DEAD-box RNA helicase subunits of the Drosha complex are required for processing of rRNA and a subset of microRNAs

Connexin32 gap junction channels deliver miR155-3p to mediate pyroptosis in renal ischemia-reperfusion injury

OBJECTIVES

To explore whether the gap junction (GJ) composed by connexin32(Cx32) mediated pyroptosis in renal ischemia-reperfusion(I/R) injury via transmitting miR155-3p, with aim to provide new strategies for the prevention and treatment of acute kidney injury (AKI) after renal I/R.

METHODS

8-10 weeks of male C57BL/ 6 wild-type mice and Cx32 knockdown mice were divided into two groups respectively: control group and renal I/R group. MCC950 (50 mg/kg. ip.) was used to inhibit NLRP3 in vivo. Human kidney tubular epithelial cells (HK - 2) and rat kidney tubular epithelial cells (NRK-52E) were divided into high-density group and low-density group, and treated with hypoxia reoxygenation (H/R) to mimic I/R. The siRNA and plasmid of Cx32, mimic and inhibitor of miR155-3p were transfected into HK - 2 cells respectively. Kidney pathological and functional injuries were measured. Western Blot and immunofluorescent staining were used to observe the expression of NLRP3, GSDMD, GSDMD-N, IL - 18, and mature IL-18. The secretion of IL-18 and IL-1β in serum, kidney tissue and cells supernatant were detected by enzyme-linked immuno sorbent assay (ELISA) kit, and the expression of NLPR3 and miR155-3p were detected by RT-qPCR and fluorescence in situ hybridization (FISH).

RESULTS

Tubular pyroptosis were found to promote AKI after I/R in vivo and Cx32-GJ regulated pyroptosis by affecting the expression of miR155-3p after renal I/R injury. In vitro, H/R could lead to pyroptosis in HK-2 and NRK-52E cells. When the GJ channels were not formed, and Cx32 was inhibited or knockdown, the expression of miR155-3p was significantly reduced and the pyroptosis was obviously inhibited, leading to the reduction of injury and the increase of survival rate. Moreover, regulating the level of miR155-3p could affect survival rate and pyroptosis in vitro after H/R.

CONCLUSIONS

The GJ channels composed of Cx32 regulated tubular pyroptosis in renal I/R injury by transmitting miR155-3p. Inhibition of Cx32 could reduce the level of miR155-3p further to inhibit pyroptosis, leading to alleviation of renal I/R injury which provided a new strategy for preventing the occurrence of AKI. Video Abstract.

Ribosomal protein L24 mediates mammalian microRNA processing in an evolutionarily conserved manner

To investigate the mechanism(s) underlying the expression of primate-specific microRNAs (miRs), we sought DNA regulatory elements and proteins mediating expression of the primate-specific hsa-miR-608 (miR-608), which is located in the SEMA4G gene and facilitates the cholinergic blockade of inflammation by targeting acetylcholinesterase mRNA. 'Humanized' mice carrying pre-miR-608 flanked by 250 bases of endogenous sequences inserted into the murine Sema4g gene successfully expressed miR-608. Moreover, by flanking miR-608 by shortened fragments of its human genome region we identified an active independent promoter within the 150 nucleotides 5' to pre-miR-608, which elevated mature miR-608 levels by 100-fold in transfected mouse- and human-originated cells. This highlighted a regulatory role of the 5' flank as enabling miR-608 expression. Moreover, pull-down of the 150-base 5' sequence revealed its interaction with ribosomal protein L24 (RPL24), implicating an additional mechanism controlling miR-608 levels. Furthermore, RPL24 knockdown altered the expression of multiple miRs, and RPL24 immunoprecipitation indicated that up- or down-regulation of the mature miRs depended on whether their precursors bind RPL24 directly. Finally, further tests showed that RPL24 interacts directly with DDX5, a component of the large microprocessor complex, to inhibit miR processing. Our findings reveal that RPL24, which has previously been shown to play a role in miR processing in Arabidopsis thaliana, has a similar evolutionarily conserved function in miR biogenesis in mammals. We thus characterize a novel extra-ribosomal role of RPL24 in primate miR regulation.

Association of DDX5/p68 protein with the upstream erythroid enhancer element (EHS1) of the gene encoding the KLF1 transcription factor

EKLF/KLF1 is an essential transcription factor that plays a global role in erythroid transcriptional activation. Regulation of KLF1 is of interest, as it displays a highly restricted expression pattern, limited to erythroid cells and its progenitors. Here we use biochemical affinity purification to identify the DDX5/p68 protein as an activator of KLF1 by virtue of its interaction with the erythroid-specific DNAse hypersensitive site upstream enhancer element (EHS1). We further show that this protein associates with DEK and CTCF. We postulate that the range of interactions of DDX5/p68 with these and other proteins known to interact with this element render it part of the enhanseosome complex critical for optimal expression of KLF1 and enables the formation of a proper chromatin configuration at the Klf1 locus. These individual interactions provide quantitative contributions that, in sum, establish the high-level activity of the Klf1 promoter and suggest they can be selectively manipulated for clinical benefit.

Helicases in R-loop Formation and Resolution

With the development and wide usage of CRISPR technology, the presence of R-loop structures, which consist of an RNA-DNA hybrid and a displaced single-strand (ss) DNA, has become well accepted. R-loop structures have been implicated in a variety of circumstances and play critical roles in the metabolism of nucleic acid and relevant biological processes, including transcription, DNA repair, and telomere maintenance. Helicases are enzymes that use an ATP-driven motor force to unwind double-strand (ds) DNA, dsRNA, or RNA-DNA hybrids. Additionally, certain helicases have strand-annealing activity. Thus, helicases possess unique positions for R-loop biogenesis: they utilize their strand-annealing activity to promote the hybridization of RNA to DNA, leading to the formation of R-loops; conversely, they utilize their unwinding activity to separate RNA-DNA hybrids and resolve R-loops. Indeed, numerous helicases such as senataxin (SETX), Aquarius (AQR), WRN, BLM, RTEL1, PIF1, FANCM, ATRX (alpha-thalassemia/mental retardation, X-linked), CasDinG, and several DEAD/H-box proteins are reported to resolve R-loops; while other helicases, such as Cas3 and UPF1, are reported to stimulate R-loop formation. Moreover, helicases like DDX1, DDX17, and DHX9 have been identified in both R-loop formation and resolution. In this review, we will summarize the latest understandings regarding the roles of helicases in R-loop metabolism. Additionally, we will highlight challenges associated with drug discovery in the context of targeting these R-loop helicases.

Targeting microRNAs as a promising anti-cancer therapeutic strategy against traffic-related air pollution-mediated lung cancer

Air pollutants are increasingly emitted into the atmosphere because of the high dependency of humans on fossil-derived fuels. Wind speed and direction assisted high dispersibility and uncontrolled nature of air pollution across geo-/demographical borders, making it one of the major global concerns. Besides climate change, air pollution has been found to be associated with various diseases, such as cancer. Lung cancer, which is the world's most common type of cancer, has been found to be associated with traffic-related air pollution. Research and political efforts have been taken to explore green/renewable energy sources. However, these efforts at the current intensity cannot cope with the increasing need for fossil fuels. More specifically, political tensions such as the Russian-Ukraine war, economic tension (e.g., China-USA economic tensions), and other issues (e.g., pandemic, higher inflation rate, and poverty) significantly hindered phasing out fossil fuels. In this context, an increasing global population will be exposed to traffic-related air pollution, which justifies the current uptrend in the number of lung cancer patients. To combat this health burden, novel treatments with higher efficiency and specificity must be designed. One of the potential "life changer" options is microRNA (miRNA)-based therapy to target the expression of oncogenic genes. That said, this review discusses the association of traffic-related air pollution with lung cancer, the changes in indigenous miRNAs in the body during lung cancer, and the current status of miRNA therapeutics for lung cancer treatment. We believe that the article will significantly appeal to a broad readership of oncologists, environmentalists, and those who work in the field of (bio)energy. It may also gain the policymakers' attention to establish better health policies and regulations about air pollution, for example, by promoting (bio)fuel exploration, production, and consumption.

