inhibition of GDNF in GBM cells.

METHODS

Promoter-targeted dsRNA-induced transcriptional gene silencing or activation was recently achieved in human cells. This approach has the potential to specifically regulate gene transcription via epigenetic modifications. In this study, we designed six candidate dsRNAs targeting the enhancer or silencer in GDNF gene promoter II to check their effects on GDNF transcription and GBM progression.

RESULTS

Among these dsRNAs, enhancer II-targeted dsRNA significantly inhibited U251 GBM progression by downregulating GDNF (P < 0.05), while silencer II-targeted dsRNA exerted an opposite effect. Moreover, enhancer II-targeted dsRNA did not significantly change GDNF expression in human astrocytes (HA) and the proliferation and migration of HA cells (P > 0.05). Bisulfate PCR and chromatin immunoprecipitation analyses revealed that both DNA methylation and trimethylation of histone 3 at lysine 9 (H3K9me3) at silencer II-targeted region significantly increased, and H3K9me3 at enhancer II-targeted region significantly decreased, in U251 cells compared with HA cells in non-intervention condition (P < 0.05). Both enhancer II- and silencer II-targeted dsRNA significantly increased H3K9me3 methylation rather than DNA at the targeted site in U251 cells (P < 0.05). The expression and activity of histone methyltransferase SETDB1 increased dramatically in U251 cells compared with HA cells, and it was recruited to enhancer II targeting region after enhancer II-targeted dsRNA treatment in U251 cells (P < 0.05).

CONCLUSIONS

Our results demonstrate that a promoter-targeted dsRNA can silence or promote gene transcription depending on its targeted site in different cis-acting elements in the gene promoter. Targeted inhibition of GDNF by enhancer II-targeted dsRNA may be explored as a novel treatment for GBM.

Epigenetic inactivation of IRX4 is responsible for acceleration of cell growth in human pancreatic cancer

Epigenetic gene silencing by aberrant DNA methylation is one of the important mechanisms leading to loss of key cellular pathways in tumorigenesis. Methyl-CpG-targeted transcriptional activation (MeTA) reactivates hypermethylation-mediated silenced genes in a different way from DNA-demethylating agents. Microarray coupled with MeTA (MeTA-array) identified seven commonly hypermethylation-mediated silenced genes in 12 pancreatic ductal adenocarcinoma (PDAC) cell lines. Among these, we focused on IRX4 (Iroquois homeobox 4) because IRX4 is located at chromosome 5p15.33 where PDAC susceptibility loci have been identified through genome-wide association study. IRX4 was greatly downregulated in all of the analyzed 12 PDAC cell lines by promoter hypermethylation. In addition, the IRX4 promoter region was found to be frequently and specifically hypermethylated in primary resected PDACs (18/28: 64%). Reexpression of IRX4 inhibited colony formation and proliferation in two PDAC cell lines, PK-1 and PK-9. In contrast, knockdown of IRX4 accelerated cell proliferation in an IRX4-expressing normal pancreatic ductal epithelial cell line, HPDE-1. Because IRX4 is a sequence-specific transcription factor, downstream molecules of IRX4 were pursued by microarray analyses utilizing tetracycline-mediated IRX4 inducible PK-1 and PK-9 cells; CRYAB, CD69, and IL32 were identified as IRX4 downstream candidate genes. Forced expression of these genes suppressed colony formation abilities for both PK-1 and PK-9. These results suggest that DNA methylation-mediated silencing of IRX4 contributes to pancreatic tumorigenesis through aberrant transcriptional regulation of several cancer-related genes.

Early Over-Expressing of microRNA-145 Effectively Precludes the Development of Neuropathic Mechanical Hyperalgesia via Suppressing Nav1.8 in Diabetic Rats

BACKGROUND

Painful diabetic neuropathy (PDN) is a common complication secondary to diabetes mellitus. Nav1.8 is an isoform of voltage-gated sodium channels and its expression regulation is closely related with PDN. MicroRNA-145 (miR-145) is involved in the occurrence and development of neuropathic pain. TargetScan software has revealed that Nav1.8 (SCN10A) is the major target of miR-145. However, its function between miR-145 and Nav1.8 in PDN is unknown.

OBJECTIVES

We aim to explore the regulatory effect of miR-145 on the expression and function of Nav1.8, which plays a pivotal role in precluding the advancement of neuropathic mechanical hyperalgesia in diabetic pain.

STUDY DESIGN

An experimental, animal study.

SETTING

An animal research facility at Nanjing Maternal and Child Health Institute, China.

METHODS

The paw mechanical withdrawal threshold (PMWT) of rats was assessed with the von Frey test. The adverse regulation of Nav1.8 by miR-145 was confirmed by a dual luciferase detection system in HEK293T cells. The mRNA level and expression of Nav1.8 in dorsal root ganglion (DRG) neurons were assessed with real-time polymerase chain reaction (real-time PCR), western blotting and immunofluorescence assays following intrathecal injection of agomiR-145 in vitro and in vivo. Whole-cell patch-clamping was applied to assess alterations in the tetrodotoxin-resistant (TTX-R) sodium current (Nav1.8) in DRGs.

RESULTS

The PMWT was significantly decreased in rats following streptozotocin (STZ) injection on Day 7 and was maintained at a lower level on Day 28; this change was accompanied by changes in the expression of Nav1.8 in DRG neurons, which was increased 3 days after STZ injection and reached a maximal level on Day 14. The early knockdown of Nav1.8 with siRNA or agomiR-145 treatment on Day 8 effectively precluded the deterioration of pain behaviors in STZ-treated rats. The luciferase intensity was significantly decreased in HEK293T cells expressing wild-type SCN10A infected with miR-145 mimic. In addition, Nav1.8 overexpression was significantly repressed via overexpression of miR-145 in cultured DRG neurons, and neuronal hyperexcitability was concomitantly decreased. Furthermore, the intrathecal administration of agomiR-145 elicited a significant decrease in Nav1.8 expression in DRG neurons from STZ-treated rats on Day 14.

LIMITATIONS

The causes of PDN are likely to be multifactorial and inflammatory markers, such as IL-6, IL-2, and TNF-?, are elevated in hyperglycemia and might be the precipitating factors that contribute to miR-145 dysregulation. The curative effect of miR-145 upregulation in reversal of pain behaviors at the stage of well-established PDN wasn't investigated in this study.

CONCLUSION

Early infection with a lentiviral vector overexpressing miR-145 adversely regulated the expression and function of TTX-resistant Nav1.8 and abrogated the development of PDN. Therefore, miR-145 might be a potential therapeutic target for preventing PDN in the near future.