Kinetic and Thermodynamic Characteristics of Torrefied Acer palmatum.

The goal of this research was to investigate the effects of torrefying temperature (220, 260, and 300 °C) on the physicochemical properties, kinetics, thermodynamic parameters, and reaction processes of Acer palmatum (AP) during the pyrolysis process. The kinetics of raw materials and torrefied biomass were studied by using three kinetic models, and the main function graph approach was employed to find the reaction mechanism. The torrefied biomass produced at temperatures of 220 °C (AP-220), 260 °C (AP-260), and 300 °C (AP-300) was thermogravimetrically analyzed at four different heating rates (5, 10, 15, and 20 °C/min). In comparison to the raw material, the average activation energy of torrefied biomass declined with increasing temperature, from 174.13 to 84.67 kJ/mol (FWO), 172.52 to 81.24 kJ/mol (KAS and DAEM). The volatile contents of AP and AP-220 are higher than those of AP-260 and AP-300, indicating that the random nucleation model occupies the central position. Compared with the raw biomass, the average Gibbs free energy (ΔG) of torrefied biomass increased from 157.97 to 195.38 kJ/mol. The mean enthalpy change (ΔH) during the torrefaction process is positive, while the mean entropy change (ΔS) of the torrefaction of biomass is negative, decreasing from 16.93 to -151.53 kJ/mol (FWO) and from 14.36 to -156.06 kJ/mol (KAS and DAEM). Overall, the findings provide a comprehensive understanding of the kinetics and improved features of torrefied biomass as a high-quality solid fuel.

Direct Regioselective Reductive Allylation of Imines: Application to Synthesis of Oxazines with Halogenated Reagent.

Oxazines are an important class of compounds in oxazine ligands and medical chemistry. Here, we describe a linear-selective allylation of imines with allyl electrophiles via cross-electrophile coupling reactions, followed by cyclization with halogenated reagents, providing a new strategy to afford oxazine compounds with a tetrasubstituted carbon center. Mechanistic studies indicate that α-amino carbanion, generated by successive single-electron transfer processes, is a key intermediate for nucleophile attack on π-allylpalladium in photoredox/palladium catalysis.

Human TLR8 induces inflammatory bone marrow erythromyeloblastic islands and anemia in SLE-prone mice.

Anemia commonly occurs in systemic lupus erythematosus, a disease characterized by innate immune activation by nucleic acids. Overactivation of cytoplasmic sensors by self-DNA or RNA can cause erythroid cell death, while sparing other hematopoietic cell lineages. Whereas chronic inflammation is involved in this mechanism, less is known about the impact of systemic lupus erythematosus on the BM erythropoietic niche. We discovered that expression of the endosomal ssRNA sensor human TLR8 induces fatal anemia in Sle1.Yaa lupus mice. We observed that anemia was associated with a decrease in erythromyeloblastic islands and a block in differentiation at the CFU-E to proerythroblast transition in the BM. Single-cell RNAseq analyses of isolated BM erythromyeloblastic islands from human TLR8-expressing mice revealed that genes associated with essential central macrophage functions including adhesion and provision of nutrients were down-regulated. Although compensatory stress erythropoiesis occurred in the spleen, red blood cell half-life decreased because of hemophagocytosis. These data implicate the endosomal RNA sensor TLR8 as an additional innate receptor whose overactivation causes acquired failure of erythropoiesis via myeloid cell dysregulation.

Microbiota-derived acetate enhances host antiviral response via NLRP3.