The SWGEDWGEIW from Soybean Peptides Reduces Insulin Resistance in 3T3-L1 Adipocytes by Activating p-Akt/GLUT4 Signaling Pathway

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with anti-diabetic properties. Notably, the protective mechanism of the single peptide SWGEDWGEIW (TSP) from soybean peptides (SBPs) on insulin resistance of adipocytes in an inflammatory state was investigated by detecting the lipolysis and glucose absorption and utilization of adipocytes. The results showed that different concentrations of TSP (5, 10, 20 µg/mL) intervention can reduce 3T3-L1 adipocytes’ insulin resistance induced by inflammatory factors in a dose-dependent manner and increase glucose utilization by 34.2 ± 4.6%, 74.5 ± 5.2%, and 86.7 ± 6.1%, respectively. Thus, TSP can significantly alleviate the lipolysis of adipocytes caused by inflammatory factors. Further mechanism analysis found that inflammatory factors significantly reduced the phosphorylation (p-Akt) of Akt, two critical proteins of glucose metabolism in adipocytes, and the expression of GLUT4 protein downstream, resulting in impaired glucose utilization, while TSP intervention significantly increased the expression of these two proteins. After pretreatment of adipocytes with PI3K inhibitor (LY294002), TSP failed to reduce the inhibition of p-Akt and GLUT4 expression in adipocytes. Meanwhile, the corresponding significant decrease in glucose absorption and the increase in the fat decomposition of adipocytes indicated that TSP reduced 3T3-L1 adipocytes’ insulin resistance by specifically activating the p-Akt/GLUT4 signal pathway. Therefore, TSP has the potential to prevent obesity-induced adipose inflammation and insulin resistance.

The Antibacterial Activity of Kaempferol Combined with Colistin against Colistin-Resistant Gram-Negative Bacteria

Social hygiene is seriously threatened by the rise in colistin (COL) resistance against Gram-negative bacteria (GNB). With resistance to last-line antibiotics such as COL becoming more common, it is imperative to identify alternative treatment options. In our work, we sought to determine if COL plus kaempferol (KP) present synergistic effects on the antibacterial and antibiofilm activities against colistin-resistant (Col-R) GNB in vivo and in vitro. Twenty-four Col-R GNB were collected as the experimental strains. The synergistic activity of COL and KP was evaluated by checkerboard method, time-killing assays, and the Galleria mellonella experiment. The antibiofilm effectiveness of the COL/KP combination against Col-R GNB was assessed using biofilm inhibition and eradication assays and scanning electron microscopy (SEM). Cytotoxicity tests were performed to detect the toxicity of KP monotherapy or combination therapy. There is synergistic antibacterial activity of COL and KP combination in vitro. KP combined with COL could inhibit the formation of bacterial biofilms. The amalgamation of COL and KP considerably reduced the amount of bacteria in the biofilm, according to the SEM findings. The COL/KP combination improved the survivorship of infected larvae in the G. mellonella in vivo infection model. In addition, the combination of KP and COL showed no cytotoxicity at synergistic combined concentrations according to cytotoxicity assays. This represents the first account of the antibacterial and antibiofilm activities of KP in combination with COL against Col-R GNB. Therefore, our results may provide an effective alternative route to combat Col-R GNB infections. IMPORTANCE COL is one of the few antibiotics effective against clinical isolates of GNB. However, in recent years, GNB resistance to colistin has been increasing. As a result, the combined application of colistin in conjunction with nonantibacterial medications has garnered considerable interest. In this work, the KP/COL combination showed effective antibacterial and antibiofilm activities in vitro and in vivo. The synergistic effect of combined application may be attributed to membrane permeability. Due to the low cytotoxicity of the combined concentration, the combination exhibits a promising future for use in clinical anti-infection treatments. This finding might broaden the potential applications for COL.

The SWGEDWGEIW from Soybean Peptides Reduce Oxidative Damage-Mediated Apoptosis in PC-12 Cells by Activating SIRT3/FOXO3a Signaling Pathway

The goal of the investigation was to study the protective effects of the SWGEDWGEIW (the single peptide, TSP) from soybean peptides (SBP) on hydrogen peroxide (H2O2)-induced apoptosis together with mitochondrial dysfunction in PC-12 cells and their possible implications to protection mechanism. Meanwhile, the SBP was used as a control experiment. The results suggested that SBP and TSP significantly (p < 0.05) inhibited cellular oxidative damage and ROS-mediated apoptosis. In addition, SBP and TSP also enhanced multiple mitochondrial biological activities, decreased mitochondrial ROS levels, amplified mitochondrial respiration, increased cellular maximal respiration, spare respiration capacity, and ATP production. In addition, SBP and TSP significantly (p < 0.05) raised the SIRT3 protein expression and the downstream functional gene FOXO3a. In the above activity tests, the activity of TSP was slightly higher than that of SBP. Taken together, our findings suggested that SBP and TSP can be used as promising nutrients for oxidative damage reduction in neurons, and TSP is more effective than SBP. Therefore, TSP has the potential to replace SBP and reduce neuronal oxidative damage.

DDX17 is required for efficient DSB repair at DNA:RNA hybrid deficient loci

Proteins with RNA-binding activity are increasingly being implicated in DNA damage responses (DDR). Additionally, DNA:RNA-hybrids are rapidly generated around DNA double-strand breaks (DSBs), and are essential for effective repair. Here, using a meta-analysis of proteomic data, we identify novel DNA repair proteins and characterise a novel role for DDX17 in DNA repair. We found DDX17 to be required for both cell survival and DNA repair in response to numerous agents that induce DSBs. Analysis of DSB repair factor recruitment to damage sites suggested a role for DDX17 early in the DSB ubiquitin cascade. Genome-wide mapping of R-loops revealed that while DDX17 promotes the formation of DNA:RNA-hybrids around DSB sites, this role is specific to loci that have low levels of pre-existing hybrids. We propose that DDX17 facilitates DSB repair at loci that are inefficient at forming DNA:RNA-hybrids by catalysing the formation of DSB-induced hybrids, thereby allowing propagation of the damage response.

miR143-3p-Mediated NRG-1-Dependent Mitochondrial Dysfunction Contributes to Olanzapine Resistance in Refractory Schizophrenia

BACKGROUND

Olanzapine is an effective antipsychotic medication for treatment-resistant schizophrenia (TRS); however, the therapeutic effectiveness of olanzapine has been found to vary in individual patients. It is imperative to unravel its resistance mechanisms and find reliable targets to develop novel precise therapeutic strategies.

