Isolated non-immune mediated second-degree atrioventricular block in fetus: natural history and predictive factors for spontaneous recovery

OBJECTIVES

To uncover the clinical course of fetal isolated non-immune mediated second-degree AVB and determine the factors associated with the spontaneous recovery for fetal non-immune second-degree atrioventricular block (AVB).

METHODS

A total of 20 fetuses with isolated, non-immune mediated second-degree AVB were prospectively recruited between 2014 and 2022. These fetuses were divided into the spontaneous recovery group (n=12) and the non-spontaneous recovery group (n=8). Maternal and fetal basic characteristics, intrauterine and postnatal outcomes were compared between groups.

RESULTS

Twelve fetuses restored 1:1 atrioventricular conduction in utero and did not recur during the postnatal follow-up period. The residual eight fetuses maintained as second-degree AVB and six of them were aborted due to parental request in utero. Of the two live children with second-degree AVB, one of them progressed to complete AVB at the latest follow up at the age of 34 months, but without any symptoms, heart enlargement or dysfunction. The residual one progressed to complete AVB and was finally diagnosed with type 2 long-QT syndrome. Fetuses in the spontaneous recovery group presented with earlier gestational age at diagnosis (20.0[17.0-26.0] vs. 24.5[18.0-35.0] weeks, p=0.004) and higher atrial rate (147[130-160] vs 138.00[125.00-149.00] bpm, p=0.006) in comparison with the non-spontaneous recovery group. A cut-off value of 22.5 weeks of gestational age and 144 bpm of atrial rate at diagnosis could predict the failure of spontaneous recovery, with sensitivities of 87.5%, 75%, and specificities of 92.0%, 87.5%, respectively.

CONCLUSIONS

The outcome of fetal non-immune second-degree AVB was favorable. Earlier gestational age at diagnosis and higher atrial rate were related to spontaneous reversion for isolated non-immune-mediated second-degree AVB. However, prenatal gene test should be performed for those with persistent AVB to exclude the heritable disorders including LQTS. These findings may provide important references for clinical management and prenatal counseling. This article is protected by copyright. All rights reserved.

GM-CSF, Flt3-L and IL-4 affect viability and function of conventional dendritic cell types 1 and 2

Conventional type 1 dendritic cells (cDC1) and conventional type 2 dendritic cells (cDC2) have attracted increasing attention as alternatives to monocyte-derived dendritic cells (moDCs) in cancer immunotherapy. Use of cDCs for therapy has been hindered by their low numbers in peripheral blood. In the present study, we found that extensive spontaneous apoptosis and cDC death in culture within 24hrs represent an additional challenge. Different media conditions that maintain cDC viability and function were investigated. CD141+ cDC1 and CD1c+ cDC2 were isolated from healthy blood donor buffy coats. Low viabilities were found with CellGenix DC, RPMI-1640, and X-VIVO 15 standard culture media and with several supplements at 24hrs and 48hrs. Among multiple factors it was found that GM-CSF improved both cDC1 and cDC2 viability, whereas Flt3-L and IL-4 only increased viability of cDC1 and cDC2, respectively. Combinations of these three cytokines improved viability of both cDCs further, both at 24hrs and 48hrs time points. Although these cytokines have been extensively investigated for their role in myeloid cell differentiation, and are also used clinically, their effects on mature cDCs remain incompletely known, in particular effects on pro-inflammatory or tolerogenic cDC features. HLA-DR, CD80, CD83, CD86, PD-L1 and PD-L2 cDC membrane expressions were relatively little affected by GM-CSF, IL-4 and Flt3-L cytokine supplements compared to the strong induction following Toll-like receptor (TLR) stimulation for 24hrs. With minor exceptions the three cytokines appeared to be permissive to the TLR-induced marker expression. Allogeneic mixed leukocyte reaction showed that the cytokines promoted T-cell proliferation and revealed a potential to boost both Th1 and Th2 polarizing cytokines. GM-CSF and Flt3-L and their combination improved the capability of cDC1 for dextran uptake, while in cDC2, dextran capture was improved by GM-CSF. The data suggest that GM-CSF, IL-4 and Flt3-L and combinations might be beneficial for DC viability and function in vitro. Limited viability of cDCs could be a confounding variable experimentally and in immunotherapy.

