Key gp120 Glycans Pose Roadblocks to the Rapid Development of VRC01-Class Antibodies in an HIV-1-Infected Chinese Donor.

VRC01-class antibodies neutralize diverse HIV-1 strains by targeting the conserved CD4-binding site. Despite extensive investigations, crucial events in the early stage of VRC01 development remain elusive. We demonstrated how VRC01-class antibodies emerged in a Chinese donor by antigen-specific single B cell sorting, structural and functional studies, and longitudinal antibody and virus repertoire analyses. A monoclonal antibody DRVIA7 with modest neutralizing breadth was isolated that displayed a subset of VRC01 signatures. X-ray and EM structures revealed a VRC01-like angle of approach, but less favorable interactions between the DRVIA7 light-chain CDR1 and the N terminus with N276 and V5 glycans of gp120. Although the DRVIA7 lineage was unable to acquire broad neutralization, longitudinal analysis revealed a repertoire-encoded VRC01 light-chain CDR3 signature and VRC01-like neutralizing heavy-chain precursors that rapidly matured within 2 years. Thus, light chain accommodation of the glycan shield should be taken into account in vaccine design targeting this conserved site of vulnerability.

Rapid and Sensitive Quantification of Bacterial Viability Using Ratiometric Fluorescence Sensing.

Bacterial viability assessment plays an important role in food-borne pathogen detection and antimicrobial drug development. Here, we first used GelRed as a DNA-binding stain for a bacterial viability assessment. It was found that live bacteria were able to exclude GelRed, which however could easily penetrate dead ones and be absorbed nonspecifically on the bacterial periplasm. Cations were used to reduce the nonspecific adsorption and greatly increase the red fluorescence ratio of dead to live bacteria. Combined with SYTO 9 (a membrane-permeable dye) for double-staining, a ratiometric fluorescent method was established. Using Escherichia coli O157:H7 as a bacteria model, the ratiometric fluorescent method can probe dead bacteria as low as 0.1%. A linear correlation between the ratiometric fluorescence and the theoretical ratio of dead bacteria was acquired, with a correlation coefficient R2 of 0.97. Advantages in sensitivity, accuracy, and safety of the GelRed/SYTO9-based ratiometric fluorescent method against traditional methods were demonstrated. The established method was successfully applied to the assessment of germicidal efficacy of different heat treatments. It was found that even 50 °C treatment could lead to the death of minor bacteria. The as-developed method has many potential applications in microbial researches, and we believe it could be expanded to the viability assessment of mammalian cells.

Insufficient secretion of pancreatic FGF21 is the toxicological mechanism and therapeutic target of asparaginase-associated pancreatitis.

Asparaginase-associated pancreatitis (AAP) is a severe and potentially life-threatening drug-induced pancreas targeted toxicity in the combined chemotherapy of acute lymphoblastic leukemia among children and adolescents. The toxicological mechanism of AAP is not yet clear, and there are no effective preventive and treatment measures available clinically. Fibroblast growth factor 21 (FGF21) is a secretory hormone that regulates lipid, glucose, and energy metabolism balance. Acinar tissue is the main source of pancreatic FGF21 protein and plays an important role in maintaining pancreatic metabolic balance. In this study, we found that the decrease of FGF21 in pancreas is closely related to AAP. Pegaspargase (1 IU/g) induces widespread edema and inflammatory infiltration in the pancreas of rats/mice. The specific expression of FGF21 in the acinar tissue of AAP rats was significantly downregulated. Asparaginase caused dysregulation of the ATF4/ATF3/FGF21 axis in acinar tissue or cells, and thus mediated the decrease of FGF21. It greatly activated ATF3 in the acinar, which competed with ATF4 for the Fgf21 promoter, thereby inhibiting the expression of FGF21. Pharmacological replacement of FGF21 (1 mg/kg) or PERK inhibitors (GSK2656157, 25 mg/kg) can significantly mitigate the pancreatic tissue damage and reduce markers of inflammation associated with AAP, representing potential strategies for the prevention and treatment of AAP.

Factors associated with the intrinsic capacity in older adults: A scoping review.

