[Identification of key genes in Wilms tumor based on high-throughput RNA sequencing and their impacts on prognosis and immune responses]

OBJECTIVE

To identify the key genes differentially expressed in Wilms tumor and analyze their potential impacts on prognosis and immune responses of the patients.

METHODS

High-throughput RNA sequencing was used to identify the differentially expressed mRNAs in clinical samples of Wilms tumor and paired normal tissues, and their biological functions were analyzed using GO, KEGG and GSEA enrichment analyses. The hub genes were identified using STRING database, based on which a prognostic model was constructed using LASSO regression. The mutations of the key hub genes were analyzed and their impacts on immunotherapy efficacy was predicted using the cBioPortal platform. RT-qPCR was used to verify the differential expressions of the key hub genes in Wilms tumor.

RESULTS

Of the 1612 differentially expressed genes identified in Wilms tumor, 1030 were up-regulated and 582 were down-regulated, involving mainly cell cycle processes and immune responses. Ten hub genes were identified, among which 4 genes (TP53, MED1, CCNB1 and EGF) were closely related to the survival of children with Wilms tumor. A 3-gene prognostic signature was constructed through LASSO regression analysis, and the patients stratified into with high- and low-risk groups based on this signature had significantly different survival outcomes (HR=1.814, log-rank P=0.002). The AUCs of the 3-, 5- and 7-year survival ROC curves of this model were all greater than 0.7. The overall mutations in the key hub genes or the individual mutations in TP53/CCNB1 were strongly correlated with a lower survival rates, and a high TP53 expression was correlated with a poor immunotherapy efficacy. RT-qPCR confirmed that the key hub genes had significant differential expressions in Wilms tumor tissues and cells.

CONCLUSION

TP53 gene plays an important role in the Wilms tumor and may potentially serve as a new immunotherapeutic biomarker as well as a therapeutic target.

Sophora tonkinensis: response and adaptation of physiological characteristics, functional traits, and secondary metabolites to drought stress

The medicinal plant Sophora tonkinensis is a characteristic Chinese shrub of karst areas. The arid climate in karst areas produces high-quality S. tonkinensis; however, the mechanisms of drought tolerance are not clear, which restricts sustainable plantings of S. tonkinensis. This study involved a 20-day drought stress experiment with potted S. tonkinensis and threee soil water regimes: control (CK), mild drought (MDT), and severe drought (SDT). Plant morphology, biomass, physiological indicators, alkaloid content, and other changes under drought stress were monitored. The content of soluble sugars and proteins, and activity of antioxidant enzymes in leaves and roots were higher under drought than CK, indicating that S. tonkinensis is tolerant to osmotic stress in early drought stages. Content of matrine and oxymatrine increased gradually with increasing drought duration in the short term. The epidermis of S. tonkinensis leaves have characteristics of desert plants, including upper epidermal waxy layer, lower epidermal villi, and relatively sunken stomata, suggesting that S. tonkinensis has strong drought tolerance. In conclusion, drought stress changed the cell structure of S. tonkinensis, induced antioxidant enzyme activity and increased its resistance to drought.

Extracellular vesicle-derived CircWhsc1 promotes cardiomyocyte proliferation and heart repair by activating TRIM59/STAT3/Cyclin B2 pathway

INTRODUCTION

Extracellular vesicles (EVs)-mediated cell-to-cell communication is crucial for hypoxia-induced cell proliferation and tissue repair, but its function in endogenous cardiac regeneration is still unknown.

OBJECTIVES

Herein, we aimed to determine whether hypoxia-inducible circWhsc1 in endothelial EVs promoted cardiomyocyte (CM) proliferation and cardiac regeneration.

METHODS

RNA-sequence data was used to identify EV circRNAs that were involved into endogenous cardiac regeneration. Quantitative polymerase chain reactions were conducted to determine circRNA expression in tissue, cells and EVs. Gain- and loss-of-function assays were performed to explore the function of EV-derived circWhsc1 during cardiac regeneration. Western blotting and RNA pulldown assays were used to investigate its underlying mechanism.

RESULTS

We found that circWhsc1 was enriched in neonatal mouse hearts, particularly in cardiac ECs, and was further upregulated both in ECs and EC-derived EVs under hypoxic conditions. When cocultured with hypoxia-preconditioned neonatal ECs or their secreted EVs, both neonatal and adult CMs exhibited an increased proliferation rate and G2/M ratio, which could be attenuated by knockdown of circWhsc1 in ECs. In vivo, EC-restricted overexpression of circWhsc1 and EV-mediated delivery of circWhsc1 induced CM proliferation, alleviated cardiac fibrosis and restored cardiac function following myocardial infarction in adult mice. Mechanistic studies revealed that EV-derived circWhsc1 activated TRIM59 by enhancing its phosphorylation, thereby reinforcing the binding of TRIM59 to STAT3, phosphorylating STAT3 and inducing CM proliferation.

CONCLUSION

The current study demonstrated that hypoxia-inducible circWhsc1 in EC-derived EVs induces CM proliferation and heart regeneration. EC-CM communication mediated by EV-derived circWhsc1 might represent a prospective therapeutic target for inducing cardiac repair post-myocardial infarction.

Clearance of Stress-Induced Premature Senescent Cells Alleviates the Formation of Abdominal Aortic Aneurysms

Abdominal aortic aneurysm (AAA) is a multifactorial disease characterized by various pathophysiological processes, including chronic inflammation, oxidative stress, and proteolytic activity in the aortic wall. Stress-induced premature senescence (SIPS) has been implicated in regulating these pathophysiological processes, but whether SIPS contributes to AAA formation remains unknown. Here, we detected SIPS in AAA from patients and young mice. The senolytic agent ABT263 prevented AAA development by inhibiting SIPS. Additionally, SIPS promoted the transformation of vascular smooth muscle cells (VSMCs) from a contractile phenotype to a synthetic phenotype, whereas inhibition of SIPS by the senolytic drug ABT263 suppressed VSMC phenotypic switching. RNA sequencing and single-cell RNA sequencing analysis revealed that fibroblast growth factor 9 (FGF9), secreted by stress-induced premature senescent VSMCs, was a key regulator of VSMC phenotypic switching and that FGF9 knockdown abolished this effect. We further showed that the FGF9 level was critical for the activation of PDGFRβ/ERK1/2 signaling, facilitating VSMC phenotypic change. Taken together, our findings demonstrated that SIPS is critical for VSMC phenotypic switching through the activation of FGF9/PDGFRβ/ERK1/2 signaling, promoting AAA development and progression. Thus, targeting SIPS with the senolytic agent ABT263 may be a valuable therapeutic strategy for the prevention or treatment of AAA.

