[18F]F-AraG imaging reveals association between neuroinflammation and brown- and bone marrow adipose tissue.

Brown and brown-like adipose tissues have attracted significant attention for their role in metabolism and therapeutic potential in diabetes and obesity. Despite compelling evidence of an interplay between adipocytes and lymphocytes, the involvement of these tissues in immune responses remains largely unexplored. This study explicates a newfound connection between neuroinflammation and brown- and bone marrow adipose tissue. Leveraging the use of [18F]F-AraG, a mitochondrial metabolic tracer capable of tracking activated lymphocytes and adipocytes simultaneously, we demonstrate, in models of glioblastoma and multiple sclerosis, the correlation between intracerebral immune infiltration and changes in brown- and bone marrow adipose tissue. Significantly, we show initial evidence that a neuroinflammation-adipose tissue link may also exist in humans. This study proposes the concept of an intricate immuno-neuro-adipose circuit, and highlights brown- and bone marrow adipose tissue as an intermediary in the communication between the immune and nervous systems. Understanding the interconnectedness within this circuitry may lead to advancements in the treatment and management of various conditions, including cancer, neurodegenerative diseases and metabolic disorders.

Preclinical Development of PNT6555, a Boronic Acid-Based, Fibroblast Activation Protein-α (FAP)-Targeted Radiotheranostic for Imaging and Treatment of FAP-Positive Tumors.

The overexpression of fibroblast activation protein-α (FAP) in solid cancers relative to levels in normal tissues has led to its recognition as a target for delivering agents directly to tumors. Radiolabeled quinoline-based FAP ligands have established clinical feasibility for tumor imaging, but their therapeutic potential is limited due to suboptimal tumor retention, which has prompted the search for alternative pharmacophores. One such pharmacophore is the boronic acid derivative N-(pyridine-4-carbonyl)-d-Ala-boroPro, a potent and selective FAP inhibitor (FAPI). In this study, the diagnostic and therapeutic (theranostic) potential of N-(pyridine-4-carbonyl)-d-Ala-boroPro-based metal-chelating DOTA-FAPIs was evaluated. Methods: Three DOTA-FAPIs, PNT6555, PNT6952, and PNT6522, were synthesized and characterized with respect to potency and selectivity toward soluble and cell membrane FAP; cellular uptake of the Lu-chelated analogs; biodistribution and pharmacokinetics in mice xenografted with human embryonic kidney cell-derived tumors expressing mouse FAP; the diagnostic potential of 68Ga-chelated DOTA-FAPIs by direct organ assay and small-animal PET; the antitumor activity of 177Lu-, 225Ac-, or 161Tb-chelated analogs using human embryonic kidney cell-derived tumors expressing mouse FAP; and the tumor-selective delivery of 177Lu-chelated DOTA-FAPIs via direct organ assay and SPECT. Results: DOTA-FAPIs and their natGa and natLu chelates exhibited potent inhibition of human and mouse sources of FAP and greatly reduced activity toward closely related prolyl endopeptidase and dipeptidyl peptidase 4. 68Ga-PNT6555 and 68Ga-PNT6952 showed rapid renal clearance and continuous accumulation in tumors, resulting in tumor-selective exposure at 60 min after administration. 177Lu-PNT6555 was distinguished from 177Lu-PNT6952 and 177Lu-PNT6522 by significantly higher tumor accumulation over 168 h. In therapeutic studies, all 3 177Lu-DOTA-FAPIs exhibited significant antitumor activity at well-tolerated doses, with 177Lu-PNT6555 producing the greatest tumor growth delay and animal survival. 225Ac-PNT6555 and 161Tb-PNT6555 were similarly efficacious, producing 80% and 100% survival at optimal doses, respectively. Conclusion: PNT6555 has potential for clinical translation as a theranostic agent in FAP-positive cancer.

Patient and public involvement in research: Reflections and experiences of doctoral cancer nurse researchers in Europe.

