CREBZF mRNA nanoparticles suppress breast cancer progression through a positive feedback loop boosted by circPAPD4.

BACKGROUND: Breast cancer (BC) negatively impacts the health of women worldwide. Circular RNAs (circRNAs) are a group of endogenous RNAs considered essential regulatory factor in BC tumorigenesis and progression. However, the underlying molecular mechanisms of circRNAs remain unclear. METHODS: Expression levels of circPAPD4, miR-1269a, CREBZF, and ADAR1 in BC cell lines and tissues were measured using bioinformatics analysis, RT-qPCR, ISH, and IHC. Cell proliferation and apoptosis were measured using CCK8, EdU staining, flow cytometry, and TUNEL assays. Pearson correlation analysis, RNA pull-down, dual-luciferase reporter, and co-immunoprecipitation assays were used to explore the correlation among circPAPD4, miR-1269a, CREBZF, STAT3, and ADAR1. Effects of circPAPD4 overexpression on tumor progression were investigated using in vivo assays. Moreover, CREBZF mRNA delivered by polymeric nanoparticles (CREBZF-mRNA-NPs) was used to examine application value of our findings. RESULTS: CircPAPD4 expression was low in BC tissues and cells. Functionally, circPAPD4 inhibited proliferation and promoted apoptosis in vitro and in vivo. Mechanistically, circPAPD4 biogenesis was regulated by ADAR1. And circPAPD4 promoted CREBZF expression by competitively binding to miR-1269a. More importantly, CREBZF promoted circPAPD4 expression by suppressing STAT3 dimerization and ADAR1 expression, revealing a novel positive feedback loop that curbed BC progression. Systematic delivery of CREBZF-mRNA-NPs effectively induced CREBZF expression and activated the positive feedback loop of circPAPD4/miR-1269a/CREBZF/STAT3/ADAR1, which might suppress BC progression in vitro and in vivo. CONCLUSION: Our findings firstly illustrated that circPAPD4/miR-1269a/CREBZF/STAT3/ADAR1 positive feedback loop mediated BC progression, and delivering CREBZF mRNA nanoparticles suppressed BC progression in vitro and in vivo, which might provide novel insights into therapeutic strategies for breast cancer.

Suppressing circIDE/miR-19b-3p/RBMS1 axis exhibits promoting-tumour activity through upregulating GPX4 to diminish ferroptosis in hepatocellular carcinoma.

Ferroptosis is a newly characterized form of iron-dependent non-apoptotic cell death, which is closely associated with cancer progression. However, the functions and mechanisms in regulation of escaping from ferroptosis during hepatocellular carcinoma (HCC) progression remain unknown. In this study, we reported that the RNA binding motif single stranded interacting protein 1 (RBMS1) participated in HCC development，and functioned as a regulator of ferroptosis. Clinically, the downregulation of RBMS1 occurred in HCC tissues, and low RBMS1 expression was associated with worse HCC patients survival. Mechanistically, RBMS1 overexpression inhibited HCC cell growth by attenuating the expression of glutathione peroxidase 4 (GPX4)and further facilitated ferroptosis in vitro and in vivo. More importantly, a novel circIDE (hsa_circ_0000251) was identified to elevate RBMS1 expression via sponging miR-19b-3p in HCC cells. Collectively, our findings established circIDE/miR-19b-3p/RBMS1 axis as a regulator of ferroptosis, which could be a promising therapeutic target and prognostic factor.

Green synthesis of CQDs for determination of iron and isoniazid in pharmaceutical formulations.

Camphor leaves were used as the precursor for the hydrothermal synthesis of carbon quantum dots. The preparation method is simple and rapid, and the raw material is environmentally friendly and easy to obtain. Without additional modification, the carbon quantum dots were used as fluorescent probes for the sensitive and selective detection of Fe3+ and isoniazid at different excitation wavelengths. For Fe3+, at the excitation wavelength of 320 nm, the ratio of fluorescence intensity of CQD solution after adding Fe3+ to CQD solution without Fe3+ addition, F/F0, and Fe3+ concentration showed a good linear relationship in the range of 2.72 × 10-5 to 1.00 × 10-4 mol L-1 (R2 = 0.9912), and the limit of detection was 8.16 µmol L-1. For isoniazid, at the excitation wavelength of 270 nm, the ratio of fluorescence intensity of CQDs solution with isoniazid to CQDs solution without isoniazid, F/F0, and isoniazid concentration showed good linear relationships in the range of 3.81 × 10-6 to 1.00 × 10-5 mol L-1 (R2 = 0.9941) and 1.00 × 10-5 to 2.10 × 10-4 mol L-1 (R2 = 0.9910) respectively, and the limit of detection was 1.14 µmol L-1. A fluorescence method for the determination of Fe and isoniazid content was proposed. The method has been used to detect iron in iron supplement tablets and isoniazid in isoniazid tablets with satisfactory results.

