Pharmacological modulation of gp130 signalling enhances Achilles tendon repair by regulating tenocyte migration and collagen synthesis via SHP2-mediated crosstalk of the ERK/AKT pathway.

Tendon injuries typically display limited reparative capacity, often resulting in suboptimal outcomes and an elevated risk of recurrence or rupture. While cytokines of the IL-6 family are primarily recognised for their inflammatory properties, they also have multifaceted roles in tissue regeneration and repair. Despite this, studies examining the association between IL-6 family cytokines and tendon repair remained scarce. gp130, a type of glycoprotein, functions as a co-receptor for all cytokines in the IL-6 family. Its role is to assist in the transmission of signals following the binding of ligands to receptors. RCGD423 is a gp130 modulator. Phosphorylation of residue Y759 of gp130 recruits SHP2 and SOCS3 and inhibits activation of the STAT3 pathway. In our study, RCGD423 stimulated the formation of homologous dimers of gp130 and the phosphorylation of Y759 residues without the involvement of IL-6 and IL-6R. Subsequently, the phosphorylated residues recruited SHP2 kinase, activating the downstream ERK and AKT pathways. These mechanisms ultimately promoted the migration ability of tenocytes and matrix synthesis, especially collagen I. Moreover, RCGD423 also demonstrated significant improvements in collagen content, alignment of collagen fibres, and biological and biomechanical function in a rat Achilles tendon injury model. In summary, we demonstrated a promising gp130 modulator (RCGD423) that could potentially enhance tendon injury repair by redirecting downstream signalling of IL-6, suggesting its potential therapeutic application for tendon injuries.

Inhibition of CC chemokine receptor 1 ameliorates osteoarthritis in mouse by activating PPAR-γ.

BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage destruction and inflammation. CC chemokine receptor 1 (CCR1), a member of the chemokine family and its receptor family, plays a role in the autoimmune response. The impact of BX471, a specific small molecule inhibitor of CCR1, on CCR1 expression in cartilage and its effects on OA remain underexplored. METHODS: This study used immunohistochemistry (IHC) to assess CCR1 expression in IL-1ß-induced mouse chondrocytes and a medial meniscus mouse model of destabilization of the medial meniscus (DMM). Chondrocytes treated with varying concentrations of BX471 for 24 h were subjected to IL-1ß (10 ng/ml) treatment. The levels of the aging-related genes P16INK4a and P21CIP1 were analyzed via western blotting, and senescence-associated ß-galactosidase (SA-ß-gal) activity was measured. The expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), aggrecan (AGG), and the transcription factor SOX9 were determined through western blotting and RT‒qPCR. Collagen II, matrix metalloproteinase 13 (MMP13), and peroxisome proliferator-activated receptor (PPAR)-γ expression was analyzed via western blot, RT‒qPCR, and immunofluorescence. The impact of BX471 on inflammatory metabolism-related proteins under PPAR-γ inhibition conditions (using GW-9662) was examined through western blotting. The expression of MAPK signaling pathway-related molecules was assessed through western blotting. In vivo, various concentrations of BX471 or an equivalent medium were injected into DMM model joints. Cartilage destruction was evaluated through Safranin O/Fast green and hematoxylin-eosin (H&E) staining. RESULTS: This study revealed that inhibiting CCR1 mitigates IL-1ß-induced aging, downregulates the expression of iNOS, COX-2, and MMP13, and alleviates the IL-1ß-induced decrease in anabolic indices. Mechanistically, the MAPK signaling pathway and PPAR-γ may be involved in inhibiting the protective effect of CCR1 on chondrocytes. In vivo, BX471 protected cartilage in a DMM model. CONCLUSION: This study demonstrated the expression of CCR1 in chondrocytes. Inhibiting CCR1 reduced the inflammatory response, alleviated cartilage aging, and retarded degeneration through the MAPK signaling pathway and PPAR-γ, suggesting its potential therapeutic value for OA.

Multiarmed DNA jumper and metal-organic frameworks-functionalized paper-based bioplatform for small extracellular vesicle-derived miRNAs assay.