Pathogenic viral infections represent a major challenge to human health. Host immune responses to respiratory viruses are closely associated with microbiome and metabolism via the gut-lung axis. It has been known that host defense against influenza A virus (IAV) involves activation of the NLRP3 inflammasome, however, mechanisms behind the protective function of NLRP3 are not fully known. Here we show that an isolated bacterial strain, Bifidobacterium pseudolongum NjM1, enriched in the gut microbiota of Nlrp3-/- mice, protects wild-type but not Nlrp3 deficient mice against IAV infection. This effect depends on the enhanced production of type I interferon (IFN-I) mediated by NjM1-derived acetate. Application of exogenous acetate reproduces the protective effect of NjM1. Mechanistically, NLRP3 bridges GPR43 and MAVS, and promotes the oligomerization and signalling of MAVS; while acetate enhances MAVS aggregation upon GPR43 engagement, leading to elevated IFN-I production. Thus, our data support a model of NLRP3 mediating enhanced induction of IFN-I via acetate-producing bacterium and suggest that the acetate-GPR43-NLRP3-MAVS-IFN-I signalling axis is a potential therapeutic target against respiratory viral infections.

Noncoding Mutations in a Thyroid Hormone Receptor Gene That Impair Cone Photoreceptor Function.

The function of a hormone receptor requires mechanisms to control precisely where, when, and at what level the receptor gene is expressed. An intriguing case concerns the selective induction of thyroid hormone receptor ß2 (TRß2), encoded by Thrb, in the pituitary and also in cone photoreceptors, in which it critically regulates expression of the opsin photopigments that mediate color vision. Here, we investigate the physiological significance of a candidate enhancer for induction of TRß2 by mutagenesis of a conserved intron region in its natural context in the endogenous Thrb gene in mice. Mutation of e-box sites for bHLH (basic-helix-loop-helix) transcription factors preferentially impairs TRß2 expression in cones whereas mutation of nearby sequences preferentially impairs expression in pituitary. A deletion encompassing all sites impairs expression in both tissues, indicating bifunctional activity. In cones, the e-box mutations disrupt chromatin acetylation, blunt the developmental induction of TRß2, and ultimately impair cone opsin expression and sensitivity to longer wavelengths of light. These results demonstrate the necessity of studying an enhancer in its natural chromosomal context for defining biological relevance and reveal surprisingly critical nuances of level and timing of enhancer function. Our findings illustrate the influence of noncoding sequences over thyroid hormone functions.

Effect of Evolution of Carbon Structure during Torrefaction in Woody Biomass on Thermal Degradation.

Torrefaction is an effective method for upgrading biomass. Cedar torrefaction is carried out in a fixed bed reactor at the temperature of 200-300 °C. The structural parameters are obtained from elemental analysis and 13C nuclear magnetic resonance (NMR). Thermal degradation behavior of raw and torrefied cedar is monitored by thermogravimetry analysis. The results show that carbon structure varied during torrefaction has a significant effect on thermal degradation of cedar. Some unstable oxygen functional groups, such as C1 of hemicellulose, ß-O-4 linked bonds, and amorphous C6 of cellulose, are decomposed at mild torrefaction of torrefied temperature ≤ 200 °C. The temperature of maximum weight loss rate increases from 348 °C of raw cedar to 373 °C of C-200. The amorphous cellulose is partly re-crystallized at moderate torrefaction of torrefied temperature 200-250 °C. The aromaticity of torrefied cedar increases from 0.45 of C-200 to 0.73 of C-250. The covalent bond in the side chain of aromatic rings in cedar was further broken during torrefaction at severe torrefaction of torrefied temperature 250-300 °C. The area percentage of DTG mainly signed at 387 °C of C-300. The proton aromatic carbon increases from 12.35% of C-250 to 21.69% of C-300. These results will further facilitate the utilization of biomass for replacing fossil fuel to drive carbon neutrality.

Aim2 Couples With Ube2i for Sumoylation-Mediated Repression of Interferon Signatures in Systemic Lupus Erythematosus.