PURPOSE: Early career researchers lack guidance about patient and public involvement (PPI). The overall aim of the study was to explore the knowledge and experiences of using PPI in research among doctoral students who are registered nurses. METHODS: This qualitative study included findings generated from reflective essays and focus groups involving ten registered cancer nurses who are undertaking doctoral research. The study has two stages of data collection. Participants initially wrote a reflective essay using a set of guiding questions to structure a response which was subsequently analysed. Two focus groups were then conducted to provide further insight into the themes identified in the reflective essays. Reflective thematic analysis was used to identify, name, and define the final themes. RESULTS: There were ten participants from seven countries and were at various stages of their doctoral study. Analysis of data from reflective essays (n = 10) and focus groups (n = 2) identified four themes namely, (a) evolving recognition and appreciation of PPI, (b) embracing PPI and impact on doctoral studies, (c) the influence of the research environment, and (d) the need to empower doctoral students to integrate PPI in their research journey. CONCLUSION: Participants reported differing experiences of PPI awareness showing disparity in guidance about PPI for junior researchers across Europe. We recommend provision of early PPI training for doctoral students to support and encourage involvement of patients and the public in their research. Opportunities for sharing PPI experiences to help improve PPI culture in research environments that support doctoral students should be explored.

"It's part of our life now": a qualitative exploration of the social eating experiences of family members of patients living with head and neck cancer.

PURPOSE: Family members (FMs) of patients with head and neck cancer (HNC) report a change in their social eating experience. They miss out on the opportunities and benefits that eating with others provides. However, few studies investigate FM's social eating experiences, with existing research primarily focusing on the patient experience. Therefore, the aim of this study was to explore the social eating experiences of FMs of patients who have had treatment for HNC. METHODS: A qualitative research design using semi-structured interviews was used to understand FM's social eating experiences. Key themes were inductively developed from the data using reflexive thematic analysis. RESULTS: Twelve interviews were conducted with FMs, and three key themes were identified: (1) changes and challenges experienced by FMs due to HNC patients' social eating difficulties, (2) living with social eating changes is a balancing act, and (3) FMs' efforts to promote social eating for a patient with HNC. FMs expressed significant changes to their social eating habits within and outside the home, indicating the need for support to meet their own emotional, psychological and social needs. CONCLUSION: FMs experience many demands and tensions, having to balance the psychological impact they experience, which are often minimised, whilst attempting to find the best ways to support, protect and encourage their loved ones to adjust and adapt to social eating changes. Therefore, interventions need to support FMs' challenges and equip them to know how to best support patients living with HNC and themselves.

Armeniaspirol analogues with more potent Gram-positive antibiotic activity show enhanced inhibition of the ATP-dependent proteases ClpXP and ClpYQ.

Antibiotics with fundamentally new mechanisms of action such as the armeniaspirols, which target the ATP-dependent proteases ClpXP and ClpYQ, must be developed to combat antimicrobial resistance. While the mechanism of action of armeniaspirol against Gram-positive bacteria is understood, little is known about the structure-activity relationship for its antibiotic activity. Based on the preliminary data showing that modifications of armeniaspirol's N-methyl group increased antibiotic potency, we probed the structure-activity relationship of N-alkyl armeniaspirol derivatives. A series of focused derivatives were synthesized and evaluated for antibiotic activity against clinically relevant pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. Replacement of the N-methyl with N-hexyl, various N-benzyl, and N-phenethyl substituents led to substantial increases in antibiotic activity and potency for inhibition of both ClpYQ and ClpXP. Docking studies identified binding models for ClpXP and ClpYQ that were consistent with the inhibition data. This work confirms the role of ClpXP and ClpYQ in the mechanism of action of armeniaspirol and provides important lead compounds for further antibiotic development.

Experiences and perceptions of social eating for patients living with and beyond head and neck cancer: a qualitative study.