METHODS

Unbiased RNA sequencing analysis was performed using homogeneous populations of neural stem cells derived from induced pluripotent stem cells in 3 olanzapine responder (reduction of Positive and Negative Syndrome Scale score ≥25%) and 4 nonresponder (reduction of Positive and Negative Syndrome Scale score <25%) inpatients with TRS. We also used a genotyping study from patients with TRS to assess the candidate genes associated with the olanzapine response. CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9-mediated genome editing, neurologic behavioral tests, RNA silencing, and microRNA sequencing were used to investigate the phenotypic mechanisms of an olanzapine resistance gene in patients with TRS.

RESULTS

Neuregulin-1 (NRG-1) deficiency-induced mitochondrial dysfunction is associated with olanzapine treatment outcomes in TRS. NRG-1 knockout mice showed schizophrenia-relevant behavioral deficits and yielded olanzapine resistance. Notably, miR143-3p is a critical NRG-1 target related to mitochondrial dysfunction, and miR143-3p levels in neural stem cells associate with severity to olanzapine resistance in TRS. Meanwhile, olanzapine resistance in NRG-1 knockout mice could be rescued by treatment with miR143-3p agomir via intracerebral injection.

CONCLUSIONS

Our findings provide direct evidence of olanzapine resistance resulting from NRG-1 deficiency-induced mitochondrial dysfunction, and they link olanzapine resistance and NRG-1 deficiency-induced mitochondrial dysfunction to an NRG-1/miR143-3p axis, which constitutes a novel biomarker and target for TRS.

miRNAs and the Hippo pathway in cancer: Exploring the therapeutic potential (Review)

Cancer is recognized as the leading cause of death worldwide. The hippo signaling pathway regulates organ size by balancing cell proliferation and cell death; hence dysregulation of the hippo pathway promotes cancer‑like conditions. miRNAs are a type of non‑coding RNA that have been shown to regulate gene expression. miRNA levels are altered in various classes of cancer. Researchers have also uncovered a crosslinking between miRNAs and the hippo pathway, which has been linked to cancer. The components of the hippo pathway regulate miRNA synthesis, and various miRNAs regulate the components of the hippo pathway both positively and negatively, which can lead to cancer‑like conditions. In the present review article, the mechanism behind the hippo signaling pathway and miRNAs biogenesis and crosslinks between miRNAs and the hippo pathway, which result in cancer, shall be discussed. Furthermore, the article will cover miRNA‑related therapeutics and provide an overview of the development of resistance to anticancer drugs. Understanding the underlying processes would improve the chances of developing effective cancer treatment therapies.

MicroRNAs: master regulators in host-parasitic protist interactions

MicroRNAs (miRNAs) are a group of small non-coding RNAs present in a wide diversity of organisms. MiRNAs regulate gene expression at a post-transcriptional level through their interaction with the 3' untranslated regions of target mRNAs, inducing translational inhibition or mRNA destabilization and degradation. Thus, miRNAs regulate key biological processes, such as cell death, signal transduction, development, cellular proliferation and differentiation. The dysregulation of miRNAs biogenesis and function is related to the pathogenesis of diseases, including parasite infection. Moreover, during host-parasite interactions, parasites and host miRNAs determine the probability of infection and progression of the disease. The present review is focused on the possible role of miRNAs in the pathogenesis of diseases of clinical interest caused by parasitic protists. In addition, the potential role of miRNAs as targets for the design of drugs and diagnostic and prognostic markers of parasitic diseases is also discussed.

Physico-chemical properties, antioxidant activity, and ACE inhibitory activity of protein hydrolysates from wild jujube seed

Wild jujube seed protein (WJSP) as one kind of functional food material has attracted much attention due to its highly nutritive and medicinal value in anti-inflammatory and improving immunomodulatory ability. However, owing to its large molecular weight and complex structure, biological activities of WJSP were greatly limited and cannot be fully utilized by the human body. Therefore, how to improve the bioavailability of WJSP and develop promising WJSP nutritious materials is a great challenge. In this work, wild jujube seed protein hydrolysates (WJSPHs) were prepared from WJSP via enzymatic hydrolysis method, and their physico-chemical properties, antioxidant activity, and angiotensin converting enzyme (ACE) inhibitory activity in vitro have been investigated for the first time. SDS-PAGE electrophoresis and size-exclusion chromatographic results indicate that WJSPHs have lower molecular weight distribution (< 5,000 Da) than WJSP. Circular dichroism (CD) spectroscopy and Fourier transform infrared spectroscopy (FTIR) results illustrated that random coil is the main secondary structure of WJSPHs. Antioxidant experiments indicate that WJSPHs exhibit high radicals-scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (94.60%), 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS⁺ ) radicals (90.84%), superoxide radicals (44.77%), and hydroxyl radicals (47.77%). In vitro, WJSPHs can significantly decrease the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), and increase the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in HepG2 cells. Moreover, ACE activity was found that can be significantly inhibited by WJSPHs (73.02%). Therefore, all previously mentioned results suggest that WJSPHs may be a promising antioxidant food to prevent oxidative-related diseases in future. PRACTICAL APPLICATION: This study shows that WJSPHs exhibit high antioxidant activity and ACE inhibitory activity in vitro, which provide potential application value as antioxidant peptides to prevent oxidative-related diseases.

miR-155-3p: processing by-product or rising star in immunity and cancer?

MicroRNAs (miRNAs) are key players in gene regulation that target specific mRNAs for degradation or translational repression. Each miRNA is synthesized as a miRNA duplex comprising two strands (5p and 3p). However, only one of the two strands becomes active and is selectively incorporated into the RNA-induced silencing complex in a process known as miRNA strand selection. Recently, significant progress has been made in understanding the factors and processes involved in strand selection. Here, we explore the selection and functionality of the miRNA star strand (either 5p or 3p), which is generally present in the cell at low levels compared to its partner strand and, historically, has been thought to possess no biological activity. We also highlight the concepts of miRNA arm switching and miRNA isomerism. Finally, we offer insights into the impact of aberrant strand selection on immunity and cancer. Leading us through this journey is miR-155, a well-established regulator of immunity and cancer, and the increasing evidence that its 3p strand plays a role in these arenas. Interestingly, the miR-155-5p/-3p ratio appears to vary dependent on the timing of the immune response, and the 3p strand seems to play a regulatory role upon its partner 5p strand.

Secondary structures in RNA synthesis, splicing and translation

Even though the functional role of mRNA molecules is primarily decided by the nucleotide sequence, several properties are determined by secondary structure conformations. Examples of secondary structures include long range interactions, hairpins, R-loops and G-quadruplexes and they are formed through interactions of non-adjacent nucleotides. Here, we discuss advances in our understanding of how secondary structures can impact RNA synthesis, splicing, translation and mRNA half-life. During RNA synthesis, secondary structures determine RNA polymerase II (RNAPII) speed, thereby influencing splicing. Splicing is also determined by RNA binding proteins and their binding rates are modulated by secondary structures. For the initiation of translation, secondary structures can control the choice of translation start site. Here, we highlight the mechanisms by which secondary structures modulate these processes, discuss advances in technologies to detect and study them systematically, and consider the roles of RNA secondary structures in disease.