OBJECTIVE: Systemic lupus erythematosus (SLE) involves kidney damage, and the inflammasome-caspase-1 axis has been demonstrated to promote renal pathogenesis. The present study was designed to explore the function of the Absent in Melanoma 2 (Aim2) protein in SLE. METHODS: Female wild-type Aim2-/- , Aim2-/- Ifnar1-/- , Aim2-/- Rag1-/- , and Asc-/- mice ages 8-10 weeks received 1 intraperitoneal injection of 500 µl pristane or saline, and survival of mice was monitored twice a week for 6 months. RESULTS: The absence of Aim2, but not Asc, led to enhanced SLE in mice that received pristane treatment. Increased immune cell infiltration and type I interferon (IFN) signatures in the kidneys of Aim2-/- mice coincided with severity of lupus, which was alleviated by blockade of Ifnar1-mediated signal. Adaptive immune cells were also involved in the glomerular lesions of Aim2-/- mice after pristane challenge. Importantly, even in the absence of pristane, plasmacytoid dendritic cells in the kidneys of Aim2-/- mice were significantly increased compared to control animals. Accordingly, transcriptome analysis revealed that Aim2 deficiency led to enhanced expression of type I IFN-induced genes in the kidneys even at an early developmental stage. Mechanistically, Aim2 bound ubiquitin-conjugating enzyme 2i (Ube2i), which mediates sumoylation-based suppression of type I IFN expression deficiency of Aim2 decreased cellular sumoylation, resulting in an augmented type I IFN signature and kidney pathogenesis. CONCLUSION: The present study demonstrates a critical role for Aim2 in an optimal Ube2i-mediated sumoylation-based suppression of type I IFN generation and development of SLE. As such, the Aim2-Ube2i axis can thus be a novel target for intervention in SLE.

Acute Liver Failure in a Healthy Young Female With COVID-19.

Several well-described manifestations of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported. Among them, a transient elevation of liver enzymes is the typical presentation of coronavirus disease 2019 (COVID-19) liver-related injury. The mechanism of liver involvement is likely a combination of viral injury and immune-mediated inflammation. In contrast, acute liver failure in the setting of COVID-19 has rarely been reported. Herein, we report a case of pediatric acute liver failure in a previously healthy female adolescent infected with SARS-CoV-2 with biopsy evidence of replicating virus in hepatocytes, which has not been previously reported.

Azo-inserted responsive hybrid liposomes for hypoxia-specific drug delivery.

Stimuli-responsive drug delivery systems using endogenous stimuli from tumor microenvironments such as acidic pH, over-expressed enzyme, and high redox potential as triggers have shown tremendous promise in cancer therapy. However, their clinical application is severely limited because of tumor heterogeneity. Hypoxia, a physiological feature observed in almost all solid tumors and even in nodules with very small size, has currently emerged as a more general but efficient stimulus to trigger release. Herein, we developed hypoxia-responsive hybrid liposomes (HR-HLPs), composed of azo-inserted organokoxysilane-based lipid analogue as a responsive component and commercial phospholipid for reducing the rigidity of liposomal membrane caused by azo, for drug delivery targeting tumor hypoxia. HR-HLPs had the advantages of high structural stability to avoid premature drug leakage when circulating in the blood and high sensitivity in responding to hypoxia once reaching tumor sites. HR-HLPs exhibit deep tumor penetration capability, enabling effective delivery to hypoxic regions distant from tumor vessels. Moreover, HR-HLPs could selectively release their payload, co-localizing with over-expressed hypoxia inducible factor 1α (HIF-1α) in vitro and in vivo. As a result, HR-HLPs showed improved therapeutic outcome accompanied by reduced adverse effects. The results highlighted the potential application of azo-inserted responsive hybrid liposomes for hypoxia-targeted drug delivery. STATEMENT OF SIGNIFICANCE.

Calreticulin is important for the development of renal fibrosis and dysfunction in diabetic nephropathy.

