TFTG: A comprehensive database for human transcription factors and their targets.

Transcription factors (TFs) are major contributors to gene transcription, especially in controlling cell-specific gene expression and disease occurrence and development. Uncovering the relationship between TFs and their target genes is critical to understanding the mechanism of action of TFs. With the development of high-throughput sequencing techniques, a large amount of TF-related data has accumulated, which can be used to identify their target genes. In this study, we developed TFTG (Transcription Factor and Target Genes) database (http://tf.liclab.net/TFTG), which aimed to provide a large number of available human TF-target gene resources by multiple strategies, besides performing a comprehensive functional and epigenetic annotations and regulatory analyses of TFs. We identified extensive available TF-target genes by collecting and processing TF-associated ChIP-seq datasets, perturbation RNA-seq datasets and motifs. We also obtained experimentally confirmed relationships between TF and target genes from available resources. Overall, the target genes of TFs were obtained through integrating the relevant data of various TFs as well as fourteen identification strategies. Meanwhile, TFTG was embedded with user-friendly search, analysis, browsing, downloading and visualization functions. TFTG is designed to be a convenient resource for exploring human TF-target gene regulations, which will be useful for most users in the TF and gene expression regulation research.

Rigid Fe(III) Chelate with Phosphonate Pendants: A Stable and Effective Extracellular MRI Contrast Agent.

A novel Fe(III) complex, Fe-tBPCDTA, was synthesized and explored as a potential contrast agent for MRI. Compared to established agents like Fe-EDTA and Fe-tCDTA, Fe-tBPCDTA exhibited moderate relaxivity (r1 = 1.17 s-1·mmol-1) due to its enhanced second-sphere mechanism. It also displayed improved kinetic inertness, lower cytotoxicity, and enhanced redox stability. In vivo studies demonstrated its function as an extracellular fluid agent, providing tumor contrast comparable to that of Gd-DTPA at a higher dosage. Complete renal clearance occurred within 24 h. These findings suggest Fe-tBPCDTA as a promising candidate for further development as a safe and effective extracellular MRI contrast agent.

Optical coherence elastography under homolateral parallel acoustic radiation force excitation for ocular elasticity quantification.

Alteration in the elastic properties of biological tissues may indicate changes in the structure and components. Acoustic radiation force optical coherence elastography (ARF-OCE) can assess the elastic properties of the ocular tissues non-invasively. However, coupling the ultrasound beam and the optical beam remains challenging. In this Letter, we proposed an OCE method incorporating homolateral parallel ARF excitation for measuring the elasticity of the ocular tissues. An acoustic-optic coupling unit was established to reflect the ultrasound beam while transmitting the light beam. The ARF excited the ocular tissue in the direction parallel to the light beam from the same side of the light beam. We demonstrated the method on the agar phantoms, the porcine cornea, and the porcine retina. The results show that the ARF-OCE method can measure the elasticity of the cornea and the retina, resulting in higher detection sensitivity and a more extensive scanning range.

Facile Synthesis of Rigid Binuclear Manganese Complexes for Magnetic Resonance Angiography and SLC39A14-Mediated Hepatic Imaging.

Manganese(II)-based contrast agents (MBCAs) are potential candidates for gadolinium-free enhanced magnetic resonance imaging (MRI). In this work, a rigid binuclear MBCA (Mn2-PhDTA2) with a zero-length linker was developed via facile synthetic routes, while the other dimer (Mn2-TPA-PhDTA2) with a longer rigid linker was also synthesized via more complex steps. Although the molecular weight of Mn2-PhDTA2 is lower than that of Mn2-TPA-PhDTA2, their T1 relaxivities are similar, being increased by over 71% compared to the mononuclear Mn-PhDTA. In the presence of serum albumin, the relaxivity of Mn2-PhDTA2 was slightly lower than that of Mn2-TPA-PhDTA2, possibly due to the lower affinity constant. The transmetalation reaction with copper(II) ions confirmed that Mn2-PhDTA2 has an ideal kinetic inertness with a dissociation half-life of approximately 10.4 h under physiological conditions. In the variable-temperature 17O NMR study, both Mn-PhDTA and Mn2-PhDTA2 demonstrated a similar estimated q close to 1, indicating the formation of monohydrated complexes with each manganese(II) ion. In addition, Mn2-PhDTA2 demonstrated a superior contrast enhancement to Mn-PhDTA in in vivo vascular and hepatic MRI and can be rapidly cleared through a dual hepatic and renal excretion pattern. The hepatic uptake mechanism of Mn2-PhDTA2 mediated by SLC39A14 was validated in cellular uptake studies.