Change of Cell Toxicity of Food-Borne Nanoparticles after Forming Protein Coronas with Human Serum Albumin

Nanoparticles (NPs) can form protein coronas with plasma proteins after entering the biological environment due to their surface adsorption ability. In this study, the effects of protein coronas of roast squid food-borne nanoparticles (FNPs) with human serum albumin (HSA) on the HepG-2 and normal rat kidney (NRK) cells were investigated. The hydrodynamic diameters of the HSA and HSA-FNPs were 8 and 13 nm, respectively. The cytotoxicity and cell membrane damage of FNPs to HepG-2 cells increased with the increase of roasting temperature. The presence of 4.78 × 10^-3 mol/L FNPs increased the numbers of cellular necrosis and prolonged the G₂ phase of the cell cycle. The formation of protein coronas of squid FNPs mitigated the autophagy phenomenon by FNPs on HepG-2 cells. Moreover, protein coronas reduced the mitochondrial membrane potential in the HepG-2 and NRK cells and the production of reactive oxygen species caused by FNPs. The abnormal contents of oxidative stress indicators such as glutathione, superoxide dismutase, malondialdehyde, and catalase in HepG-2 and NRK cells induced by FNPs were alleviated due to the presence of HSA. These results suggested that the protein coronas formed by HSA on FNPs mitigated the cytotoxicity compared with the bare FNPs, thus providing insights into the interaction of squid FNPs with HSA.

Antioxidant activity of SSeCAHK in HepG2 cells: a selenopeptide identified from selenium-enriched soybean protein hydrolysates

This paper is aimed at purifying and identifying selenium (Se)-containing antioxidative peptides from Se-enriched soybean peptides (SSP). In this work, the SSP was separated into five fractions (F1 to F5). Fraction F4, displaying the highest antioxidative activity, was further separated, and sub-fractions F4-1 to F4-5 were selected for antioxidative activity evaluation using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzo-thiazoline-6-sulphonic acid)diammonium salt (ABTS), and OH⁻ radical scavenging assays. The Se-containing antioxidative peptides with sequence Ser–SeC–Ala–His–Lys (SSeCAHK) were identified in sub-fraction F4-1 and chemically synthesized. This Se-containing pentapeptide showed a preventive effect against hydrogen peroxide (H₂O₂)-induced oxidative stress in HepG2 cells. Pretreating the cells for 2 h with SSeCAHK (0.13–0.50 mg mL⁻¹) induced strong intracellular, reactive oxygen species (ROS) scavenging activity while preventing a decrease in reduced glutathione (GSH) and an increase in malondialdehyde (MDA). Therefore, SSeCAHK treatment improved H₂O₂-induced oxidative stress in HepG2 cells, demonstrating the significant potential of SSeCAHK as a natural antioxidative functional material for dietary supplementation.

Se-containing antioxidative soybean peptides were isolated and identified as SSeCAHK. The SSeCAHK had protective effects against H₂O₂-induced oxidative stress in HepG2 cells and could be used as a natural food-born antioxidant.

Manuscript Title: Analysis of tripartite motif (TRIM) family gene expression in prostate cancer bone metastases

Tripartite motif (TRIM) family proteins are post-translational protein modifiers with E3-ubiquitin ligase activity, thereby involved in various biological processes. The molecular mechanisms driving prostate cancer (PCa) bone metastasis (BM) are incompletely understood, and targetable genetic alterations are lacking in the majority of cases. Therefore, we aimed to explore the expression and potential functional relevance of 71 TRIM members in bone metastatic PCa. We performed transcriptome analysis of all human TRIM family members and 770 cancer-related genes in 29 localized PCa and 30 PCa BM using Nanostring. KEGG, STRING and Ubibrowser were used for further bioinformatic gene correlation and pathway enrichment analyses. Compared to localized tumors, six TRIMs are under-expressed while nine TRIMs are over-expressed in BM. The differentially expressed TRIM proteins are linked to TNF-, TGFβ-, PI3K/AKT- and HIF-1-signaling, and to features such as proteoglycans, platelet activation, adhesion and ECM-interaction based on correlation to cancer-related genes. The identification of TRIM-specific E3-ligase-substrates revealed insight into functional connections to oncogenes, tumor suppressors and cancer-related pathways including androgen receptor- and TGFβ signaling, cell cycle regulation and splicing. In summary, this is the first study that comprehensively and systematically characterizes the expression of all TRIM members in PCa BM. Our results describe post-translational protein modification as an important regulatory mechanism of oncogenes, tumor suppressors, and pathway molecules in PCa progression. Therefore, this study may provide evidence for novel therapeutic targets, in particular for the treatment or prevention of BM.

Current Implications of microRNAs in Genome Stability and Stress Responses of Ovarian Cancer

Genomic alterations and aberrant DNA damage signaling are hallmarks of ovarian cancer (OC), the leading cause of mortality among gynecological cancers worldwide. Owing to the lack of specific symptoms and late-stage diagnosis, survival chances of patients are significantly reduced. Poly (ADP-ribose) polymerase (PARP) inhibitors and replication stress response inhibitors present attractive therapeutic strategies for OC. Recent research has focused on ovarian cancer-associated microRNAs (miRNAs) that play significant regulatory roles in various cellular processes. While miRNAs have been shown to participate in regulation of tumorigenesis and drug responses through modulating the DNA damage response (DDR), little is known about their potential influence on sensitivity to chemotherapy. The main objective of this review is to summarize recent findings on the utility of miRNAs as cancer biomarkers, in particular, ovarian cancer, and their regulation of DDR or modified replication stress response proteins. We further discuss the suppressive and promotional effects of various miRNAs on ovarian cancer and their participation in cell cycle disturbance, response to DNA damage, and therapeutic functions in multiple cancer types, with particular focus on ovarian cancer. Improved understanding of the mechanisms by which miRNAs regulate drug resistance should facilitate the development of effective combination therapies for ovarian cancer.

Roles of microRNAs in Regulating Cancer Stemness in Head and Neck Cancers

Head and neck squamous cell carcinomas (HNSCCs) are epithelial malignancies with 5-year overall survival rates of approximately 40-50%. Emerging evidence indicates that a small population of cells in HNSCC patients, named cancer stem cells (CSCs), play vital roles in the processes of tumor initiation, progression, metastasis, immune evasion, chemo-/radioresistance, and recurrence. The acquisition of stem-like properties of cancer cells further provides cellular plasticity for stress adaptation and contributes to therapeutic resistance, resulting in a worse clinical outcome. Thus, targeting cancer stemness is fundamental for cancer treatment. MicroRNAs (miRNAs) are known to regulate stem cell features in the development and tissue regeneration through a miRNA-target interactive network. In HNSCCs, miRNAs act as tumor suppressors and/or oncogenes to modulate cancer stemness and therapeutic efficacy by regulating the CSC-specific tumor microenvironment (TME) and signaling pathways, such as epithelial-to-mesenchymal transition (EMT), Wnt/β-catenin signaling, and epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF1R) signaling pathways. Owing to a deeper understanding of disease-relevant miRNAs and advances in in vivo delivery systems, the administration of miRNA-based therapeutics is feasible and safe in humans, with encouraging efficacy results in early-phase clinical trials. In this review, we summarize the present findings to better understand the mechanical actions of miRNAs in maintaining CSCs and acquiring the stem-like features of cancer cells during HNSCC pathogenesis.

