Constructing a Hydrophilic Microsensor for High-Antifouling Neurotransmitter Dopamine Sensing.

Real-time sensing of dopamine is essential for understanding its physiological function and clarifying the pathophysiological mechanism of diseases caused by impaired dopamine systems. However, severe fouling from nonspecific protein adsorption, for a long time, limited conventional neural recording electrodes concerning recording stability. This study reported a high-antifouling nanocrystalline boron-doped diamond microsensor grown on a carbon fiber substrate. The antifouling properties of this diamond sensor were strongly related to the grain size (i.e., nanocrystalline and microcrystalline) and surface terminations (i.e., oxygen and hydrogen terminals). Experimental observations and molecular dynamics calculations demonstrated that the oxygen-terminated nanocrystalline boron-doped diamond microsensor exhibited enhanced antifouling characteristics against protein adsorption, which was attributed to the formation of a strong hydration layer as a physical and energetic barrier that prevents protein adsorption on the surface. This finally allowed for in vivo monitoring of dopamine in rat brains upon potassium chloride stimulation, thus presenting a potential solution for the design of next-generation antifouling neural recording sensors. Experimental observations and molecular dynamics calculations demonstrated that the oxygen-terminated nanocrystalline boron-doped diamond (O-NCBDD) microsensor exhibited ultrahydrophilic properties with a contact angle of 4.9°, which was prone to forming a strong hydration layer as a physical and energetic barrier to withstand the adsorption of proteins. The proposed O-NCBDD microsensor exhibited a high detection sensitivity of 5.14 µA µM-1 cm-2 and a low detection limit of 25.7 nM. This finally allowed for in vivo monitoring of dopamine with an average concentration of 1.3 µM in rat brains upon 2 µL of potassium chloride stimulation, thus presenting a potential solution for the design of next-generation antifouling neural recording sensors.

Acetylation is required for full activation of the NLRP3 inflammasome.

Full activation of the NLRP3 inflammasome needs two sequential signals: a priming signal, followed by a second, assembly signal. Several studies have shown that the two signals trigger post-translational modification (PTM) of NLRP3, affecting activity of the inflammasome, however, the PTMs induced by the second signal are less well characterized. Here, we show that the assembly signal involves acetylation of NLRP3 at lysine 24, which is important for the oligomerization and the actual assembly of NLRP3 without affecting its recruitment to dispersed trans-Golgi network (dTGN). Accordingly, NLRP3 inflammasome activation is impaired in NLRP3-K24R knock-in mice. We identify KAT5 as an acetyltransferase able to acetylate NLRP3. KAT5 deficiency in myeloid cells and pharmacological inhibition of KAT5 enzymatic activity reduce activation of the NLRP3 inflammasome, both in vitro and in vivo. Thus, our study reveals a key mechanism for the oligomerization and full activation of NLRP3 and lays down the proof of principle for therapeutic targeting of the KAT5-NLRP3 axis.

The noncanonical inflammasome-induced pyroptosis and septic shock.

Sepsis remains one of the most common and lethal conditions globally. Currently, no proposed target specific to sepsis improves survival in clinical trials. Thus, an in-depth understanding of the pathogenesis of sepsis is needed to propel the discovery of effective treatment. Recently attention to sepsis has intensified because of a growing recognition of a non-canonical inflammasome-triggered lytic mode of cell death termed pyroptosis upon sensing cytosolic lipopolysaccharide (LPS). Although the consequences of activation of the canonical and non-canonical inflammasome are similar, the non-canonical inflammasome formation requires caspase-4/5/11, which enzymatically cleave the pore-forming protein gasdermin D (GSDMD) and thereby cause pyroptosis. The non-canonical inflammasome assembly triggers such inflammatory cell death by itself; or leverages a secondary activation of the canonical NLRP3 inflammasome pathway. Excessive cell death induced by oligomerization of GSDMD and NINJ1 leads to cytokine release and massive tissue damage, facilitating devastating consequences and death. This review summarized the updated mechanisms that initiate and regulate non-canonical inflammasome activation and pyroptosis and highlighted various endogenous or synthetic molecules as potential therapeutic targets for treating sepsis.