Splicing factor SNRPA associated with microvascular invasion promotes hepatocellular carcinoma metastasis through activating NOTCH1/Snail pathway and is mediated by circSEC62/miR-625-5p axis.

Microvascular invasion (MVI) is a crucial risk factor related to the metastasis of hepatocellular carcinoma (HCC), but the underlying mechanisms remain to be revealed. Characterizing the inherent mechanisms of MVI may aid in the development of effective treatment strategies to improve the prognosis of HCC patients with metastasis. Through the Gene Expression Omnibus (GEO) database, we identified that small nuclear ribonucleoprotein polypeptide A (SNRPA) was related to MVI in HCC. SNRPA was overexpressed in MVI-HCC and correlated with poor patient survival. Mechanistically, SNRPA promoted the epithelial-mesenchymal transition (EMT)-like process for HCC cells to accelerate metastasis by activating the NOTCH1/Snail pathway in vitro and in vivo. Importantly, circSEC62 upregulated SNRPA expression in HCC cells via miR-625-5p sponging. Taking these results together, our study identified a novel regulatory mechanism among SNRPA, miR-625-5p, circSEC62 and the NOTCH1/Snail pathway in HCC, which promoted metastasis of HCC and may provide effective suggestions for improving the prognosis of HCC patients with metastasis.

The regulatory activities of MALAT1 in the development of bone and cartilage diseases.

Long non-coding RNAs (lncRNAs) have been comprehensively implicated in various cellular functions by mediating transcriptional or post-transcriptional activities. MALAT1 is involved in the differentiation, proliferation, and apoptosis of multiple cell lines, including BMSCs, osteoblasts, osteoclasts, and chondrocytes. Interestingly, MALAT1 may interact with RNAs or proteins, regulating cellular processes. Recently, MALAT1 has been reported to be associated with the development of bone and cartilage diseases by orchestrating the signaling network. The involvement of MALAT1 in the pathological development of bone and cartilage diseases makes it available to be a potential biomarker for clinical diagnosis or prognosis. Although the potential mechanisms of MALAT1 in mediating the cellular processes of bone and cartilage diseases are still needed for further elucidation, MALAT1 shows great promise for drug development.

Exogenous Otx2 protects midbrain dopaminergic neurons from MPP+ by interacting with ATP5a1 and promoting ATP synthesis.

Mitochondrial dysfunction is the main pathological mechanism responsible for the death of midbrain dopaminergic (mDA) neurons. Thus, mitochondria-targeting therapy is a potential therapeutic strategy for Parkinson's disease (PD). Homeodomain transcription factors such as Otx2 can translocate between cells and exert non-cellular autonomous functions in recipient cells to stimulate neuronal survival. In this study, we investigated if exogenous Otx2 acts as a survival factor for mDA neurons by protecting them against MPP+-induced neurotoxicity in vitro. We show that subacute MPTP dosing regimen induces significant reduction in the levels of Otx2 homeoprotein in the ventral midbrain of PD mice. We also show that exogenous Otx2-myc recombinant protein protected primary mDA neurons against MPP+ by interacting with ATP5a1and promoting ATP synthesis.

circRNA-0002109 promotes glioma malignant progression via modulating the miR-129-5P/EMP2 axis.

Glioma is a common intracranial malignant tumor with high mortality and high recurrence rate. In recent years, increasing evidence has demonstrated that circular RNAs (circRNAs) are potential biomarkers and therapeutic targets for many tumors. However, the role of circRNAs in glioma remains unclear. In this study, we found that circRNA-0002109 was highly expressed in glioma tissues and cell lines. Downregulation of circRNA-0002109 expression inhibited the proliferation, migration, and invasion of glioma cells and inhibited the malignant progression of tumors in vivo. Investigations into the relevant mechanisms showed that circRNA-0002109 upregulated the expression of EMP2 through endogenous competitive binding of microRNA-129-5P (miR-129-5P), which partially alleviated the inhibitory effect of miR-129-5P on epithelial membrane protein-2 (EMP2) and ultimately promoted the malignant development of glioma. Our results indicate that circRNA-0002109 plays an important role in the proliferation, invasion, and migration of glioma cells by regulating the miR-129-5P/EMP2 axis, which provides a new potential therapeutic target for glioma.