Tong-Qiao-Huo-Xue decoction activates PI3K/Akt/mTOR pathway to reduce BMECs autophagy after cerebral ischemia/reperfusion injury

ETHNOPHARMACOLOGICAL RELEVANCE

Tong-Qiao-Huo-Xue Decoction (TQHXD) is a traditional classic Chinese Medicinal Formula (CMF) used for clinical treatment of ischemic stroke. TQHXD leads to improvement in the symptoms of the acute period of cerebral infarction and recovery period after stroke. Our previous studies also showed that TQHXD produced a significant protective effect on the brain after cerebral ischemia-reperfusion (I/R) injury. It is reported that autophagy is closely related to ischemic brain injury; however, the functional contribution of TQHXD to brain microvascular endothelial cell (BMEC) autophagy and its underlying mechanism remains unclear.

AIM OF THE STUDY

The purpose of this study was to investigate the effects and mechanism of TQHXD in inhibiting cerebral ischemia-induced endothelial autophagy.

MATERIALS AND METHODS

The high-performance liquid chromatography (HPLC) fingerprint of the chemical constituents from TQHXD was established for the quality control, and the Longa method was used to evaluate the efficacy of TQHXD in rats with middle cerebral artery occlusion (MCAO). The expression of LC3 was determined by immunofluorescence double staining. To evaluate the protective effects of TQHXD-containing cerebrospinal fluid (CSF) on BMECs injured by oxygen-glucose deprivation and reperfusion, cell survival rate was determined using the CCK-8 assay and cell apoptosis was determined by fluorescein isothiocyanate (FITC)-Annexin V/PI. Autophagy was detected using transmission electron microscopy.

RESULTS

The results showed that TQHXD-CSF significantly ameliorated oxygen-glucose deprivation/reperfusion (OGD/R)-induced injury in BMECs. Confocal microscopy and Western blot results showed that TQHXD-CSF reduced autophagy-related protein expression and autophagosome number. The results of the western blotting indicated that TQHXD-CSF caused a marked increase in the phosphorylation of protein kinase B and phosphoinsotide-3 kinase (Akt/p-Akt and PI3K/p-PI3K, respectively) and their expression levels were down-regulated after treatment with pathway inhibitor, ZSTK474. Furthermore, in a MCAO model in rats, TQHXD markedly increased p-PI3K, p-Akt and p-mTOR, whereas the autophagy related proteins decreased.

CONCLUSIONS

Taken together, these findings demonstrate that TQHXD protects against ischemic insult by inhibiting autophagy through the regulation of the PI3K/Akt/mammalian target of rapamycin (mTOR) pathway and that TQHXD may have therapeutic value for protecting BMECs from cerebral ischemia.

Study on the mechanism of Tong-Qiao-Huo-Xue decoction regulating apoptosis via ASK1/MKK4/JNK pathway in MCAO/R rats

BACKGROUND

Activation of blood stasis is a crucial aspect of stroke treatment, and the Tong-Qiao-Huo-Xue-Decoction (TQHXD) formula is commonly utilized for this purpose. However, the mechanism underlying the protective effects of TQHXD against cerebral ischemia-reperfusion (I/R) injury is unclear.

PURPOSE

Identification of the TQHXD components responsible for its protective effects and determination of their mode of action against cerebral I/R injury.

METHODS

Gas chromatography (GC) and high-performance liquid chromatography (HPLC) were carried out to determine the active aspects of TQHXD. The active components and targets of TQHXD were looked up in the TCMSP and HERB databases; the Genecards, OMIM, TTD, and DrugBank databases were used to identify targets related to cerebral infarction; and the intersecting targets were obtained. The drug-ingredient-target-disease network and PPI network were subsequently built using Cytoscape 3.7.1 and STRING websites. Autodock VINA was used to perform molecular docking between the core target ASK1 and the active components of TQHXD detected by HPLC and GC. After successfully creating a rat model of middle cerebral artery occlusion (MCAO), the therapeutic effect of TQHXD was observed using triphenyltetrazolium and hematoxylin-eosin staining. We used Tunel-NeuN staining and transmission electron microscopy (TEM) to quantify hippocampal apoptosis. RT-qPCR and western blotting were used to detect protein and mRNA expression, respectively.

RESULTS

HPLC and GC identified six active ingredients. Network pharmacology analyses were performed to test 66 intersection targets, including ASK1, MKK4, and JNK. Ferulic acid, HSYA, ligustilide, paeoniflorin, and muscone all displayed high binding affinity with ASK1 in molecular docking studies. The neuroprotective effects of TQHXD in I/R rats were demonstrated in the experimental models. In comparison with the model group, TQHXD decreased the apoptosis rate and reduced the protein levels of p-ASK1, caspase 3, p-MKK4, CytC, p-c-Jun, Bax/Bcl-2, and p-JNK, while considerably increasing the mRNA levels of Bcl-2 and decreasing those of Bax.

CONCLUSION

By controlling the ASK1/MKK4/JNK pathway, TQHXD protects neurons from I/R damage and prevents apoptosis. Thus, TQHXD may be effective for the treatment of ischemic stroke. And the mechanism behind these therapeutic actions of TQHXD is supported by this research.