Small extracellular vesicle-derived microRNAs (sEV-miRNAs) have emerged as promising noninvasive biomarkers for early cancer diagnosis. Herein, we developed a molecular probe based on three-dimensional (3D) multiarmed DNA tetrahedral jumpers (mDNA-Js)-assisted DNAzyme activated by Na+, combined with a disposable paper-based electrode modified with a Zr-MOF-rGO-Au NP nanocomplex (ZrGA) to fabricate a novel biosensor for sEV-miRNAs Assay. Zr-MOF tightly wrapped by rGO was prepared via a one-step method, and it effectively aids electron transfer and maximizes the effective reaction area. In addition, the mechanically rigid, and nanoscale-addressable mDNA-Js assembled from the bottom up ensure the distance and orientation between fixed biological probes as well as avoid probe entanglement, considerably improving the efficiency of molecular hybridization. The fabricated bioplatform achieved the sensitive detection of sEV-miR-21 with a detection limit of 34.6 aM and a dynamic range from100 aM to 0.2 µM. In clinical blood sample tests, the proposed bioplatform showed results highly consistent with those of qRT-PCRs and the signal increased proportionally with the NSCLC staging. The proposed biosensor with a portable wireless USB-type analyzer is promising for the fast, easy, low-cost, and highly sensitive detection of various nucleic acids and their mutation derivatives, making it ideal for POC biosensing.

Dynamic insights into research trends and trajectories in early reading: an analytical exploration via dynamic topic modeling.

Introduction: Early reading has gained significant attention in the academic community. With the increasing volume of literature on this subject, it has become crucial to assess the current research landscape and identify emerging trends. Methods: This study utilized the dynamic topic model to analyze a corpus of 1,638 articles obtained from the Web of Science Core Collection to furnish a lucid understanding of the prevailing research and forecast possible future directions. Results: Our in-depth assessment discerned 11 cardinal topics, among which notable ones were interventions' impacts on early reading competencies; foundational elements of early reading: phonological awareness, letters, and, spelling; and early literacy proficiencies in children with autism spectrum disorder. Although most topics have received consistent research attention, there has been a marked increase in some topics' popularity, such as foundational elements of early reading and early literary proficiencies in children with autism spectrum disorder. Conversely, other topics exhibited a downturn. Discussion: This analytical endeavor has yielded indispensable insights for scholars, decision-makers, and field practitioners, steering them toward pivotal research interrogatives, focal interest zones, and prospective research avenues. As per our extensive survey, this paper is a pioneering holistic purview of the seminal areas of early reading that highlights expected scholarly directions.

Carveol alleviates osteoarthritis progression by acting on synovial macrophage polarization transformation: An in vitro and in vivo study.

Osteoarthritis (OA) is a heterogeneous disease that affects the entire joint. Its pathogenesis involves hypertrophy and hyperplasia of synovial cells and polarization infiltration of macrophages, in which macrophages, as a potential target, can delay the progression of the disease by improving the immune microenvironment in OA. To investigate the role and regulatory mechanism of Carveol in cartilage and synovial macrophage reprogramming and crosstalk during the development of OA. RAW264.7 mouse macrophage cell line was mainly used to stimulate macrophages to polarization towards M1 and M2 by LPS, IL4+IL13, respectively. Different concentrations of Carveol were given to intervene, and macrophage culture medium was collected to intervene mouse C57BL6J chondrocytes. ROS assay kit, western blotting, cellular immunofluorescence, scanning microscope and section histology were used to evaluate the effect of Carveol on anti-M1-polarization, M2-polarization promotion and cartilage protection. The mouse destabilization of medial meniscus (DMM) model was observed by micro-CT scan and histology. We found that CA could inhibit the increase of macrophage inflammation level under the intervention of LPS and promote the production of M2 anti-inflammatory substances under the intervention of IL-4+IL13. In addition, Carveol activated NRF2/HO-1/NQO1 pathway and enhanced ROS clearance in chondrocytes under the intervention of macrophage culture medium. The phosphorylation of I-κBα is inhibited, which further reduces the phosphorylation of P65 downstream of nuclear factor-κB (NF-κB) signaling pathway. In addition, Carveol inhibits mitogen activated protein kinase (MAPK) signaling molecules P-JNK, P-ERK and P-P38, and inhibits the production of inflammatory mediators. In vivo, Carveol can reduce osteophytes and bone spurs induced by DMM, reduce hypertrophy of synovial cells, reduce infiltration of macrophages, inhibit subchondral bone destruction, and reduce articular cartilage erosion. Our study suggests that synovial macrophages are potential targets for OA treatment, and Carveol is an effective candidate for OA treatment.

