Harnessing the Lysosomal Sorting Signals of the Cation-Independent Mannose-6-Phosphate Receptor for Targeted Degradation of Membrane Proteins.

Membrane proteins are a crucial class of therapeutic targets that remain challenging to modulate using traditional occupancy-driven inhibition strategies or current proteolysis-targeting degradation approaches. Here, we report that the inherent endolysosomal sorting machinery can be harnessed for the targeted degradation of membrane proteins. A new degradation technique, termed signal-mediated lysosome-targeting chimeras (SignalTACs), was developed by genetically fusing the signaling motif from the cation-independent mannose-6-phosphate receptor (CI-M6PR) to a membrane protein binder. Antibody-based SignalTACs were constructed with the CI-M6PR signal peptides fused to the C-terminus of both heavy and light chains of IgG. We demonstrated the scope of this platform technology by degrading five pathogenesis-related membrane proteins, including HER2, EGFR, PD-L1, CD20, and CD71. Furthermore, two simplified constructs of SignalTACs, nanobody-based and peptide-based SignalTACs, were created and shown to promote the lysosomal degradation of target membrane proteins. Compared to the parent antibodies, SignalTACs exhibited significantly higher efficiency in inhibiting tumor cell growth both in vitro and in vivo. This work provides a simple, general, and robust strategy for degrading membrane proteins with molecular precision and may represent a powerful platform with broad research and therapeutic applications.

Different Performances of BF3, BCl3, and BBr3 in Hypervalent Iodine-Catalyzed Halogenations.

Herein, hypervalent iodine-catalyzed halogenation of aryl-activated alkenes using BX3 (X = Cl, Br) as the halogen source and activating reagents was reported. Various halogenated 1,3-oxazine/2-oxazoline derivatives were obtained in good-to-high yields. Using BF3 resulted in different substitute sites from BBr3 and BCl3 of the products, indicating different reactive intermediates and reaction pathways. The reaction underwent a "ligand coupling/oxidative addition/intermolecular nucleophilic attack/1,2-aryl migration/reductive elimination/intramolecular nucleophilic attack" cascade when BF3 was applied as the halogen source, while 1,2-aryl migration has "disappeared" when the halogen source was BBr3 or BCl3. Possible catalytic cycles were proposed, and DFT calculations were conducted to demonstrate the differences among BX3 (X = F, Cl, Br) in the hypervalent iodine-catalyzed halogenations.

Development, validation and application of a UHPLC-MS/MS method for quantification of the adiponectin-derived active peptide ADP355 in rat plasma.

A UHPLC-MS/MS method for the quantification of ADP355, an adiponectin-derived active peptide, was developed and validated. The extraction method employed simple protein precipitation using methanol and chromatographic separation was achieved on anAccucore™ RP-MS C18 column (100 × 2.1 mm, 2.6 µm, 80 Å), using 0.1% formic acid in both water and acetonitrile with gradient elution at the flow rate of 400 µl/min within 4.0 min. Detections were performed under positive ion mode with multiple reaction monitoring ion transitions m/z 1109.2 → 309.8 and 871.4 → 310.1 for ADP355 and Jt003 respectively at unit resolution. The linearity range of the calibration curve was 2-1,000 ng/ml with a lower limit detection of 0.5 ng/ml. The selectivity, linearity, precision, accuracy, recovery, matrix effect and stability were validated, and all items met the requirement of US Food and Drug Administration guidance. This method was successfully applied to an intravenous pharmacokinetic study of ADP355 in rats and the in-vitro stability in rat serum, plasma and whole blood was also assessed.

Visible-Light-Driven Redox Neutral Direct C-H Amination of Glycine Derivatives and Peptides with N-Acyloxyphthalimides.

A room temperature, visible-light-promoted and redox neutral direct C-H amination of glycine and peptides has been firstly accomplished by using N-acyloxyphthalimide or -succinimide as nitrogen-radical precursor. The present strategy provides ways to introduce functionalities such as N-acyloxyphthalimide or -succinimide specifically to terminal glycine segment of peptides. Herein, mild conditions and high functional-group tolerance allow the preparation of non-natural α-amino acids and modification of corresponding peptides in this way.

A CDR-based approach to generate covalent inhibitory antibody for human rhinovirus protease.