Abstract 1404: Novel STAT3 inhibitors targeting the STAT3 dimerization

Background The STAT3 pathway may drive prostate cancer (PCa) progression to metastatic castration-resistant prostate cancer (mCRPC). STAT3 may serve as a good target for the treatment of prostate cancer. The function of STAT3 relies significantly on its SH2 domain, which promotes STAT3 homo- or hetero-dimerization, protein-protein interaction and nuclear translocation of the STAT3 dimers needed for transcription. Due to this important role, the STAT3 SH2 domain becomes an attractive therapeutic target. In a drug discovery and development program we have found two small molecular compounds named 323-1 and 323-2 that were identified as novel STAT3 SH2 domain inhibitors in a series of experiments.

Material and methods In silico computational modeling, Drug Affinity Responsive Target Stability (DARTS) and Fluorescence Polarization (FP) assays were performed to examine whether compounds 323-1 and 323-2 could bind to the STAT3 protein. The antitumor activity of compounds 323-1 and 323-2 was firstly determined by clonogenic assays in different prostate tumor cells, then validated in the humanised NOD/SCID mouse CRPC model. Effects of compound 323-1 and 323-2 on STAT3 transcriptional activity were determined by the luciferase assay and protein levels by western blotting.

Results In silico computational modeling, DARTS and FP assays altogether determined 323-1 and 323-2 as direct STAT3 inhibitors targeting the STAT3 SH2 domain and inhibiting both phosphorylated and non-phosphorylated STAT3 dimerization. Computational docking predicted that both 323 compounds bind to three subpockets of the STAT3 SH2 domain with full inhibition of STAT3. FP assay further confirmed that 323s target the STAT3 SH2 domain by competitively abrogating the interaction between STAT3 and the SH2-binding peptide GpYLPQTV. Compared with S3I-201, the 323 compounds exhibited stronger inhibition of STAT3 and reduced the level of IL-6-stimulated phosphorylation of STAT3 (Tyr705) in LNCaP cells over the phosphorylation of STAT1 (Tyr701) induced by IFN-ɣ in PC3 cells or the phosphorylation of STAT1 (Ser727) in DU145 cells. Both compounds down-regulated STAT3 target genes MCL1 and cyclin D1. The in-vivo data supported that 323s significantly inhibited LNCaP cell generated CRPC tumor growth. Thus, the two compounds are promising leading compounds for the treatment of cancers with hyper-activated STAT3.

Conclusions Here we report that these compounds modulate the IL-6/STAT3 pathway by 1) inhibition of STAT3 phosphorylation on Tyr705 and 2) disruption of STAT3 dimerization by directly targeting its SH2 domain; 3) inhibition of STAT3 transcriptional activity. Thus, the compounds 323-1 and 323-2 are promising new leading compounds for therapeutic STAT3 inhibition.

Citation Format: Yaping Hua, Waqas Azeem, Anne Margrete Øyan, Karl-Henning Kalland. Novel STAT3 inhibitors targeting the STAT3 dimerization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1404.

Abstract 3568: Robust and potent dendritic cells for cancer immunotherapy

Background: Dendritic cells (DCs) are fundamental to adaptive immunity by detecting, engulfing and presenting foreign or changed antigenic peptides to lymphocytes that thereafter initiate antigen-specific immune attacks. DC-based immunotherapy against cancer has been promising for a long time, but has not yet met expectations. Cancer cell heterogeneity and numerous immune evasion mechanisms represent challenges. According to textbook renderings, DCs may induce either tolerance or immune activation depending upon the nature of the encountered antigen and the status of the microenvironment. Recently, we have discovered a more complicated scenario according to which monocyte-derived DCs (moDCs) exhibit dual pro- and anti-inflammatory features, suggesting that selected conditions that enhance pro-inflammatory features and counteract tolerogenic features could generate more robust and potent DCs for cancer therapy.

Materials and Methods: Healthy blood donor buffy coats were used for the isolation of monocytes and conventional CD141+ and CD1c+ natural circulating DCs. IL-4 and GM-CSF were used to differentiate monocytes into immature moDCs. Toll-like receptor agonists were used to induce DC maturation, and specific agonists and inhibitors were tested in different DC variants. Flow cytometry, ELISA determination of cytokine secretion, HPLC-based quantitation of kynurenine secretion, genome-wide gene expression analyses and functional assays, such as antigen uptake, migration and the mixed leukocyte reaction were used for evaluation of treated DCs.