INTRODUCTION: In 2015, the term 'intrinsic capacity' (IC) was proposed by the World Health Organisation to promote healthy aging. However, the factors associated with IC are still discrepant and uncertain. AIM: We aim to synthesise the factors connected with IC. METHODS: This scoping review followed the five-stage framework of Arksey and O'Malley and was reported using PRISMA-ScR guidelines. RESULTS: In all, 29 articles were included. IC of older adults is associated with demographic characteristics, socioeconomic factors, disease conditions, behavioural factors, and biomarkers. Age, sex, marital status, occupation status, education, income/wealth, chronic diseases, hypertension, diabetes, disability, smoking status, alcohol consumption, and physical activity were emerged as important factors related to the IC of older adults. CONCLUSIONS: This review shows that IC is related to multiple factors. Understanding these factors can provide the healthcare personnel with the theoretical basis for intervening and managing IC in older adults. RELEVANCE TO CLINICAL PRACTICE: The influencing factors identified in the review help to guide older adults to maintain their own intrinsic capacity, thereby promoting their health and well-being. The modifiable factors also provide evidence for healthcare personnel to develop targeted intervention strategies to delay IC decline. NO PATIENT OR PUBLIC CONTRIBUTION: As this is a scoping review, no patient or public contributions are required.

Autophagy modulates the stability of Wee1 and cell cycle G2/M transition.

The mammalian cell cycle is divided into four sequential phases, namely G1 (Gap 1), S (synthesis), G2 (Gap 2), and M (mitosis). Wee1, whose turnover is tightly and finely regulated, is a well-known kinase serving as a gatekeeper for the G2/M transition. However, the mechanism underlying the turnover of Wee1 is not fully understood. Autophagy, a highly conserved cellular process, maintains cellular homeostasis by eliminating intracellular aggregations, damaged organelles, and individual proteins. In the present study, we found autophagy deficiency in mouse liver caused G2/M arrest in two mouse models, namely Fip200 and Atg7 liver-specific knockout mice. To uncover the link between autophagy deficiency and G2/M transition, we combined transcriptomic and proteomic analysis for liver samples from control and Atg7 liver-specific knockout mice. The data suggest that the inhibition of autophagy increases the protein level of Wee1 without any alteration of its mRNA abundance. Serum starvation, an autophagy stimulus, downregulates the protein level of Wee1 in vitro. In addition, the half-life of Wee1 is extended by the addition of chloroquine, an autophagy inhibitor. LC3, a central autophagic protein functioning in autophagy substrate selection and autophagosome biogenesis, interacts with Wee1 as assessed by co-immunoprecipitation assay. Furthermore, overexpression of Wee1 leads to G2/M arrest both in vitro and in vivo. Collectively, our data indicate that autophagy could degrade Wee1-a gatekeeper of the G2/M transition, whereas the inhibition of autophagy leads to the accumulation of Wee1 and causes G2/M arrest in mouse liver.

FGF4 protects the liver from nonalcoholic fatty liver disease by activating the AMP-activated protein kinase-Caspase 6 signal axis.

BACKGROUND AND AIMS: NAFLD represents an increasing health problem in association with obesity and diabetes with no effective pharmacotherapies. Growing evidence suggests that several FGFs play important roles in diverse aspects of liver pathophysiology. Here, we report a previously unappreciated role of FGF4 in the liver. APPROACH AND RESULTS: Expression of hepatic FGF4 is inversely associated with NAFLD pathological grades in both human patients and mouse models. Loss of hepatic Fgf4 aggravates hepatic steatosis and liver damage resulted from an obesogenic high-fat diet. By contrast, pharmacological administration of recombinant FGF4 mitigates hepatic steatosis, inflammation, liver damage, and fibrogenic markers in mouse livers induced to develop NAFLD and NASH under dietary challenges. Such beneficial effects of FGF4 are mediated predominantly by activating hepatic FGF receptor (FGFR) 4, which activates a downstream Ca2+ -Ca2+ /calmodulin-dependent protein kinase kinase beta-dependent AMP-activated protein kinase (AMPK)-Caspase 6 signal axis, leading to enhanced fatty acid oxidation, reduced hepatocellular apoptosis, and mitigation of liver damage. CONCLUSIONS: Our study identifies FGF4 as a stress-responsive regulator of liver pathophysiology that acts through an FGFR4-AMPK-Caspase 6 signal pathway, shedding light on strategies for treating NAFLD and associated liver pathologies.