Previously, our lab showed that the endoplasmic reticulum (ER) and calcium regulatory protein, calreticulin (CRT), is important for collagen transcription, secretion, and assembly into the extracellular matrix (ECM) and that ER CRT is critical for TGF-ß stimulation of type I collagen transcription through stimulation of ER calcium release and NFAT activation. Diabetes is the leading cause of end stage renal disease. TGF-ß is a key factor in the pathogenesis of diabetic nephropathy. However, the role of calreticulin (Calr) in fibrosis of diabetic nephropathy has not been investigated. In current work, we used both in vitro and in vivo approaches to assess the role of ER CRT in TGF-ß and glucose stimulated ECM production by renal tubule cells and in diabetic mice. Knockdown of CALR by siRNA in a human proximal tubular cell line (HK-2) showed reduced induction of soluble collagen when stimulated by TGF-ß or high glucose as compared to control cells, as well as a reduction in fibronectin and collagen IV transcript levels. CRT protein is increased in kidneys of mice made diabetic with streptozotocin and subjected to uninephrectomy to accelerate renal tubular injury as compared to controls. We used renal-targeted ultrasound delivery of Cre-recombinase plasmid to knockdown specifically CRT expression in the remaining kidney of uninephrectomized Calr fl/fl mice with streptozotocin-induced diabetes. This approach reduced CRT expression in the kidney, primarily in the tubular epithelium, by 30-55%, which persisted over the course of the studies. Renal function as measured by the urinary albumin/creatinine ratio was improved in the mice with knockdown of CRT as compared to diabetic mice injected with saline or subjected to ultrasound and injected with control GFP plasmid. PAS staining of kidneys and immunohistochemical analyses of collagen types I and IV show reduced glomerular and tubulointerstitial fibrosis. Renal sections from diabetic mice with CRT knockdown showed reduced nuclear NFAT in renal tubules and treatment of diabetic mice with 11R-VIVIT, an NFAT inhibitor, reduced proteinuria and renal fibrosis. These studies identify ER CRT as an important regulator of TGF-ß stimulated ECM production in the diabetic kidney, potentially through regulation of NFAT-dependent ECM transcription.

Gasdermin D Drives the Nonexosomal Secretion of Galectin-3, an Insulin Signal Antagonist.

The inflammasomes play critical roles in numerous pathological conditions largely through IL-1ß and/or IL-18. However, additional effectors have been implied from multiple studies. In this study, through two independent mass spectrometry-based secretome screening approaches, we identified galectin-3 as an effector protein of the NLRP3 inflammasome. Although the activation of AIM2 or NLRC4 inflammasome also led to galectin-3 secretion, only the NLRP3 inflammasome controlled the serum galectin-3 level under physiological condition. Mechanistically, active gasdermin D drove the nonexosomal secretion of galectin-3 through the plasma membrane pores. In vivo, high-fat diet-fed Nlrp3-/- mice exhibited decreased circulating galectin-3 compared with wild-type animals. Of note, the improved insulin sensitivity in such Nlrp3-/- mice was aggravated by infusion of recombinant galectin-3. Moreover, galectin-3 was essential for insulin resistance induction in mice harboring the hyperactive Nlrp3A350V allele. Thus, the inflammasome-galectin-3 axis has been demonstrated as a promising target to intervene inflammasome and/or galectin-3 related diseases.

Antiviral effects of simeprevir on multiple viruses.

Simeprevir was developed as a small molecular drug targeting the NS3/4A protease of hepatitis C virus (HCV). Unexpectedly, our current work discovered that Simeprevir effectively promoted the transcription of IFN-ß and ISG15, inhibited the infection of host cells by multiple viruses including Zika virus (ZIKV), Enterovirus A71 (EV-A71), as well as herpes simplex virus type 1 (HSV-1). However, the inhibitory effects of Simeprevir on ZIKV, EV-A71 and HSV-1 were independent from IFN-ß and ISG15. This study thus demonstrates that the application of Simeprevir can be extended to other viruses besides HCV.