PURPOSE: Patients with head and neck cancer (HNC) describe eating as more than a physical activity for nutrition and calories. After treatment for HNC, patients report a changed social experience around food, with eating and drinking in front of family and friends depicted as a challenge. However, there is limited research exploring how patients with HNC adapt and cope with social eating difficulties. This study aims to explore patients' experiences and perceptions of social eating and drinking following treatment for HNC. METHODS: A qualitative research design using semi-structured interviews was employed to understand the experiences of social eating of patients living with and beyond HNC. Reflexive thematic analysis was used to inductively develop key themes from the data. RESULTS: Fourteen interviews were conducted with patients, and two key themes were identified: (1) "Social eating became a conscious process" and (2) "Strategies to maximise social eating participation". To maximise social eating enjoyment, patients attempted to minimise the attention on their eating function and the fuss created around food. Patients with HNC established psychological and cognitive adaptations to manage expectations and promote positive participation in social eating. CONCLUSION: This paper identifies key barriers limiting or diminishing social eating for patients with HNC; including being self-conscious, lack of understanding from others and functional issues with eating and drinking. This research highlights the need to raise awareness of social eating challenges and for the social dimensions of eating to be addressed through family-centred, supportive holistic interventions implemented early in the patient's cancer journey.

Armeniaspirols inhibit the AAA+ proteases ClpXP and ClpYQ leading to cell division arrest in Gram-positive bacteria.

Multi-drug-resistant bacteria present an urgent threat to modern medicine, creating a desperate need for antibiotics with new modes of action. As natural products remain an unsurpassed source for clinically viable antibiotic compounds, we investigate the mechanism of action of armeniaspirol. The armeniaspirols are a structurally unique class of Gram-positive antibiotic discovered from Streptomyces armeniacus for which resistance cannot be readily obtained. We show that armeniaspirol inhibits the ATP-dependent proteases ClpXP and ClpYQ in vitro and in the model Gram-positive Bacillus subtilis. This inhibition dysregulates the divisome and elongasome supported by an upregulation of key proteins FtsZ, DivIVA, and MreB inducing cell division arrest. The inhibition of ClpXP and ClpYQ to dysregulate cell division represents a unique antibiotic mechanism of action and armeniaspirol is the only known natural product inhibitor of the coveted anti-virulence target ClpP. Thus, armeniaspirol possesses a promising lead scaffold for antibiotic development with unique pharmacology.

A qualitative systematic review of the social eating and drinking experiences of patients following treatment for head and neck cancer.

PURPOSE: Patients living with and beyond head and neck cancer (HNC) often have long-term, functional challenges as a result of treatment. A key functional challenge relates to eating and drinking; often associated with physical, emotional, and social difficulties. Eating and drinking with family members and friends can become a struggle, increasing the risk of social isolation and loneliness. This systematic review aims to identify and synthesise the literature on the experiences of social eating and drinking for patients following treatment for HNC. METHODS: Six electronic databases (Pubmed, Web of Science, CINAHL, EMBASE, PsychINFO, and Scopus) were systematically searched using subject headings and free-text word searches in February 2020. Citation chaining and Google Scholar were used to identify grey literature. PRISMA procedures were followed. RESULTS: Of 6910 records identified, 24 studies met the inclusion criteria. Synthesis of the research findings results in two major themes: (1) the experience of loss associated with social eating and drinking, and (2) adjusting and support to promote social eating and drinking. CONCLUSION: Losses associated with social eating affect a patient's psychological and emotional well-being and impact on close relationships. To promote positive participation in social eating, patients were more likely to seek and receive support from someone within their close social network, rather than a healthcare professional. Family and friends are an essential source of support and are integral in facilitating engagement with social eating following treatment for HNC. Future interventions should promote family orientated resources, incorporating self-management strategies.

Synthesis of a 11C-Isotopologue of the B-Raf-Selective Inhibitor Encorafenib Using In-Loop [11C]CO2 Fixation.

The serine/threonine kinase B-Raf is an essential regulator of cellular growth, differentiation, and survival. B-Raf protein expression is elevated throughout melanoma progression, making it an attractive target for noninvasive imaging using positron-emission tomography. Encorafenib is a potent and highly selective inhibitor of B-Raf used in the clinical management of melanoma. In this study, the radiosynthesis of a 11C-isotopologue of encorafenib was developed using an in-loop [11C]CO2 fixation reaction. Optimization of reaction conditions reduced the formation of a radiolabeled side product and improved the isolated yields of [11C]encorafenib (14.5 ± 2.4% radiochemical yield). The process was fully automated using a commercial radiosynthesizer for the production of 6845 ± 888 MBq of [11C]encorafenib in high molar activity (177 ± 5 GBq µmol-1), in high radiochemical purity (99%), and in a formulation suitable for animal injection. An in vitro cellular binding experiment demonstrated saturable binding of the radiotracer to A375 melanoma cells.