Results: Conventional DCs were more susceptible to apoptosis, and dependent upon culture conditions, than moDCs. Inhibition of β-catenin signaling stimulated several pro-inflammatory features, e.g. increased IL-12 and decreased IL-10 secretion, with reciprocal effects caused by β-catenin stimulation. Maturation of moDCs was accompanied by very strong induction of indoleamine 2, 3-dioxygenase 1 (IDO1) transcription and paralleled by increased kynurenine secretion, but this was partially counteracted by β-catenin stimulation.

Conclusions: Preparation of more potent DCs for cancer therapy needs to take into account DC longevity and conflicting activation patterns of pro- and anti-inflammatory abilities.

Citation Format: Waqas Azeem, Seyed Mohammad Lellahi, Yaping Hua, Anne Margrete Øyan, Benjamin Gabriel, Karl-Henning Kalland. Robust and potent dendritic cells for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3568.

Novel STAT3 Inhibitors Targeting STAT3 Dimerization by Binding to the STAT3 SH2 Domain

Our drug discovery model has identified two novel STAT3 SH2 domain inhibitors 323–1 and 323–2 (delavatine A stereoisomers) in a series of experiments. In silico computational modeling, drug affinity responsive target stability (DARTS), and fluorescence polarization (FP) assays altogether determined that 323–1 and 323–2 directly target the STAT3 SH2 domain and inhibited both phosphorylated and non-phosphorylated STAT3 dimerization. Computational docking predicted that compound 323s bind to three subpockets of the STAT3 SH2 domain. The 323s inhibition of STAT3 dimerization was more potent than the commercial STAT3 SH2 domain inhibitor S3I-201 in the co-immunoprecipitation assay, correlating with computational docking data. The fluorescence polarization assay further confirmed that the compound 323s target the STAT3 SH2 domain by competitively abrogating the interaction between STAT3 and the SH2-binding peptide GpYLPQTV. Compared with S3I-201, the 323 compounds exhibited stronger inhibition of STAT3 and reduced the level of IL-6-stimulated phosphorylation of STAT3 (Tyr705) in LNCaP cells over the phosphorylation of STAT1 (Tyr701) induced by IFN-ɣ in PC3 cells or the phosphorylation of STAT1 (Ser727) in DU145 cells. Both compounds downregulated STAT3 target genes MCL1 and cyclin D1. Thus, the two compounds are promising lead compounds for the treatment of cancers with hyper-activated STAT3.

Highly efficient generation of narrowband terahertz radiation driven by a two-spectral-line laser in PPLN

We demonstrate record ∼0.9% efficiencies for optical conversion to narrowband (<1% relative bandwidth) terahertz (THz) radiation by strongly cascaded difference frequency generation. These results are achieved using a novel, to the best of our knowledge, laser source, customized for high efficiencies, with two narrow spectral lines of variable separation and pulse duration (≥250 ps). THz radiation generation in 5% MgO-doped periodically poled lithium niobate (PPLN) crystals of varying poling period was explored at cryogenic and room temperature operation as well as with different crystal lengths. This work addresses an increasing demand for high-field THz radiation pulses which has, up to now, been largely limited by low optical-to-THz radiation conversion efficiencies.

Stabilization and sensory evaluation of calcium-enriched soymilk prepared using different chelating agents

It is generally acknowledged that calcium lactate (ca-lactate) fortification of soymilk to achieve the equivalent calcium level in cow’s milk (1.2 mg/g) causes instability in soymilk. In order to produce acceptable calcium-enriched soymilk with great stability, three different kinds of chelating agents were added, namely tripotassium citrate (TPC), trisodium citrate (TSC), and sodium hexametaphosphate (SHMP). In this study, the addition of ca-lactate was found to reduce the pH (6.62 to 5.37) and increase the particle diameter (268.66 to 1,222.81 nm) and sedimentation (0.19 to 8.75%) of soymilk. Meanwhile, the addition of TPC and TSC produced calcium-enriched soymilks with smaller particle diameter (295.21-452.22 nm and 297.61-461.80 nm) and lower sedimentation levels (0.25-1.55% and 0.26-1.58%). The pH of calcium-enriched soymilk was also increased when both chelating agents were added. The application of SHMP as a chelating agent was not as effective as TPC and TSC because the particle diameter (527.98-703.40 nm) and sedimentation level were still relatively higher (4.24-5.68%) than the unfortified soymilk. Even though both TPC and TSC showed no significant difference (P>0.05) in stability, the sensory evaluation showed different results. Soymilk with TSC added was saltier and sourer than samples with TPC added. The study recommends the use of TPC as the chelating agent in soymilk enriched with ca-lactate.

