Covalent targeted radioligands potentiate radionuclide therapy.

Targeted radionuclide therapy, in which radiopharmaceuticals deliver potent radionuclides to tumours for localized irradiation, has addressed unmet clinical needs and improved outcomes for patients with cancer1-4. A therapeutic radiopharmaceutical must achieve both sustainable tumour targeting and fast clearance from healthy tissue, which remains a major challenge5,6. A targeted ligation strategy that selectively fixes the radiopharmaceutical to the target protein in the tumour would be an ideal solution. Here we installed a sulfur (VI) fluoride exchange (SuFEx) chemistry-based linker on radiopharmaceuticals to prevent excessively fast tumour clearance. When the engineered radiopharmaceutical binds to the tumour-specific protein, the system undergoes a binding-to-ligation transition and readily conjugates to the tyrosine residues through the 'click' SuFEx reaction. The application of this strategy to a fibroblast activation protein (FAP) inhibitor (FAPI) triggered more than 80% covalent binding to the protein and almost no dissociation for six days. In mice, SuFEx-engineered FAPI showed 257% greater tumour uptake than did the original FAPI, and increased tumour retention by 13-fold. The uptake in healthy tissues was rapidly cleared. In a pilot imaging study, this strategy identified more tumour lesions in patients with cancer than did other methods. SuFEx-engineered FAPI also successfully achieved targeted ß- and α-radionuclide therapy, causing nearly complete tumour regression in mice. Another SuFEx-engineered radioligand that targets prostate-specific membrane antigen (PSMA) also showed enhanced therapeutic efficacy. Considering the broad scope of proteins that can potentially be ligated to SuFEx warheads, it might be possible to adapt this strategy to other cancer targets.

WTAP-induced N6-methyladenosine of PD-L1 blocked T-cell-mediated antitumor activity under hypoxia in colorectal cancer.

N6-Methyladenosine (m6A) is a important process regulating gene expression post-transcriptionally. Programmed death ligand 1 (PD-L1) is a major immune inhibitive checkpoint that facilitates immune evasion and is expressed in tumor cells. In this research we discovered that Wilms' tumor 1-associated protein (WTAP) degradation caused by ubiquitin-mediated cleavage in cancer cells (colorectal cancer, CRC) under hypoxia was inhibited by Pumilio homolog 1 (PUM1) directly bound to WTAP. WTAP enhanced PD-L1 expression in a way that was m6A-dependent. m6A "reader," Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) identified methylated PD-L1 transcripts and subsequently fixed its mRNA. Additionally, we found that T-cell proliferation and its cancer cell-killing effects were prevented by overexpression of WTAP in vitro and in vivo. Overexpression prevented T cells from proliferating and killing CRC by maintaining the expression of PD-L1. Further evidence supporting the WTAP-PD-L1 regulatory axis was found in human CRC and organoid tissues. Tumors with high WTAP levels appeared more responsive to anti-PD1 immunotherapy, when analyzing samples from patients undergoing treatment. Overall, our findings demonstrated a novel PD-L1 regulatory mechanism by WTAP-induced mRNA epigenetic regulation and the possible application of targeting WTAP as immunotherapy for tumor hypoxia.

A bis-boron boramino acid PET tracer for brain tumor diagnosis.

PURPOSE: Boramino acids are a class of amino acid biomimics that replace the carboxylate group with trifluoroborate and can achieve the 18F-labeled positron emission tomography (PET) and boron neutron capture therapy (BNCT) with identical chemical structure. METHODS: This study reports a trifluoroborate-derived boronophenylalanine (BBPA), a derived boronophenylalanine (BPA) for BNCT, as a promising PET tracer for tumor imaging. RESULTS: Competition inhibition assays in cancer cells suggested the cell accumulation of [18F]BBPA is through large neutral amino acid transporter type-1 (LAT-1). Of note, [18F]BBPA is a pan-cancer probe that shows notable tumor uptake in B16-F10 tumor-bearing mice. In the patients with gliomas and metastatic brain tumors, [18F]BBPA-PET shows good tumor uptake and notable tumor-to-normal brain ratio (T/N ratio, 18.7 ± 5.5, n = 11), higher than common amino acid PET tracers. The [18F]BBPA-PET quantitative parameters exhibited no difference in diverse contrast-enhanced status (P = 0.115-0.687) suggesting the [18F]BBPA uptake was independent from MRI contrast-enhancement. CONCLUSION: This study outlines a clinical trial with [18F]BBPA to achieve higher tumor-specific accumulation for PET, provides a potential technique for brain tumor diagnosis, and might facilitate the BNCT of brain tumors.