Stroke increases the expression of ACE2, the SARS-CoV-2 binding receptor, in murine lungs.

BACKGROUND: The newly emerged severe acute respiratory syndrome coronavirus (SARS-CoV-2) has caused a worldwide pandemic of human respiratory disease. Angiotensin-converting enzyme (ACE) 2 is the key receptor on lung epithelial cells to facilitate initial binding and infection of SARS-CoV-2. The binding to ACE2 is mediated via the spike glycoprotein present on the viral surface. Recent clinical data have demonstrated that patients with previous episodes of brain injuries are a high-risk group for SARS-CoV-2 infection. An explanation for this finding is currently lacking. Sterile tissue injuries including stroke induce the release of several inflammatory mediators that might modulate the expression levels of signaling proteins in distant organs. Whether systemic inflammation following brain injury can specifically modulate ACE2 expression in different vital tissues has not been investigated. METHODS: For the induction of brain stroke, mice were subjected to a surgical procedure for transient interruption of blood flow in the middle cerebral artery for 45 min and sacrificed after 1 and 3 days for analysis of brain, lung, heart, and kidney tissues. Gene expression and protein levels of ACE2, ACE, IL-6 and IL1ß were measured by quantitative PCR and Western blot, respectively. The level of soluble ACE2 in plasma and bronchial alveolar lavage (BAL) was measured using an immunoassay. Immune cell populations in lymphoid organs were analyzed by flow cytometry. Post-stroke pneumonia in mice was examined by bacterial cultures from lung homogenates and whole blood. RESULTS: Strikingly, 1 day after surgery, we observed a substantial increase in the protein levels of ACE2 in the lungs of stroke mice compared to sham-operated mice. However, the protein levels of ACE2 were found unchanged in the heart, kidney, and brain of these animals. In addition, we found increased transcriptional levels of alveolar ACE2 after stroke. The increased expression of ACE2 was significantly associated with the severity of behavioral deficits after stroke. The higher protein levels of alveolar ACE2 persisted until 3 days of stroke. Interestingly, we found reduced levels of soluble ACE2 in plasma but not in BAL in stroke-operated mice compared to sham mice. Furthermore, stroke-induced parenchymal and systemic inflammation was evident with the increased expression of IL-6 and IL-1ß. Reduced numbers of T-lymphocytes were present in the blood and spleen as an indicator of sterile tissue injury-induced immunosuppression. CONCLUSIONS: We demonstrate specific augmented alveolar ACE2 levels and inflammation in murine lungs after experimental stroke. These pre-clinical findings suggest that patients with brain injuries may have increased binding affinity to SARS-CoV-2 in their lungs which might explain why stroke is a risk factor for higher susceptibility to develop COVID-19.

A novel simple experimental model for low-osmolar contrast-induced acute kidney injury using different definitions based on the levels of serum creatinine and cystatin C.

BACKGROUND: It remained lack of a kind of contrast-induced acute kidney injury (CI-AKI) model which was widely used in clinical practice and comparable to CI-AKI in humans. METHODS: Fifty Sprague-Dawley rats were divided into five groups of 10 rats each: (1) sham group (normal saline [NS] + NS); (2) NS plus low osmolality contrast medium (CM15) (NS + CM15); (3) furosemide (FM) plus NS (FM + NS); (4) FM + CM10; and (5) FM + CM15.We measured the levels of serum creatinine (SCr), cystatin C (cys-C) and histopathological scores of kidney tissues. RESULTS: SCr level in the FM + CM15 group were significantly increased after CM exposure compared with baseline levels (32.9 ± 4.57 vs. 158.7 ± 14.48 µmol/L, p < 0.001). Minor changes were found about the SCr levels between the pre- and post-exposure CM or NS treatment in the other groups. Additionally, the cys-C levels after CM exposure were increased compared with pretreatment levels in the FM + CM15 group (0.08 ± 0.03 vs. 0.18 ± 0.05 mg/L, p < 0.001). Minor changes were noted in the FM + NS group before and after NS administration. Only rats in the FM + CM15 group developed CI-AKI with the definitions of SCr or cys-C. Comparing to the FM + NS group, the histopathological scores were significantly increased in the FM + CM15 group. CONCLUSIONS: A simple and reliable animal model for low osmolality contrast medium-induced AKI was established, which is similar to clinical CI-AKI based on different definitions for AKI.

