Metabolic Stability Research Articles

METTL5 promotes gastric cancer progression via sphingomyelin metabolism

BACKGROUND The treatment of gastric cancer (GC) has caused an enormous social burden worldwide. Accumulating studies have reported that N6-methyladenosine (m6A) is closely related to tumor progression. METTL5 is a m6A methyltransferase that plays a pivotal role in maintaining the metabolic stability of cells. However, its aberrant regulation in GC has not been fully elucidated. AIM To excavate the role of METTL5 in the development of GC. METHODS METTL5 expression and clinicopathological characteristics were analyzed via The Cancer Genome Atlas dataset and further verified via immunohistochemistry, western blotting and real-time quantitative polymerase chain reaction in tissue microarrays and clinical samples. The tumor-promoting effect of METTL5 on HGC-27 and AGS cells was explored in vitro by Cell Counting Kit-8 assays, colony formation assays, scratch healing assays, transwell assays and flow cytometry. The tumor-promoting role of METTL5 in vivo was evaluated in a xenograft tumor model. The EpiQuik m6A RNA Methylation Quantification Kit was used for m6A quantification. Next, liquid chromatography-mass spectrometry was used to evaluate the association between METTL5 and sphingomyelin metabolism, which was confirmed by Enzyme-linked immunosorbent assay and rescue tests. In addition, we investigated whether METTL5 affects the sensitivity of GC cells to cisplatin via colony formation and transwell experiments. RESULTS Our research revealed substantial upregulation of METTL5, which suggested a poor prognosis of GC patients. Increased METTL5 expression indicated distant lymph node metastasis, advanced cancer stage and pathological grade. An increased level of METTL5 correlated with a high degree of m6A methylation. METTL5 markedly promotes the proliferation, migration, and invasion of GC cells in vitro . METTL5 also promotes the growth of GC in animal models. METTL5 knockdown resulted in significant changes in sphingomyelin metabolism, which implies that METTL5 may impact the development of GC via sphingomyelin metabolism. In addition, high METTL5 expression led to cisplatin resistance. CONCLUSION METTL5 was found to be an oncogenic driver of GC and may be a new target for therapy since it facilitates GC carcinogenesis through sphingomyelin metabolism and cisplatin resistance.

Impact of hormone replacement therapy on cardiovascular risk in patients with hypothyroidism: a systematic review

Hypothyroidism, which is developed in 4-10 % of the population, and subclinical hypothyroidism found in more than 10 % of people which are highly associated with cardiovascular pathophysiology at some level. Hypothyroidism, which is the most frequent endocrine disorder with a lack of enough thyroid hormones, presents a wide range of cardiovascular complications, including coronary artery disease, heart failure, and dyslipidemia. Thyroid hormone replacement therapy, particularly levothyroxine (LT4), continues to be the central management of hypothyroidism, which aims to restore euthyroidism and other cardiac comorbidities as well as relieving symptoms. Nonetheless, the complex interworking of thyroid function and cardiovascular health requires a detailed clarification of the processes associated with disease development and drug therapy. Hypothyroidism triggers a chain of cardiovascular alterations such as aberrant lipid metabolism, endothelial dysfunction, and lessened cardiac contractility primarily by lowering the thyroid hormone level. Besides, these modifications eventually lead to raised rates of atherosclerosis, myocardial infarction, and heart failure. LT4 replacement therapy achieves normalization of hyperthyroidism with the replacement of thyroid hormone deficiency, which restores the cardiovascular system to normal by doing so. LT4 modulates lipid metabolism, improves endothelial function, and stimulates myocardial contractility via several different mechanisms. LT4 therapy acts on systemic inflammation and oxidation to accentuate the protective effects of the cardiovascular system. Apart from this, there is an increasing awareness about the use of new thyroid hormone formulations, like LH4, in the therapy of hypothyroidism. LH4, the thyromimetic compound, demonstrated a similar binding affinity at the thyroid hormone receptor as T3 (triiodothyronine) but with better tissue selectivity and more metabolic stability. Clinical trials have proven the potency of LH4 in lowering symptoms of hypothyroidism, for example, fatigue, weight gain which are leading cause of cardiovascular disorders. LH4 administration has been safe for up to six months, and only mild adverse effects have been reported when it is used more than a year.