A Universal Strategy for Enhancing the Circulating miRNAs' Detection Performance of Rolling Circle Amplification by Using a Dual-Terminal Stem-Loop Padlock.

Rolling circle amplification (RCA) is one of the most promising nucleic acid detection technologies and has been widely used in the molecular diagnosis of disease. Padlock probes are often used to form circular templates, which are the core of RCA. However, RCA often suffers from insufficient specificity and sensitivity. Here we report a reconstruction strategy for conventional padlock probes to promote their overall performance in nucleic acid detection while maintaining probe functions uncompromised. When two rationally designed stem-loops were strategically placed at the two terminals of linear padlock probes, the specificity of target recognition was enhanced and the negative signal was significantly delayed. Our design achieved the best single-base discrimination compared with other structures and over a 1000-fold higher sensitivity than that of the conventional padlock probe, validating the effectiveness of this reconstruction. In addition, the underlying mechanisms of our design were elucidated through molecular dynamics simulations, and the versatility was validated with longer and shorter padlocks targeting the same target, as well as five additional targets (four miRNAs and dengue virus - 2 RNA mimic (DENV-2)). Finally, clinical applicability in multiplex detection was demonstrated by testing real plasma samples. Our exploration of the structures of nucleic acids provided another perspective for developing high-performance detection systems, improving the efficacy of practical detection strategies, and advancing clinical diagnostic research.

An in vitro and in vivo study: Valencene protects cartilage and alleviates the progression of osteoarthritis by anti-oxidative stress and anti-inflammatory effects.

BACKGROUND: Osteoarthritis (OA) is a heterogeneous disease involving the whole joint. The pathogenesis involves oxidative stress levels and chronic inflammation, and Valencene (VA) has excellent anti-inflammatory and antioxidant stress abilities. PURPOSE: The objective was to study the effects of VA therapy on combating oxidative stress and to evaluate the protective effect of chondrocytes to alleviate the progression of OA. METHODS: C57BL6J mouse chondrocytes were used as the primary cells in this study. Mouse chondrocytes were stimulated with IL-1ß, and VA was administered in different concentrations. Reactive oxygen species (ROS) assay kits, western blotting, cellular immunofluorescence, and scanning microscopy were used to evaluate VA's antioxidant stress mechanism, anti-inflammatory effect, and cartilage protective ability. The mouse arthritis model constructed by destabilization of medial meniscus (DMM) was observed by micro-CT scan and histology after different treatments. RESULTS: We found that VA can reverse the rise of ROS under IL-1ß, the degeneration of the cartilage extracellular matrix, and the production of inflammatory mediators. In terms of mechanism, VA activated NRF2/HO-1/NQO1 pathway, thus enhancing ROS clearance. The phosphorylation of IκBα is inhibited, which further reduces the downstream phosphorylation of P65 in nuclear factor-κB (NF-κB) signaling. In addition, VA inhibited mitogen-activated protein kinase (MAPK) signaling molecules P-JNK, P-ERK, and P-P38, inhibiting the production of inflammatory mediators and thus inhibiting Aggrecan and Collagen Type II （COL2）degeneration. In vivo, VA reduced DMM-induced osteophytes and spurs, suppressed subchondral bone destruction, and reduced articular cartilage erosion. CONCLUSION: Our study demonstrated that VA is an effective candidate for OA treatment.

Algicidal bacteria in phycosphere regulate free-living Symbiodinium fate via triggering oxidative stress and photosynthetic system damage.