RNA Interference against ATP as a Gene Therapy Approach for Prostate Cancer.

Chemotherapeutic agents targeting energy metabolism have not achieved satisfactory results in different types of tumors. Herein, we developed an RNA interference (RNAi) method against adenosine triphosphate (ATP) by constructing an interfering plasmid-expressing ATP-binding RNA aptamer, which notably inhibited the growth of prostate cancer cells through diminishing the availability of cytoplasmic ATP and impairing the homeostasis of energy metabolism, and both glycolysis and oxidative phosphorylation were suppressed after RNAi treatment. Further identifying the mechanism underlying the effects of ATP aptamer, we surprisingly found that it markedly reduced the activity of membrane ionic channels and membrane potential which led to the dysfunction of mitochondria, such as the decrease of mitochondrial number, reduction in the respiration rate, and decline of mitochondrial membrane potential and ATP production. Meanwhile, the shortage of ATP impeded the formation of lamellipodia that are essential for the movement of cells, consequently resulting in a significant reduction of cell migration. Both the downregulation of the phosphorylation of AMP-activated protein kinase (AMPK) and endoplasmic reticulum kinase (ERK) and diminishing of lamellipodium formation led to cell apoptosis as well as the inhibition of angiogenesis and invasion. In conclusion, as the first RNAi modality targeting the blocking of ATP consumption, the present method can disturb the respiratory chain and ATP pool, which provides a novel regime for tumor therapies..

Analysis of the spatiotemporal patterns and decoupling effects of China's water resource spatial equilibrium.

The significance of water resource spatial equilibrium (WRSE) research is to maximally remove the spatial restrictions of water on regional development, including social development, economic development and eco-environmental maintenance. Although great achievements have been made, national-scale WRSE research is rare; besides, the spatiotemporal patterns and decoupling effects of WRSE have been poorly studied in current research. Thus, the aim of this research is to measure the WRSE in China for the period 2008-2019 by using an improved coupling coordination model and to empirically analyse its distribution dynamics and decoupling effects. The results show that the WRSE status of China's 31 provincial administrative regions from 2008 to 2019 is at a moderate level. Based on the spatiotemporal patterns and decoupling effects analysis, areas in urgent need of improving WRSE status are identified, and tailored countermeasures are provided for each area. To our knowledge, this paper is the first nationwide study of the spatiotemporal patterns and decoupling effects of WRSE.

REM sleep behavior disorder correlates with constipation in de novo Chinese Parkinson's disease patients.

BACKGROUND: Constipation, rapid eye movement sleep behavior disorder (RBD) and hyposmia are common prodromal symptoms of Parkinson's disease (PD), and they may represent two distinct types of disease origin, from the body or the brain. Our study aimed to compare the clinical characteristics of de novo PD patients with and without constipation and identify which prodromal symptoms were associated with constipation. METHODS: A total of 111 de novo, drug-naïve Chinese PD patients were consecutively enrolled from Jan 2017 to Sept 2021. Patients were classified into PD with and without constipation based on item 5 of the Scales for Outcomes in Parkinson's disease-Autonomic Dysfunction (SCOPA-AUT). The demographic data, motor, and non-motor symptoms were compared between the two groups. The associated factors of constipation were analyzed by the multivariate logistic regression analysis. RESULTS: In total, 44.1% (n = 49) of de novo PD patients had constipation. PD patients with constipation were older (p = 0.028), had higher proportions of Hoehn and Yahr (H-Y) stage [Formula: see text] 2 (p = 0.002), clinical possible RBD (cpRBD) (p = 0.002) and depression (p = 0.023), as well as marginal increase of hyposmia (p = 0.058) and freezing of gait (p = 0.069). After adjusting for H-Y stage and other confounding factors, cpRBD (OR = 3.508, p = 0.009), rather than hyposmia or depression, was closely related to constipation in de novo Chinese PD patients. CONCLUSIONS: RBD is closely associated with constipation in de novo Chinese PD patients. Our results support the theory that prodromal symptoms that represent the same pathological origin are closely related to each other.

Does information disclosure among public hospitals stimulate medical cost change efforts? A pilot study in Shanghai.