Fast and slow skeletal myosin binding protein-C and aging

Aging is associated with skeletal muscle strength decline and cardiac diastolic dysfunction. The structural arrangements of the sarcomeric proteins, such as myosin binding protein-C (MyBP-C) are shown to be pivotal in the pathogenesis of diastolic dysfunction. Yet, the role of fast (fMyBP-C) and slow (sMyBP-C) skeletal muscle MyBP-C remains to be elucidated. Herein, we aimed to characterize MyBP-C and its paralogs in the fast tibialis anterior (TA) muscle from adult and old mice. Immunoreactivity preparations showed that the relative abundance of the fMyBP-C paralog was greater in the TA of both adult and old, but no differences were noted between groups. We further found that the expression level of cardiac myosin binding protein-C (cMyBP-C), an important modulator of cardiac output, was lowered by age. Standard SDS-PAGE along with Pro-Q Diamond phosphoprotein staining did not identify age-related changes in phosphorylated MyBP-C proteins from TA and cardiac muscles; however, it revealed that MyBP-C paralogs in fast skeletal and cardiac muscle were highly phosphorylated. Mass spectrometry further identified glycogen phosphorylase, desmin, actin, troponin T, and myosin regulatory light chain 2 as phosphorylated myofilament proteins in both ages. MyBP-C protein-bound carbonyls were determined using anti-DNP immunostaining and found the carbonyl level of fMyBP-C, sMyBP-C, and cMyBP-C to be similar between old and adult animals. In summary, our data showed some differences regarding the MyBP-C paralog expression and identified an age-related reduction of cMyBP-C expression. Future studies are needed to elucidate which are the age-driven post-translational modifications in the MyBP-C paralogs.

CircRNA Samd4 induces cardiac repair after myocardial infarction by blocking mitochondria-derived ROS output

Reactive oxygen species (ROS) derived from oxygen-dependent mitochondrial metabolism are the essential drivers of cardiomyocyte (CM) cell-cycle arrest in adulthood. Mitochondria-localized circular RNAs (circRNAs) play important roles in regulating mitochondria-derived ROS production, but their functions in cardiac regeneration are still unknown. Herein, we investigated the functions and underlying mechanism of mitochondria-localized circSamd4 in cardiac regeneration. We found that circSamd4 was selectively expressed in fetal and neonatal CMs. The transcription factor Nrf2 controlled circSamd4 expression by binding to the promoter of circSamd4 host gene. CircSamd4 overexpression reduced while circSamd4 silenced increased mitochondrial oxidative stress and subsequent oxidative DNA damage. Moreover, circSamd4 overexpression induced CM proliferation and prevented CM apoptosis, which reduced the size of the fibrotic area and improved cardiac function after myocardial infarction (MI). Mechanistically, circSamd4 reduced oxidative stress generation and maintained mitochondrial dynamics by inducing the mitochondrial translocation of the Vcp protein, which downregulated Vdac1 expression and prevented the mitochondrial permeability transition pore (mPTP) from opening. Our findings suggest that circSamd4 is a novel therapeutic target for heart failure after MI.

Circular RNA Cdyl promotes abdominal aortic aneurysm formation by inducing M1 macrophage polarization and M1-type inflammation

Macrophage polarization plays a crucial role in regulating abdominal aortic aneurysm (AAA) formation. Circular RNAs (circRNAs) are important regulators of macrophage polarization during the development of cardiovascular diseases. How-ever, the roles of circRNAs in regulating AAA formation through modulation of macrophage polarization remain unknown. In the present study, we compared circRNA microarray data under two distinct polarizing conditions (M1 and M2 macrophages) and identified an M1-enriched circRNA, circCdyl. Loss- and gain-of-function assay results demonstrated that circCdyl overexpression accelerated angiotensin II (Ang II)- and calcium chloride (CaCl₂)-induced AAA formation by promoting M1 polarization and M1-type inflammation, while circCdyl deficiency showed the opposite effects. RNA pulldown, mass spectrometry analysis, and RNA immunoprecipitation (RIP) assays were conducted to elucidate the underlying mechanisms by which circCdyl regulates AAA formation and showed that circCdyl promotes vascular inflammation and M1 polarization by inhibiting interferon regulatory factor 4 (IRF4) entry into the nucleus, significantly inducing AAA formation. In addition, circCdyl was shown to act as a let-7c sponge, promoting C/EBP-δ expression in macrophages to induce M1 polarization. Our results indicate an important role for circCdyl-mediated macrophage polarization in AAA formation and provide a potent therapeutic target for AAA treatment.

LncRNA Snhg1-driven self-reinforcing regulatory network promoted cardiac regeneration and repair after myocardial infarction

Rationale: Most current cardiac regeneration approaches result in very limited cell division and little new cardiomyocyte (CM) mass. Positive feedback loops are vital for cell division, but their role in CM regeneration remains unclear. We aimed to determine whether the lncRNA small nucleolar RNA host gene 1 Snhg1 (Snhg1) could form a positive feedback loop with c-Myc to induce cardiac regeneration.

Methods: Quantitative PCR and in situ hybridization experiments were performed to determine the Snhg1 expression patterns in fetal and myocardial infarction (MI) hearts. Gain- and Loss-of-function assays were conducted to explore the effect of Snhg1 on cardiomyocyte (CM) proliferation and cardiac repair following MI. We further constructed CM-specific Snhg1 knockout mice to confirm the proliferative effect exerted by Snhg1 using CRISPR/Cas9 technology. RNA sequencing and RNA pulldown were performed to explore how Snhg1 mediated cardiac regeneration. Chromatin immunoprecipitation and luciferase reporter assays were used to demonstrate the positive feedback loop between Snhg1 and c-Myc.

Results: Snhg1 expression was increased in human and mouse fetal and myocardial infarction (MI) hearts, particularly in CMs. Overexpression of Snhg1 promoted CM proliferation, angiogenesis, and inhibited CM apoptosis after myocardial infarction, which further improved post-MI cardiac function. Antagonism of Snhg1 in early postnatal mice inhibited CM proliferation and impaired cardiac repair after MI. Mechanistically, Snhg1 directly bound to phosphatase and tensin homolog (PTEN) and induced PTEN degradation, activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway to promote CM proliferation. The c-Myc protein, one of downstream targets of PI3K/AKT signaling, functioned as a transcription factor by binding to the promoter regions of Snhg1. Perturbation of the positive feedback between Snhg1 and c-Myc by mutation of the binding sequence significantly affected Snhg1-induced CM proliferation.

Conclusions: Snhg1 effectively elicited CM proliferation and improved cardiac function post-MI by forming a positive feedback loop with c-Myc to sustain PI3K/Akt signaling activation, and thus may be a promising cardiac regeneration strategy in treating heart failure post-MI.

[ELF4 promotes proliferation and inhibits apoptosis of human insulinoma cells by activating Akt signaling]

OBJECTIVE

To investigate the effect of overexpression of the oncogenic transcription factor ELF4 on proliferation and apoptosis in human insulinoma cells and explore the underlying mechanism.

METHODS

A human insulinoma BON cell line with stable overexpression of ELF4 (BON-ELF4 cells) was constructed using a recombinant retrovirus vector and the expression of ELF4 protein was verified using Western blotting. MTT assay was used to assess the proliferation of BON-ELF4 cells and BON-Vector cells, and the cell apoptosis induced by treatment with epirubicin (0.1 μmol/L for 24 h) was analyzed by detecting the expressions of cleaved caspase-8, caspase-9, and PARP using Western blotting. Flow cytometry with Annexin VFITC/PI staining was performed to analyze the numbers of apoptotic BON-Vector or BON-ELF4 cells. The expressions of phosphorylated Akt and total Akt in the cells were detected using Western blotting.