Epidemiological characteristics of patients with Hutchinson-Gilford progeria syndrome and progeroid laminopathies in China.

BACKGROUND: Hutchinson-Gilford progeria syndrome (HGPS) and progeroid laminopathies (PL) are extremely rare genetic diseases with extremely poor prognoses. This study aims to investigate the epidemiological and genotypic characteristics of patients with HGPS/PL in China. METHODS: Using a cross-sectional study design, general characteristics and genotypic data of 46 patients with HGPS/PL from 17 provinces in China were analyzed. RESULTS: Among the 46 patients with HGPS/PL, 20 patients are HGPS, and the rest are PL; the identified total prevalence of HGPS/PL is 1/23 million. Among 42 patients with gene reports, 3 carried compound heterozygous mutations in the ZMPSTE24 while the other 39 carried LMNA mutations. Among PL, LMNA c.1579 C > T homozygous mutation was the most common. The onset of classic genotype HGPS is skin sclerosis in the first month after birth. The primary clinical manifestations of PL patients include skin abnormalities, growth retardation, and joint stiffness. The median age of onset for PL was 12 (6,12) months. CONCLUSIONS: In China, the identified total prevalence of HGPS/PL is 1/23 million. 92.8% of the genetic mutations of HGPS/PL were located in LMNA, and the rest in ZMPSTE24. Most patients of HGPS/PL have skin abnormalities as the earliest manifestation. Compared to PL, the classic genotype HGPS starts earlier. IMPACT STATEMENT: Hutchinson-Gilford progeria syndrome (HGPS) and progeroid laminopathies (PL) are extremely rare genetic diseases with extremely poor prognoses. To date, there is a paucity of epidemiological data related to HGPS/PL in China. This study first examined the genotypic, phenotypic, and prevalence characteristics of 40-50% of the cases of HGPS/PL in mainland China through a collaborative international registry effort. In China, the identified total prevalence of HGPS/PL is 1/23 million. 92.8% of the genetic mutations of HGPS/PL are located in LMNA. LMNA c.1579 C > T homozygous mutations are the most common form of gene mutations among the Chinese PL population.

Efficient Catalyst-Free One-Pot Synthesis of Polysaccharide-Polypeptide Hydrogels in Aqueous Solution.

The preparation of polysaccharide-peptide hydrogels usually involves multiple synthetic steps, thus reducing the effectiveness and practicality of these approaches. Inspired by recent discoveries in aqueous N-carboxyanhydride (NCA) ring-opening polymerization (ROP) and ring-opening polymerization-induced nanogelation, we present an aqueous one-pot strategy to prepare polysaccharide-polypeptide hydrogels. In this study, water-soluble polysaccharide carboxymethyl chitosan is used as the macromolecular initiator to prepare polysaccharide-polypeptide copolymers through the aqueous ROP of NCA. The catalyst-free approach afforded hydrogels with properties that could be controlled by adjusting the type and amount of NCA used, with the elastic modulus ranging from 50 Pa to 18000 Pa. The hydrogen bond-cross-linked hydrogel exhibited self-healing and injectable properties. Morphology characterization revealed that micelles were formed in the early stage of reaction, suggesting that the polymerization follows an aqueous ring-opening polymerization-induced self-assembly (ROPISA) mechanism and that aggregation of micelles during the reaction caused the gelation. Moreover, the hydrogels displayed high swelling ratios (>95% water content), and hemolysis and cytotoxicity experiments demonstrated that the hydrogels had excellent biocompatibility, indicating their potential in medical applications.

Dextran Macroinitiator for Synthesis of Polysaccharide-b-Polypeptide Block Copolymers via NCA Ring-Opening Polymerization.