A pan-cancer atlas of somatic mutations in miRNA biogenesis genes

It is a well-known and intensively studied phenomenon that the levels of many miRNAs are differentiated in cancer. miRNA biogenesis and functional expression are complex processes orchestrated by many proteins cumulatively called miRNA biogenesis proteins. To characterize cancer somatic mutations in the miRNA biogenesis genes and investigate their potential impact on the levels of miRNAs, we analyzed whole-exome sequencing datasets of over 10 000 cancer/normal sample pairs deposited within the TCGA repository. We identified and characterized over 3600 somatic mutations in 29 miRNA biogenesis genes and showed that some of the genes are overmutated in specific cancers and/or have recurrent hotspot mutations (e.g. SMAD4 in PAAD, COAD and READ; DICER1 in UCEC; PRKRA in OV and LIN28B in SKCM). We identified a list of miRNAs whose level is affected by particular types of mutations in either SMAD4, SMAD2 or DICER1 and showed that hotspot mutations in the RNase domains in DICER1 not only decrease the level of 5p-miRNAs but also increase the level of 3p-miRNAs, including many well-known cancer-related miRNAs. We also showed an association of the mutations with patient survival. Eventually, we created an atlas/compendium of miRNA biogenesis alterations providing a useful resource for different aspects of biomedical research.

MiRNA Regulatory Functions in Photoreceptors

MicroRNAs (miRNAs) are important regulators of gene expression. These small, non-coding RNAs post-transcriptionally silence messenger RNAs (mRNAs) in a sequence-specific manner. In this way, miRNAs control important regulatory functions, also in the retina. If dysregulated, these molecules are involved in several retinal pathologies. For example, several miRNAs have been linked to essential photoreceptor functions, including light sensitivity, synaptic transmission, and modulation of inflammatory responses. Mechanistic miRNA knockout and knockdown studies further linked their functions to degenerative retinal diseases. Of note, the type and timing of genetic manipulation before, during, or after retinal development, is important when studying specific miRNA knockout effects. Within this review, we focus on miR-124 and the miR-183/96/182 cluster, which have assigned functions in photoreceptors in health and disease. As a single miRNA can regulate hundreds of mRNAs, we will also discuss the experimental validation and manipulation approaches to study complex miRNA/mRNA regulatory networks. Revealing these networks is essential to understand retinal pathologies and to harness miRNAs as precise therapeutic and diagnostic tools to stabilize the photoreceptors’ transcriptomes and, thereby, function.

Regulation of DNA break repair by RNA

Genomic stability is critical for cell survival and its effective repair when damaged is a vital process for preserving genetic information. Failure to correctly repair the genome can lead to the accumulation of mutations that ultimately drives carcinogenesis. Life has evolved sophisticated surveillance, repair pathways, and mechanisms to recognize and mend genomic lesions to preserve its integrity. Many of these pathways involve a cascade of protein effectors that act to identify the type of damage, such as double-strand (ds) DNA breaks, propagate the damage signal, and recruit an array of other protein factors to resolve the damage without loss of genetic information. It is now becoming increasingly clear that there are a number of RNA processing factors, such as the transcriptional machinery, and microRNA biogenesis components, as well as RNA itself, that facilitate the repair of DNA damage. Here, some of the recent work unravelling the role of RNA in the DNA Damage Response (DDR), in particular the dsDNA break repair pathway, will be reviewed.

Soybean protein-derived peptides inhibit inflammation in LPS-induced RAW264.7 macrophages via the suppression of TLR4-mediated MAPK-JNK and NF-kappa B activation

This study aimed to determine the effect of soybean protein-derived peptides (SBP) on the inhibition of lipopolysaccharide (LPS)-induced RAW264.7 cell inflammation. The mRNA of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), Lymphocyte Antigen 96 (LY96), and nuclear factor-κB (NF-κB) were detected with RT-qPCR. The concentrations of cytokines (TNF-α, IL-6, and IL-1β) secreted were detected by ELISA Kit. The results indicated that SBP inhibited the inflammatory stress induced by LPS in RAW264.7 cells. Western blot analysis was used to examine this anti-inflammatory molecular mechanism. The findings showed that SBP impeded the increase of toll-like receptor 4 activity by restricting LY96, while also inhibiting the mitogen-activated protein kinase-c-Jun N-terminal kinase pathway in cells, as well as LPS-induced NF-κB activation caused by the degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα). Consequently, the release of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) was inhibited, preventing LPS-induced inflammation of RAW 264.7 cells. Therefore, this research highlighted the potential application of SBP in the development of anti-inflammatory foods that prevented inflammatory-immune diseases. PRACTICAL APPLICATIONS: Inflammation is the root cause of almost all pathology and is related to many human diseases, including arthritis, obesity, cancer and atherosclerosis. Therefore, the development of products that can regulate and intervene inflammation has a broad application prospect. Soybean protein and soybean peptide have many functional properties, including immunoregulation, anti-inflammatory, anti-oxidation and so on. However, there are still some shortcomings in the development of soy protein supplements, such as solubility and absorption. Compared with soybean protein, derived peptide is easy to digest, and has high solubility. As a good nutritional supplement, the nutritional support of soybean protein-derived peptides may help to reduce inflammation and improve the level of cytokines combined with drugs.

CircLONP2 enhances colorectal carcinoma invasion and metastasis through modulating the maturation and exosomal dissemination of microRNA-17

Background

Metastasis causes the vast majority of colorectal carcinoma (CRC)-related deaths. However, little is known about the specific traits and underlying mechanisms of metastasis-initiating cells in primary CRC. And whether or not circular RNAs (circRNAs) take part in this particular event remain not adequately stated yet.

Methods

A screening method based on Transwell assay was first applied to build CRC subgroups with different metastatic potential. High throughput RNA sequencing was used to find out novel metastatic drivers in CRC metastasis-initiating step. A series of in vitro and in vivo assays were further applied to elucidate the functions and underlying molecular mechanisms of circRNAs in CRC metastasis.

Results

A circRNA consisting of exon 8–11 of LONP2, termed as circLONP2, was upregulated in metastasis-initiating CRC subgroups. Aberrant higher expression of circLONP2 was observed in primary CRC tissues with established metastasis, and along the invasive margin in metastatic site. High expression of circLONP2 predicted unfavorable overall survival. Functional studies revealed that circLONP2 could enhance the invasiveness of CRC cells in vitro, and targeting circLONP2 through anti-sense oligonucleotide (ASO) dramatically reduced the penetrance of metastasis to foreign organs in vivo. Mechanically, circLONP2 directly interacted with and promoted the processing of primary microRNA-17 (pri-miR-17), through recruiting DiGeorge syndrome critical region gene 8 (DGCR8) and Drosha complex in DDX1-dependent manner. Meanwhile, upregulated mature miR-17-5p could be assembled into exosomes and internalized by neighboring cells to enhance their aggressiveness.

Conclusions

Our data indicate that circLONP2 acts as key metastasis-initiating molecule during CRC progression through modulating the intracellular maturation and intercellular transfer of miR-17, resulting in dissemination of metastasis-initiating ability in primary site and acceleration of metastasis formation in foreign organs. circLONP2 could serve as an effective prognostic predictor and/or novel anti-metastasis therapeutic target in CRC treatment.

Effect of soybean peptides against hydrogen peroxide induced oxidative stress in HepG2 cells via Nrf2 signaling

The aim of this study was to determine the effects of soybean protein hydrolysates against intracellular antioxidant activity.