SARS-CoV-2 Z-RNA activates the ZBP1-RIPK3 pathway to promote virus-induced inflammatory responses.

SARS-CoV-2 infection can trigger strong inflammatory responses and cause severe lung damage in COVID-19 patients with critical illness. However, the molecular mechanisms by which the infection induces excessive inflammatory responses are not fully understood. Here, we report that SARS-CoV-2 infection results in the formation of viral Z-RNA in the cytoplasm of infected cells and thereby activates the ZBP1-RIPK3 pathway. Pharmacological inhibition of RIPK3 by GSK872 or genetic deletion of MLKL reduced SARS-CoV-2-induced IL-1ß release. ZBP1 or RIPK3 deficiency leads to reduced production of both inflammatory cytokines and chemokines during SARS-CoV-2 infection both in vitro and in vivo. Furthermore, deletion of ZBP1 or RIPK3 alleviated SARS-CoV-2 infection-induced immune cell infiltration and lung damage in infected mouse models. These results suggest that the ZBP1-RIPK3 pathway plays a critical role in SARS-CoV-2-induced inflammatory responses and lung damage. Our study provides novel insights into how SARS-CoV-2 infection triggers inflammatory responses and lung pathology, and implicates the therapeutic potential of targeting ZBP1-RIPK3 axis in treating COVID-19.

Expert consensus on the monitoring and treatment of sepsis-induced immunosuppression.

Emerged evidence has indicated that immunosuppression is involved in the occurrence and development of sepsis. To provide clinical practice recommendations on the immune function in sepsis, an expert consensus focusing on the monitoring and treatment of sepsis-induced immunosuppression was developed. Literature related to the immune monitoring and treatment of sepsis were retrieved from PubMed, Web of Science, and Chinese National Knowledge Infrastructure to design items and expert opinions were collected through an online questionnaire. Then, the Delphi method was used to form consensus opinions, and RAND appropriateness method was developed to provide consistency evaluation and recommendation levels for consensus opinions. This consensus achieved satisfactory results through two rounds of questionnaire survey, with 2 statements rated as perfect consistency, 13 as very good consistency, and 9 as good consistency. After summarizing the results, a total of 14 strong recommended opinions, 8 weak recommended opinions and 2 non-recommended opinions were produced. Finally, a face-to-face discussion of the consensus opinions was performed through an online meeting, and all judges unanimously agreed on the content of this consensus. In summary, this expert consensus provides a preliminary guidance for the monitoring and treatment of immunosuppression in patients with sepsis.

Tail-stiffness optimization for a flexible robotic fish.

Undulation regulation in a robotic fish propelled by a passive flexible tail is more similar to that of a natural fish than with a rigid tail, owing to the smooth curvature of the flexible tail. Moreover, it has been observed that fish change the stiffness of their bodies to adapt to various swimming states. Inspired by this, a stiffness optimization scheme is explored for a novel elastic tail, which can improve the performance of the robotic fish. Spring steels are used as passive flexible joints of the fishtail; these can be easily expanded into multi-joint structures and the joint stiffness can be altered by changing the joint size. In this study, the Lagrangian dynamic method is employed to establish a dynamic model of the robotic fish in which passive flexible joints are simplified by a pseudo-rigid-body model. In addition, the hydrodynamics of the head and tail are analyzed using the simplified Morison equation and quasi-steady wing theory, respectively. Furthermore, to determine unknown hydrodynamic parameters in the dynamic model, a parameter identification method is applied. The results show that the identified simulation speeds fit the experimental speeds well within a wide range of stiffness values. Finally, to improve performance, the influence of joint stiffness and frequency on swimming speed is investigated based on the identified dynamic model. At each frequency, the optimal joint stiffness distribution is one that reduces the stiffness from the front to the rear. At the maximum driving frequency of 2.5 Hz, the optimal swimming speed is 0.3 body lengths per second, higher than that when rigid joints are used.

Impaired interferon-γ signaling promotes the development of silicosis.