BACKGROUND: In 2013, the Shanghai Hospital Development Center issued a policy to advocate public hospitals to report their information about costs on diseases. The objective was to evaluate the impact of interhospital disclosure of costs on diseases on medical costs and compare costs per case following information disclosure between hospitals of different rankings. METHODS: The study uses the hospital-level performance report issued by Shanghai Hospital Development Center in the fourth quarter of 2013, which covers quarterly aggregated hospital-level discharge data from 14 tertiary public hospitals participating in thyroid malignant tumors and colorectal malignant tumors information disclosure from the first quarter of 2012 to the third quarter of 2020. An interrupted time series model with segmented regression analysis is employed to examine changes in quarterly trends with respect to costs per case and length of stay before and after information disclosure. We identified high- and low-cost hospitals by ranking them on a costs per case basis per disease group. RESULTS: This research identified significant differences in cost changes for thyroid malignant tumors and colorectal malignant tumors between hospitals after disclosing information. A hospital's discharge costs per case for thyroid malignant tumors increased significantly among top-cost hospitals (1629.251 RMB, P = 0.019), while decreased for thyroid and colorectal malignant tumors among low-cost hospitals (-1504.189 RMB, P = 0.003; -6511.650 RMB, P = 0.024, respectively). CONCLUSION: Our findings indicate that information disclosure of costs on diseases results in changes in discharge costs per case. And low-cost hospitals continued to maintain their leading edge, whereas the high-cost hospitals changed their position in the industry by reducing discharge costs per case after information disclosure.

Variations in the impact of the new case-based payment reform on medical costs, length of stay, and quality across different hospitals in China: an interrupted time series analysis.

BACKGROUND: In 2018, an innovative case-based payment scheme called Diagnosis-Intervention Packet (DIP) was piloted in a large developed city in southern China. This study aimed to investigate the impact of the new payment method on total medical expenditure per case, length of stay (LOS), and in-hospital mortality rate across different hospitals. METHODS: We used the de-identified patient-level discharge data of hospitalized patients from 2016 to 2019 in our study city. The interrupted time series model was used to examine the impact of the DIP payment reform on inflation-adjusted total expenditure per case, LOS, and in-hospital mortality rate across different hospitals, which were stratified into different hospital ownerships (public and private) and hospital levels (tertiary, secondary, and primary). RESULTS: We included 2.08 million and 2.98 million discharge cases of insured patients before and after the DIP payment reform, respectively. The DIP payment reform resulted in a significant increase of the monthly trend of adjusted total expenditure per case in public (1.1%, P = 0.000), tertiary (0.6%, P = 0.000), secondary (0.4%, P = 0.047) and primary hospitals (0.9%, P = 0.039). The monthly trend of LOS increased significantly in public (0.022 days, P = 0.041) and primary (0.235 days, P = 0.032) hospitals. The monthly trend of in-hospital mortality rate decreased significantly in private (0.083 percentage points, P = 0.002) and secondary (0.037 percentage points, P = 0.002) hospitals. CONCLUSIONS: We conclude that implementing the DIP payment reform yields inconsistent consequences across different hospitals. DIP reform encouraged public hospitals and high-level hospitals to treat patients with higher illness severities and requiring high treatment intensity, resulting in a significant increase in total expenditure per case. The inconsistencies between public and private hospitals may be attributed to their different baseline levels prior to the reform and their different responses to the incentives created by the reform.

How do inpatients' costs, length of stay, and quality of care vary across age groups after a new case-based payment reform in China? An interrupted time series analysis.

CONTEXT: A patient classification-based payment system called diagnosis-intervention packet (DIP) was piloted in a large city in southeast China in 2018. OBJECTIVE: This study evaluates the impact of DIP payment reform on total costs, out-of-pocket (OOP) payments, length of stay (LOS), and quality of care in hospitalised patients of different age. METHODS: An interrupted time series model was employed to examine the monthly trend changes of outcome variables before and after the DIP reform in adult patients, who were stratified into a younger (18-64 years) and an older group (≥ 65 years), further stratified into young-old (65-79 years) and oldest-old (≥ 80 years) groups. RESULTS: The adjusted monthly trend of costs per case significantly increased in the older adults (0.5%, P = 0.002) and oldest-old group (0.6%, P = 0.015). The adjusted monthly trend of average LOS decreased in the younger and young-old groups (monthly slope change: -0.058 days, P = 0.035; -0.025 days, P = 0.024, respectively), and increased in the oldest-old group (monthly slope change: 0.107 days, P = 0.030) significantly. The changes of adjusted monthly trends of in-hospital mortality rate were not significant in all age groups. CONCLUSION: Implementation of the DIP payment reform associated with increase in total costs per case in the older and oldest-old groups, and reduction in LOS in the younger and young-old groups without deteriorating quality of care.