Evaluating Oral Probiotic Supplements as Complementary Treatment in Advanced Lung Cancer Patients Receiving ICIs: A Prospective Real-World Study.

OBJECTIVE: To evaluate the effectiveness of oral probiotic supplements in patients undergoing immune checkpoint inhibitors (ICIs) for the treatment of advanced lung cancer. METHODS: This prospective real-world study enrolled patients with advanced lung cancer who were receiving ICIs as part of their treatment. The patients were divided into 2 groups: Group OPS received oral probiotic supplements along with ICIs, while Group C did not. The primary endpoint was progression-free survival (PFS). The secondary outcome measure was the objective response rate (ORR). RESULTS: A total of 253 patients were included in the study, with 71 patients in Group OPS and 182 patients in the control group (Group C). No significant differences were observed in the median PFS between the 2 groups for all patients. However, for small cell lung cancer (SCLC) patients, the median PFS was significantly better in the Group OPS compared to the Group C (11.1 months vs 7.0 months, P = .049). No significant differences were observed in median PFS for the non-small cell lung cancer (NSCLC) cohort between the 2 groups, but a trend towards better median PFS in Group OPS was noticed (16.5 months vs 12.3 months, P = .56). The ORR for the entire cohort was 58.0%. CONCLUSION: Oral probiotics supplements in combination with ICIs included regimen may improve the outcome in patients with advanced SCLC. The above points should be proved by further study.

This study examined whether the addition of oral probiotic supplements to ICIs could enhance the treatment of advanced lung cancer. A total of 253 patients with advanced lung cancer were involved in the study, with some receiving probiotics in combination with ICIs and others not. The findings revealed that patients with SCLC who took probiotics had significantly better PFS compared to those who did not. Additionally, there was a tendency towards enhanced PFS in NSCLC patients who received probiotics. In conclusion, the study indicates that incorporating oral probiotics with ICIs may lead to better outcomes for patients with advanced SCLC, although further research is necessary to validate these results.This real world study explores whether oral probiotic supplements along with immune checkpoint inhibitors (ICIs) can help treat advanced lung cancer. The study included 253 patients with advanced lung cancer receiving ICIs treatment, part of them taking probiotics along with ICIs. The results showed that patients with small cell lung cancer (SCLC) who took probiotics had better progression-free survival (PFS) compared to those who didn't. There was also a trend towards better PFS in non-small cell lung cancer (NSCLC) patients who took probiotics. Overall, the study suggests that taking oral probiotics along with ICIs may improve outcomes for patients with advanced SCLC, but more research is needed to confirm these findings.

Pillararenes: a new frontier in antimicrobial therapy.

Pillararenes have gained great interest among researchers in many fields due to their symmetric structure and facile functionalization. In this review, we summarize recent progress for pillararenes as antimicrobial agents, ranging from cationic pillararenes and peptide-modified pillararenes to sugar-functionalized pillararenes. Moreover, their structure-activity relationships are presented, and their mechanisms of action are discussed. As a state-of-the-art technology, their opportunities and outlook are also outlined in this emerging field. Overall, their potent inhibitory activity and high biocompatibility give them potential for the development of novel antimicrobial agents.

Nicotinamide riboside attenuates myocardial ischemia-reperfusion injury via regulating SIRT3/SOD2 signaling pathway.