Covalent target modulation with small molecules has been emerging as a promising strategy for drug discovery. However, covalent inhibitory antibody remains unexplored due to the lack of efficient strategies to engineer antibody with desired bioactivity. Herein, we developed an intracellular selection method to generate covalent inhibitory antibody against human rhinovirus 14 (HRV14) 3C protease through unnatural amino acid mutagenesis along the heavy chain complementarity-determining region 3 (CDR-H3). A library of antibody mutants was thus constructed and screened in vivo through co-expression with the target protease. Using this screening strategy, six covalent antibodies with proximity-enabled bioactivity were identified, which were shown to covalently target HRV14-3C protease with high inhibitory potency and exquisite selectivity. Compared to structure-based rational design, this library-based screening method provides a simple and efficient way for the discovery and engineering of covalent antibody for enzyme inhibition.

Suzuki Cross-Coupling Reaction with Genetically Encoded Fluorosulfates for Fluorogenic Protein Labeling.

A palladium-catalyzed cross-coupling reaction with aryl halide functionalities has recently emerged as a valuable tool for protein modification. Herein, a new fluorogenic modification methodology for proteins, with genetically encoded fluorosulfate-l-tyrosine, which exhibits high efficiency and biocompatibility in bacterial cells as well as in aqueous medium, is described. Furthermore, the cross-coupling of 4-cyanophenylboronic acid on green fluorescent protein was shown to possess a unique fluorogenic property, which could open up the possibility of a responsive "off/on" switch with great potential to enable spectroscopic imaging of proteins with minimal background noise. Taken together, a convenient and efficient catalytic system has been developed that may provide broad utilities in protein visualization and live-cell imaging.

Protein labeling approach to improve lysosomal targeting and efficacy of antibody-drug conjugates.

An anti-EGFR nanobody was labeled at the C-terminus with a lysosome-sorting NPGY (Asn-Pro-Gly-Tyr) motif via sortase-mediated ligation to enhance the engagement of the clathrin-mediated endocytosis. The synergistic effects of NPGY motif and nona-arginine peptide were found to induce robust internalization and lysosomal trafficking, which in turn improved anti-tumor activity of an antibody-drug conjugate.

Rapeseed Protein-Derived Antioxidant Peptide RAP Ameliorates Nonalcoholic Steatohepatitis and Related Metabolic Disorders in Mice.

Rapeseed protein hydrolysates have recently shown in vitro antioxidant and anti-inflammatory activities. However, scant data exist about their in vivo activities. Here, we report that the peptide DHNNPQIR (hereinafter referred to as RAP-8), a bioactive peptide originated from rapeseed protein, exhibits excellent in vivo efficacy in mouse models of nonalcoholic steatohepatitis (NASH) and hepatic fibrosis. We demonstrated that RAP-8 significantly reduced hepatic steatosis and improved insulin resistance and lipid metabolism. Furthermore, RAP-8 showed markedly reduced hepatic inflammation, fibrosis, liver injury, and metabolic deterioration. In particular, RAP-8 directly suppressed fibrosis-associated gene expression, including α-smooth muscle actin (α-Sma) and collagen type I (Col-1α) in the liver of mice in vivo. In addtion, RAP-8 significantly decreased macrophage infiltration and reduced pro-inflammatory cytokines secretion. Finally, we found that RAP-8 administration significantly decreased oxidative stress-induced apoptosis in liver injury induced by CCl4. Therefore, our results suggest that RAP-8 could be available for treatment of NASH and NASH-related metabolic disorders as a potential therapeutic candidate.

Highly efficient regio-selective ring-opening nucleophilic fluorination of aziridines and azetidines: access to ß- or γ-fluorinated amino acid derivatives.

Herein, we have presented a facile and efficient method of ring-opening nucleophilic fluorination of aziridines, affording highly regio-selective ß-fluorinated amines. Firstly, the example of ring-opening hydrofluorination of azetidines was reported. Then, the Olah's reagent also provided a promising method for the construction of enantioenriched ß-fluoro-α-amino acid derivatives, which could be used for the preparation of peptide-based bioactive molecules.