Synthesis of polysaccharide-b-polypeptide block copolymers represents an attractive goal because of their promising potential in delivery applications. Inspired by recent breakthroughs in N-carboxyanhydride (NCA) ring-opening polymerization (ROP), we present an efficient approach for preparation of a dextran-based macroinitiator and the subsequent synthesis of dextran-b-polypeptides via NCA ROP. This is an original approach to creating and employing a native polysaccharide macroinitiator for block copolymer synthesis. In this strategy, regioselective (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidation of the sole primary alcohol located at the C-6 position of the monosaccharide at the nonreducing end of linear dextran results in a carboxylic acid. This motif is then transformed into a tetraalkylammonium carboxylate, thereby generating the dextran macroinitiator. This macroinitiator initiates a wide range of NCA monomers and produces dextran-b-polypeptides with a degree of polymerization (DP) of the polypeptide up to 70 in a controlled manner (D < 1.3). This strategy offers several distinct advantages, including preservation of the original dextran backbone structure, relatively rapid polymerization, and moisture tolerance. The dextran-b-polypeptides exhibit interesting self-assembly behavior. Their nanostructures have been investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and adjustment of the structure of block copolymers allows self-assembly of spherical micelles and worm-like micelles with varied diameters and aspect ratios, revealing a range of diameters from 60 to 160 nm. Moreover, these nanostructures exhibit diverse morphologies, including spherical micelles and worm-like micelles, enabling delivery applications.

Washed microbiota transplantation improves symptoms and intestinal barrier function in patients with functional bowel disorders: a propensity-score matching analysis.

BACKGROUND: Alterations in the intestinal microbiota may play a role in the pathogenesis of functional bowel disorders (FBDs). Probiotics are widely used to improve intestinal dysbacteriosis in FBDs. In the context of FBDs, washed microbiota transplantation (WMT) appear to be a promising therapeutic option. We aimed to compare probiotics with WMT by using a propensity-score matching analysis (PSMA). METHODS: We conducted a retrospective investigation of 103 patients with FBDs, including irritable bowel syndrome (IBS), functional constipation (FC), functional diarrhea (FDr), functional abdominal bloating (FAB). Patients were divided into the WMT group or probiotics group (taking probiotics capsules). Data on the following parameters were matched for PSMA: age; sex; disease course; body mass index; anxiety; insomnia; tobacco smoking; alcohol consumption; and levels of D-lactate, diamine oxidase, and lipopolysaccharide. Intestinal barrier function (IBF) and symptoms were evaluated both before and after treatment initiation. Prognostic factors were assessed by Cox proportional hazards regression analysis. RESULTS: PSMA identified in 34 matched pairs (11 IBS, 12 FC, 7 FDr, and 4 FAB in the probiotics group and 14 IBS, 13 FC, 5 FDr, and 2 FAB in the WMT group. Improvement of FBD symptoms was greater with WMT than probiotics (P = 0.002). The WMT group had significantly fewer patients with intestinal barrier damage than the probiotics group (38.2% vs. 67.6%, P = 0.041). This improvement of FBD with WMT was further reflected as a reduction in D-lactate levels (P = 0.031). Increased D-lactate levels which were identified as a prognostic factor for FBDs (HR = 0.248, 95%CI 0.093-0.666, P = 0.006) in multivariate Cox regression analysis. CONCLUSION: WMT could improve symptoms and IBF in patients with FBDs. Increased D-lactate levels in patients with FBDs may predict a favorable response to WMT treatment.

Immune-stealth VP28-conjugated heparin nanoparticles for enhanced and reversible anticoagulation.

Heparins are a family of sulfated linear negatively charged polysaccharides that have been widely used for their anticoagulant, antithrombotic, antitumor, anti-inflammatory, and antiviral properties. Additionally, it has been used for acute cerebral infarction relief as well as other pharmacological actions. However, heparin's self-aggregated macrocomplex may reduce blood circulation time and induce life-threatening thrombocytopenia (HIT) complicating the use of heparins. Nonetheless, the conjugation of heparin to immuno-stealth biomolecules may overcome these obstacles. An immunostealth recombinant viral capsid protein (VP28) was expressed and conjugated with heparin to form a novel nanoparticle (VP28-heparin). VP28-heparin was characterized and tested to determine its immunogenicity, anticoagulation properties, effects on total platelet count, and risk of inducing HIT in animal models. The synthesized VP28-heparin trimeric nanoparticle was non-immunogenic, possessed an average hydrodynamic size (8.81 ± 0.58 nm) optimal for the evasion renal filtration and reticuloendothelial system uptake (hence prolonging circulating half-life). Additionally, VP28-heparin did not induce mouse death or reduce blood platelet count when administered at a high dosein vivo(hence reducing HIT risks). The VP28-heparin nanoparticle also exhibited superior anticoagulation properties (2.2× higher prothrombin time) and comparable activated partial thromboplastin time, but longer anticoagulation period when compared to unfractionated heparin. The anticoagulative effects of the VP28-heparin can also be reversed using protamine sulfate. Thus, VP28-heparin may be an effective and safe heparin derivative for therapeutic use.