Evaluation and prediction of water-energy-carbon nexus efficiency in China based on a new multiregional input-output perspective.

Water, energy and carbon are three basic environmental factors that affect countries. An in-depth study of the water-energy-carbon (WEC) nexus is of great significance for realizing regional sustainable development. However, at present, research on the evaluation and prediction of large-scale WEC nexus based on multiple perspectives is not sufficiently mature, especially the prediction of WEC nexus efficiency. This study evaluates and predicts the WEC nexus efficiency in 30 regions of China based on a new comprehensive perspective. The WEC efficiency and the slack variables of 30 regions from 2006 to 2020 were calculated by using the slack-based measure model. The 30 regions were divided into 4 efficiency groups using hierarchical cluster analysis. Efficiency trends in 2006-2020 were analyzed for specific regions. The coupling interaction between the WEC nexus is studied based on the perspective of the coupling degree and coupling coordination degree. More importantly, this study is the first to quantitatively predict the WEC efficiency of 30 regions in China from 2021 to 2030, using the rank set pair analysis model. The following results were obtained in this paper. The WEC efficiency has a slow decreasing trend in 2006-2020. A total of 16.7% and 33.3% of the regions are in the extreme and high coupling coordination stages, respectively, and are mainly concentrated in the northern and southeastern parts of China. Fifty percent of the regions have moderate coupling coordination, mainly concentrated in the central and southern regions. From 2021 to 2030, the WEC efficiency of Beijing, Tianjin and Qinghai will remain at a high level; the WEC efficiency of Shandong and other regions will remain at a low level; and 70% of the regions' water efficiency will remain low. This paper has important guiding significance for promoting the regional WEC nexus balance and sustainable development of the economy, society and environment. According to the characteristics of the four efficiency groups, some valuable suggestions on regional sustainable development are proposed.

Insight into the Molecular Mechanism for Enhanced Longevity of Supramolecular Vesicular Photocatalysts.

Supramolecular self-assembly is a promising strategy for stabilizing the photo-sensitive components in photocatalysis. However, the underlying correlation between the enhanced photostability and supramolecular structure at the molecular level has not yet been fully understood. Herein, we develop a biomimetic vesicular membrane-based polyporphyrin photocatalyst exhibiting excellent photocatalytic stability with at least activity time of 240 h in hydrogen generation. Time-domain ab initio modelling together with transient absorption spectroscopy, visual frontier orbitals and Gibbs free energy calculation disclose that the ordered aggregation of porphyrin units in the vesicle membrane facilitates "hot" electron relaxation and the rapid dissipation of photo-generated charges, thereby contributing to the longevity. This work deepens the molecular-level understanding on photostability and photocatalytic mechanism of supramolecular photocatalysts.

Direct Excitation of Aldehyde to Activate the C(sp2 )-H Bond by Cobaloxime Catalysis toward Fluorenones Synthesis with Hydrogen Evolution.

A new way to form fluorenones via the direct excitation of substrates instead of photocatalyst to activate the C(sp2 )-H bond under redox-neutral condition is reported. Our design relies on the photoexcited aromatic aldehyde intermediates that can be intercepted by cobaloxime catalyst through single electron transfer for following ß-H elimination. The generation of acyl radical and successful interception by a metal catalyst cobaloxime avoid the use of a photocatalyst and stoichiometric external oxidants, affording a series of highly substituted fluorenones, including six-membered ketones, such as xanthone and thioxanthone derivatives in good to excellent yields, and with hydrogen as the only byproduct. This catalytic system features a readily available metal catalyst, mild reaction conditions and broad substrate scope, in which sunlight reaction and scale-up experiments by continuous-flow approach make the new methodology sustainable and amenable for potentially operational procedures.

Transition-Metal-Free, Site-Selective C-F Arylation of Polyfluoroarenes via Electrophotocatalysis.