Development of ß-elemene and Cisplatin Co-Loaded Liposomes for Effective Lung Cancer Therapy and Evaluation in Patient-Derived Tumor Xenografts.

PURPOSE: ß-elemene and cisplatin combined chemotherapy currently is one of the most important settings available for lung cancer therapy in China. However, the clinical outcome is limited by their pharmacokinetic drawbacks. On the other hand, most of nanomedicines have failed in clinical development due to the huge differences between heterogeneous clinical tumor tissues and homogenous cell-derived xenografts. In this work, we fabricated a ß-elemene and cisplatin co-loaded liposomal system to effectively treat lung cancer. METHOD: In vitro cytotoxicity of co-loaded liposomes was studied by MTT, trypan and Hoechst/PI staining, and western blot in A549, A549/DDP, and LCC cells. In vivo antitumor efficacy was evaluated in cell-derived and clinically relevant patient-derived xenografts. RESULTS: Co-loaded liposomes were more cytotoxic to cancer cells, especially than the combination of single-loaded liposomes, benefiting from their simultaneous drug internalization and release. As a result, they exhibited desirable therapeutic outcome in both cell-derived and patient-derived xenografts. CONCLUSION: ß-elemene and cisplatin co-loaded liposomes are a clinically promising candidate for effective lung cancer therapy.

Hyperactivation of the NLRP3 inflammasome protects mice against influenza A virus infection via IL-1ß mediated neutrophil recruitment.

Host innate immune system is critical for combating invading microbes including Influenza A virus (IAV). As an important arm of the innate immunity, the NLRP3 inflammasome has been found essential for protecting host against IAV challenge, while the mechanism remained elusive. Here we found that mice carrying a gain-of-function mutation in the Nlrp3 gene (Nlrp3R258W) are strongly resistant to IAV infection. Upon H1N1 IAV infection, the Nlrp3R258W mice exhibited decreased weight loss, increased survival rate and attenuated lung damage compared with WT littermate controls. Mechanistically, the resistance of Nlrp3R258W mice to IAV infection was dependent on IL-1ß-mediated neutrophil recruitment. Upon IAV infection, mice carrying the Nlrp3R258W mutation produced more IL-1ß than WT mice in the lung, which enhanced neutrophil recruitment locally. The recruited neutrophils facilitated IAV clearance, so that the viral load in Nlrp3R258W mice was lower than that in control mice. Conversely, neutrophil depletion in Nlrp3R258W mice compromised IAV clearance. Taken together, our results demonstrate a previously undescribed mechanism by which hyperactivation of the NLRP3 Inflammasome protects mice from IAV infection through IL-1ß mediated neutrophil recruitment, thus suggest that positively fine tuning the physiological function of NLRP3 inflammasome can be beneficial for a mammalian host against IAV challenge.

Nitroimidazole derivative incorporated liposomes for hypoxia-triggered drug delivery and enhanced therapeutic efficacy in patient-derived tumor xenografts.

Hypoxia is not merely a tumor microenvironment byproduct, but rather an active participant in tumor development, invasion, and metastasis. Hypoxia contributes to poor outcomes in tumor treatment and has currently emerged as an important therapeutic target. In this work, a facile hypoxia-responsive liposomal drug delivery system was developed by incorporating derivatized nitroimidazole into liposome membranes. Under hypoxic conditions, hypoxia-induced reductive metabolism of the nitroimidazole derivative facilitated disassembly of the liposomes for triggered drug release. The liposomes showed high sensitivity to hypoxia, even at the cellular level, and could release payload in an oxygen-dependent manner, leading to high cytotoxicity in hypoxic conditions. In vivo fluorescence imaging revealed that there was a selective release of the liposomes at the hypoxic tumor site. As a result, the liposomes exhibited enhanced therapeutic efficacy in treating a hypoxic tumor in both cell line-derived and clinically relevant patient-derived xenograft models. Thus, hypoxia-responsive liposomes are a promising drug delivery system for hypoxia targeted tumor therapy. STATEMENT OF SIGNIFICANCE: 1. A facile but smart hypoxia-responsive liposomal drug delivery system is developed by incorporating nitroimidazole derivative, one of representative hypoxia-responsive moieties, into phospholipid bilayer of the liposomes. 2. The liposomes show extremely high sensitivity to hypoxia and can selectively release payload in hypoxic cells and hypoxic tumor. 3. The liposomes show enhanced therapeutic efficacy not only in cell line-derived xenograft model but also in clinically relevant patient-derived xenograft model, indicating their promising prospect in clinical application.