Ischemic heart disease invariably leads to devastating damage to human health. Nicotinamide ribose (NR), as one of the precursors of NAD+ synthesis, has been discovered to exert a protective role in various neurological and cardiovascular disorders. Our findings demonstrated that pretreatment with 200 mg/kg NR for 3 h significantly reduced myocardial infarct area, decreased levels of CK-MB and LDH in serum, and improved cardiac function in the rats during myocardial ischemia-reperfusion (I/R) injury. Meanwhile, 0.5 mM NR also effectively increased the viability and decreased the LDH release of H9c2 cells during OGD/R. We had provided evidence that NR pretreatment could decrease mitochondrial reactive oxygen species (mtROS) production and MDA content, and enhance SOD activity, thereby mitigating mitochondrial damage and inhibiting apoptosis during myocardial I/R injury. Further investigations revealed that NR increased NAD+ content and upregulated SIRT3 protein expression in myocardium. Through using of SIRT3 small interfering RNA and the SIRT3 deacetylase activity inhibitor 3-TYP, we had confirmed that the cardioprotective effect of NR on cardiomyocytes was largely dependent on the inhibition of mitochondrial oxidative stress via SIRT3-SOD2 axis. Overall, our study suggested that exogenous supplementation with NR mitigated mitochondrial damage and inhibited apoptosis during myocardial I/R injury by reducing mitochondrial oxidative stress via SIRT3-SOD2-mtROS pathway.

Immunotherapy for patients with advanced non-small cell lung cancer harboring oncogenic driver alterations other than EGFR: a multicenter real-world analysis.

Background: The administration of immune checkpoint inhibitors (ICIs) in advanced non-small cell lung cancer (NSCLC) with oncogenic driver alterations other than epidermal growth factor receptor (EGFR) aroused a heated discussion. We thus aimed to evaluate ICI treatment in these patients in real-world routine clinical practice. Methods: A multicenter, retrospective study was conducted for NSCLC patients with at least one gene alteration (KRAS, HER2, BRAF, MET, RET, ALK, ROS1) receiving ICI monotherapy or combination treatment. The data regarding clinicopathologic characteristics, clinical efficacy, and safety were investigated. Results: A total of 216 patients were included, the median age was 60 years, 72.7% of patients were male, and 46.8% had a smoking history. The molecular alterations involved KRAS (n=95), HER2 (n=42), BRAF (n=22), MET (n=21), RET (n=14), ALK (n=14), and ROS1 (n=8); 56.5% of patients received immunotherapy in the first-line, and the rest 43.5% were treated as a second-line and above. For the entire cohort who received immunotherapy-based regimens in the first-line, the median progression-free survival (PFS) was 7.5 months and the median overall survival (OS) was 24.8 months. For the entire cohort who received immunotherapy-based regimens in the second-line and above, the median PFS was 4.7 months and median OS was 17.1 months. KRAS mutated NSCLC treated with immunotherapy-based regimens in the first-line setting had a median PFS and OS were 7.8 and 26.1 months, respectively. Moreover, the median PFS and OS of immunotherapy-based regimens for KRAS-mutant NSCLC that progressed after chemotherapy were 5.9 and 17.1 months. Programmed death ligand 1 (PD-L1) expression level was not consistently associated with response to immunotherapy across different gene alteration subsets. In the KRAS group, PD-L1 positivity [tumor proportion score (TPS) ≥1%] was associated with better PFS and OS according to the multivariate Cox analysis. No statistically significant association was found for smoking status, age, or gender with clinical efficacy in any gene group analyses. Conclusions: KRAS-mutant NSCLC could obtain clinical benefits from ICIs either for treatment-naive patients or those who have experienced progression after chemotherapy, and PD-L1 positive expression (TPS >1%) may be a potential positive predictor. For NSCLC with ALK, RET and ROS1 rearrangement, MET exon 14 skipping mutation, or BRAF V600E mutation, effectiveness of single or combined ICI therapy remains limited, therefore, targeted therapies should be considered prior to immunotherapy regimens. Future studies should address the investigation of better predictive biomarkers for immunotherapy response in oncogene-driven NSCLC.

Last Glacial Maximum pattern effects reduce climate sensitivity estimates.