Potent effects of amino acid scanned antimicrobial peptide Feleucin-K3 analogs against both multidrug-resistant strains and biofilms of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is particularly difficult to treat because it possesses a variety of resistance mechanisms and because it often forms biofilms. Antimicrobial peptides represent promising candidates for future templates of antibiotic-resistant bacterial infections due to their unique mechanism of antimicrobial action. In this study, we first found that the antimicrobial peptide Feleucin-K3 has potent antimicrobial activity against not only the standard strain of P. aeruginosa but also against the multidrug-resistant strains isolated from clinics. Then, the structure-activity relationship of the peptide was investigated using alanine and D-amino acid scanning. Among the analogs synthesized, FK-1D showed much more potent antimicrobial activity, superior stability, and very low toxicity, and it was able to permeabilize bacterial membranes. Furthermore, it exhibited significant anti-biofilm activity. More importantly, FK-1D showed excellent antimicrobial activity in vivo, especially against clinical multidrug-resistant bacteria, in contrast to ceftazidime. Our results suggested that FK-1D could be subjected to fixed-point modification in the first and fourth sites to further optimize its medicinal properties and potential as a lead compound for the treatment of infections caused by multidrug-resistant P. aeruginosa and the associated biofilms.

MgII -Catalyzed Desymmetrization Reaction of meso-Aziridines with Hydroxylamines: Synthesis of Novel Chiral 1,2-Diamine Skeletons.

A MgII -catalyzed desymmetrization reaction of meso-aziridines with hydroxylamines has been disclosed for the first time. A series of novel chiral 1,2-diamine skeletons were obtained in good yields and enantioselectivities. The reaction employed magnesium catalysis generated in situ from a simple oxazoline-OH chiral ligand. Obviously, the diverse structures of the obtained chiral 1,2-diamine compounds could allow them to be potential chiral ligands in future catalytic asymmetric synthesis studies.

Mg(II) -Mediated Catalytic Asymmetric Dearomatization (CADA) Reaction of ß-Naphthols with Dialkyl Acetylenedicarboxylates.

A Mg(II) -mediated catalytic asymmetric dearomatization (CADA) reaction of ß-naphthols has been developed. The reaction proceeds under ambient temperature and give a series of chiral trisubstituted olefins with good chemoselectivities, Z/E ratios, and excellent enantioselectivities. A fluorinated ß-naphthol was designed to generate chiral organofluorine skeletons through the current CADA reaction. Moreover, an interesting tandem cyclization reaction was observed in the following transformation process through an undiscovered intramolecular hydride transfer pathway.

Diastereoselective Synthesis of Biheterocyclic Tetrahydrothiophene Derivatives via Base-Catalyzed Cascade Michael-Aldol [3 + 2] Annulation of 1,4-Dithiane-2,5-diol with Maleimides.

A highly diastereoselective intermolecular [3 + 2] annulation of 1,4-dithiane-2,5-diol to maleimides has been developed by using DABCO as a catalyst, which provides a series of highly functionalized biheterocyclic tetrahydrothiophene derivatives containing tetrahydrothiophene and pyrolidine backbones in excellent yields and diastereoselectivities (up to 98% yield and >20:1 d.r.). The cascade Michael-aldol reaction is capable of tolerating organic solvents as well as water.

Development and Application of O-(Trimethylsilyl)aryl Fluorosulfates for the Synthesis of Arynes.

A class of o-(trimethylsilyl)aryl fluorosulfates was synthesized by a concise method and successfully used as aryne precursors for the first time. Different trapping agents such as azides, furans, and acyl acetoacetates could successfully react with the aryne precursors under mild conditions with good to excellent yields.

The roles and potential mechanisms of plant polysaccharides in liver diseases: a review.

Plant polysaccharides (PP) demonstrate a diverse array of biological and pharmacological properties. This comprehensive review aims to compile and present the multifaceted roles and underlying mechanisms of plant polysaccharides in various liver diseases. These diseases include non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), fibrosis, drug-induced liver injury (DILI), and hepatocellular carcinoma (HCC). This study aims to elucidate the intricate mechanisms and therapeutic potential of plant polysaccharides, shedding light on their significance and potential applications in the management and potential prevention of these liver conditions. An exhaustive literature search was conducted for this study, utilizing prominent databases such as PubMed, Web of Science, and CNKI. The search criteria focused on the formula "(plant polysaccharides liver disease) NOT (review)" was employed to ensure the inclusion of original research articles up to the year 2023. Relevant literature was extracted and analyzed from these databases. Plant polysaccharides exhibit promising pharmacological properties, particularly in the regulation of glucose and lipid metabolism and their anti-inflammatory and immunomodulatory effects. The ongoing progress of studies on the molecular mechanisms associated with polysaccharides will offer novel therapeutic strategies for the treatment of chronic liver diseases (CLDs).

Design and discovery of a highly potent ultralong-acting GLP-1 and glucagon co-agonist for attenuating renal fibrosis.