Silicosis is caused by inhalation of crystalline silica dust particles and known as one of the most serious occupational diseases worldwide. However, little is known about intrinsic factors leading to disease susceptibility. Single-cell sequencing of bronchoalveolar lavage fluid cells of mine workers with silicosis and their co-workers who did not develop silicosis revealed that the impaired interferon (IFN)-γ signaling in myeloid cells was strongly associated with the occurrence of silicosis. Global or myeloid cell-specific deletion of interferon γ receptor (IFN-γR) markedly enhanced the crystalline silica-induced pulmonary injury in wild-type but not in NLRP3 deficient mice. In vitro, IFN-γ priming of macrophages suppressed the crystalline silica-induced NLRP3 inflammasome activation partly by inducing the formation of spacious phagosomes with relatively reduced ratio of crystalline silica/phagosomal areas volumes to resistant crystalline silica-induced lysosomal membrane damage. Thus, these findings provide molecular insights into the intricate mechanisms underlying innate immunity-mediated host responses to environmental irritants.

A Study on the Effectiveness of Rumor Control via Social Media Networks to Alleviate Public Panic About COVID-19.

The COVID-19 outbreak triggered a massive spread of unverified news on social media and has become a source of rumors. This paper studies the impact of a virtual rumor control center (RCC) on Weibo user behavior. The collected COVID-19 breaking news stories were divided into positive, negative, and neutral categories, while the moderating effect model was used to analyze the influence of anti-rumor on user behavior (forwarding, liking, and commenting). Our research found that rumor refuting does not directly affect user behavior but does have an indirect moderating effect. Rumor refuting has a profound impact on user forwarding behavior in cases of positive and negative news. Specifically, when the epidemic becomes more serious, the role of rumor refuting becomes critical, and vice versa. Refuting rumors reduces user willingness to forward positive or negative news, with more impact on negative news. Time lag analysis shows a significant moderation of unverified news within 72 h of refuting rumors but indicated an apparent weakening trend over time. Furthermore, we discovered non-linear feature and counter-cyclical phenomena in the moderating effect of rumor refutation.

Z-DNA binding protein 1 promotes heatstroke-induced cell death.

Heatstroke is a heat stress-induced, life-threatening condition associated with circulatory failure and multiple organ dysfunctions. If global warming continues, heatstroke might become a more prominent cause of mortality worldwide, but its pathogenic mechanism is not well understood. We found that Z-DNA binding protein 1 (ZBP1), a Z-nucleic acid receptor, mediated heatstroke by triggering receptor-interacting protein kinase 3 (RIPK3)-dependent cell death. Heat stress increased the expression of ZBP1 through heat shock transcription factor 1 (HSF1) and activated ZBP1 through a mechanism independent of the nucleic acid sensing action. Deletion of ZBP1, RIPK3, or both mixed lineage kinase domain-like (MLKL) and caspase-8 decreased heat stress-induced circulatory failure, organ injury, and lethality. Thus, ZBP1 appears to have a second function that orchestrates host responses to heat stress.

Intrinsic Radical Species Scavenging Activities of Tea Polyphenols Nanoparticles Block Pyroptosis in Endotoxin-Induced Sepsis.

Sepsis, a life-threating illness caused by deregulated host immune responses to infections, is characterized by overproduction of multiple reactive oxygen and nitrogen species (RONS) and excessive pyroptosis, leading to high mortality. However, there is still no approved specific molecular therapy to treat sepsis. Here we reported drug-free tea polyphenols nanoparticles (TPNs) with intrinsic broad-spectrum RONS scavenging and pyroptosis-blocking activities to treat endotoxin (LPS)-induced sepsis in mice. The RONS scavenging activities originated from the polyphenols-derived structure, while the pyroptosis blockage was achieved by inhibiting gasdermin D (GSDMD) mediating the pore formation and membrane rupture, showing multifunctionalities for sepsis therapy. Notably, TPNs suppress GSDMD by inhibiting the oligomerization of GSDMD rather than the cleavage of GSDMD, thus displaying high pyroptosis-inhibition efficiency. As a result, TPNs showed an excellent therapeutic efficacy in sepsis mice model, as evidenced by survival rate improvement, hypothermia amelioration, and the organ damage protection. Collectively, TPNs present biocompatible candidates for the treatment of sepsis.