First-in-Class Phosphorylated-p68 Inhibitor RX-5902 Inhibits β-Catenin Signaling and Demonstrates Antitumor Activity in Triple-Negative Breast Cancer

RX-5902 is a first-in-class anticancer agent targeting phosphorylated-p68 and attenuating nuclear shuttling of β-catenin. The purpose of this study was to evaluate the efficacy of RX-5902 in preclinical models of triple-negative breast cancer (TNBC) and to explore effects on β-catenin expression. A panel of 18 TNBC cell lines was exposed to RX-5902, and changes in proliferation, apoptosis, cellular ploidy, and effector protein expression were assessed. Gene expression profiling was used in sensitive and resistant cell lines with pathway analysis to explore pathways associated with sensitivity to RX-5902. The activity of RX-5902 was confirmed in vivo in cell line and patient-derived tumor xenograft (PDX) models. RX-5902 demonstrated potent antiproliferative activity in vitro against TNBC cell lines with an average IC₅₀ of 56 nmol/L in sensitive cell lines. RX-5902 treatment resulted in the induction of apoptosis, G₂-M cell-cycle arrest, and aneuploidy in a subset of cell lines. RX-5902 was active in vivo against TNBC PDX models, and treatment resulted in a decrease in nuclear β-catenin. RX-5902 exhibited dose-proportional pharmacokinetics and plasma and tumor tissue in nude mice. Pathway analysis demonstrated an increase in the epithelial-to-mesenchymal transformation (EMT), TGFβ, and Wnt/β-catenin pathways associated with sensitivity to RX-5902. RX-5902 is active against in vitro and in vivo preclinical models of TNBC. Target engagement was confirmed with decreases in nuclear β-catenin and MCL-1 observed, confirming the proposed mechanism of action. This study supports the continued investigation of RX-5902 in TNBC and combinations with immunotherapy.

LncRNA CCAT1 Promotes Prostate Cancer Cell Proliferation by Interacting with DDX5 and MIR-28-5P

Accumulated evidence indicates that CCAT1 functions as an oncogene in the progression of a variety of tumors. However, little is known as to how CCAT1 impacts tumorigenesis in human prostate cancer. In this study, we found from The Cancer Genome Atlas and Memorial Sloan Kettering Cancer Center database that CCAT1 is highly upregulated in castration-resistant prostate cancer (CRPC) compared with androgen-dependent prostate cancer (ADPC). Higher level of CCAT1 leads to increased mortality in patients with CRPC. In vitro and in vivo studies show that CCAT1 promotes prostate cancer cell proliferation as well as the tumor growth of prostate cancer xenografts. Mechanistically, in cytoplasm, CCAT1 sponges MIR-28-5P to prevent the anticancer effect. In nucleus, CCAT1 acts as a scaffold for DDX5 (P68) and AR transcriptional complex to facilitate the expression of AR-regulated genes, thus stimulating CRPC progression. Our findings suggest that CCAT1 is an oncogenic factor in the progression of CRPC with different regulatory mechanisms in the nucleus and cytoplasm of cells.

Opposing transcriptional and post-transcriptional roles for Scalloped in binary Hippo-dependent neural fate decisions

The Hippo tumor suppressor pathway plays many fundamental cell biological roles during animal development. Two central players in controlling Hippo-dependent gene expression are the TEAD transcription factor Scalloped (Sd) and its transcriptional co-activator Yorkie (Yki). Hippo signaling phosphorylates Yki, thereby blocking Yki-dependent transcriptional control. In post-mitotic Drosophila photoreceptors, a bistable negative feedback loop forms between the Hippo-dependent kinase Warts/Lats and Yki to lock in green vs blue-sensitive neuronal subtype choices, respectively. Previous experiments indicate that sd and yki mutants phenocopy each other's functions, both being required for promoting the expression of the blue photoreceptor fate determinant melted (melt) and the blue-sensitive opsin Rh5. Here, we demonstrate that Sd ensures the robustness of this neuronal fate decision via multiple antagonistic gene regulatory roles. In Hippo-positive (green) photoreceptors, Sd directly represses both melt and Rh5 gene expression through defined TEAD binding sites, a mechanism that is antagonized by Yki in Hippo-negative (blue) cells. Additionally, in blue photoreceptors, Sd is required to promote the translation of the Rh5 protein through a 3'UTR-dependent and microRNA-mediated process. Together, these studies reveal that Sd can drive context-dependent cell fate decisions through opposing transcriptional and post-transcriptional mechanisms.

MicroRNA regulation of vascular function

MicroRNAs (miRNAs) are small non-coding RNAs that orchestrate genetic networks by modulating gene expression. Given their importance in vascular development, homeostasis and diseases, along with the technical feasibility in deploying their function in vivo, the so-called ‘vascular miRNAs’ have become key targets for therapeutic intervention. Herein, we have summarised the state-of-the-art on vascular miRNAs and we have discussed the role miRNA biogenesis and the extracellular vesicles (EVs) miRNA transport in vascular biology.

Functional Interplay between RNA Viruses and Non-Coding RNA in Mammals

Exploring virus–host interactions is key to understand mechanisms regulating the viral replicative cycle and any pathological outcomes associated with infection. Whereas interactions at the protein level are well explored, RNA interactions are less so. Novel sequencing methodologies have helped uncover the importance of RNA–protein and RNA–RNA interactions during infection. In addition to messenger RNAs (mRNAs), mammalian cells express a great number of regulatory non-coding RNAs, some of which are crucial for regulation of the immune system whereas others are utilized by viruses. It is thus becoming increasingly clear that RNA interactions play important roles for both sides in the arms race between virus and host. With the emerging field of RNA therapeutics, such interactions are promising antiviral targets. In this review, we discuss direct and indirect RNA interactions occurring between RNA viruses or retroviruses and host non-coding transcripts upon infection. In addition, we review RNA virus derived non-coding RNAs affecting immunological and metabolic pathways of the host cell typically to provide an advantage to the virus. The relatively few known examples of virus–host RNA interactions suggest that many more await discovery.

P68 RNA helicase promotes invasion of glioma cells through negatively regulating DUSP5

Gliomas are the most common central nervous system tumors. They show malignant characteristics indicating rapid proliferation and a high invasive capacity and are associated with a poor prognosis. In our previous study, p68 was overexpressed in glioma cells and correlated with both the degree of glioma differentiation and poor overall survival. Downregulating p68 significantly suppressed proliferation in glioma cells. Moreover, we found that the p68 gene promoted glioma cell growth by activating the nuclear factor‐κB signaling pathway by a downstream molecular mechanism that remains incompletely understood. In this study, we found that dual specificity phosphatase 5 (DUSP5) is a downstream target of p68, using microarray analysis, and that p68 negatively regulates DUSP5. Upregulating DUSP5 in stably expressing cell lines (U87 and LN‐229) suppressed proliferation, invasion, and migration in glioma cells in vitro, consistent with the downregulation of p68. Furthermore, upregulating DUSP5 inhibited ERK phosphorylation, whereas downregulating DUSP5 rescued the level of ERK phosphorylation, indicating that DUSP5 might negatively regulate ERK signaling. Additionally, we show that DUSP5 levels were lower in high‐grade glioma than in low‐grade glioma. These results suggest that the p68‐induced negative regulation of DUSP5 promoted invasion by glioma cells and mediated the activation of the ERK signaling pathway.