Proteasome-Mediated Regulation of GATA2 Expression and Androgen Receptor Transcription in Benign Prostate Epithelial Cells

GATA2 has been shown to be an important transcription factor together with androgen receptor (AR) in prostate cancer cells. Less is known about GATA2 in benign prostate epithelial cells. We have investigated if GATA2 exogenous expression in prostate epithelial basal-like cells could induce AR transcription or luminal differentiation. Prostate epithelial basal-like (transit amplifying) cells were transduced with lentiviral vector expressing GATA2. Luminal differentiation markers were assessed by RT-qPCR, Western blot and global gene expression microarrays. We utilized our previously established AR and androgen-dependent fluorescence reporter assay to investigate AR activity at the single-cell level. Exogenous GATA2 protein was rapidly and proteasome-dependently degraded. GATA2 protein expression was rescued by the proteasome inhibitor MG132 and partly by mutating the target site of the E3 ligase FBXW7. Moreover, MG132-mediated proteasome inhibition induced AR mRNA and additional luminal marker gene transcription in the prostate transit amplifying cells. Different types of intrinsic mechanisms restricted GATA2 expression in the transit amplifying cells. The appearance of AR mRNA and additional luminal marker gene expression changes following proteasome inhibition suggests control of essential cofactor(s) of AR mRNA expression and luminal differentiation at this proteolytic level.

Average SAR prediction, validation, and evaluation for a compact MR scanner head-sized RF coil

A recently developed compact 3 T (C3T) MRI scanner with high performance gradients [1, 2] has a dedicated radiofrequency (RF) transmit coil that exposes only the head, neck and a small portion of the upper body region during head-first scanning. Due to the unique coil geometry and patient positioning, the established SAR model used for a conventional whole-body scanner cannot be directly translated to the C3T. Here a specific absorption rate (SAR) estimation and validation framework was developed and used to implement a dedicated and accurate SAR prediction model for the C3T. Two different SAR prediction models for the C3T were defined and evaluated: one based on an anatomically derived exposed mass, and one using a fixed anatomical position located caudally to the RF coil to determine the exposed mass. After coil modeling and virtual human body simulation, the designed SAR prediction model was implemented on the C3T and verified with calorimetry and in vivo scan power monitoring. The fixed-demarcation exposed mass model was selected as appropriate exposed mass region to accurately estimate the SAR deposition in the patient on the C3T.

Five lncRNAs associated with the survival of hepatocellular carcinoma: a comprehensive study based on WGCNA and competing endogenous RNA network

OBJECTIVE

The competing endogenous RNA (ceRNA) presents a comprehensive regulatory network among lncRNAs, miRNAs and mRNA. The ceRNA provides significant information in understanding the pathology of cancer. This study aimed to explore a lncRNA-associated ceRNA network for predicting the overall survival of patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

In this study, RNA-sequencing data of HCC were downloaded from The Cancer Genomes Atlas (TCGA) database. The module-trait relationship was analyzed with Weighted gene co-expression network analysis (WGCNA). The key module associated with tumor was identified, as well as the involved lncRNAs, mRNAs and miRNAs. The preliminary ceRNA network was constructed with Cytoscape. The survival analysis was further performed to screen survival-relevant lncRNAs, mRNAs and miRNAs, and then the survival-associated ceRNA network was reconstructed.

RESULTS

Eventually, 5 lncRNAs, 10 miRNAs, and 25 mRNAs were included in the reconstructed ceRNA network.

CONCLUSIONS

The identified lncRNAs were promising candidate biomarkers in HCC diagnosis and therapeutics. This analysis process was effective to construct ceRNA network. The result will be conductive to explore the significant lncRNAs and regulatory mechanism.

Development of a PET/EPRI combined imaging system for assessing tumor hypoxia

Precise quantitative delineation of tumor hypoxia is essential in radiation therapy treatment planning to improve the treatment efficacy by targeting hypoxic sub-volumes. We developed a combined imaging system of positron emission tomography (PET) and electron para-magnetic resonance imaging (EPRI) of molecular oxygen to investigate the accuracy of PET imaging in assessing tumor hypoxia. The PET/EPRI combined imaging system aims to use EPRI to precisely measure the oxygen partial pressure in tissues. This will evaluate the validity of PET hypoxic tumor imaging by (near) simultaneously acquired EPRI as ground truth. The combined imaging system was constructed by integrating a small animal PET scanner (inner ring diameter 62 mm and axial field of view 25.6 mm) and an EPRI subsystem (field strength 25 mT and resonant frequency 700 MHz). The compatibility between the PET and EPRI subsystems were tested with both phantom and animal imaging. Hypoxic imaging on a tumor mouse model using 18F-fluoromisonidazole radio-tracer was conducted with the developed PET/EPRI system. We report the development and initial imaging results obtained from the PET/EPRI combined imaging system.