Here, we show that the Last Glacial Maximum (LGM) provides a stronger constraint on equilibrium climate sensitivity (ECS), the global warming from increasing greenhouse gases, after accounting for temperature patterns. Feedbacks governing ECS depend on spatial patterns of surface temperature ("pattern effects"); hence, using the LGM to constrain future warming requires quantifying how temperature patterns produce different feedbacks during LGM cooling versus modern-day warming. Combining data assimilation reconstructions with atmospheric models, we show that the climate is more sensitive to LGM forcing because ice sheets amplify extratropical cooling where feedbacks are destabilizing. Accounting for LGM pattern effects yields a median modern-day ECS of 2.4°C, 66% range 1.7° to 3.5°C (1.4° to 5.0°C, 5 to 95%), from LGM evidence alone. Combining the LGM with other lines of evidence, the best estimate becomes 2.9°C, 66% range 2.4° to 3.5°C (2.1° to 4.1°C, 5 to 95%), substantially narrowing uncertainty compared to recent assessments.

Mitochondria-associated endoplasmic reticulum membranes involve in oxidative stress-induced intestinal barrier injury and mitochondrial dysfunction under diquat exposing.

Many factors induced by environmental toxicants have made oxidative stress a risk factor for the intestinal barrier injury and growth restriction, which is serious health threat for human and livestock and induces significant economic loss. It is well-known that diquat-induced oxidative stress is implicated in the intestinal barrier injury. Although some studies have shown that mitochondria are the primary target organelle of diquat, the underlying mechanism remains incompletely understood. Recently, mitochondria-associated endoplasmic reticulum membranes (MAMs) have aroused increasing concerns among scholars, which participate in mitochondrial dynamics and signal transduction. In this study, we investigated whether MAMs involved in intestinal barrier injury and mitochondrial dysfunction induced by diquat-induced oxidative stress in piglets and porcine intestinal epithelial cells (IPEC-J2 cells). The results showed that diquat induced growth restriction and impaired intestinal barrier. The mitochondrial reactive oxygen species (ROS) was increased and mitochondrial membrane potential was decreased following diquat exposure. The ultrastructure of mitochondria and MAMs was also disturbed. Meanwhile, diquat upregulated endoplasmic reticulum stress marker protein and activated PERK pathway. Furthermore, loosening MAMs alleviated intestinal barrier injury, decrease of antioxidant enzyme activity and mitochondrial dysfunction induced by diquat in IPEC-J2 cells, while tightening MAMs exacerbated diquat-induced mitochondrial dysfunction. These results suggested that MAMs may be associated with the intestinal barrier injury and mitochondrial dysfunction induced by diquat in the jejunum of piglets.

Functional characterization of Helicoverpa assulta CYP6B6 in insecticide metabolism.

The oriental tobacco budworm Helicoverpa assulta (Lepidoptera: Noctuidae) is a specialist pest that may cause serious damages to important crops such as chili pepper and tobacco. Various man-made insecticides have been applied to control the infestation of this pest. To understand how this pest copes with insecticides, it is required to identify key players involved in insecticide transformation. In this study, a P450 gene of CYP6B subfamily was identified in the oriental tobacco budworm, and its expression pattern was revealed. Moreover, the activities of HassCYP6B6 against 12 insecticides were explored using recombinant enzymes produced in the facile Escherichia coli. Data from metabolic experiments showed that HassCYP6B6 was able to metabolize conventional insecticides including organophosporates (diazinon, malathion, phoxim), carbamate propoxur, and pyrethroid esfenvalerate, while no significant metabolism was observed towards new-type pesticides such as neonicotinoids (acetamiprid, imidacloprid), diamides (chlorantraniliprole, cyantraniliprole), macrocyclic lactone (emamectin benzoate, ivermectin), and metaflumizone. Structures of metabolites were proposed based on mass spectrometry analyses. The results demonstrate that HassCYP6B6 plays important roles in the transformation of multiple insecticides via substrate-dependent catalytic mechanisms including dehydrogenation, hydroxylation and oxidative desulfurization. The findings have important applied implications for the usage of insecticides.