The role of DEAD-box RNA helicase p68 (DDX5) in the development and treatment of breast cancer

RNA helicase p68 or DEAD (Asp-Glu-Ala-Asp) box polypeptide 5 (DDX5) is a unique member of the highly conserved protein family, which is involved in a broad spectrum of biological processes, including transcription, translation, precursor messenger RNA processing or alternative splicing, and microRNA (miRNA) processing. It has been shown that p68 is necessary for cell growth and participates in the early development and maturation of some organs. Interestingly, p68 is a transcriptional coactivator of numerous oncogenic transcription factors, including nuclear factor-κβ (NF-κβ), estrogen receptor α (ERα), β-catenin, androgen receptor, Notch transcriptional activation complex, p53 and signal transducer, and activator of transcription 3 (STAT3). Recent studies on the role of p68 (DDX5) in multiple dysregulated cellular processes in various cancers and its abnormal expression indicate the importance of this factor in tumor development. Discussion of the precise role of p68 in cancer is complex and depends on the cellular microenvironment and interacting factors. In terms of the deregulated expression of p68 in breast cancer and the high prevalence of this cancer among women, it can be informative to review the precise function of this factor in the breast cancer. Therefore, an attempt will be made in this review to clarify the tumorigenic function of p68 in association with its targeting potential for the treatment of breast cancer.

DEAD-box helicases: the Yin and Yang roles in viral infections

Viruses hijack the host cell machinery and recruit host proteins to aid their replication. Several host proteins also play vital roles in inhibiting viral replication. Emerging class of host proteins central to both of these processes are the DEAD-box helicases: a highly conserved family of ATP-dependent RNA helicases, bearing a common D-E-A-D (Asp-Glu-Ala-Asp) motif. They play key roles in numerous cellular processes, including transcription, splicing, miRNA biogenesis and translation. Though their sequences are highly conserved, these helicases have quite diverse roles in the cell. Interestingly, often these helicases display contradictory actions in terms of the support and/or clearance of invading viruses. Increasing evidence highlights the importance of these enzymes, however, little is known about the structural basis of viral RNA recognition by the members of the DEAD-box family. This review summarizes the current knowledge in the field for selected DEAD-box helicases and highlights their diverse actions upon viral invasion of the host cell. We anticipate that through a better understanding of how these helicases are being utilized by viral RNAs and proteins to aid viral replication, it will be possible to address the urgent need to develop novel therapeutic approaches to combat viral infections.

miRNA regulation of innate immunity

MicroRNAs (miRNAs) are small noncoding RNA and are pivotal posttranscriptional regulators of both innate and adaptive immunity. They act by regulating the expression of multiple immune genes, thus, are the important elements to the complex immune regulatory network. Deregulated expression of specific miRNAs can lead to potential autoimmunity, immune tolerance, hyper-inflammatory phenotype, and cancer initiation and progression. In this review, we discuss the contributory pathways and mechanisms by which several miRNAs influence the development of innate immunity and fine-tune immune response. Moreover, we discuss the consequence of deregulated miRNAs and their pathogenic implications.

Multitargeting activity of miR-24 inhibits long-term melatonin anticancer effects

We have previously shown that melatonin exerts tumor suppressor activities by inducing the p38-p53 axis. This occurred within a few hours while no data are available on how melatonin pathway can be sustained on the long term. Here we show that miR-24, which has been demonstrated to target genes involved in the DNA repair process, targets p38, p53, PML and H2AX simultaneously. We show that long-term treatment with melatonin can decrease miR-24 levels post-transcriptionally, which pairs with a long-wave regulation of genes involved in cell proliferation, DNA damage, RNA metabolism and cell shape and transformation. Moreover, we show that melatonin can inhibit cell proliferation and migration, at least in part, by downregulating miR-24. Furthermore, we propose the involvement of hnRNP A1, which is downregulated by melatonin and involved in miRNA processing, in the regulation of miR-24 levels by melatonin. We conclude showing that miR-24 is upregulated in colon, breast and head and neck datasets and its levels negatively correlate with overall survival.

RNase H2-Dependent Polymerase Chain Reaction and Elimination of Confounders in Sample Collection, Storage, and Analysis Strengthen Evidence That microRNAs in Bovine Milk Are Bioavailable in Humans

Background

Evidence suggests that dietary microRNAs (miRs) are bioavailable and regulate gene expression across species boundaries. Concerns were raised that the detection of dietary miRs in plasma might have been due to sample contamination or lack of assay specificity. Objectives: The objectives of this study were to assess potential confounders of plasma miR analysis and to detect miRs from bovine milk in human plasma.

Methods

Potential confounders of plasma miR analysis (circadian rhythm, sample collection and storage, calibration, and erythrocyte hemolysis) were assessed by quantitative reverse transcriptase polymerase chain reaction (PCR) by using blood from healthy adults (7 men, 6 women; aged 23-57 y). Bovine miRs were analyzed by RNase H2-dependent PCR (rhPCR) in plasma collected from a subcohort of 11 participants before and 6 h after consumption of 1.0 L of 1%-fat bovine milk.

Results

The use of heparin tubes for blood collection resulted in a complete loss of miRs. Circadian variations did not affect the concentrations of 8 select miRs. Erythrocyte hemolysis caused artifacts for some miRs if plasma absorbance at 414 nm was >0.300. The stability of plasma miRs depended greatly on the matrix in which the miRs were stored and whether the plasma was frozen before analysis. Purified miR-16, miR-200c, and cel-miR-39 were stable for ≤24 h at room temperature, whereas losses equaled ≤80% if plasma was frozen, thawed, and stored at room temperature for as little as 4 h. rhPCR distinguished between bovine and human miRs with small variations in the nucleotide sequence; plasma concentrations of Bos taurus (bta)-miR-21-5p and bta-miR-30a-5p were >100% higher 6 h after milk consumption than before milk consumption.

Conclusions

Confounders in plasma miR analysis include the use of heparin tubes, erythrocyte hemolysis, and storage of thawed plasma at room temperature. rhPCR is a useful tool to detect dietary miRs.

Cytoprotective effects of a tripeptide from Chinese Baijiu against AAPH-induced oxidative stress in HepG2 cells via Nrf2 signaling

Antioxidant peptides have been widely reported, whereas the intracellular antioxidant activity of a tripeptide (Pro-His-Pro, PHP), which was newly isolated and identified from Chinese Baijiu in our previous study, are still poorly understood. This study investigated the protective effects of PHP on 2,2′-azobis (2-methyl-propanimidamidine) dihydrochloride (AAPH)-induced oxidative stress in HepG2 cells and the involved molecular mechanisms. Pretreatment with PHP suppressed the generations of reactive oxygen species (ROS), malondialdehyde (MDA) and oxidized glutathione (GSSG), prevented a decrease in reduced glutathione (GSH), and up-regulated the activities of cellular antioxidant enzymes. Moreover, PHP treatment stimulated the mRNA and protein expression levels of antioxidant enzymes and nuclear factor E2 related factor 2 (Nrf2). Meanwhile, PHP markedly reduced the level of Kelch-like ECH-associated protein 1 (Keap1), suggesting that PHP effectively activated Nrf2/antioxidant response element (ARE)-mediated activity. These findings provide the first molecular basis for the health-promoting effects of PHP to prevent AAPH-induced oxidative stress.

PHP up-regulated gene and protein expression levels of intracellular antioxidant enzymes by activation of the Nrf2/ARE pathway in HepG2 cells.