Radiosynthesis of the 11 C-methyl derivative of LBQ657 for PET investigation of the neprilysin inhibitor sacubitril.

Neprilysin, also known as neutral endopeptidase, is a cell surface membrane metalo-endopeptidase that cleaves various peptides. Altered neprilysin expression has been correlated with various cancers and cardiovascular diseases. In this work, we present the radiosynthesis of the novel O-11 C-methylated derivative of LBQ657 (a potent neprilysin inhibitor). (2R,4S)-5-(Biphenyl-4-yl)-4-[(3-carboxypropionyl)amino]-2-methylpentanoic acid [11 C]methyl ester ([11 C]MeOLBQ) is an analog of sacubitril where the alkyl ester is a 11 C-methyl instead of an ethyl. [11 C]MeOLBQ was produced in a one-pot two-step synthesis. The O-11 C-methylation of the pentanoic acid part was done with [11 C]methyl triflate followed by the deprotection of the tert-butyl ester precursor in acidic conditions. [11 C]MeOLBQ ([11 C]7) was produced in 9.5 ± 2.5% RCY (25 ± 6% decay-corrected from [11 C]CO2 , n = 3) high molar activity 348 ± 100 GBq/µmol (9425 ± 2720 mCi/µmol) at EOS, in high chemical (>95%) and radiochemical (>99%) purities. The total synthesis time including HPLC purification and reformulation was 29 minutes. To our knowledge, this is the first PET-labeled analog of the clinically used NEP inhibitor sacubitril.

Trapping biosynthetic acyl-enzyme intermediates with encoded 2,3-diaminopropionic acid.

Many enzymes catalyse reactions that proceed through covalent acyl-enzyme (ester or thioester) intermediates1. These enzymes include serine hydrolases2,3 (encoded by one per cent of human genes, and including serine proteases and thioesterases), cysteine proteases (including caspases), and many components of the ubiquitination machinery4,5. Their important acyl-enzyme intermediates are unstable, commonly having half-lives of minutes to hours6. In some cases, acyl-enzyme complexes can be stabilized using substrate analogues or active-site mutations but, although these approaches can provide valuable insight7-10, they often result in complexes that are substantially non-native. Here we develop a strategy for incorporating 2,3-diaminopropionic acid (DAP) into recombinant proteins, via expansion of the genetic code11. We show that replacing catalytic cysteine or serine residues of enzymes with DAP permits their first-step reaction with native substrates, allowing the efficient capture of acyl-enzyme complexes that are linked through a stable amide bond. For one of these enzymes, the thioesterase domain of valinomycin synthetase12, we elucidate the biosynthetic pathway by which it progressively oligomerizes tetradepsipeptidyl substrates to a dodecadepsipeptidyl intermediate, which it then cyclizes to produce valinomycin. By trapping the first and last acyl-thioesterase intermediates in the catalytic cycle as DAP conjugates, we provide structural insight into how conformational changes in thioesterase domains of such nonribosomal peptide synthetases control the oligomerization and cyclization of linear substrates. The encoding of DAP will facilitate the characterization of diverse acyl-enzyme complexes, and may be extended to capturing the native substrates of transiently acylated proteins of unknown function.

Simplified and robust one-step radiosynthesis of [18 F]DCFPyL via direct radiofluorination and cartridge-based purification.

[18 F]DCFPyL is a clinical-stage PET radiotracer used to image prostate cancer. This report details the efficient production of [18 F]DCFPyL using single-step direct radiofluorination, without the use of carboxylic acid-protecting groups. Radiolabeling reaction optimization studies revealed an inverse correlation between the amount of precursor used and the radiochemical yield. This simplified approach enabled automated preparation of [18 F]DCFPyL within 28 minutes using HPLC purification (26% ± 6%, at EOS, n = 4), which was then scaled up for large-batch production to generate 1.46 ± 0.23 Ci of [18 F]DCFPyL at EOS (n = 7) in high molar activity (37 933 ± 4158 mCi/µmol, 1403 ± 153 GBq/µmol, at EOS, n = 7). Further, this work enabled the development of [18 F]DCFPyL production in 21 minutes using an easy cartridge-based purification (25% ± 9% radiochemical yield, at EOS, n = 3).

