A risk-based approach to cumulative effects assessment for large marine ecosystems to support transboundary marine spatial planning: A case study of the yellow sea.

Cumulative effects assessment (CEA) should be conducted at ecologically meaningful scales such as large marine ecosystems to halt further ocean degradation caused by anthropogenic pressures and facilitate ecosystem-based management such as transboundary marine spatial planning (MSP). However, few studies exist at large marine ecosystems scale, especially in the West Pacific seas, where countries have different MSP processes yet transboundary cooperation is paramount. Thus, a step-wise CEA would be informative to help bordering countries set a common goal. Building on the risk-based CEA framework, we decomposed CEA into risk identification and spatially-explicit risk analysis and applied it to the Yellow Sea Large Marine Ecosystem (YSLME), aiming to understand the most influential cause-effect pathways and risk distribution pattern. The results showed that (1) seven human activities including port, mariculture, fishing, industry and urban development, shipping, energy, and coastal defence, and three pressures including physical loss of seabed, input of hazardous substances, nitrogen, and phosphorus enrichment were the leading causes of environmental problems in the YSLME; (2) benthic organisms, fishes, algae, tidal flats, seabirds, and marine mammals were the most vulnerable ecosystem components on which cumulative effects acted; (3) areas with relatively high risk mainly concentrated on nearshore zones, especially Shandong, Liaoning, and northern Jiangsu, while coastal bays of South Korea also witnessed high risk; (4) certain risks could be observed in the transboundary area, of which the causes were the pervasive fishing, shipping, and sinking of pollutants in this area due to the cyclonic circulation and fine-grained sediments. In future transboundary cooperation on MSP, risk criteria and evaluation of existing management measures should be incorporated to determine whether the identified risk has exceeded the acceptable level and identify the next step of cooperation. Our study presents an example of CEA at large marine ecosystems scale and provides a reference to other large marine ecosystems in the West Pacific and elsewhere.

Single-step equipment-free extracellular vesicle concentration using super absorbent polymer beads.

Extracellular vesicles (EVs) contain useful biomarkers for disease diagnosis and are promising biomaterials for the delivery of therapeutic molecules in vivo. Accordingly, an efficient concentration method is necessary for large-scale production or high-throughput isolation of EVs from bulk liquid samples, including culture medium and body fluids, to achieve their clinical application. However, current EV concentration methods, including ultrafiltration, are limited with respect to cost, efficiency, and centrifugation time. In this study, we developed the first single-step, equipment-free EV concentration method using super absorbent polymer (SAP) beads. SAP beads absorb small molecules, including water, via nano-sized channels but expel and thereby concentrate EVs. Consequently, the beads drastically enrich EVs by reducing the solution volume in a single step, without affecting EV characteristics. Moreover, the purity of the concentrated EV solution was high due to the absorption of protein impurities by SAP beads. To further demonstrate the versatility of the method, we showed that SAP beads successfully enrich EVs in human urine samples and culture medium, enabling better isolation performance than conventional ultrafiltration. We believe the newly developed approach and insight gained in this study will facilitate the use of EVs as prominent biomaterials for disease diagnosis and therapy.

Single Step In Situ Detection of Surface Protein and MicroRNA in Clustered Extracellular Vesicles Using Flow Cytometry.

Because cancers are heterogeneous, it is evident that multiplexed detection is required to achieve disease diagnosis with high accuracy and specificity. Extracellular vesicles (EVs) have been a subject of great interest as sources of novel biomarkers for cancer liquid biopsy. However, EVs are nano-sized particles that are difficult to handle; thus, it is necessary to develop a method that enables efficient and straightforward EV biomarker detection. In the present study, we developed a method for single step in situ detection of EV surface proteins and inner miRNAs simultaneously using a flow cytometer. CD63 antibody and molecular beacon-21 were investigated for multiplexed biomarker detection in normal and cancer EVs. A phospholipid-polymer-phospholipid conjugate was introduced to induce clustering of the EVs analyzed using nanoparticle tracking analysis, which enhanced the detection signals. As a result, the method could detect and distinguish cancer cell-derived EVs using a flow cytometer. Thus, single step in situ detection of multiple EV biomarkers using a flow cytometer can be applied as a simple, labor- and time-saving, non-invasive liquid biopsy for the diagnosis of various diseases, including cancer.

Vascular Smooth Muscle Cell-Derived Exosomal MicroRNAs Regulate Endothelial Cell Migration Under PDGF Stimulation.

Intercellular communication between vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) is essential for the maintenance of vascular homeostasis. The presence of exosomes, a recently discovered player in vascular cell communication, has been associated with vascular disease progression. However, the detailed mechanism of how the signal mediated by exosomes affects the function of vascular cells during vascular pathogenesis is yet to be further understood. In this study, we investigated the expression of exosomal microRNAs (miRNAs) secreted by VSMCs and their functional relevance to ECs in pathogenesis, including their role in processes such as platelet-derived growth factor (PDGF) stimulation. We observed that PDGF stimulation contributes to a change in exosomal miRNA release from VSMCs; specifically, miR-1246, miR-182, and miR-486 were deficient in exosomes derived from PDGF-stimulated VSMCs. The reduced miRNA expression in these exosomes is associated with an increase in EC migration. These findings increase our understanding of exosome-mediated crosstalk between vascular cells under a pathological condition.

Simultaneous multiplexed detection of exosomal microRNAs and surface proteins for prostate cancer diagnosis.

Since the tumor is extremely heterogeneous, a single biomarker cannot reflect the exact symptoms of the disease or its stage. Exosomes are biomarker reservoirs that provide disease information with a high accuracy, especially when specific markers, including microRNAs (miRNAs) and proteins, are combined. However, currently available exosomal miRNA and protein detection methods are time consuming, expensive, and laborious. Meanwhile, simultaneous detection of an exosomal miRNA and protein in a single reaction is even more challenging. Thus, development of an efficient method for detecting multiple miRNAs and proteins in a single exosomal reaction is highly needed. Herein, to increase the value of using exosomes over other circulating biomarkers for prostate cancer (PCa) liquid biopsy, a method for simultaneous multiplexed in situ detection of exosomal miRNAs and proteins was developed. Exosomal miRNAs and surface proteins were simultaneously detected in captured exosomes with a high specificity, using nano-sized molecular beacons and fluorescent dye-conjugated antibodies. The method allowed the quantitative analysis of various disease-specific miRNAs and surface proteins in PCa cell-derived exosomes in a single exosomal reaction. Overall, simultaneous multiplexed in situ detection of exosomal miRNAs and surface proteins can be developed as a simple, cost-effective, non-invasive liquid biopsy method for diagnosing PCa.