MicroRNA-1286 inhibits osteogenic differentiation of mesenchymal stem cells to promote the progression of osteoporosis via regulating FZD4 expression

OBJECTIVE

The aim of this study was to investigate whether microRNA-1286 could inhibit the osteogenic differentiation of human marrow mesenchymal stem cells (hMSCs) by regulating FZD4 expression and promoting the progression of osteoporosis.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of microRNA-1286 in the serum of patients with osteoporosis. Meanwhile, microRNA-1286 expression in different stages of osteogenic differentiation of hMSCs was measured by qRT-PCR as well. After overexpression of microRNA-1286 and FZD4 in hMSCs, the mRNA expression levels of microRNA-1286, alkaline phosphatase (ALP), RUNX2 and osteocalcin (OCN) were detected by qRT-PCR. The protein expression levels of RUNX2 and OCN were detected by Western blot. Meanwhile, alkaline phosphatase (ALP) activity and expression in cells were examined using ALP assay kit and ALP staining method, respectively. Cell mineralized nodules were detected through the alizarin red staining test. Bioinformatics method was used to predict the binding site of microRNA-1286 to FZD4. Subsequent luciferase reporter gene assay was performed to verify whether microRNA-1286 could combine with FZD4. After overexpression or knockdown of microRNA-1286, the mRNA and protein expressions of FZD4 were analyzed using qRT-PCR and Western blot assay, respectively. After the simultaneous overexpression of microRNA-1286 and FZD4 in hMSCs, the mRNA expression levels of ALP, RUNX2 and OCN, ALP activity and content, and cell mineralization ability were successively examined.

RESULTS

The expression of microRNA-1286 in the serum of patients with osteoporosis was significantly higher than that of the normal population. Meanwhile, microRNA-1286 expression decreased with the increase of osteogenic differentiation days of hAMSCs. After the overexpression of microRNA-1286, ALP, RUNX2, and OCN levels, ALP activity, RUNX2, and OCN protein levels, as well as mineralized nodule formation were significantly reduced. However, results were reversed when FZD4 was simultaneously up-regulated. Luciferase reporter gene assay results verified that microRNA-1286 could bind to FZD4. After the overexpression of microRNA-1286, the mRNA and protein expressions of FZD4 were found significantly down-regulated. However, results were reversed after knocking down microRNA-1286. Furthermore, the simultaneous overexpression of microRNA-1286 and FZD4 could counteract the inhibitory effect of over-expression of microRNA-1286 on osteogenic differentiation of hMSCs.

CONCLUSIONS

MicroRNA-1286 can regulate FZD4 expression and inhibit osteogenic differentiation of hMSCs, thereby promoting the development of osteoporosis.

Design, evaluation and initial imaging results of a PET insert based on strip-line readout for simultaneous PET/MRI

We present the development of a PET insert system for potential simultaneous PET/MR imaging using a 9.4 T small animal MRI scanner to test our system. The detectors of the system adopt a strip-line based multiplexing readout method for SiPM signals. In this readout, multiple SiPM outputs in a row share a common strip-line. The position information about a hit SiPM is encoded in the propagation time difference of the signals arriving at the two ends of the strip-line. The use of strip-lines allows us to place the data acquisition electronics remotely from the detector module to greatly simplify the design of the detector module and minimize the mutual electromagnetic interference. The prototype is comprised of 14 detector modules, each of which consists of an 8x4 LYSO scintillator array (each LYSO crystal is 3x3x10 mm³) coupled to two units of Hamamatsu MPPC arrays (4x4, 3.2 mm pitch) that are mounted on a strip-line board. On the strip-line board, outputs of the 32 SiPMs are routed to 2 strip-lines so that 16 SiPM signals share a strip-line. The detector modules are installed inside a plastic cylindrical supporting structure with an inner and outer diameter of 60 mm and 115 mm, respectively, to fit inside a Bruker BioSpec 9.4 Tesla MR scanner. The axial field of view of the prototype is 25.4 mm. The strip-lines were extended by using 5-meter cables to a sampling data acquisition (DAQ) board placed outside the magnet. The detectors were not shielded in the interest of investigating how they may affect and be affected by the MRI. Experimental tests were conducted to evaluate detection performance, and phantom and animal imaging were carried out to assess the spatial resolution and the MR compatibility of the PET insert. Initial results are encouraging and demonstrate that the prototype insert PET can potentially be used for PET/MR imaging if appropriate shielding will be implemented for minimizing the mutual interference between the PET and MRI systems.