Impact of Detergents on Membrane Protein Complex Isolation.

Detergents play an essential role during the isolation of membrane protein complexes. Inappropriate use of detergents may affect the native fold of the membrane proteins, their binding to antibodies, or their interaction with partner proteins. Here we used cadherin-11 (Cad11) as an example to examine the impact of detergents on membrane protein complex isolation. We found that mAb 1A5 could immunoprecipitate Cad11 when membranes were solubilized by dodecyl maltoside (DDM) but not by octylglucoside, suggesting that octylglucoside interferes with Cad11-mAb 1A5 interaction. Furthermore, we compared the effects of Brij-35, Triton X-100, cholate, CHAPSO, Zwittergent 3-12, Deoxy BIG CHAP, and digitonin on Cad11 solubilization and immunoprecipitation. We found that all detergents except Brij-35 could solubilize Cad11 from the membrane. Upon immunoprecipitation, we found that ß-catenin, a known cadherin-interacting protein, was present in Cad11 immune complex among the detergents tested except Brij-35. However, the association of p120 catenin with Cad11 varied depending on the detergents used. Using isobaric tag for relative and absolute quantitation (iTRAQ) to determine the relative levels of proteins in Cad11 immune complexes, we found that DDM and Triton X-100 were more efficient than cholate in solubilization and immunoprecipitation of Cad11 and resulted in the identification of both canonical and new candidate Cad11-interacting proteins.

First-in-class small molecule potentiators of cancer virotherapy.

The use of engineered viral strains such as gene therapy vectors and oncolytic viruses (OV) to selectively destroy cancer cells is poised to make a major impact in the clinic and revolutionize cancer therapy. In particular, several studies have shown that OV therapy is safe and well tolerated in humans and can infect a broad range of cancers. Yet in clinical studies OV therapy has highly variable response rates. The heterogeneous nature of tumors is widely accepted to be a major obstacle for OV therapeutics and highlights a need for strategies to improve viral replication efficacy. Here, we describe the development of a new class of small molecules for selectively enhancing OV replication in cancer tissue. Medicinal chemistry studies led to the identification of compounds that enhance multiple OVs and gene therapy vectors. Lead compounds increase OV growth up to 2000-fold in vitro and demonstrate remarkable selectivity for cancer cells over normal tissue ex vivo and in vivo. These small molecules also demonstrate enhanced stability with reduced electrophilicity and are highly tolerated in animals. This pharmacoviral approach expands the scope of OVs to include resistant tumors, further potentiating this transformative therapy. It is easily foreseeable that this approach can be applied to therapeutically enhance other attenuated viral vectors.

Gene PA2449 is essential for glycine metabolism and pyocyanin biosynthesis in Pseudomonas aeruginosa PAO1.

Many pseudomonads produce redox active compounds called phenazines that function in a variety of biological processes. Phenazines are well known for their toxicity against non-phenazine-producing organisms, which allows them to serve as crucial biocontrol agents and virulence factors during infection. As for other secondary metabolites, conditions of nutritional stress or limitation stimulate the production of phenazines, but little is known of the molecular details underlying this phenomenon. Using a combination of microarray and metabolite analyses, we demonstrate that the assimilation of glycine as a carbon source and the biosynthesis of pyocyanin in Pseudomonas aeruginosa PAO1 are both dependent on the PA2449 gene. The inactivation of the PA2449 gene was found to influence the transcription of a core set of genes encoding a glycine cleavage system, serine hydroxymethyltransferase, and serine dehydratase. PA2449 also affected the transcription of several genes that are integral in cell signaling and pyocyanin biosynthesis in P. aeruginosa PAO1. This study sheds light on the unexpected relationship between the utilization of an unfavorable carbon source and the production of pyocyanin. PA2449 is conserved among pseudomonads and might be universally involved in the assimilation of glycine among this metabolically diverse group of bacteria.