RESULTS

BON-ELF4 cell line with stable overexpression of ELF4 was successfully established. ELF4 overexpression significantly promoted the proliferation (P < 0.05) and obviously suppressed epirubicin- induced apoptosis in BON cells, resulting also in significantly reduced expressions of cleaved caspase-8, caspase-9 and PARP (P < 0.05). The results of flow cytometry showed a significantly lower apoptotic rate in BON-ELF4 cells than in BON-Vector cells following epirubicin treatment (6.03% vs 22.90%). The phosphorylation levels of Akt (Thr308 and Ser473) were significantly increased (P < 0.05) while the level of total Akt remained unchanged (P>0.05) in ELF4- overexpressing cells.

CONCLUSION

ELF4 overexpression enhances the proliferation and suppresses apoptosis of insulinomas cells by activating Akt signaling.

Sodium butyrate relieves lung ischemia-reperfusion injury by inhibiting NF-κB and JAK2/STAT3 signaling pathways

OBJECTIVE

Ischemia-reperfusion (IR) is the main cause of acute lung injury (ALI) in clinical lung transplantation, extracorporeal circulation, lung sleeve resection, trauma and cardiopulmonary resuscitation. The inflammatory response and oxidative stress following IR are factors that cause and aggravate its secondary damage. The purpose of this study was to investigate the efficacy and mechanism of sodium butyrate (NaB) on lung ischemia-reperfusion injury (LIRI).

MATERIALS AND METHODS

We used male C57BL/6 mice to construct the LIRI model and administered the mice with NaB. By examining the expression of inflammatory factors and oxidative stress-related molecules in mouse lung tissue, we investigated the effects of NaB on inflammation and oxidative stress in lung tissue after IR. In addition, the changes in the activity of the NF-κB and JAK2/STAT3 signaling pathways were also examined to determine the mechanism of NaB.

RESULTS

The expression levels of the inflammatory factors (IL-1β, IL-6 and TNF-α) in lung tissue of mice after IR were significantly increased, while NaB reduced the expression of inflammatory factors. In addition, the oxidative stress level of mouse lung tissue after IR increased significantly, showing the decrease of antioxidant molecules SOD1/2, catalase (CAT), and Peroxiredoxin 1 (Prdx1), while the intake of NaB increased the antioxidant level of mouse lung tissue. The activities of NF-κB and JAK2/STAT3 signaling pathways were significantly increased in lung tissue after IR, whereas NaB inhibited the activity of NF-κB and JAK2/STAT3 signaling pathways.

CONCLUSIONS

NaB relieves LIRI by inhibiting NF-κB and JAK2/STAT3 signaling pathways to reduce inflammation and oxidative stress levels in lung tissue of mice after IR.

Does active surveillance avoid overtreatment in prostate cancer? Lessons learned from salvage radical prostatectomies

OBJECTIVE

Determine whether our institution´s active surveillance (AS) protocol is a suitable strategy to minimise prostate cancer overtreatment.

MATERIAL AND METHODS

Retrospective analysis of 516 patients on AS after prostate cancer diagnosis. Population divided into "per-protocol" vs "induced" AS depending on fulfilment of protocol´s inclusion criteria. Radical prostatectomies after AS were selected and stratified based on: reclassification, progression or patient anxiety. Clinicopathological features and biochemical relapse-free survival were studied. Primary endpoint was overtreatment ratio based on the presence of insignificant prostate cancer and adverse pathological features in the surgical specimen. Kaplan-Meier curves were used to estimate the biochemical relapse-free survival and compared with log-rank test.

RESULTS

304 patients fulfilled inclusion criteria; 100 proceeded to radical prostatectomy (31% "induced", 69% "per-protocol" AS). Surgery indications were reclassification, progression and anxiety in 66%, 18% and 16% of patients respectively. Rate of positive lymph nodes was higher in the progression group (11%) compared to reclassification and anxiety (5% and 0% respectively, P = .002). Positive surgical margins were more frequently reported in the progression cohort compared to reclassification (28% vs 20%). Median follow-up from diagnosis until last radical prostatectomy was 48.3 months (32.4-70). 3 year biochemical relapse-free survival in the salvage radical prostatectomy was 85.4% (95 CI 78.3-93.2). Insignificant cancer was noticed in 7% of patients (Epstein´s vs 24% Wolters´ criteria). Rate of patients with adverse pathological features was 36%.

CONCLUSIONS

The majority of patients who underwent salvage surgery after AS were not overtreated. Radical prostatectomy should be considered a safe rescue treatment.

Multiple hospitalisations towards the end of life among patients with serious mental illness: A retrospective cohort study in England, UK

Introduction

Multiple hospitalisations towards the end of life is an indicator of poor-quality care. Understanding the characteristics of patients who experience hospitalisations at the end-of-life and how they vary is important for improved care planning.

Objectives

To describe socio-demographic and clinical characteristics of patients diagnosed with serious mental illness who experienced multiple hospitalisations in the last 90 days of life.

Methods

Data for all adult patients with a diagnosis of serious mental illness who died in 2018-2019 in England, UK were extracted from the National Mental Health Services Data Set linked with Hospital Episode Statistics and death registry data. Variables of interest included age, gender, marital status, underlying and contributory cause of death, ethnicity, place of death, deprivation status, urban-rural indicator, and patient’s region of residence. The number of hospitalisations and patient’s sociodemographic & clinical were described using descriptive statistics and percentages, respectively.

Results

Of the 45924 patients, 38.1% (n=17505, Male=42.9%, Female=57.1%, Mean age:78.4) had at least one hospitalisation in the last 90 days of life. The median number of hospitalisations was 2(StdDev:1.64, Minimum=1,Maximum=23). Most of those hospitalised (n=11808, 67.5%), died in a health care establishment (e.g. Hospital or hospice). There were marked geographic differences in the proportions of hospitalisations.The North West region of England recorded the most hospitalisations (n= 2906,16.6%), compared to other regions.

Conclusions

Further analysis is needed to understand factors independently associated with hospitalisations in people with serious mental illness. Funding: This project is supported by the National Institute for Health Research (NIHR) Applied Research Collaborations (ARC) South London.

Clash of the calculators: External validation of prostate cancer risk calculators in men undergoing mpMRI and transperineal biopsy

Objective

To compare the accuracy of the European Randomized Study of Screening for Prostate Cancer (ERSPC) RC, MRI‐ERSPC‐RC, and Prostate Biopsy Collaborative Group (PBCG) RC in patients undergoing transperineal prostate biopsy.

Patients and methods

We identified 392 patients who underwent mpMRI before transperineal prostate biopsy across multiple public and private institutions between January 2017 and August 2019. The estimated probabilities of detecting PCa and significant PCa were calculated using the MRI‐ERSPC‐RC, ERSPC‐RC, and PBCG‐RC. Receiver operating characteristic (ROC) curves for each calculator were generated and the area underneath the curve (AUC) was compared. Calibration and clinical utility were assessed with calibration plots and decision curve analysis, respectively.