Predicting prognosis in intrahepatic cholangiocarcinoma by the histopathological features.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a highly heterogeneous liver tumor. The associations between histopathological feature and prognosis of ICC are limited. The present study aimed to investigate the prognostic significance of glandular structure and tumor budding in ICC. METHODS: Patients received radical hepatectomy for ICC were included. Glandular structure and tumor budding were detected by Hematoxylin-eosin staining. The Kaplan-Meier method and the Cox proportional hazards regression model were used to calculate the survival and hazard ratio. Based on the results of multivariate analysis, nomograms of OS and DFS were constructed. C-index and Akaike information criterion (AIC) were used to assess accuracy of models. RESULTS: A total of 323 ICC patients who underwent surgery were included in our study. Glandular structure was associated with worse overall survival (OS) [hazard ratio (HR): 2.033, 95% confidence interval (CI): 1.047 to 3.945] and disease-free survival (DFS) [HR: 1.854, 95% CI: 1.082 to 3.176]. High tumor budding was associated with worse DFS [HR: 1.636, 95%CI: 1.060 to 2.525]. Multivariate analysis suggested that glandular structure, tumor number, lymph node metastasis, and CA19-9 were independent risk factors for OS. Independent predictor factors for DFS were tumor budding, glandular structure, tumor number, and lymph node metastasis. The c-index (0.641 and 0.642) and AIC (957.69 and 1188.52) showed that nomograms of OS and DFS have good accuracy. CONCLUSION: High tumor budding and glandular structure are two important histopathological features that serve as prognostic factors for ICC patients undergoing hepatectomy.

High-performance asymmetric supercapacitors assembled with novel disc-like MnCo2O4 microstructures as advanced cathode material.

Herein, porous MnCo2O4 with disc-like (MnCo2O4-discs) and ring-like (MnCo2O4-rings) microstructures were respectively synthesized using an initial hydrothermal method at different temperatures and a calcination treatment in air. The electrochemical properties of these MnCo2O4 materials were investigated in three-electrode and two-electrode systems, and as such, MnCo2O4 presented a battery-like electrochemical response. The specific capacity of MnCo2O4-discs was determined to be 296.1C/g at 1 A/g, superior to 246.3C/g for MnCo2O4-rings. An asymmetric supercapacitor (ASC) was assembled with MnCo2O4 as the cathode and activated carbon (AC) as the anode to evaluate the potential for practical application. The MnCo2O4-discs//AC ASC exhibited an energy density (Ed) of 35.8 W h kg-1 at a power density (Pd) of 927.5 W kg-1. For the MnCo2O4-rings//AC ASC, an inferior Ed of 31.4 W h kg-1 under 890.9 W kg-1 was achieved. Furthermore, the two ASCs presented outstanding cyclic performance after 5000 cycles at 6 A/g. The exceptional properties of MnCo2O4 microstructures can be applied to the assembly of ASC devices, which can have promising potential for application in electrochemical energy storage. This synthetic method is straightforward, cost-effective, and can be extended to fabricate similar electrode materials with superior electrochemical performance.

Chiral Pyclen-Based Heptadentate Chelates as Highly Stable MRI Contrast Agents.

In recent years, pyclen-based complexes have attracted a great deal of interest as magnetic resonance imaging (MRI) contrast agents (CAs) and luminescent materials, as well as radiopharmaceuticals. Remarkably, gadopiclenol, a Gd(III) bishydrated complex featuring a pyclen-based heptadentate ligand, received approval as a novel contrast agent for clinical MRI application in 2022. To maximize stability and efficiency, two novel chiral pyclen-based chelators and their complexes were developed in this study. Gd-X-PCTA-2 showed significant enhancements in both thermodynamic and kinetic stabilities compared to those of the achiral parent derivative Gd-PCTA. 1H NMRD profiles reveal that both chiral gadolinium complexes (Gd-X-PCTA-1 and Gd-X-PCTA-2) have a higher relaxivity than Gd-PCTA, while variable-temperature 17O NMR studies show that the two inner-sphere water molecules have distinct residence times τMa and τMb. Furthermore, in vivo imaging demonstrates that Gd-X-PCTA-2 enhances the signal in the heart and kidneys of the mice, and the chiral Gd complexes exhibit the ability to distinguish between tumors and normal tissues in a 4T1 mouse model more efficiently than that of the clinical agent gadobutrol. Biodistribution studies show that Gd-PCTA and Gd-X-PCTA-2 are primarily cleared by a renal pathway, with 24 h residues of Gd-X-PCTA-2 in the liver and kidney being lower than those of Gd-PCTA.