Achieving physical examination competence through optimizing hands-on practice cycles: a prospective cohort comparative study of medical students.

BACKGROUND: Deliberate practice (DP) was proposed for effective clinical skill training, which highlights focused, repetitive practice and feedback as the key points for practice. Although previous studies have investigated the effect of feedback in DP, little is known about the proper repetitive cycles of clinical skills training especially in physical examination (PE) training. METHODS: We drew learning curves and designed a comparative study to find out the optimal number of hands-on practice cycles, an important aspect of DP, in abdominal PE training for medical students. A comparative study was conducted to validate the optimal number of hands-on practice by dividing students into two cohorts including Cohort A (high-frequency hand-on training) and B (low-frequency hand-on training). RESULTS: The learning curve study of 16 students exhibited a threshold of four repetitive practices when 81.25% students reached the competence score. A total of 74 students' final exam scores were collected for analysis. Students in Cohort A (4-5 PEs) scored significantly higher than those in Cohort B (≤3 PEs) (84.41 ± 11.78 vs 76.83 ± 17.51] in the final exam (P = 0.030)). CONCLUSION: High-frequency practice can improve students' competence of abdominal PE skill. We recommend four cycles of hands-on practice for each student in a training course like PE training.

YAP promotes the activation of NLRP3 inflammasome via blocking K27-linked polyubiquitination of NLRP3.

The transcription coactivator YAP plays a vital role in Hippo pathway for organ-size control and tissue homeostasis. Recent studies have demonstrated YAP is closely related to immune disorders and inflammatory diseases, but the underlying mechanisms remain less defined. Here, we find that YAP promotes the activation of NLRP3 inflammasome, an intracellular multi-protein complex that orchestrates host immune responses to infections or sterile injuries. YAP deficiency in myeloid cells significantly attenuates LPS-induced systemic inflammation and monosodium urate (MSU) crystals-induced peritonitis. Mechanistically, YAP physically interacts with NLRP3 and maintains the stability of NLRP3 through blocking the association between NLRP3 and the E3 ligase ß-TrCP1, the latter increases the proteasomal degradation of NLRP3 via K27-linked ubiquitination at lys380. Together, these findings establish a role of YAP in the activation of NLRP3 inflammasome, and provide potential therapeutic target to treat the NLRP3 inflammasome-related diseases.

A small molecule binding HMGB1 inhibits caspase-11-mediated lethality in sepsis.

Caspase-11, a cytosolic lipopolysaccharide (LPS) receptor, mediates lethal immune responses and coagulopathy in sepsis, a leading cause of death worldwide with limited therapeutic options. We previously showed that over-activation of caspase-11 is driven by hepatocyte-released high mobility group box 1 (HMGB1), which delivers extracellular LPS into the cytosol of host cells during sepsis. Using a phenotypic screening strategy with recombinant HMGB1 and peritoneal macrophages, we discovered that FeTPPS, a small molecule selectively inhibits HMGB1-mediated caspase-11 activation. The physical interaction between FeTPPS and HMGB1 disrupts the HMGB1-LPS binding and decreases the capacity of HMGB1 to induce lysosomal rupture, leading to the diminished cytosolic delivery of LPS. Treatment of FeTPPS significantly attenuates HMGB1- and caspase-11-mediated immune responses, organ damage, and lethality in endotoxemia and bacterial sepsis. These findings shed light on the development of HMGB1-targeting therapeutics for lethal immune disorders and might open a new avenue to treat sepsis.

Heparin prevents caspase-11-dependent septic lethality independent of anticoagulant properties.