Free-living Symbiodinium, which forms symbiotic relationships with many marine invertebrates, plays an important role in the vast ocean. Nutrient levels have been shown to significantly impact microbial community structure and regulate algal communities. In this study, the bacterial community structure within the phycosphere of free-living Symbiodinium underwent significant changes in response to nutrient stimulation. Alteromonas exhibited dominance in Zobell 2216E broth nutrient stimulation concomitant with the demise of algal cells. Alteromonas abrolhosensis JY-JZ1, a marine bacterium isolated from the phycosphere of Symbiodinium, demonstrated an algicidal effect on Symbiodinium cells. Optical and scanning electron microscopy revealed that the algal cell membrane structure was disrupted, leading to intracellular leakage. Strain JY-JZ1 exerted its cytotoxicity by producing and secreting bioactive compounds into the supernatant. The marked declines in the chlorophyll a content, photosynthetic efficiency (Fv/Fm) and the electron transport rate (rETR) indicated that the photosynthetic system of Symbiodinium was damaged by JY-JZ1 supernatant. The observed elevation in levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) content suggested that the algal cells experienced oxidative stress. Moreover, the supernatant exhibited remarkable adaptability to temperature and pH. Additionally, it displayed exceptional algicidal efficacy against various harmful algae species. To the best of our knowledge, this study represents the first successful isolation of an algicidal bacterial strain from the phycosphere of free-living Symbiodinium and subsequent investigation into its mechanism for controlling Symbiodinium growth, thereby providing novel insights into algae-bacteria interactions. The remarkable algicidal efficacy exhibited by strain JY-JZ1 against other harmful algae species suggests its significant potential for harmful algal blooms (HABs) control.

A comprehensive analysis of single-cell RNA transcriptome reveals unique SPP1+ chondrocytes in human osteoarthritis.

Osteoarthritis (OA) has become the most common degenerative disease in the world, which brings a serious economic burden to society and the country. Although epidemiological studies have shown that the occurrence of osteoarthritis is associated with obesity, sex, and trauma, the biomolecular mechanisms for the development and progression of osteoarthritis remain ambiguous. Several studies have drawn a connection between SPP1 and osteoarthritis. SPP1 was first found to be highly expressed in osteoarthritic cartilage, and later more studies have shown that SPP1 is also highly expressed in subchondral bone and synovial in OA patients. However, the biological function of SPP1 remains unclear. Single-cell RNA sequencing (scRNA-seq) is a novel technique that reflects gene expression at the cellular level, making it better depict the state of different cells than ordinary transcriptome data. However, most of the existing chondrocyte scRNA-seq studies focus on the occurrence and development of OA chondrocytes and lack analysis of normal chondrocyte development. Therefore, to better understand the mechanism of OA, scRNA-seq analysis of a larger cell volume containing normal and osteoarthritic cartilage is of great importance. Our study identifies a unique cluster of chondrocytes characterized by high SPP1 expression. The metabolic and biological characteristics of these clusters were further investigated. Besides, in animal models, we found that the expression of SPP1 is spatially heterogeneous in cartilage. Overall, our work provides novel insight into the potential role of SPP1 in OA, which sheds light on understanding the role of SPP1 in OA, promoting the progress of the treatment and prevention in the field of OA.

A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique.

Transiliac-transsacral screw fixation is challenging in clinical practice as the screws need to break through six layers of cortical bone. Transiliac-transsacral screws provide a longer lever arm to withstand the perpendicular vertical shear forces. However, the screw channel is so long that a minor discrepancy can lead to iatrogenic neurovascular injuries. The development of medical robots has improved the precision of surgery. The present protocol describes how to use a new teleoperated robotic system to execute transiliac-transacral screw fixation. The Robot was operated remotely to position the entry point and adjust the orientation of the sleeve. The screw positions were evaluated using postoperative computed tomography (CT). All the screws were safely implanted, as confirmed using intraoperative fluoroscopy. Postoperative CT confirmed that all the screws were in the cancellous bone. This system combines the doctor's initiative with the Robot's stability. The remote control of this procedure is possible. Robot-assisted surgery has a higher position-retention capacity compared with conventional methods. In contrast to active robotic systems, surgeons have full control over the operation. The robot system is fully compatible with operating room systems and does not require additional equipment.

Cadmium chloride exposure impairs the growth and behavior of Drosophila via ferroptosis.