New Global Insights on the Regulation of the Biphasic Life Cycle and Virulence Via ClpP-Dependent Proteolysis in Legionella pneumophila.

Legionella pneumophila, an environmental bacterium that parasitizes protozoa, causes Legionnaires' disease in humans that is characterized by severe pneumonia. This bacterium adopts a distinct biphasic life cycle consisting of a nonvirulent replicative phase and a virulent transmissive phase in response to different environmental conditions. Hence, the timely and fine-tuned expression of growth and virulence factors in a life cycle-dependent manner is crucial for survival and replication. Here, we report that the completion of the biphasic life cycle and bacterial pathogenesis is greatly dependent on the protein homeostasis regulated by caseinolytic protease P (ClpP)-dependent proteolysis. We characterized the ClpP-dependent dynamic profiles of the regulatory and substrate proteins during the biphasic life cycle of L. pneumophila using proteomic approaches and discovered that ClpP-dependent proteolysis specifically and conditionally degraded the substrate proteins, thereby directly playing a regulatory role or indirectly controlling cellular events via the regulatory proteins. We further observed that ClpP-dependent proteolysis is required to monitor the abundance of fatty acid biosynthesis-related protein Lpg0102/Lpg0361/Lpg0362 and SpoT for the normal regulation of L. pneumophila differentiation. We also found that the control of the biphasic life cycle and bacterial virulence is independent. Furthermore, the ClpP-dependent proteolysis of Dot/Icm (defect in organelle trafficking/intracellular multiplication) type IVB secretion system and effector proteins at a specific phase of the life cycle is essential for bacterial pathogenesis. Therefore, our findings provide novel insights on ClpP-dependent proteolysis, which spans a broad physiological spectrum involving key metabolic pathways that regulate the transition of the biphasic life cycle and bacterial virulence of L. pneumophila, facilitating adaptation to aquatic and intracellular niches.

Outcomes of gonioscopy-assisted transluminal trabeculotomy in primary congenital glaucoma treatment: a retrospective study.

BACKGROUND: This retrospective study aimed to evaluate the efficacy and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in Chinese patients with primary congenital glaucoma (PCG) and identify factors influencing surgical success. METHODS: Fourteen patients (24 eyes) diagnosed with PCG who underwent gonioscopy-assisted transluminal trabeculotomy were recruited, and data on intraocular pressure (IOP), antiglaucoma medication, surgery-related complications, and additional treatments were collected during preoperative and postoperative visits. Surgical success was defined as IOP ≤ 21 mmHg and a reduction of > 30% from baseline, with (partial success) or without (complete success) antiglaucoma medication. RESULTS: Mean preoperative IOP was 30.41 ± 6.09 mmHg. At the final visit, mean IOP reduction was 16.1 ± 9.1 mmHg (52%), and 19 of 24 eyes were topical medication-free. IOP was significantly decreased at each postoperative visit compared with baseline (P < 0.05 for all time points). Cumulative proportions of complete and partial success were 79.2% and 95.8%, respectively, at three years postsurgery. Patients without prior antiglaucoma procedures, without postoperative IOP spikes, and those undergoing complete trabeculotomy exhibited improved surgical prognosis. No permanent vision-threatening complications occurred in the 24 eyes by the end of the respective follow-ups. CONCLUSION: Gonioscopy-assisted transluminal trabeculotomy emerged as a safe and effective procedure for PCG treatment, characterized by outstanding IOP reduction efficacy and high surgical success rates.