Results

PCa was detected in 285 patients (72.7%) with significant PCa found in 200 patients (51.1%). ROC curve analysis found the MRI‐ERSPC‐RC outperformed the ERSPC‐RC and PBCG‐RC. For the prediction of PCa, the AUC was 0.756, 0.696, and 0.675 for the MRI‐ERSPC‐RC, ERSPC‐RC, and PBCG‐RC, respectively. The AUC for the prediction of significant PCa was 0.803, 0.745, and 0.746 for the MRI‐ERSPC‐RC, ERSPC‐RC, and PBCG‐RC, respectively.

Conclusions

Our study validated the ERSPC‐RC, MRI‐ERSPC‐RC, and PBCG‐RC in a cohort undergoing transperineal prostate biopsy with the MRI‐ERSPC‐RC performing the best. These RCs may enable improved shared decision making and help to guide patient selection for biopsy.

Hydrogen sulfide-loaded microbubbles combined with ultrasound mediate thrombolysis and simultaneously mitigate ischemia-reperfusion injury in a rat hindlimb model

BACKGROUND

Thromboembolism and subsequent ischemia/reperfusion injury (IRI) remain major clinical challenges.

OBJECTIVES

To investigate whether hydrogen sulfide (H2 S)-loaded microbubbles (hs-Mbs) combined with ultrasound (US) radiation (hs-Mbs+US) dissolve thrombi and simultaneously alleviate tissue IRI through local H2 S release.

METHODS

hs-Mbs were manufactured and US-triggered H2 S release was recorded. White and red thromboembolisms were established ex vivo and in rats left iliac artery. All subjects randomly received control, US, Mbs+US, or hs-Mbs+US treatment for 30 minutes.

RESULTS

H2 S was released from hs-Mbs+US both ex vivo and in vivo. Compared with control and US, hs-Mbs+US and Mbs+US showed comparable substantial decreases in thrombotic area, clot mass, and flow velocity increases for both ex vivo macrothrombi. In vivo, hs-Mbs+US and Mbs+US caused similarly increased recanalization rates, blood flow velocities, and hindlimb perfusion for both thrombi compared with the other treatments, with no obvious influence on hemodynamics, respiration, and macrophage vitality. More importantly, hs-Mbs+US substantially alleviated skeletal muscle IRI by reducing reactive oxygen species, cellular apoptosis, and proapoptotic Bax, caspase-3, and caspase-9 and increasing antiapoptotic Bcl-2 compared with other treatments. In vitro, hypoxia/reoxygenation-predisposed skeletal muscle cells and endothelial cells treated with normal saline solution exhibited similar trends, which were largely reversed by an H2 S scavenger or an inhibitor of Akt phosphorylation.

CONCLUSION

hs-Mbs+US effectively dissolved both white and red macrothrombi and simultaneously alleviated skeletal muscle IRI through the US-triggered, organ-specific release of H2 S. This integrated therapeutic strategy holds promise for treating thromboembolic diseases and subsequent IRI.

[Effect of piRNA NU13 in regulating biological behaviors of human Wilms tumor cells in vitro]

OBJECTIVE

To investigate the role of the differential piRNA NU13 derived from piwil2-induced cancer stem-like cells (piwil2-iCSCs) in regulating biological behaviors of Wilms tumor cells (G401).

OBJECTIVE

The expressions of piRNA NU13 and NOP56 were detected in Wilms tumor cell line G401 using RT-qPCR. G401 cells were transfected with piRNA NU13 mimics and inhibitor for its over-expression and inhibition, and the transfection efficiency was verified with RT-qPCR. The changes in proliferation of G401 cells after transfection were detected using CCK8 assay, and cell apoptosis was analyzed using flow cytometry. Wound healing assay and Transwell assay were performed to examine the changes in migration and invasion abilities of the transfected cells. The binding of NOP56 and piRNA NU13 was detected using dual luciferase experiment. The protein expressions of MMP2, MMP9, BAX, Bcl2, and NOP56 in the cells were detected with Western blotting.

OBJECTIVE

RTqPCR showed that the expression of piRNA NU13 decreased significantly in human Wilms tumor G401 cells as compared with that in renal tubular epithelial cell line HK2 (P < 0.05), and NOP56 was highly expressed in G401 cells and Wilms tumor tissues (P < 0.05). Over-expression of piRNA NU13 significantly suppressed the proliferation, migration and invasion of G401 cells, promoted cell apoptosis (P < 0.05), inhibited the expression of MMP2, MMP9 and Bcl2, and enhanced the expression of BAX (P < 0.05). The results of dual luciferase experiment showed that piRNA NU13 did not bind to NOP56 directly but regulated the expression of NOP56 in an indirect manner.

OBJECTIVE

piRNA NU13 is down-regulated and NOP56 is highly expressed in Wilms tumor. piNU13 may regulate the expression of NOP56 indirectly to inhibit the proliferation, migration and invasion and promote apoptosis of Wilms tumor cells in vitro.

Does active surveillance avoid overtreatment in prostate cancer? Lessons learned from salvage radical prostatectomies

OBJECTIVE

Determine whether our institution's active surveillance (AS) protocol is a suitable strategy to minimise prostate cancer overtreatment.

MATERIAL AND METHODS

Retrospective analysis of 516 patients on AS after prostate cancer diagnosis. Population divided into «per-protocol» vs «induced» AS depending on fulfilment of protocol's inclusion criteria. Radical prostatectomies after AS were selected and stratified based on reclassification, progression or patient anxiety. Clinicopathological features and biochemical relapse-free survival were studied. Primary endpoint was overtreatment ratio based on the presence of insignificant prostate cancer and adverse pathological features in the surgical specimen. Kaplan-Meier curves were used to estimate the biochemical relapse-free survival and compared with log-rank test.

RESULTS

304 patients fulfilled inclusion criteria; 100 proceeded to radical prostatectomy (31% «induced», 69% «per-protocol» AS). Surgery indications were reclassification, progression and anxiety in 66%, 18% and 16% of patients, respectively. Rate of positive lymph nodes was higher in the progression group (11%) compared to reclassification and anxiety (5% and 0%, respectively; P=.002). Positive surgical margins were more frequently reported in the progression cohort compared to reclassification (28% vs 20%). Median follow-up from diagnosis until last radical prostatectomy was 48.3months (32.4-70). Three year biochemical relapse-free survival in the salvage radical prostatectomy was 85.4% (95%CI: 78.3-93.2). Insignificant cancer was noticed in 7% of patients (Epstein's vs 24% Wolters' criteria). Rate of patients with adverse pathological features was 36%.

CONCLUSIONS

The majority of patients who underwent salvage surgery after AS were not overtreated. Radical prostatectomy should be considered a safe rescue treatment.