Heparin, a mammalian polysaccharide, is a widely used anticoagulant medicine to treat thrombotic disorders. It is also known to improve outcomes in sepsis, a leading cause of mortality resulted from infection-induced immune dysfunction. Whereas it is relatively clear how heparin exerts its anticoagulant effect, the immunomodulatory mechanisms enabled by heparin remain enigmatic. Here, we show that heparin prevented caspase-11-dependent immune responses and lethality in sepsis independent of its anticoagulant properties. Heparin or a chemically modified form of heparin without anticoagulant function inhibited the alarmin HMGB1-lipopolysaccharide (LPS) interaction and prevented the macrophage glycocalyx degradation by heparanase. These events blocked the cytosolic delivery of LPS in macrophages and the activation of caspase-11, a cytosolic LPS receptor that mediates lethality in sepsis. Survival was higher in septic patients treated with heparin than those without heparin treatment. The identification of this previously unrecognized heparin function establishes a link between innate immune responses and coagulation.

Silencing IFNγ inhibits A1 astrocytes and attenuates neurogenesis decline and cognitive impairment in endotoxemia.

Cognitive impairment, acute or long-term, is a common complication in patients with severe bacterial infection. However, the underlying mechanisms are not fully verified and effective medicine is not available in clinics. Interferon gamma (IFNγ) is a pivotal cytokine against infection and is believed to be a tune in homeostasis of cognitive function. Here, we collected blood and cerebrospinal fluid (CF) from human subjects and mice, and found that plasma and CF levels of IFNγ were significantly increased in septic patients and endotoxin-challenged mice when compared with healthy controls. IFNγ signaling was boosted in the hippocampus of mice after a challenge of lipopolysaccharide (LPS), which was accompanied with cognitive impairment and decline of neurogenesis. Deficiency of IFNγ or its receptor (IFNγR) dramatically attenuated microglia-induced A1 astrocytes and consequently restored neurogenesis and cognitive function in endotoxemia mice model. Using primary microglia, astrocytes and neurons, we found that IFNγ remarkably increased LPS-mediated release of TNFα and IL-1α in microglia and consequently induced the transformation of astrocyte to A1 subtype, which ultimately resulted in neuron damage. Thus, IFNγ promotes cognitive impairment in endotoxemia by enhancing microglia-induced A1 astrocytes. Targeting IFNγ would be a novel strategy for preventing or treating cognitive dysfunction in patients with Gram-negative infection.

Toward Sustainable Environmental Quality: Priority Research Questions for Asia.

Environmental and human health challenges are pronounced in Asia, an exceptionally diverse and complex region where influences of global megatrends are extensive and numerous stresses to environmental quality exist. Identifying priorities necessary to engage grand challenges can be facilitated through horizon scanning exercises, and to this end we identified and examined 23 priority research questions needed to advance toward more sustainable environmental quality in Asia, as part of the Global Horizon Scanning Project. Advances in environmental toxicology, environmental chemistry, biological monitoring, and risk-assessment methodologies are necessary to address the adverse impacts of environmental stressors on ecosystem services and biodiversity, with Asia being home to numerous biodiversity hotspots. Intersections of the food-energy-water nexus are profound in Asia; innovative and aggressive technologies are necessary to provide clean water, ensure food safety, and stimulate energy efficiency, while improving ecological integrity and addressing legacy and emerging threats to public health and the environment, particularly with increased aquaculture production. Asia is the largest chemical-producing continent globally. Accordingly, sustainable and green chemistry and engineering present decided opportunities to stimulate innovation and realize a number of the United Nations Sustainable Development Goals. Engaging the priority research questions identified herein will require transdisciplinary coordination through existing and nontraditional partnerships within and among countries and sectors. Answering these questions will not be easy but is necessary to achieve more sustainable environmental quality in Asia. Environ Toxicol Chem 2020;39:1485-1505. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Application of clinical indices in pathological acute and chronic index prediction in lupus nephritis. / ä¸´åºŠæŒ‡æ ‡åœ¨ç‹¼ç–®è‚¾ç‚Žç— ç†å­¦æ€¥æ ¢æ€§æŒ‡æ•°é¢„æµ‹ä¸­çš„åº”ç”¨.