Diversity and abundance of comammox bacteria in the sediments of an urban lake

AIMS

Although comammox have been discovered in a variety of ecosystems, there are few studies in urban lakes. This paper attempted to confirm whether this ammonia-oxidizing microbe exists in urban lakes and to determine the factors influencing its existence.

METHODS AND RESULTS

This study investigated the diversity and abundance of comammox bacteria in sediments of a typical urban lake in China, and their ecological relationship with other ammonia-oxidizing micro-organisms. The phylogenetic analysis indicated that comammox clade A existed in the sediment of Lake Donghu, and the comammox bacteria co-existed with ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing (anammox) bacteria in the sediment of this lake. The abundances of the ammonia monooxygenase subunit A (amoA) genes for comammox, AOA, AOB and anammox 16S rRNA were 2·43 × 10⁸ , 1·07 × 10⁸ , 3·24 × 10⁷ and 3·21 × 10¹¹ copies per gram dry sediment respectively. Moreover, the amoA gene abundance of comammox was positively correlated with that of AOA and AOB. The redundancy analysis showed that the abundance of the comammox amoA gene was negatively correlated with the concentration of main indicators for nitrogen status in both the sediment and the water column, indicating that eutrophication may inhibit the growth of comammox bacteria.

CONCLUSIONS

Comammox bacteria play an important ecological role in the nitrogen cycle of urban lake sediments.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results indicated comammox bacteria were widespread in urban lakes and eutrophication may inhibit their growth.

Frequency-comb-based laser system producing stable optical beat pulses with picosecond durations suitable for high-precision multi-cycle terahertz-wave generation and rapid detection

We generate temporally modulated optical pulses with a beat frequency of 255 GHz, a duration of 360 ps, and a repetition rate of 2 MHz. The temporal envelope, beat frequency, and repetition rate are computer-programmable. A frequency comb serves as a phase and frequency reference for the locking of two laser lines. The system enables beat frequencies that are adjustable in steps of the frequency comb's repetition rate and exhibit Hz-level precision and accuracy. We expect the optical beat pulses to be well suited for versatile multi-cycle terahertz-wave generation with controllable carrier-envelope phase. We demonstrate that the inherent synchronization of the frequency comb's ultra-short pulse train and the synthesized optical beat (or later the multi-cycle terahertz) pulses enables rapid and phase-sensitive sampling of such pulses.

Dual androgen receptor (AR) and STAT3 inhibition by a compound targeting the AR amino-terminal domain

Prostate cancer (PCa) often recurs as incurable castration-resistant prostate cancer (CRPC) after the failure of androgen deprivation therapy. CRPC development relies on androgen receptor (AR) signaling. The IL6/STAT3 pathway is also a key driver of CRPC. The crosstalk between IL6/STAT3 and the AR pathways provides opportunities to explore next-generation agents to treat PCa. Through screening of around 600 natural compounds in our newly established prostate tumorigenesis model, potential STAT3 signaling inhibitors were found and additionally examined for effects on AR signaling. The small molecular compound 154 exhibited dual effects on IL6/STAT3 and AR pathways. We show here that compound 154 inhibits AR and STAT3 transcriptional activity, reduces the expression of phosphorylation of STAT3 (Y705) and downregulates the mRNA levels of AR target genes. Compound 154 also inhibits protein expression of AR and AR splice variants (ARv567es and AR-V7) without altering AR mRNA levels. Compound 154 binds to AR directly, but not to STAT3 and is identified as an antagonist of the AR amino-terminal domain (NTD) by disrupting protein-protein interactions between STAT3 and the AR NTD. Moreover, compound 154 does not reduce AR nuclear translocation. Compound 154 possesses the potential to become a leading compound in novel therapies against CRPC.

[Clinical characteristics analysis of children with reversible posterior leukoen-cephalopathy syndrome during the treatment of hematological tumor]

OBJECTIVE

To analyze the clinical characteristics of patients with hematological tumor or disease before and after reversible posterior leukoen-cephalopathy syndrome (RPLS).

METHODS

Five patients were both from Peking University First Hospital Pediatric Hematology-oncology Department in the period from March 2012 to March 2017. The gender, age, BMI, underlying diseases, with or without renal damage, hypertension family history, clinical manifestations of convulsions, hemoglobin, and blood pressure, serum sodium levels before and after convulsion, and other data of the children with RPLS were retrospectively analyzed. In the meantime, we followed up the five patients for 6 months to 66 months, kept a watchful eye on their original condition and the recovery of symptoms and signs of the nervous system. The relevant literature was reviewed.