Fever-induced acute sleep terrors in children and adolescents following SARS-CoV-2 infection.

OBJECTIVE: This study aims to provide physicians with insights into the clinical manifestations and outcomes of children and young adolescents experiencing sleep terrors following SARS-CoV-2 infection. METHODS: We enrolled patients who developed new onset sleep terrors after SARS-CoV-2infection fromDecember2022to April 2023 in the Xijing hospital, Xi'an, China. RESULTS: We enrolled six patients who experienced sleep terrors following SARS-CoV-2 infection. Out of these patients, five were children and only one was an adolescent, with a mean age of 9 years. Neuroimaging results were negative for all cases. Sleep terrors occurred during both the active course of COVID-19 illness and the recovery period in all patients. Symptoms included crying or screaming in terror, hyperactivity, inappropriate behavior and periods of mental confusion during sleep. These episodes typically occurred 40 min to 1 h after falling asleep. EEG monitoring confirmed two patients' episodes occurred during non-rapid eye movement (NREM) stage 3 sleep. The duration of sleep terrors ranged from 3mines to30 mines, with each patient experiencing 3-4 to 30-40 instances. Initially, the frequency of episodes was highest at 3-4 times per night, gradually decreasing to once a night, then once a week, until complete disappearance. No medical intervention was required. Clinical follow-up ranged from 6 to 12 months, with spontaneous remission occurring within 1 week to 2 months for different patients. CONCLUSION: SARS-CoV-2 infection may precipitate acute sleep terrors in children and adolescents. The course of these sleep terrors is generally benign, with all patients achieving spontaneous complete remission over time.

Targeting myeloperoxidase to stabilize unruptured aneurysm: an imaging-guided approach.

Inflammation plays a key role in pathogenesis and rupture of aneurysms. Non-invasively and dynamically monitoring aneurysm inflammation is critical. This study evaluated myeloperoxidase (MPO) as an imaging biomarker and therapeutic target for aneurysm inflammation using an elastase-induced rabbit model treated with or without 4-aminobenzoic acid hydrazide (ABAH), an irreversible inhibitor of MPO. Myeloperoxidase-sensitive magnetic resonance imaging (MRI) using Mn-TyrEDTA, a peroxidase activity-dependent contrast agent, revealed weak contrast enhancement in contralateral arteries and decreased contrast enhancement in aneurysm walls with ABAH treatment, indicating MPO activity decreased and inflammation mitigated. This was supported by reduced immune cell infiltration, matrix metalloproteinases (MMP-2 and - 9) activity, ROS production and arterial wall destruction on histology. Finally, the aneurysm expansion rate remained < 50% throughout the study in the ABAH(+) group, but increased gradually in the ABAH(-) group. Our results suggest that inhibition of MPO attenuated inflammation and expansion of experimental aneurysm and MPO-sensitive MRI showed promise as a noninvasive tool for monitoring aneurysm inflammation.

Presence of Multiple Genetic Mutations Related to Insecticide Resistance in Chinese Field Samples of Two Phthorimaea Pest Species.