Cadmium (Cd) is a widely distributed toxic heavy metal that enters the environment via anthropogenic mobilization and accumulates in plants and animals, causing metabolic abnormalities even mortality. Although the toxic effects and stress damage of cadmium have been investigated extensively over the past few decades, research on its ability to trigger ferroptosis, growth retardation, and behavioral abnormalities is insufficient. As a result, the effects of CdCl2 exposure on growth and development, activity and sleep, and ferroptosis in this study were examined in fruit fly (Drosophila melanogaster). When exposed to 0.5 mM CdCl2, the entire growth period from larvae to adults was prolonged, and the rates of pupation and eclosion were decreased. Additionally, CdCl2 exposure resulted in a decrease in body weight and individual size of fruit fly and high lethality rate. Moreover, CdCl2 exposure altered fruit fly behavior, including decreased activity and increased sleep duration, particularly in females. Ferrostatin-1 (Fer-1) is a potent selective ferroptosis inhibitor that effectively slows lipid hydroperoxide accumulation to rescue body size reduction and restore activity and sleep in CdCl2-exposed female flies. CdCl2 exposure could induce ferroptosis in fruit fly mechanistically, as evidenced by inhibition of Nrf2 signaling pathway, accumulation of lipid peroxidation, impairment of GPX4 antioxidant system, and upregulation of iron metabolism. Our findings suggest that Cd exposure triggers ferroptosis, which leads to growth retardation and behavioral disorders in fruit fly.

Modularized Enzymatic Tandem Reaction for tsRNA Detection.

tRNA-derived small RNA (tsRNA) has emerged as a new biomarker for early diagnosis and prognosis prediction of breast cancer. Like the detection of other small non-coding RNAs, the traditional DNA circuit could be used for the tsRNA detection. However, the highly coupling DNA strands in the circuit increase the difficulty of design and could raise a false-positive signal. Here, we demonstrated a versatile modularized enzymatic tandem reaction, namely, reverse-transcribed nicking exponential truncation (RT-NExT). This enzymatic reaction was constructed by cohesive modules, which can work independently or in assembly. Each module could amplify and initiate the downstream module. The RT-NExT reaction could detect 10-18 M ts-66 or ts-86 within 10 min and exhibited excellent consistency to the qRT-PCR when measuring the tsRNA expression level of breast cancer or healthy patients. RT-NExT provides an appealing detection strategy for further research on the clinical diagnosis with tsRNAs.

Mapping Neuroscience in the Field of Education through a Bibliometric Analysis.

This study aimed to explore the core knowledge topics and future research trends in neuroscience in the field of education (NIE). In this study, we have explored the diffusion of neuroscience and different neuroscience methods (e.g., electroencephalography, functional magnetic resonance imaging, eye tracking) through and within education fields. A total of 549 existing scholarly articles and 25,886 references on neuroscience in the field of education (NIE) from the Web of Science Core Collection databases were examined during the following two periods: 1995-2013 and 2014-2022. The science mapping software Vosviewer and Bibliometrix were employed for data analysis and visualization of relevant literature. Furthermore, performance analysis, collaboration network analysis, co-citation network analysis, and strategic diagram analysis were conducted to systematically sort out the core knowledge in NIE. The results showed that children and cognitive neuroscience, students and medical education, emotion and empathy, and education and brain are the core intellectual themes of current research in NIE. Curriculum reform and children's skill development have remained central research issues in NIE, and several topics on pediatric research are emerging. The core intellectual themes of NIE revealed in this study can help scholars to better understand NIE, save research time, and explore a new research question. To the best of our knowledge, this study is one of the earliest documents to outline the NIE core intellectual themes and identify the research opportunities emerging in the field.

Programming a DNA tetrahedral nanomachine as an integrative tool for intracellular microRNA biosensing and stimulus-unlocked target regulation.