RESULTS

All of the subjects were females in school-age or pre-school age. The underlying diseases were malignant tumor associated with renal involvement or on one side of nephrectomy in 4 of these subjects, while the other one was refractory autoimmune hemolytic anemia. All of the subjects suffered from mild or moderate anemia. The day before RPLS occurred they received chemotherapy made up with cyclophosphamide, vincristine, and actinomycin-D, or the therapy with cyclosporin A and glucocorticoid. The clinical manifestations were afebrile convulsion after getting up in the mooring or in the afternoon. We observed elevation of blood pressure and cutting down of serum sodium compared with themselves. All of the cases recovered soon after management with diazepam, furosemide and amlodipine besylate. Four of them had a good outcomes and did not remain any sequela, while only one girl became childish in emotion and behavior, and then returned gradually to normal two years later. However, by long-term follow-up, the elevation of blood pressure was mainly reviewed in literature.

CONCLUSION

The patients attacked by RPLS, with hematology or oncology cases, could have the underlying disease of renal damage and anemia. Blood pressure elevation and serum sodium falling down at the same time may play an important role during the occurrence of RPLS. Remaining stable of blood pressure and electrolyte level together will possibly reduce or mitigate RPLS.

The expression significance of serum MiR-21 in patients with osteosarcoma and its relationship with chemosensitivity

OBJECTIVE

To investigate the expression level of serum microRNA-21 (miR-21) in 69 patients with osteosarcoma, to analyze the changes in miR-21 expression in the serum and tumor tissues before and after chemotherapy in patients with osteosarcoma, and to investigate the relationship between the expression of serum miR-21 in patients with osteosarcoma and chemosensitivity.

PATIENTS AND METHODS

Real-time polymerase chain reaction (RT-PCR) was used to detect the expression level of serum miR-21 in 69 patients with osteosarcoma before and after chemotherapy, and analyze the relationship between the expression of miR-21 with tumor necrosis grading and chemosensitivity. The expression level of programmed cell death protein 4 (PDCD4) in tumor tissues of patients with osteosarcoma before and after chemotherapy was detected by Western blot.

RESULTS

The expression level of serum miR-21 in patients with osteosarcoma was significantly higher than that in normal control subjects. The expression of serum miR-21 before and after chemotherapy was positively correlated with the expression of miR-21 in the corresponding tissues. In the group where chemotherapy was effective (the effective group), expression levels of miR-21 in patients with osteosarcoma before and after chemotherapy were significantly different. After chemotherapy, the expression level of target genes of miR-21 was increased, and the follow-up results showed that the 5-year survival rate was relatively higher after surgery.

CONCLUSIONS

The expression level of serum miR-21 in patients with osteosarcoma is closely related to the therapeutic effects of osteosarcoma, which can be used as one of the potential biomarkers and therapeutic targets for the diagnosis and prediction of osteosarcoma.

[Autoimmune disorder secondary to DiGeorge syndrome: a long-term follow-up case report and literature review]

DiGeorge syndrome is the most common chromosome microdeletion disease. The classical complications include congenital heart disease, hypothyroidism, immunodeficiency, facial abnormalities, and hypocalcemia. According to whether there is an absence or hypoplasia of the thymus, DiGeorge syndrome can be divided into two types, complete DiGeorge syndrome and partial DiGeorge syndrome. The patient was a female born with congenital heart disease, facial abnormalities and cleft palate. When the patient went to school, she had learning difficulty and had problems in communication and personal social behavior. Breath-holding occurred when she was 6 years old. She got infections about 2-3 times a year, which was easy to be cured each time. Chromosome microdeletion test of peripheral blood showed the classical 22q11.2 microdeletion, and no evidence showed that she has thymus absence, thus her disease was diagnosed as partial DiGeorge syndrome. When the patient was 6 years old, the blood routine test showed slight thrombocytopenia, and reexaminations after that indicated the similar result. When 9 years old, she was found with anemia and severe thrombocytopenia. At the age of 10, the patient was admitted to our hospital, complaining of petechia in the body and mucous of mouth. According to the various examinations results, doctors eventually considered the situation as an autoimmune disorder phenomenon. After being treated by pulse-dose methylprednisolone for three days, the bleeding ceased. Then the patient orally took prednisone acetate and pulse-dose cyclophosphamide, however the thrombocyte and hemoglobin levels had not been back to a normal range. But when the dose of prednisone acetate was reduced, the blood platelet count declined again while the hemoglobin kept normal. The long-term follow-up of this case lasted for more than 20 years. Until now, the patient is taking orally prednisone acetate as a maintainance treatment, and the anemia has been improved since, but thrombocytopenia still exists. The mechanism of DiGeorge syndrome in combination with immunodeficiency is still unclear. The most likely reason is that this phenomenon has some relationship with the dysfunction of the thymus and finally had an effect on the function of T cells. The clinical manifestation is always stubborn and need treatment and follow-up visit for a long time.