An injectable conductive Gelatin-PANI hydrogel system serves as a promising carrier to deliver BMSCs for Parkinson's disease treatment.

Parkinson's disease (PD) is a long-term neurodegenerative disorders that characterized by a progressive loss of dopaminergic neurons in substantia nigra pars compacta (SNc). Bone marrow stromal cells (BMSCs) are promising therapeutic agents for neurodegenerative disease due to their multipotent capacity. To promote the potential therapeutic effect of BMSCs on PD, we developed an injectable Gelatin-PANI hydrogels as a novel carrier for delivering BMSCs to the SNc region in mice with PD by stereotactic injection. Histology results showed that the BMSCs-loaded hydrogels lead to increased numbers of tyrosine hydroxylase positive (TH+) dopaminergic neurons and fibers in the SNc and striatum, and increased expression of brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) in the SNc. Meanwhile, rotarod and open field evaluation demonstrated BMSCs-loaded hydrogels significantly improved the behavioral performance of PD mice. Importantly, BMSCs-loaded hydrogels imparted more sustained protective effects than BMSCs alone in PD mice. Overall, the current data indicate that the hydrogel serves as a promising carrier to deliver BMSCs to the SNc for the treatment of PD.

Determination of thorium (IV) using isophthalaldehyde-tetrapyrrole as probe by resonance light scattering, second-order scattering and frequency-doubling scattering spectra.

The coordination reaction of thorium (IV) with a ditopic bidentate ligand to form supramolecular polymer was studied by resonance light scattering (RLS) spectra, second-order scattering (SOS) spectra and frequency-doubling scattering (FDS) spectra, respectively. The ditopic bidentate ligand is isophthalaldehyde-tetrapyrrole (IPTP). It was synthesized through a condensation reaction of isophthalaldehyde with pyrrole. The formation of supramolecular polymer results in remarkable intensity enhancements of the three light scattering signals. The maximum scattering wavelengths of RLS, FDS and SOS were 290, 568 and 340nm, respectively. The reaction was used to establish new light scattering methods for the determination of thorium (IV) by using IPTP as probe. Under optimum conditions, the intensity enhancements of RLS, SOS and FDS were directly proportional to the concentration of thorium (IV) in the ranges of 0.01 to 1.2µgmL-1, 0.05 to 1.2µgmL-1 and 0.05 to 1.2µgmL-1, respectively. The detection limits were 0.003µgmL-1, 0.012µgmL-1 and 0.021µgmL-1, respectively. The methods were suitable for analyzing thorium (IV) in actual samples. The results show acceptable recoveries and precision compared with a reference method.

Hundred top-cited articles focusing on acute kidney injury: a bibliometric analysis.

BACKGROUND: Acute kidney injury (AKI) is a major global health issue, associated with poor short-term and long-term outcomes. Research on AKI is increasing with numerous articles published. However, the quantity and quality of research production in the field of AKI is unclear. METHODS AND ANALYSIS: To analyse the characteristics of the most cited articles on AKI and to provide information about achievements and developments in AKI, we searched the Science Citation Index Expanded for citations of AKI articles. For the top 100 most frequently cited articles (T100), we evaluated the number of citations, publication time, province of origin, journal, impact factor, topic or subspecialty of the research, and publication type. RESULTS: The T100 articles ranged from a maximum of 1971 citations to a minimum of 215 citations (median 302 citations). T100 articles were published from 1951 to 2011, with most articles published in the 2000s (n=77), especially the 5-year period from 2002 to 2006 (n=51). The publications appeared in 30 journals, predominantly in the general medical journals, led by New England Journal of Medicine (n=17), followed by expert medical journals, led by the Journal of the American Society of Nephrology (n=16) and Kidney International (n=16). The majority (83.7%) of T100 articles were published by teams involving ≥3 authors. T100 articles originated from 15 countries, led by the USA (n=81) followed by Italy (n=9). Among the T100 articles, 69 were clinical research, 25 were basic science, 21 were reviews, 5 were meta-analyses and 3 were clinical guidelines. Most clinical articles (55%) included patients with any cause of AKI, followed by the specific causes of contrast-induced AKI (25%) and cardiac surgery-induced AKI (15%). CONCLUSIONS: This study provides a historical perspective on the scientific progress on AKI, and highlights areas of research requiring further investigations and developments.

A drug delivery hydrogel system based on activin B for Parkinson's disease.