Itaconate prevents abdominal aortic aneurysm formation through inhibiting inflammation via activation of Nrf2

BACKGROUND

Identifying effective drugs to suppress vascular inflammation is a promising strategy to delay the progression of abdominal aortic aneurysm (AAA). Itaconate has a vital role in regulating inflammatory activation in various inflammatory diseases. However, the role of itaconate in the progression of AAA is unknown. In this study, we explored the inhibitory effect of itaconate on AAA formation and its underlying mechanisms.

METHODS

Quantitative PCR, western blotting and immunohistochemistry were used to determine Irg1 and downstream Nrf2 expression in human and mouse AAA samples. Liquid chromatograph-mass spectrometry (LC-MS) analysis was performed to measure the abundance of itaconate. OI treatment and Irg1 knockdown were performed to study the role of OI in AAA formation. Nrf2 intervention in vivo was performed to detect the critical role of Nrf2 in the beneficial effect of OI on AAA.

FINDINGS

We found that itaconate suppressed the formation of angiotensin II (Ang II)-induced AAA in apolipoprotein E-deficient (Apoe^-/-) mice, while Irg1 deficiency exerted the opposite effect. Mechanistically, itaconate inhibited vascular inflammation by enabling Nrf2 to function as a transcriptional repressor of downstream inflammatory genes via alkylation of Keap1. Moreover, Nrf2 deficiency significantly aggravated inflammatory factor expression and promoted AAA formation. In addition, Keap1 overexpression significantly promoted Ang II-induced AAA formation, which was inhibited by itaconate.

INTERPRETATION

Itaconate inhibited AAA formation by suppressing vascular inflammation, and therapeutic approaches to increase itaconate are potentially beneficial for preventing AAA formation.

FUNDING

National Natural Science Foundations of China and Guangzhou regenerative medicine and Health Laboratory of Guangdong.

Enhanced β-glucan and pullulan production by Aureobasidium pullulans with zinc sulfate supplementation

The effects of mineral salts on the production of exopolysaccharides, including β-glucan and pullulan, by Aureobasidium pullulans CCTCC M 2012259 were investigated. Zinc sulfate at certain concentrations decreased dry biomass but favored to the biosynthesis of both exopolysaccharides. When 100 mg/L zinc sulfate was added to the fermentation medium, production of β-glucan and pullulan increased by 141.7 and 10.2%, respectively, when compared with that noted in the control without zinc sulfate addition. To reveal the physiological mechanism underlying improved β-glucan and pullulan production, key enzymes activities, energy metabolism substances, intracellular uridine diphosphate glucose (UDPG) levels, and gene expression were determined. The results indicated that zinc sulfate up-regulated the transcriptional levels of pgm1, ugp, fks, and kre6 genes, increased activities of key enzymes involved in the biosynthesis of UDPG, β-glucan and pullulan, enhanced intracellular UDPG content, and improved energy supply, all of which contributed to the increment in β-glucan and pullulan production. The present study not only provides a feasible approach to improve the production of exopolysaccharides but also contributes to better understanding of the physiological characteristics of A. pullulans.

Magnetic Targeting Improves the Therapeutic Efficacy of Microbubble-Mediated Obstructive Thrombus Sonothrombolysis

Background Magnetic targeting may help microbubbles (MBs) reach obstructive thrombi and improve the efficacy of MB-mediated sonothrombolysis, but the role of magnetic targeting in MB-mediated sonothrombolysis remains elusive.

Objectives We investigate the feasibility and efficacy of magnetically targeted MB-mediated sonothrombolysis for the treatment of obstructive thrombi.

Materials and Methods Red and white thromboembolic models were established in vitro and in vivo. The models were randomly assigned to the control, ultrasound plus control MB (US + C-MB), ultrasound plus magnetic MB (US + M-MB), or US + M-MB + recombinant tissue-type plasminogen activator (r-tPA) groups and treated for 30 minutes. The recanalization rate, average blood flow velocity, hindlimb perfusion, and skeletal muscle injury marker levels were recorded.

Results The recanalization rate, average blood flow velocity, and hindlimb perfusion in the red and white thromboembolic models were all significantly higher in the US + M-MB and US + M-MB + r-tPA groups than in the control and US + C-MB groups both in vitro and in vivo. Moreover, the levels of the skeletal muscle injury markers were all significantly lower in the US + M-MB and US + M-MB + r-tPA groups than in the other two groups in vivo for both thromboembolic models. However, the thrombolytic effects of red thrombi performed better than those of white thrombi in the US + M-MB + r-tPA group.

Conclusion M-MB-mediated sonothrombolysis improves the efficacy of thrombolysis both in vitro and in vivo, and reduces tissue damage in clogging model; thus, this method may serve as a promising approach for treating thrombus-occlusive diseases.

Long noncoding RNA GAS5 induces abdominal aortic aneurysm formation by promoting smooth muscle apoptosis

Objective: Long noncoding RNAs (lncRNAs) may serve as specific targets for the treatment of abdominal aortic aneurysms (AAAs). LncRNA GAS5, functionally associated with smooth muscle cell (SMC) apoptosis and proliferation, is likely involved in AAA formation, but the exact role of GAS5 in AAA is unknown. We thus explored the contribution of GAS5 to SMC-regulated AAA formation and its underlying mechanisms.

Methods: Human specimens were used to verify the diverse expression of GAS5 in normal and AAA tissues. The angiotensin II (Ang II)-induced AAA model in ApoE-/- mice and the CaCl₂-induced AAA model in wild-type C57BL/6 mice were used. RNA pull-down and luciferase reporter gene assays were performed in human aortic SMCs to detect the interaction between GAS5 and its downstream targets of protein or microRNA (miR).

Results: GAS5 expression was significantly upregulated in human AAA specimens and two murine AAA models compared to human normal aortas and murine sham-operated controls. GAS5 overexpression induced SMC apoptosis and repressed its proliferation, thereby promoting AAA formation in two murine AAA models. Y-box-binding protein 1 (YBX1) was identified as a direct target of GAS5 while it also formed a positive feedback loop with GAS5 to regulate the downstream target p21. Furthermore, GAS5 acted as a miR-21 sponge to release phosphatase and tensin homolog from repression, which blocked the activation and phosphorylation of Akt to inhibit proliferation and promote apoptosis in SMCs.

Conclusion: The LncRNA GAS5 contributes to SMC survival during AAA formation. Thus, GAS5 might serve as a novel target against AAA.

Loss of Super-Enhancer-Regulated circRNA Nfix Induces Cardiac Regeneration After Myocardial Infarction in Adult Mice

Supplemental Digital Content is available in the text.

Background:

circRNAs (circular RNAs) are emerging as powerful regulators of cardiac development and disease, but their roles in cardiac regeneration are still unknown. This study used superenhancers to distinguish key circRNAs in the regulation of cardiac regeneration and explored the mechanisms underlying circRNA functions.