Are miRNAs critical determinants in herpes simplex virus pathogenesis?

miRNAs are small noncoding RNA that play a crucial role in gene regulation by inhibiting translation or promoting mRNA degradation. Viruses themselves express miRNAs that can target either the host or viral mRNA transcriptome. Moreover, viral infection of cells causes a drastic change in host miRNAs. This complex interaction between the host and viruses often favors the virus to evade immune elimination and favors the establishment and maintenance of latency. In this review we discuss the function of both host and viral miRNAs in regulating herpes simplex virus pathogenesis and also discuss the prospect of using miRNAs as biomarkers and therapeutic tools.

p68 prompts the epithelial-mesenchymal transition in cervical cancer cells by transcriptionally activating the TGF-β1 signaling pathway

Overexpression of p68 has been reported in various types of cancer. However, little study has been conducted on the expression and role of p68 in cervical cancer. Therefore, the present study focuses on the role of p68 in cervical cancer cells, which may elucidate its potential mechanism of cervical cancer progression and shed light on the precision medical treatment of cervical cancer. Firstly, the expression of p68 was analyzed using reverse transcription-quantitative polymerase chain reaction and western blot analysis. The changes to cell morphology were observed using an inverted microscope (XDS-500D; Shanghai Caikon Optical Instrument Co., Ltd., Shanghai, China). Cell migration was determined using an in vitro scratch assay. The present study demonstrated that the mRNA and protein levels of p68 were significantly enhanced in cervical cancer CaSki, HeLa [human papillomavirus (HPV)-18-positive], SiHa (HPV-16-positive) and C-33A (HPV-negative) cell lines compared with the human keratinocyte HaCaT cell line. Overexpression of p68 induced an elongated and spindle-shaped morphology in CaSki cells. Upregulation of p68 increased the expression of α-smooth muscle actin, vimentin and fibronectin however, epithelial marker E-cadherin was significantly decreased. Furthermore, the in vitro scratch assay demonstrated that overexpression of p68 markedly enhanced CaSki cell migration capacity at 24 and 48 h. Knockdown of p68 partially reversed transforming growth factor-β1 (TGF-β1)-induced changes in epithelial-mesenchymal transition (EMT) markers and cell morphological changes. In summary, the present study demonstrated that p68 transcriptionally activated the expression of TGF-β1, thereby prompting EMT in cervical cancer cells.

Structural Characterization of a Tetrapeptide from Sesame Flavor-Type Baijiu and Its Preventive Effects against AAPH-Induced Oxidative Stress in HepG2 Cells

Peptides are rarely reported from Chinese Baijiu (Chinese liquor) because they are often present in very low concentrations in the complex matrix. A tetrapeptide, Ala-Lys-Arg-Ala (AKRA), was recently identified by high-performance liquid chromatography and quadrupole-time-of-flight-mass spectrometry (HPLC-Q-TOF-MS) from sesame flavor-type Baijiu at a concentration of 8.497 ± 0.753 μg/L (P > 0.05), and this tetrapeptide showed preventive effects against 2,2'-azobis(2-methylpropanimidamidine) dihydrochloride (AAPH)-induced oxidative stress in HepG2 cells. The cellular antioxidant activity assay results showed that AKRA protected AAPH-induced oxidative stress in HepG2 cells in a concentration-dependent manner. Pretreatment of the cells for 2 h with AKRA (0.38-1.50 mg/mL) caused strong intracellular reactive oxygen species (ROS) scavenging activities and prevented a decrease in reduced glutathione (GSH) and increases in oxidized glutathione (GSSG) and malondialdehyde (MDA). In addition, AKRA treatment prevented significant decreases in glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) induced by AAPH. Thus, AKRA treatment ameliorated AAPH-induced oxidative stress in HepG2 cells. This study will be important for the design and regulation of functional Baijiu production.

Involvement of RNA helicase p68 in skin wound healing process in rats

PURPOSE

RNA helicase p68 plays an important role in organ development and maturation through tuning cell proliferation. However, the character and role of p68 in the whole wound healing process need more study.

METHODS

First, we characterize expression of p68 in normal rat skin development postnatal. Then, we assayed dynamic change of p68 in rat skin from different stage after injury, and explored the role of p68 in proliferation and migration of three types of wound healing related cells.

RESULTS

p68 was down-regulated during skin developmental and maturation process, up-regulated after wound, peaked on day 14 and then significantly decreased. Wound fluid enhanced wound healing related cell proliferation and up-regulated expression of p68. Conversely, reducing p68 expression by RNA interference resulted in significantly slower proliferation and migration.

CONCLUSION

Our results define an important role of RNA helicase p68 in skin wound healing process.

DDX17 nucleocytoplasmic shuttling promotes acquired gefitinib resistance in non-small cell lung cancer cells via activation of β-catenin

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective for non-small cell lung cancer (NSCLC) patients with EGFR mutations, almost all these patients will eventually develop acquired resistance to EGFR-TKI. However, the molecular mechanisms responsible for gefitinib resistance remain still not fully understood. Here, we report that elevated DDX17 levels are observed in gefitinib-resistant NSCLC cells than gefitinib-sensitive cells. Upregulation of DDX17 enhances the gefitinib resistance, whereas DDX17-silenced cells partially restore gefitinib sensitivity. Mechanistically, we demonstrate that DDX17 disassociates the E-cadherin/β-catenin complex, resulting in β-catenin nuclear translocation and subsequently augmenting the transcription of β-catenin target genes. Moreover, we identify two nuclear localization signal (NLS) and four nuclear export signal (NES) sequences mediated DDX17 nucleocytoplasmic shuttling via an exportin/importin-dependent pathways. Interruption of dynamic nucleocytoplasmic shuttling of DDX17 impairs DDX17-mediating the activation of β-catenin and acquired resistance in NSCLC cells. In conclusion, our findings reveal a novel and important mechanism by which DDX17 contributes to acquired gefitinib resistance through exportin/importin-dependent cytoplasmic shuttling and followed by activation of β-catenin, and DDX17 inhibition may be a promising strategy to overcome acquired resistance of gefitinib in NSCLC patients.

Upregulation of p72 Enhances Malignant Migration and Invasion of Glioma Cells by Repressing Beclin1 Expression

p72 is the member of the DEAD-box RNA helicase family, which can unwind double-stranded RNA and is efficient for microRNA (miRNA, miR) processing. However, its specific role in glioma has not been elucidated. First, the expression of p72 in glioma cell lines and tissues was explored using Western blot. To explore the role of p72 on glioma progression, adenovirus inhibiting p72 was transfected into A172 and T98G cells. Cell autophagy was determined using GFP-LC3 dots, and cell apoptosis was determined using flow cytometry. The effect of Beclin1 was explored using GFP-LC3 dots, flow cytometry, and colony formation. The possible miRNAs that target the 3'-untranslated region (3'-UTR) of Beclin1 were predicted using TargetScan. Dual luciferase reporter assay was applied to determine whether these miRNAs bind to the 3'-UTR of Beclin1. The expression of p72 was significantly increased in glioma cell lines and tissues. Autophagy-related protein Beclin1 was found to be significantly enhanced when p72 was inhibited. The accumulation of GFP-LC3 dots was significant in cells transfected with ad-sh-p72 compared with ad-con. Colony formation capacity and cell apoptosis were also found to be significantly decreased with p72 inhibition. Furthermore, upregulation of Beclin1 contributes to A172 cell autophagy, invasion, and apoptosis. Overexpression of p72 induces increased miR-34-5p and miR-5195-3p expression in A172 and T98G cells. Beclin1 was the target gene of miR-34-5p and miR-5195-3p. In conclusion, we found for the first time that overexpression of p72 decreased Beclin1 expression partially by increasing miR-34-5p and miR-5195-3p expression in A172 and T98G cells.