Direct CAr-F arylation is effective and sustainable for synthesis of polyfluorobiaryls with different degrees of fluorination, which are important motifs in medical and material chemistry. However, with no aid of transition metals, the engagement of CAr-F bond activation has proved difficult. Herein, an unprecedented transition-metal-free strategy is reported for site-selective CAr-F arylation of polyfluoroarenes with simple (het)arenes. By merging N,N-bis(2,6-diisopropylphenyl)perylene-3,4,9,10-bis(dicarboximide)-catalyzed electrophotocatalytic reduction and anodic nitroxyl radical oxidation in an electrophotocatalytic cell, various polyfluoroaromatics (2F-6F and 8F), especially inactive partially fluorinated aromatics, undergo sacrificial-reagents-free C-F bond arylation with high regioselectivity, and the yields are comparable to those for reported transition-metal catalysis. This atom- and step-economic protocol features a paired electrocatalysis with organic mediators in both cathodic and anodic processes. The broad substrate scope and good functional-group compatibility highlight the merits of this operationally simple strategy. Moreover, the easy gram-scale synthesis and late-stage functionalization collectively advocate for the practical value, which would promote the vigorous development of fluorine chemistry.

TET2-mediated Cdkn2A DNA hydroxymethylation in midbrain dopaminergic neuron injury of Parkinson's disease.

It has been reported that abnormal epigenetic modification is associated with the occurrence of Parkinson's disease (PD). Here, we found that a ten-eleven translocation 2 (TET2), a staff of the DNA hydroxylases family, was increased in dopaminergic neurons in vitro and in vivo. Genome-wide mapping of DNA 5-hydroxymethylcytosine (5-hmC)-sequencing has revealed an aberrant epigenome 5-hmC landscape in 1-methyl-4-phenylpyridinium iodide (MPP+)-induced SH-SY5Y cells. The TET family of DNA hydroxylases could reverse DNA methylation by oxidization of 5-methylcytosine (5-mC) to 5-hmC. However, the relationship between modification of DNA hydroxymethylation and the pathogenesis of PD is not clear. According to the results of 5-hmC-sequencing studies, 5-hmC was associated with gene-rich regions in the genomes related to cell cycle, especially gene-cyclin-dependent kinase inhibitor 2A (Cdkn2A). Downregulation of TET2 expression could significantly rescue MPP+-stimulated SH-SY5Y cell damage and cell cycle arrest. Meanwhile, knockdown of Tet2 expression in the substantia nigra pars compacta of MPTP-induced PD mice resulted in attenuated MPTP-induced motor deficits and dopaminergic neuronal injury via p16 suppression. In this study, we demonstrated a critical function of TET2 in PD development via the CDKN2A activity-dependent epigenetic pathway, suggesting a potential new strategy for epigenetic therapy.

Membrane Env Liposomes Facilitate Immunization with Multivalent Full-Length HIV Spikes.

A major goal of HIV vaccine design is to elicit broadly neutralizing antibodies (bNAbs). Such bNAbs target HIV's trimeric, membrane-embedded envelope glycoprotein spikes (mEnv). Soluble Env (sEnv) trimers have been used as vaccines, but engineering sEnvs for stability, multivalency, and desired antigenicity is problematic and deletes key neutralizing epitopes on glycoprotein 41 (gp41) while creating neoepitopes that elicit unwanted antibodies. Meanwhile, multivalent mEnv vaccines are challenging to develop due to trimer instability and low mEnv copy number amid other extraneous proteins on virus-like particles. Here, we describe a multivalent mEnv vaccine platform that does not require protein engineering or extraneous proteins. mEnv trimers were fixed, purified, and combined with naked liposomes in mild detergent. On removal of detergent, mEnv spikes were observed embedded in liposome particles (mean diameter, 133 nm) in correct orientation. These particles were recognized by HIV bNAbs and not non-NAbs and are designated mEnv liposomes (MELs). Following a sequential immunization scheme in rabbits, MELs elicited antibodies that neutralized tier 2 HIV isolates. Analysis of serum antibody specificities, including those to epitopes involving a missing conserved N-glycosylation site at position 197 near the CD4 binding site on two of the immunogens, provides clues on how NAb responses can be improved with modified immunogens. In sum, MELs are a biochemically defined platform that enables rational immunization strategies to elicit HIV bNAbs using multimerized mEnv. IMPORTANCE A vaccine that induced broadly neutralizing antibodies against HIV would likely end the AIDS pandemic. Such antibodies target membrane-embedded envelope glycoprotein spikes (mEnv) that HIV uses to enter cells. Due to HIV Env's low expression and instability, soluble stabilized Env trimers have been used as vaccine candidates, but these have an altered base that disrupts targets of HIV broadly neutralizing antibodies that bind near the membrane and are not available for all HIV isolates. Here, we describe membrane Env liposomes (MELs) that display a multivalent array of stable mEnvs on liposome particles. MELs showed the expected antibody recognition properties, including targeting parts of mEnv missing on soluble Envs. Immunization with MELs elicited antibodies that neutralized diverse HIV isolates. The MEL platform facilitates vaccine development with potentially any HIV Env at high valency, and a similar approach may be useful for eliciting antibodies to membrane-embedded targets of therapeutic interest.