Methods:

We used integrated bioinformatics analysis of RNA sequencing data and superenhancer catalogs to identify superenhancer-associated circRNAs. Quantitative polymerase chain reactions and in situ hybridization were performed to determine the circRNA expression patterns in hearts. Gain- and loss-of-function assays were conducted to detect the role of circRNAs in cardiomyocyte proliferation and cardiac repair after myocardial infarction. Chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assays were used to determine the binding of Meis1 (Meis homeobox 1) on circNfix-associated superenhancers. RNA pulldown and luciferase reporter assays were used to study circRNA interactions with proteins and miRNAs (micro RNAs).

Results:

We identified a circRNA, Nfix circRNA (circNfix), that was regulated by a superenhancer and overexpressed in the adult heart in humans, rats, and mice. The transcription factor Meis1 bound to the superenhancer at the circNfix locus, and increased its expression. In vitro and in vivo, cardiomyocyte proliferation was increased by knockdown of circNfix, whereas it was inhibited by circNfix overexpression. Moreover, circNfix downregulation promoted cardiomyocyte proliferation and angiogenesis and inhibited cardiomyocyte apoptosis after myocardial infarction, attenuating cardiac dysfunction and improving the prognosis. Mechanistically, circNfix reinforced the interaction of Ybx1 (Y-box binding protein 1) with Nedd4l (an E3 ubiquitin ligase), and induced Ybx1 degradation through ubiquitination, repressing cyclin A2 and cyclin B1 expression. In addition, circNfix acted as a sponge for miR-214 to promote Gsk3β (glycogen synthase kinase 3 β) expression and repress β-catenin activity.

Conclusions:

Loss of superenhancer-regulated circNfix promotes cardiac regenerative repair and functional recovery after myocardial infarction by suppressing Ybx1 ubiquitin-dependent degradation and increasing miR-214 activity and thus may be a promising strategy for improving the prognosis after MI.

Abstract P5-18-02: A quantitative centrosomal amplification score (CAS) predicts local recurrence in ductal carcinoma in situ

Background: About 60-80% of ductal carcinoma in situ (DCIS) cases are high-grade (HG) DCIS with an elevated risk of local recurrence (LR) even after a lumpectomy. Patients are often under or over treated due to the lack of accurate recurrence risk prediction models. Current prognostic models such as OncotypeDX and Van Nuys Prognostic Index (VNPI) lack consistency and are limited to a specific subset of patients. Here in this study, we show that the extent of centrosome amplification (CA) in a DCIS lesion can predict the risk of LR after lumpectomy. CA refers to presence of supernumerary or large centrosomes and is a characteristic of pre-invasive lesions, and breast tumors, and promotes erroneous mitoses and chromosomal instability.

Methods: We have pioneered a semi-automated pipeline that integrates immunofluorescence confocal microscopy with digital image analysis and yields a quantitative Centrosomal Amplification Score (CAS) for each patients' tumor sample by evaluating severity and frequency of centrosomal aberrations therein. To this end, we first immunofluorescently stained centrosomes in formalin fixed paraffin embedded resection samples from DCIS patients (discovery cohort n=133 and a validation cohort n=119) using an antibody against γ-tubulin, and co-stained nuclei with DAPI. Next, we imaged the slides and processed the raw 3D image data using IMARIS Biplane 8.2 3D volume rendering software. Finally, we calculated centrosome numbers and volume in ˜250 cells from each patient sample. Using a mathematical algorithm, we generated a composite CAS score for each patient sample by integrating the numerical (CASi) and structural (CASm) aberrations.

Results: We found that DCIS patients with recurrence exhibited higher CAS. Intriguingly, higher CAS was also associated with greater risk of developing ipsilateral breast events [Hazard ratio (HR) =7.58 for discovery cohort and HR=5.8 for validation cohort, p&lt;0.0001] which remained significant (HR=8.5 for discovery and HR=3.39, p&lt;0.0001) after accounting for the confounding factors like age, tumor size, comedo necrosis and radiotherapy. Kaplan Meir survival analysis indicated that high CAS was associated with poor recurrence-free survival (RFS) (p&lt;0.001). For the high and low CAS groups, the 5-year risk of recurrence was 87.5% and 12.5% respectively (p&lt;0.001). In our discovery cohort, a head-to-head comparison of the ability of VNPI and CAS to predict recurrence illuminated that CAS was able to stratify the DCIS group in recurrence and recurrence-free group with much higher significance (p&lt;0.0001) than the Van Nuys Prognostic Index (VNPI) (HRs for CAS- 8.8 vs. VNPI 0.959). Finally, the Harrell's concordance index using SAS PROC PHREG tests yielded that the probability of a patient with poorer/lower RFS to be in the high CAS group is 76.2%.

Conclusion: Our data compellingly show that CAS quantifies the risk of recurrence in DCIS patients with the highest concordance and provides a novel and innovative tool to tailor their treatment based on their risk profile.

Citation Format: Mittal K, Kaur J, Wei G, Toss MS, Osan RM, Janssen EA, Søiland H, Rakha EA, Rida PC, Aneja R. A quantitative centrosomal amplification score (CAS) predicts local recurrence in ductal carcinoma in situ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-02.

Association between androgen receptor polymorphic CAG and GGC repeat lengths and cryptorchidism: A meta-analysis of case-control studies

INTRODUCTION

Previous studies have revealed the relationship between androgen receptor (AR) CAG and/or GGC polymorphisms and risk of cryptorchidism, yet the results have been elusive and controversial.

AIM

To determine whether AR polymorphic CAG and/or GGC repeats are related to cryptorchidism.

STUDY DESIGN

The relevant studies were obtained from PubMed, Embase, China National Knowledge Infrastructure, and Wanfang. The pooled odds ratios with 95% confidence intervals (CIs) were used to assess the strength of associations. Subgroup analyses were performed based on ethnicity and source of controls. Moreover, Begg's funnel plots and Egger's linear regression test were conducted to determine publication bias.

RESULTS

Eight case-control studies containing 321 patients and 784 normal controls were included. There was a significant association between longer CAG repeats and cryptorchidism risk (weighted mean difference (WMD) = 0.62; 95% CIs 0.06, 1.18; P = 0.031). Moreover, there was a significant association between the longer GGC repeats and cryptorchidism risk (WMD = 0.87; 95% CIs 0.04, 1.74; P = 0.040). There was significant association between the longer CAG repeats and bilateral cryptorchidism (WMD = 0.88; 95% CIs -0.18, 1.94; P = 0.011), while there was no significant association between the longer CAG repeats and unilateral cryptorchidism (WMD = -0.09; 95% CIs -0.50, 0.31; P = 0.554). There were significant associations between the longer GGC repeats and unilateral cryptorchidism (WMD = 0.88; 95% CIs -0.30, 2.05; P = 0.005) and bilateral cryptorchidism (WMD = 1.35; 95% CIs -0.52, 3.21; P = 0.000). Stratifying analysis revealed an association between longer CAG/GGC repeats and cryptorchidism in Caucasian populations from Europe (WMD = 0.73; 95% CIs 0.00, 1.46; P = 0.017), while there was no association with Asian populations.