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Activins are members of the superfamily of transforming growth factors and have many potential neuroprotective effects. Herein, at the first place, we verified activin B's neuroprotective role in a PD model, and revealed that activin B's fast release has limited function in the PD therapy. To this end, we developed a multi-functional crosslinker based thermosensitive injectable hydrogels to deliver activin B, and stereotactically injected the activin B-loaded hydrogel into the striatum of a mouse model of PD. The histological evaluation showed that activin B can be detected even 5 weeks post-surgery in PD mice implanted with activin B-loaded hydrogels, and activin B-loaded hydrogels can significantly increase the density of tyrosine hydroxylase positive (TH(+)) nerve fibers and reduce inflammatory responses. The behavioral evaluation demonstrated that activin B-loaded hydrogels significantly improved the performance of the mice in the PD model. Meanwhile, we found that hydrogels can slightly induce the activation of microglia cells and astrocytes, while cannot induce apoptosis in the striatum. Overall, our data demonstrated that the developed activin B-loaded hydrogels provide sustained release of activin B for over 5 weeks and contribute to substantial cellular protection and behavioral improvement, suggesting their potential as a therapeutic strategy for PD.

An enzyme-free strategy for ultrasensitive detection of adenosine using a multipurpose aptamer probe and malachite green.

We report on an enzyme-free and label-free strategy for the ultrasensitive determination of adenosine. A novel multipurpose adenosine aptamer (MAAP) is designed, which serves as an effective target recognition probe and a capture probe for malachite green. In the presence of adenosine, the conformation of the MAAP is converted from a hairpin structure to a G-quadruplex. Upon addition of malachite green into this solution, a noticeable enhancement of resonance light scattering was observed. The signal response is directly proportional to the concentration of adenosine ranging from 75 pM to 2.2 nM with a detection limit of 23 pM, which was 100-10,000 folds lower than those obtained by previous reported methods. Moreover, this strategy has been applied successfully for detecting adenosine in human urine and blood samples, further proving its reliability. The mechanism of adenosine inducing MAAP to form a G-quadruplex was demonstrated by a series of control experiments. Such a MAAP probe can also be used to other strategies such as fluorescence or spectrophotometric ones. We suppose that this strategy can be expanded to develop a universal analytical platform for various target molecules in the biomedical field and clinical diagnosis.

A gold nanoparticles-modified aptamer beacon for urinary adenosine detection based on structure-switching/fluorescence-"turning on" mechanism.

A novel small molecule probe, aptamer beacon (AB), was introduced for adenosine (Ade) recognition and quantitative analysis. The Ade aptamer was engineered into an aptamer beacon by adding a gold nanoparticle-modified nucleotide sequence which is complementary to aptamer sequence (FDNA) at the 3'-end of FDNA. The fluorescence signal "turning on" was observed when AB was bound to Ade, which is attributed to a significant conformational change in AB from a FDNA/QDNA duplex to a FDNA-Ade complex. The Ade measurement was carried out in 20 mmol L(-1) Tris-HCl buffer solution of pH 7.4, ΔF signal linearly correlated with the concentration of Ade over the range of 2.0×10(-8) to 1.8×10(-6) mol L(-1). The limit of detection (LOD) for Ade is 6.0×10(-9) mol L(-1) with relative standard deviations (R.S.D) of 3.64-5.36%, and the recoveries were 98.6%, 100%, 102% (n=6), respectively. The present method has been successfully applied to determine Ade in human urine samples, and the obtained results were in good agreement with those obtained by the HPLC method. Our investigation shows that the unique properties of the AB could provide a promising potential for small molecules detection, and be benefit to extend the application of aptamer beacon technique.

Determination of trace formaldehyde in blood plasma by resonance fluorescence technology.

A novel method for the determination of trace formaldehyde in blood plasma has been established by using resonance fluorimetry technique. It was based on the fact that oxidation of pyronine Y by potassium bromate was catalyzed by formaldehyde in sulfuric acid. When the wavelength interval was at Δλ=0 nm, it was found that the decreased intensity (ΔF) of resonance fluorescence at 574.6 nm was proportional to the concentration of formaldehyde in the range of 1.27×10(-2) to 2.28 µg mL(-1). The limit of detection and the average recovery for formaldehyde were 3.80 ng mL(-1) and 101.6% (n=6), respectively. The present method had been applied to the determination of trace formaldehyde in blood plasma, and the obtained results were in good agreement with those obtained by the resonance light scattering method.