Antiviral effects of ferric ammonium citrate.

Iron is an essential nutrient for cell survival and is crucial for DNA replication, mitochondrial function and erythropoiesis. However, the immunological role of iron in viral infections has not been well defined. Here we found the iron salt ferric ammonium citrate (FAC) inhibited Influenza A virus, HIV virus, Zika virus, and Enterovirus 71 (EV71) infections. Of note, both iron ion and citrate ion were required for the antiviral capability of FAC, as other iron salts and citrates did not exhibit viral inhibition. Mechanistically, FAC inhibited viral infection through inducing viral fusion and blocking endosomal viral release. These were further evidenced by the fact that FAC induced liposome aggregation and intracellular vesicle fusion, which was associated with a unique iron-dependent cell death. Our results demonstrate a novel antiviral function of FAC and suggest a therapeutic potential for iron in the control of viral infections.

Remodelling of the gut microbiota by hyperactive NLRP3 induces regulatory T cells to maintain homeostasis.

Inflammasomes are involved in gut homeostasis and inflammatory pathologies, but the role of NLRP3 inflammasome in these processes is not well understood. Cryopyrin-associated periodic syndrome (CAPS) patients with NLRP3 mutations have autoinflammation in skin, joints, and eyes, but not in the intestine. Here we show that the intestines of CAPS model mice carrying an Nlrp3 R258W mutation maintain homeostasis in the gut. Additionally, such mice are strongly resistant to experimental colitis and colorectal cancer; this is mainly through a remodelled gut microbiota with enhanced anti-inflammatory capacity due to increased induction of regulatory T cells (Tregs). Mechanistically, NLRP3R258W functions exclusively in the lamina propria mononuclear phagocytes to directly enhance IL-1ß but not IL-18 secretion. Increased IL-1ß boosts local antimicrobial peptides to facilitate microbiota remodelling. Our data show that NLRP3R258W-induced remodelling of the gut microbiota, induces local Tregs to maintain homeostasis and compensate for otherwise-detrimental intestinal inflammation.

Activation of NLRP3 Inflammasome by Advanced Glycation End Products Promotes Pancreatic Islet Damage.

Accumulation of advanced glycation end products (AGEs) contributes to ageing and age-related diseases, especially type 2 diabetes. The NLRP3 inflammasome, as a vital component of the innate immune system, is implicated in the pathogenesis of type 2 diabetes. However, the role of the NLRP3 inflammasome in AGE-induced pancreatic islet damage remains largely unclear. Results showed that administration of AGEs (120 mg/kg for 6 weeks) in C57BL/6J mice induced an abnormal response to glucose (as measured by glucose tolerance and insulin release), pancreatic ß-cell ultrastructural lesion, and cell death. These effects were associated with an excessive superoxide anion level, significant increased protein expression levels for NADPH oxidase 2 (NOX2), thioredoxin-interacting protein (TXNIP), NLRP3, and cleaved IL-1ß, enhanced caspase-1 activity, and a significant increase in the levels of TXNIP-NLRP3 protein interaction. Ablation of the NLRP3 inflammasome or treatment with antioxidant N-acetyl-cysteine (NAC) clearly ameliorated these effects. In conclusion, our results reveal a possible mechanism for AGE-induced pancreatic islet damage upon NLRP3 inflammasome activation.