Potatoes hold the distinction of being the largest non-cereal food crop globally. The application of insecticides has been the most common technology for pest control. The repeated use of synthetic insecticides of the same chemical class and frequent applications have resulted in the emergence of insecticide resistance. Two closely related pests that feed on potato crops are the potato tuber moth, Phthorimaea operculella, and the tomato leafminer, Phthorimaea absoluta (syn. Tuta absoluta). Previous studies indicated the existence of insecticide resistance to various classes of insecticides including organophosphates, carbamates, and pyrethroids in field populations of P. operculella and P. absoluta. However, the exact mechanisms of insecticide resistance in P. operculella and to a lesser extent P. absoluta remain still poorly understood. Detecting resistance genotypes is crucial for the prediction and management of insecticide resistance. In this study, we identified multiple genetic mutations related to insecticide resistance in two species of Phthorimaea. An unexpected genetic divergence on target-site mutations was observed between P. operculella and P. absoluta. Three mutations (A201S, L231V, and F290V) in Ace1 (acetylcholinesterase), four mutations (M918T, L925M, T928I, and L1014F) in VGSC (voltage-gated sodium channel), and one mutation (A301S) in RDL (GABA-gated chloride channel) have been detected with varying frequencies in Chinese P. absoluta field populations. In contrast, P. operculella field populations showed three mutations (F158Y, A201S, and L231V) in Ace1, one mutation (L1014F) in VGSC at a lower frequency, and no mutation in RDL. These findings suggest that pyrethroids, organophosphates, and carbamates are likely to be ineffective in controlling P. absoluta, but not P. operculella. These findings contributed to a deeper understanding of the presence of target-site mutations conferring resistance to commonly used (and cheap) classes of insecticides in two closely related potato pests. It is recommended to consider the resistance status of both pests for the implementation of resistance management strategies in potatoes.

Lipophilic Group-Modified Manganese(II)-Based Contrast Agents for Vascular and Hepatobiliary Magnetic Resonance Imaging.

Effective vascular and hepatic enhancement and better safety are the key drivers for exploring gadolinium-free hepatobiliary contrast agents. Herein, a facile strategy proposes that the high lipophilicity may be favorable to enhancing sequentially vascular and hepatobiliary signal intensity based on the structure-activity relationship that both hepatic uptake and interaction with serum albumins partly depend on lipophilicity. Therefore, 11 newly synthesized derivatives of manganese o-phenylenediamine-N,N,N',N'-tetraacetic acid (MnLs) were evaluated as vascular and hepatobiliary agents. The maximum signal intensities of the heart, liver, and kidneys were strongly correlated with log P, a key indicator of lipophilicity. The most lipophilic agent, MnL6, showed favorable relaxivity when binding with serum albumin, good vascular enhancement, rapid excretion, and reliable hepatobiliary phases comparable to a classic hepatobiliary agent, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) for in vivo liver tumor imaging. Inhibition experiments confirmed the hepatic targeting of MnL6 is mediated by organic anion-transporting polypeptides.

A tale of two fusion proteins: understanding the metastability of human respiratory syncytial virus and metapneumovirus and implications for rational design of uncleaved prefusion-closed trimers.

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) cause human respiratory diseases and are major targets for vaccine development. In this study, we designed uncleaved prefusion-closed (UFC) trimers for the fusion (F) proteins of both viruses by examining mutations critical to F metastability. For RSV, we assessed four previous prefusion F designs, including the first and second generations of DS-Cav1, SC-TM, and 847A. We then identified key mutations that can maintain prefusion F in a native-like, closed trimeric form (up to 76%) without introducing any interprotomer disulfide bond. For hMPV, we developed a stable UFC trimer with a truncated F2-F1 linkage and an interprotomer disulfide bond. Tens of UFC constructs were characterized by negative-stain electron microscopy (nsEM), x-ray crystallography (11 RSV-F and one hMPV-F structures), and antigenic profiling. Using an optimized RSV-F UFC trimer as bait, we identified three potent RSV neutralizing antibodies (NAbs) from a phage-displayed human antibody library, with a public NAb lineage targeting sites Ø and V and two cross-pneumovirus NAbs recognizing site III. In mouse immunization, rationally designed RSV-F and hMPV-F UFC trimers induced robust antibody responses with high neutralizing titers. Our study provides a foundation for future prefusion F-based RSV and hMPV vaccine development.