The role of co-agonists of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) in chronic kidney disease (CKD) remains unclear. Herein we found that GLP-1R and GCGR expression levels were lower in the kidneys of mice with CKD compared to healthy mice and were correlated with disease severity. Interestingly, GLP-1R or GCGR knockdown aggravated the progression of kidney injury in both diabetic db/db mice and non-diabetic mice undergoing unilateral ureteral obstruction (UUO). Based on the importance of GLP-1R and GCGR in CKD, we reported a novel monomeric peptide, 1907-B, with dual-agonism on both GLP-1R and GCGR. The data confirmed that 1907-B had a longer half-life than long-acting semaglutide in rats or cynomolgus monkeys (∼2-3 fold) and exhibited better therapeutic contribution to CKD than best-in-class monoagonists, semaglutide, or glucagon, in db/db mice and UUO mice. Various lock-of-function models, including selective pharmacological activation and genetic knockdown, confirmed that 1907-B's effects on ameliorating diabetic nephropathy in db/db mice, as well as inhibiting kidney fibrosis in UUO mice, were mediated through GLP-1 and glucagon signaling. These findings highlight that 1907-B, a novel GLP-1R and GCGR co-agonist, exerts multifactorial improvement in kidney injuries and is an effective and promising therapeutic option for CKD treatment.

Design and Synthesis of Novel Ultralong-Acting Peptides as EDP-EBP Interaction Inhibitors for Pulmonary Fibrosis Treatment.

The increased remodeling of the extracellular matrix (ECM) in pulmonary fibrosis (PF) generates bioactive ECM fragments called matricryptins, which include elastin-derived peptides (EDPs). The interaction between EDPs and their receptors, including elastin-binding protein (EBP), plays a crucial role in exacerbating fibrosis. Here, we present LXJ-02 for the first time, a novel ultralong-acting inhibitor that disrupts the EDPs/EBP peptide-protein interaction, promoting macrophages to secrete matrix metalloproteinase-12 (MMP-12), and showing great promise as a stable peptide. MMP-12 has traditionally been implicated in promoting inflammation and fibrosis in various acute and chronic diseases. However, we reveal a novel role of LXJ-02 that activates the macrophage-MMP-12 axis to increase MMP-12 expression and degrade ECM components like elastin. This leads to the preventing of PF while also improving EDP-EBP interaction. LXJ-02 effectively reverses PF in mouse models with minimal side effects, holding great promise as an excellent therapeutic agent for lung fibrosis.

Anticancer effects of a novel class rosin-derivatives with different mechanisms.

In this Letter, the anticancer activity of novel rosin-derivatives introducing indicated side chains at position C18 of dehydroabietic acid (DHAA) was reported. Gratifyingly, all of these derivatives showed significantly cytotoxicity toward diverse human carcinoma cell lines. We found the compound 4 could induce cell membrane damage at high concentration as well as cell apoptosis at low concentration. However, compound 5, attachment of quinidine to dehydroabietic acid via thiourea bond, only induced apoptotic cell death. In addition, all these active compounds induced apoptosis mainly through mitochondrial-dependent pathway. Interestingly, compound 5 exhibited the highest anticancer activity and little toxicity to normal cells compared with the other derivatives. Therefore, 5 merits further investigation as a potential agent for future anticancer treatment.

An organocatalytic asymmetric double Michael cascade reaction of unsaturated ketones and unsaturated pyrazolones: highly efficient synthesis of spiropyrazolone derivatives.

The first organocatalytic double Michael cascade reaction between unsaturated ketones and unsaturated pyrazolones has been developed which provides spiropyrazolone core structures containing two interval or three consecutive stereogenic centers with excellent diastereo- (>20:1) and enantioselectivities (up to 99% ee). Moreover, a pair of enantiomers and can be achieved via different catalysts.

Catalytic highly asymmetric 1,5(6)-selective cyclization reaction of α-hydroxyimino cyclic ketones: direct approach to ring-fused hydroxyimino dihydropyrans.

Herein, we have disclosed a catalytic asymmetric 1,5(6)-selective Michael/cyclization reaction of α-hydroxyimino cyclic ketones with γ,ß-unsaturated α-keto esters. Unlike the previous catalytic strategies, this reaction provides a convenient 1,5(6)-selective asymmetric pathway to access synthetically useful ring-fused dihydropyrans. In general, high levels of yield, enantio- and diastereoselectivity (up to 99% yield, >99% ee and >20 : 1 dr) were obtained.