DISCUSSION

This meta-analysis found that CAG/GGC repeats in the AR gene were longer in cryptorchidism patients compared to controls. Both the longer CAG repeats and GGC repeats in the AR gene were associated with cryptorchidism risk. The longer CAG repeats were associated with bilateral cryptorchidism, whereas the longer GGC repeats were associated with unilateral and bilateral cryptorchidism. Stratifying analysis revealed an association between longer CAG/GGC repeats and cryptorchidism in Caucasian populations from Europe, while there was no association between longer CAG/GGC repeats and cryptorchidism in Asian populations.

CONCLUSION

The CAG/GGC repeats in the AR gene were longer in cryptorchidism than in controls. Longer CAG repeats may play a role in determining bilateral cryptorchidism, and longer GGC repeats may play a role in determining unilateral and bilateral cryptorchidism. These observations were more applicable to Caucasian populations.

Mechanism of Nucleoside Triphosphate Diphosphohydrolase-1-Associated Imbalance in Adenosine Diphosphate Degradation, B-Cell Activation, and Related Injury During Acute Antibody-Mediated Rejection

OBJECTIVE

The objective of this study was to investigate the effect of nucleoside triphosphate diphosphohydrolase-1 (NTPDase1) during acute antibody-mediated rejection (AMR).

METHODS

NTPDase1 overexpression, NTPDase1 knockout, and wild-type nude mice skin graft models were used to induce acute AMR. NTPDase1 expression in B cells, NTPDase1 messenger RNA expression in skin grafts, extracellular adenosine diphosphate (ADP) concentration, B-cell volume and surface antigens expression, average platelet transport rate, and ultrastructure and apoptosis of skin graft cells were investigated.

RESULTS

During acute AMR in nude mice, higher NTPDase1 expression caused lower extracellular ADP concentration, smaller increase in B-cell volume, and major histocompatibility complex II surface antigen expression, suggesting a negative correlation between them; higher NTPDase1 expression also caused slower average platelet transport rate and less severe skin graft injury, suggesting a negative correlation between them. Pretreatment with high-dose exogenous NTPDase1 inhibited platelet activation and protected skin grafts, but it resulted in prolonged bleeding time (by 51.4%) and prolonged coagulation time (by 44.1%).

CONCLUSION

An NTPDase1-associated imbalance in extracellular ADP degradation may contribute to B-cell activation, platelet activation, and more severe skin graft injury in nude mice. Pretreatment with high-dose exogenous NTPDase1 effectively protected skin grafts in nude mice at 1 week, but it increased the risk of bleeding.

A novel splice site mutation of the PRKAR1A gene, C.440+5 G>C, in a Chinese family with Carney complex

BACKGROUND

Carney complex (CNC) is an extremely rare, multiple endocrine neoplasia syndrome that occurs in an autosomal dominant manner. Mutations in PRKAR1A have been reported to be a common genetic cause of CNC.

METHODS

In this study, we reported a Chinese pedigree of CNC that manifests mainly as spotty skin pigmentation and primary pigmented nodular adrenocortical disease. Whole blood samples of this pedigree were collected for DNA/RNA analysis. Polymerase chain reaction (PCR) and reverse-transcription polymerase chain reaction analyses were performed to amplify the 11 exons and adjacent introns of PRKAR1A. Direct sequencing was used to detect the mutation, and DNA from 70 Han Chinese people was extracted and sequenced as a control to estimate the frequency of the identified mutation.

RESULTS

Within the pedigree, ten patients with CNC were identified, and a novel heterozygous mutation (c.440+5 G>C in intron 4a) was identified in the PRKAR1A gene. PCR amplification of cDNA from the control subjects and patients was performed. Agarose gel electrophoresis showed only one wild-type band in the cDNA corresponding to the former group, whereas an extra band was present in samples from the latter group corresponding to the skipping of exon 4a; this confirms that the variant affects PRKAR1A splicing.

CONCLUSION

In conclusion, the c.440+5 G>C mutation is a new splice site mutation that has not been reported and has the potential to broaden the mutational spectrum of PRKAR1A that is associated with CNC, which would facilitate genetic diagnosis and counseling for CNC.

Light exposure influences the diurnal oscillation of gut microbiota in mice

The gut microbiota exhibit diurnal compositional and functional oscillations that influence the host homeostasis. However, the upstream factors that affect the microbial oscillations remain elusive. Here, we focused on the potential impact of light exposure, the main factor that affects the host circadian oscillation, on the diurnal oscillations of intestinal microflora to explore the upstream factor that governs the fluctuations of the gut microbes. The gut microbiota of the mice that were underwent regular light/dark (LD) cycles exhibited a robust rhythm at both compositional and functional level, in all parts of the intestine. Comparably, constant darkness (Dark-Dark, DD) led to the loss of the rhythmic oscillations in almost all parts of the intestine. Additionally, the abundance of Clostridia in DD conditions was dramatically enhanced in the small intestine. Our data indicated light exposure is the upstream factor that governs the regular diurnal fluctuations of gut microbiota in vivo.

Comparative symbiotic plasmid analysis indicates that symbiosis gene ancestor type affects plasmid genetic evolution

Rhizobial symbiotic plasmids play vital roles in mutualistic symbiosis with legume plants by executing the functions of nodulation and nitrogen fixation. To explore the gene composition and genetic constitution of rhizobial symbiotic plasmids, comparison analyses of 24 rhizobial symbiotic plasmids derived from four rhizobial genera was carried out. Results illustrated that rhizobial symbiotic plasmids had higher proportion of functional genes participating in amino acid transport and metabolism, replication; recombination and repair; carbohydrate transport and metabolism; energy production and conversion and transcription. Mesorhizobium amorphae CCNWGS0123 symbiotic plasmid - pM0123d had similar gene composition with pR899b and pSNGR234a. All symbiotic plasmids shared 13 orthologous genes, including five nod and eight nif/fix genes which participate in the rhizobia-legume symbiosis process. These plasmids contained nod genes from four ancestors and fix genes from six ancestors. The ancestral type of pM0123d nod genes was similar with that of Rhizobium etli plasmids, while the ancestral type of pM0123d fix genes was same as that of pM7653Rb. The phylogenetic trees constructed based on nodCIJ and fixABC displayed different topological structures mainly due to nodCIJ and fixABC ancestral type discordance. The study presents valuable insights into mosaic structures and the evolution of rhizobial symbiotic plasmids.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study compared 24 rhizobial symbiotic plasmids that included four genera and 11 species, illuminating the functional gene composition and symbiosis gene ancestor types of symbiotic plasmids from higher taxonomy. It provides valuable insights into mosaic structures and the evolution of symbiotic plasmids.

Effect of renal sympathetic denervation on ventricular and neural remodeling

Background

This study assessed the therapeutic effects of renal sympathetic denervation (RDN) on post-myocardial infarction (MI) ventricular remodeling and sympathetic neural remodeling in dogs. The possible mechanisms and optimal time for treatment are discussed.