OBJECTIVES: To predict renal biopsy with pathological acute and chronic index via comprehensive analysis of clinical indices from lupus nephritis patients. METHODS: We collected 107 inpatients' data from the Third Xiangya Hospital of Central South University from January 2011 to September 2018. These inpatients have already had renal biopsy results. These clinical indices were set as variables. Using multiple linear regression, we built the prediction models for renal pathological acute and chronic index. Simultaneously, we evaluated each vital variable's importance in models by standardized coefficient of regression equation, and model prediction accuracy by 5-fold cross validation. RESULTS: Acute index and chronic index prediction models were built with 19 and 23 clinical variables, respectively. To evaluate the two models' accuracy of prediction, we used 5-fold cross validation and found that the prediction accuracy level were satisfactory with the acute index model (Q2=0.649, R2=0.791) and chronic index model (Q2=0.563, R2=0.744). Standardized coefficient of regression equation showed serum total cholesterol, serum iron, NAG, ß2 microglobulin and BUN were important variables to predict acute index while total cholesterol, ß2 microglobulin, homocystein and serum low density lipoprotein-cholesterol were important for chronic index prediction. CONCLUSIONS: Clinical indices are able to effectively predict renal biopsy conditions, which are valuable to assess lupus nephritis severity.

LPS Induces Active HMGB1 Release From Hepatocytes Into Exosomes Through the Coordinated Activities of TLR4 and Caspase-11/GSDMD Signaling.

High-mobility group box-1 (HMGB1), a ubiquitous nuclear protein, acts as a late mediator of lethality when released extracellularly during sepsis. The major source of circulating HMGB1 in sepsis is hepatocytes. However, the mechanism of HMGB1 release of hepatocytes during sepsis is not very clear. We have previously shown that bacterial endotoxin [lipopolysaccharide (LPS)] sensing pathways, including Toll-like receptor (TLR)4 and caspase-11, regulate hepatocyte HMGB1 release in response to LPS. Here, we report the novel function of caspase-11 and gasdermin D (GsdmD) in LPS-induced active HMGB1 released from hepatocytes. HMGB1 release during endotoxemia was caspase-11/GsdmD dependent via an active way in vivo and in vitro. Caspase-11/GsdmD was responsible for HMGB1 translocation from nucleus to the cytoplasm via calcium changing-induced phosphorylation of calcium-calmodulin kinase kinase (camkk)ß during endotoxemia. Cleaved GsdmD accumulated on the endoplasmic reticulum, suggesting this may lead to calcium leak and intracellular calcium increase. Furthermore, we investigated that exosome was an important pathway for HMGB1 release from hepatocytes; this process was dependent on TLR4, independent of caspase-11 and GsdmD in vivo and in vitro. These findings provide a novel mechanism that TLR4 signaling results in an increase in caspase-11 expression, as well as increased exosome release, while caspase-11/GsdmD activation/cleavage leads to accumulation of HMGB1 in the cytoplasm through a process associated with the release of calcium from the endoplasmic reticulum and camkkß activation.

ß-catenin promotes NLRP3 inflammasome activation via increasing the association between NLRP3 and ASC.

NLRP3 (NOD-, LRR- and pyrin domain- containing protein 3) inflammasome is involved in diverse inflammatory diseases, so the activation of NLRP3 inflammasome needs to be tightly regulated to prevent excessive inflammation. However, the endogenous regulatory mechanisms of NLRP3 inflammasome are still less defined. Here, we report that ß-catenin, which is the central mediator of the canonical Wnt/ß-catenin signaling, promotes NLRP3 inflammasome activation. When we suppressed the expression of ß-catenin by siRNA or pharmacological inhibitor, the NLRP3 inflammasome activation was impaired. Accordingly, ß-catenin inhibitor attenuated LPS-induced systemic inflammation in vivo. Mechanistically, we found ß-catenin interacted with NLRP3 and promoted the association between NLRP3 and ASC. Thus, our study revealed a novel role of ß-catenin in NLRP3 inflammasome activation and suggest an endogenous crosstalk between Wnt/ß-catenin signal and NLRP3 inflammasome.