HIV-1 gp120-CD4-Induced Antibody Complex Elicits CD4 Binding Site-Specific Antibody Response in Mice.

Elicitation of broadly neutralizing Ab (bNAb) responses toward the conserved HIV-1 envelope (Env) CD4 binding site (CD4bs) by vaccination is an important goal for vaccine development and yet to be achieved. The outcome of previous immunogenicity studies suggests that the limited accessibility of the CD4bs and the presence of predominant nonneutralizing determinants (nND) on Env may impede the elicitation of bNAbs and their precursors by vaccination. In this study, we designed a panel of novel immunogens that 1) preferentially expose the CD4bs by selective elimination of glycosylation sites flanking the CD4bs, and 2) minimize the nND immune response by engineering fusion proteins consisting of gp120 Core and one or two CD4-induced (CD4i) mAbs for masking nND epitopes, referred to as gp120-CD4i fusion proteins. As expected, the fusion proteins possess improved antigenicity with retained affinity for VRC01-class, CD4bs-directed bNAbs and dampened affinity for nonneutralizing Abs. We immunized C57BL/6 mice with these fusion proteins and found that overall the fusion proteins elicit more focused CD4bs Ab response than prototypical gp120 Core by serological analysis. Consistently, we found that mice immunized with selected gp120-CD4i fusion proteins have higher frequencies of germinal center-activated B cells and CD4bs-directed memory B cells than those inoculated with parental immunogens. We isolated three mAbs from mice immunized with selected gp120-CD4i fusion proteins and found that their footprints on Env are similar to VRC01-class bNAbs. Thus, using gp120-CD4i fusion proteins with selective glycan deletion as immunogens could focus Ab response toward CD4bs epitope.

Discovery of cinnamamide-barbiturate hybrids as a novel class of Nrf2 activator against myocardial ischemia/reperfusion injury.

Myocardial ischemia/reperfusion (MI/R) has been a challenge for global public health. Activation of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling could attenuate MI/R injury by maintaining cell redox balance and reducing oxidative damage. Cinnamamide derivatives have been proven to be a class of potential Nrf2 activators and cardioprotective agents. The development of novel cinnamamide derivatives to combat oxidative stress in cardiomyocytes is highly desirable. In this study, twenty-three cinnamamide-barbiturate hybrids were studied. Cell-based assays showed that most of the compounds exhibited excellent protective activity against H2O2-induced oxidative injury in H9c2 cells. Notably, compound 7w, which had the highest activity and low cytotoxicity, was demonstrated to remarkably reduce intracellular ROS accumulation by activating the mRNA expression of Nrf2 and its downstream antioxidant gene HO-1, indicating a novel promising antioxidant and Nrf2 activator. The probable binding mode between protein Keap1 and compound 7w was also studied via molecule docking. Furthermore, we found that the administration of compound 7w could significantly reduce the cardiac infarct size and improve the cardiac function against MI/R injury in rats, as well as decrease cardiac oxidative stress. Taken together, we report, for the first time, that cinnamamide-barbiturate hybrids are a novel class of potential cardioprotective agents. The excellent cardioprotective action of such compounds rely on enhancing the endogenous antioxidative system by upregulating the Nrf2 signaling pathway in vitro and in vivo against MI/R damage. These findings provide a new perspective for designing cinnamamide-barbiturate hybrids as a novel class of Nrf2 activator against cardiovascular diseases.