The synchronous detection and regulation of microRNAs (miRNAs) are essential for the early tumor diagnosis and treatment but remains a challenge. An integrative DNA tetrahedral nanomachine was self-assembled for sensitive detection and negative feedback regulation of intracellular miRNAs. This nanomachine comprised a DNA tetrahedron nanostructure as the framework, and a miRNA inhibitor-controlled allosteric DNAzyme as the core. The DNA tetrahedron brought the DNAzyme and the substrate in spatial proximity and facilitated the cellular uptake of DNAzyme. In allosteric regulation of DNAzyme, the locked tetrahedral DNAzyme (L-tetra-D) and active tetrahedral DNAzyme (A-Tetra-D) were controlled by miRNA inhibitor. The combination of miRNA inhibitor and target could trigger the conformational change from L-tetra-D to A-Tetra-D. A-Tetra-D cleaved the substrate and released fluorescence for intracellular miRNA biosensing. The DNA tetrahedral nanomachine showed excellent sensitivity (with detection limit down to 0.77 pM), specificity (with one-base mismatch discrimination), biocompatibility and stability. Simultaneously, miRNA stimulus-unlocked inhibitor introduced by our nanomachine exhibited the synchronous regulation of target cells, of which regulatory performance has been verified by the upregulated levels of downstream genes/proteins and the increased cellular apoptosis. Our study demonstrated that the DNA tetrahedral nanomachine is a promising biosense-and-treat tool for the synchronous detection and regulation of intracellular miRNA, and is expected to be applied in the early diagnosis and tailored management of cancers.

Constructing an MCF-7 breast cancer cell-based transient transfection assay for screening RARα (Ant)agonistic activities of emerging phenolic compounds.

The screening of compounds with endocrine disrupting effects has been attracting increasing attention due to the continuous release of emerging chemicals into the environment. Testing the (ant)agonistic activities of these chemicals on the retinoic acid receptor α (RARα), a vital nuclear receptor, is necessary to explain their perturbation in the endocrine system in vivo. In the present study, MCF-7 breast carcinoma cells were transiently transfected with a RARα expression vector (pEF1α-RARα-RFP) and a reporter vector containing a retinoic acid reaction element (pRARE-TA-Luc). Under optimized conditions, the performance of the newly constructed system was evaluated for its feasibility in screening the (ant)agonistic effects of emerging phenolic compounds on RARα. The results showed that this transient transfection cell model responded well to stimulation with (ant)agonists of RARα, and the EC50 and IC50 values were 0.87 nM and 2.67 µM for AM580 and Ro41-5253, respectively. Its application in testing several emerging phenolic compounds revealed that triclosan (TCS) and tetrabromobisphenol A (TBBPA) exerted notable RARα antagonistic activities. This newly developed bioassay based on MCF-7 is promising in identifying the agonistic or antagonistic activities of xenobiotics on RARα and has good potential for studying RARα signaling-involved toxicological effects of emerging chemicals of concern.

Perfluorinated Iodine Alkanes Promoted Neural Differentiation of mESCs by Targeting miRNA-34a-5p in Notch-Hes Signaling.

The neurodevelopmental process is highly vulnerable to environmental stress from exposure to endocrine-disrupting chemicals. Perfluorinated iodine alkanes (PFIs) possess estrogenic activities, while their potential neurodevelopmental toxicity remains blurry. In the present study, the effects of two PFIs, including dodecafluoro-1,6-diiodohexane (PFHxDI) and tridecafluorohexyl iodide (PFHxI), were investigated in the neural differentiation of the mouse embryonic stem cells (mESCs). Without influencing the cytobiological process of the mESCs, PFIs interfered the triploblastic development by increasing ectodermal differentiation, thus promoting subsequent neurogenesis. The temporal regulation of PFIs in Notch-Hes signaling through the targeting of mmu-miRNA-34a-5p provided a substantial explanation for the underlying mechanism of PFI-promoted mESC commitment to the neural lineage. The findings herein provided new knowledge on the potential neurodevelopmental toxicities of PFIs, which would help advance the health risk assessment of these kinds of emerging chemicals.

Discovery of benzo[d]isothiazole derivatives as novel scaffold inhibitors targeting the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) interaction through "ring fusion" strategy.