Methods

We randomly assigned 30 dogs to five groups: RDN 1 week before MI (RDN1w + MI; n = 6), RDN 1 week after MI (MI1w + RDN; n = 6), RDN 2 weeks after MI (MI2w + RDN; n = 6), control (N; n = 6), and MI (n = 6). A canine model of myocardial infarction was established by interventional occlusion with a gelatin sponge via the femoral artery. Brain natriuretic peptide (BNP) and endothelin-1 (ET-1) levels were measured and echocardiography was performed to assess cardiac function and heart size. All dogs were killed at the end of the experiment and samples of cardiac and renal arteries were obtained. The expression of matrix metalloproteinase (MMP)-2 and MMP-9 in cardiac and of tyrosine hydroxylase (TH) in renal arteries was assessed by immunohistochemistry. Sympathetic innervations in the infarction border zone were investigated via Western blotting and real-time PCR.

Results

Left ventricular function in the MI group decreased significantly, while plasma BNP and ET-1 levels as well as MMP-2 and MMP-9 expression increased. Compared with the MI group, the RD groups showed significantly reduced MMP‑2, MMP‑9, TH, and growth-associated protein (GAP) 43 expression in the RDN1w + MI, MI1w + RDN, and MI2w + RDN groups was significantly improved. Additionally, the expression of TH in renal arteries decreased after RDN.

Conclusion

RDN has preventive and therapeutic effects on post-MI ventricular remodeling and sympathetic neural remodeling. The mechanism of RDN is likely mediated through restraint of renal sympathetic nerve activity.

Photonic ring resonator filters for astronomical OH suppression

Ring resonators provide a means of filtering specific wavelengths from a waveguide, and optionally dropping the filtered wavelengths into a second waveguide. Both of these features are potentially useful for astronomical instruments. In this paper we focus on their use as notch filters to remove the signal from atmospheric OH emission lines from astronomical spectra. We derive the design requirements for ring resonators for OH suppression from theory and finite difference time domain simulations. We find that rings with small radii (< 10 μm) are required to provide an adequate free spectral range, leading to high index contrast materials such as Si and Si₃N₄. Critically coupled rings with high self-coupling coefficients should provide the necessary Q factors, suppression depth, and throughput for efficient OH suppression, but will require post-inscription tuning of the coupling and the resonant wavelengths. The overall prospects for the use of ring resonators in astronomical instruments is promising, provided efficient fibre-chip coupling can be achieved.

Expression and characterization of a lipase-related protein in the malpighian tubules of the Chinese oak silkworm, Antheraea pernyi

Lipases are ubiquitous enzymes in nature, which play a crucial role in fat metabolism by catalyzing the hydrolysis of triacylglycerol to free fatty acids and glycerol. However, reports concerning insect lipase are rare. In this study, we studied the expression and activity of a lipase-related protein from Antheraea pernyi (ApLRP). Recombinant ApLRP was expressed in Escherichia coli cells and used to raise rabbit anti-ApLRP polyclonal antibodies. ApLRP mRNA and protein expression were abundant in the midgut and malpighian tubules, respectively. After challenge with four different microorganisms (E. coli, Beauveria bassiana, Micrococcus luteus and nuclear polyhedrosis virus), the expression levels of ApLRP mRNA in midgut were inducted significantly compared with the control. The different pathogens induced different ApLRP gene expression patterns. The optimum temperature and pH for the enzyme's activity were 35°C and 7.0, respectively. ApLRP activity was stimulated in the presence of Mg2+, Na+, Ca2+ and b-mercaptoethanol; while Zn2+, Cu2+ and Fe3+ inhibited its activity. Detergents such as SDS, glycerol and Tween-20 increased the lipase activity by 20-30%. Our results indicated that ApLRP might play an important role in the innate immunity of insects.

Sea-level haemoglobin concentration is associated with greater exercise capacity in Tibetan males at 4200 m

NEW FINDINGS

What is the topic of this review? Recent developments link relatively lower hemoglobin concentration in Tibetans at high altitude to exercise capacity and components of oxygen transport. What advances does it highlight? Haemoglobin concentration (ranging from 15.2 to 22.9 g dl(-1) ) in Tibetan males was negatively associated with peak oxygen (O2 ) uptake per kilogram, cardiac output and muscle O2 diffusion conductance. Most variance in the peak O2 uptake per kilogram of Tibetan males was attributed to cardiac output, muscle diffusional conductance and arterial partial pressure of CO2 . The mechanisms underlying these differences in oxygen transport in Tibetans require additional analyses. Despite residence at >4000 m above sea level, many Tibetan highlanders, unlike Andean counterparts and lowlanders at altitude, exhibit haemoglobin concentration ([Hb]) within the typical sea-level range. Genetic adaptations in Tibetans are associated with this relatively low [Hb], yet the functional relevance of the lower [Hb] remains unknown. To address this, we examined each major step of the oxygen transport cascade [ventilation (VE), cardiac output (QT) and diffusional conductance in lung (DL) and muscle (DM)] in Tibetan males at maximal exercise on a cycle ergometer. Ranging from 15.2 to 22.9 g dl(-1) , [Hb] was negatively associated with peak O2 uptake per kilogram (r = -0.45, P < 0.05) and both cardiac output (QT/kg: r = -0.54, P < 0.02) and muscle O2 diffusion conductance (DM/kg: r = -0.44, P < 0.05) but not ventilation, arterial partial pressure of O2 or pulmonary diffusing capacity. Most variance in peak O2 uptake per kilogram was attributed to QT, DM and arterial partial pressure of CO2 (r(2)  = 0.90). In summary, lack of polycythaemia in Tibetans is associated with increased exercise capacity, which is explained by elevated cardiac, muscle and, to a small extent, ventilatory responses rather than pulmonary gas exchange. Whether lower [Hb] is the cause or result of these changes in O2 transport or is causally unrelated will require additional study.

What hides behind the MASC: clinical response and acquired resistance to entrectinib after ETV6-NTRK3 identification in a mammary analogue secretory carcinoma (MASC)

Here, we describe the dramatic response of a patient with an ETV6-NTRK3-driven mammary analogue secretory carcinoma to treatment with a pan-Trk inhibitor, and the development of acquired resistance linked to a novel NTRK3 mutation that interferes with drug binding. This case emphasizes how molecular profiling can identify therapies for rare diseases and dissect mechanisms of drug resistance.

Background

Mammary analogue secretory carcinoma (MASC) is a recently described pathologic entity. We report the case of a patient with an initial diagnosis of salivary acinic cell carcinoma later reclassified as MASC after next-generation sequencing revealed an ETV6-NTRK3 fusion.

Patients and methods

This alteration was targeted with the pan-Trk inhibitor entrectinib (Ignyta), which possesses potent in vitro activity against cell lines containing various NTRK1/2/3 fusions.

Results

A dramatic and durable response was achieved with entrectinib in this patient, followed by acquired resistance that correlated with the appearance of a novel NTRK3 G623R mutation. Structural modeling predicts that this alteration sterically interferes with drug binding, correlating to decreased sensitivity to drug inhibition observed in cell-based assays.

Conclusions

This first report of clinical activity with TrkC inhibition and the development of acquired resistance in an NTRK3-rearranged cancer emphasize the utility of comprehensive molecular profiling and targeted therapy for rare malignancies (NCT02097810).