The inhibition of programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) interaction by monoclonal antibodies (mAbs) has achieved promising outcomes in cancer immunotherapy. Due to the inherent deficiencies of mAbs drugs, such as high cost of treatment, immunogenicity, poor pharmacokinetics and penetration of solid tumors, researchers are encouraged to develop small molecule inhibitors, to overcome mAbs drugs' deficiencies and change the situation where small molecule drugs are not available on the market. Herein, we reported a series of benzo[d]isothiazole derivatives targeting the PD-1/PD-L1 interaction through "ring fusion" strategy using BMS-202 as a starting point. Among them, compound D7 exhibited the best inhibitory activity with an IC50 value of 5.7 nM by homogeneous time-resolved fluorescence (HTRF) binding assay. In immunotoxicity analysis, D7 showed low cytotoxicity to Jurkat T cells in CCK-8 assay compared to BMS-202. The binding mode between D7 and PD-L1 protein was explored by molecular docking and molecular dynamics (MD) simulations, which revealed crucial chemical groups, such as biphenyl group interacting with Ile54A, Tyr56A, Met115A, Ala121A, Ile54B, Met115B, Ala121B and Tyr123B by hydrophobic interactions, bromobenzene moiety forming π-π stacking interaction with Tyr56B, as well as l-serine moiety forming hydrogen bond (H-bond) and salt bridge interactions with Asp122A and Lys124A. Furthermore, molecular modeling studies showed that D7 is likely to bind to the FA8 (fatty acid 8) binding site of human serum albumin (HSA). Taken together, D7 significantly inhibits the PD-1/PD-L1 interaction with low cytotoxicity, indicating that D7 is a promising starting point for further drug development in cancer immunotherapy.

Enzyme-free and copper-free strategy based on cyclic click chemical-triggered hairpin stacking circuit for accurate detection of circulating microRNAs.

Accurate detection of circulating microRNAs (miRNAs) plays a vital role in the diagnosis of various diseases. However, enzyme-free amplification detection remains challenging. Here, we report an enzyme-free fluorescence resonance energy transfer assay termed "3C-TASK" (cyclic click chemical-triggered hairpin stacking kit) for the detection of circulating miRNA. In this strategy, the miRNA could initiate copper-free click chemical ligation reactions and the ligated products then trigger another hairpin stacking circuit. The first signal amplification was achieved through the recycling of the target miRNA in the click chemical ligation circuit, and the second signal amplification was realized through the recycling of ligated probes in a hairpin stacking circuit driven by thermodynamics. The two-step chain reaction event triggered by miRNAs was quantified by the fluorescence signal value so that accurate detection of target miRNA could be achieved. The 3C-TASK was easily controlled because no enzyme was involved in the entire procedure. Although simple, this strategy showed sensitivity with a detection limit of 8.63 pM and specificity for distinguishing miRNA sequences with single-base variations. In addition, the applicability of this method in complex biological samples was verified by detecting target miRNA in diluted plasma samples. Hence, our method achieved sensitive and specific detection of miRNA and may offer a new perspective for the broader application of enzyme-free chemical reaction and DNA circuits in biosensing.

Corrigendum to "Environmental pollution, a hidden culprit for health issues" [Eco-Environ. Health (2022) 31-45].

[This corrects the article DOI: 10.1016/j.eehl.2022.04.003.].

Environmental pollution, a hidden culprit for health issues.

The environmental and health impacts from the massive discharge of chemicals and subsequent pollution have been gaining increasing public concern. The unintended exposure to different pollutants, such as heavy metals, air pollutants and organic chemicals, may cause diverse deleterious effects on human bodies, resulting in the incidence and progression of different diseases. The article reviewed the outbreak of environmental pollution-related public health emergencies, the epidemiological evidence on certain pollution-correlated health effects, and the pathological studies on specific pollutant exposure. By recalling the notable historical life-threatening disasters incurred by local chemical pollution, the damning evidence was presented to criminate certain pollutants as the main culprit for the given health issues. The epidemiological data on the prevalence of some common diseases revealed a variety of environmental pollutants to blame, such as endocrine-disrupting chemicals (EDCs), fine particulate matters (PMs) and heavy metals. The retrospection of toxicological studies provided illustrative clues for evaluating ambient pollutant-induced health risks. Overall, environmental pollution, as the hidden culprit, should answer for the increasing public health burden, and more efforts are highly encouraged to strive to explore the cause-and-effect relationships through extensive epidemiological and pathological studies.