Advances in the Chemistry and Biology of Specialised Pro-Resolving Mediators (SPMs)

This review article assembles key recent advances in the synthetic chemistry and biology of specialised pro-resolving mediators (SPMs). The major medicinal chemistry developments in the design, synthesis and biological evaluation of synthetic SPM analogues of lipoxins and resolvins have been discussed. These include variations in the top and bottom chains, as well as changes to the triene core, of lipoxins, all changes intended to enhance the metabolic stability whilst retaining or improving biological activity. Similar chemical modifications of resolvins are also discussed. The biological evaluation of these synthetic SPMs is also described in some detail. Original investigations into the biological activity of endogenous SPMs led to the pairing of these ligands with the FPR2/LX receptor, and these results have been challenged in more recent work, leading to conflicting results and views, which are again discussed.

Insights of potential trypanocidal effect of the synthetic derivative (2E)-1-(4-aminophenyl)-3-(2,4-dichlorophenyl)prop-2-en-1-one: in vitro assay, MEV analysis, quantum study, molecular docking, molecular dynamics, MPO analysis, and predictive ADMET.

This study aims to evaluate the antitrypanosomiasis activity of a synthetic dichloro-substituted aminochalcone via in vitro assays against infected cell cultures, as well as a theoretical characterization of pharmacokinetics and pharmacodynamics against the protein targets of the evolutionary cycle of T. cruzi. The in vitro evaluation of parasite proliferation inhibition was performed via cytotoxicity analysis on mammalian host cells, effect on epimastigote and trypomastigote forms, and cell death analysis, while computer simulations characterized the electronic structure of (2E)-1-(4-aminophenyl)-3-(2,4-dichlorophenyl)prop-2-en-1-one (DCl), the mechanism of action against the proteins of the evolutionary cycle of T. cruzi: Cruzain, Trypanothione reductase, TcGAPDH, and CYP51 by molecular docking and dynamics and predictive pharmacokinetics by MPO-based ADMET. The in vitro tests showed that the DCl LC50 in order of 178.9 ± 23.9 was similar to the BZN, evidencing the effectiveness of chalcone against Trypomastigotes. Molecular docking and dynamics simulations suggest that DCl acts on the active site of the CYP51 receptor, with hydrogen interactions that showed a high degree of occupation, establishing a stable complex with the target. MPO analysis and ADMET prediction tests suggest that the compound presents an alignment between permeability and hepatic clearance, although it presents low metabolic stability. Chalcone showed stable pharmacodynamics against the CYP51 target, but can form reactive metabolites from N-conjugation and C = C epoxidation, as an indication of controlled oral dose, although the estimated LD50 rate > 500mg/kg is a indicative of low incidence of lethality by ingestion, constituting a promising therapeutic strategy.

Recent Advances in the Discovery of SIRT1/2 Inhibitors via Computational Methods: A Perspective

Sirtuins (SIRTs) are classified as class III histone deacetylases (HDACs), a family of enzymes that catalyze the removal of acetyl groups from the ε-N-acetyl lysine residues of histone proteins, thus counteracting the activity performed by histone acetyltransferares (HATs). Based on their involvement in different biological pathways, ranging from transcription to metabolism and genome stability, SIRT dysregulation was investigated in many diseases, such as cancer, neurodegenerative disorders, diabetes, and cardiovascular and autoimmune diseases. The elucidation of a consistent number of SIRT–ligand complexes helped to steer the identification of novel and more selective modulators. Due to the high diversity and quantity of the structural data thus far available, we reviewed some of the different ligands and structure-based methods that have recently been used to identify new promising SIRT1/2 modulators. The present review is structured into two sections: the first includes a comprehensive perspective of the successful computational approaches related to the discovery of SIRT1/2 inhibitors (SIRTIs); the second section deals with the most interesting SIRTIs that have recently appeared in the literature (from 2017). The data reported here are collected from different databases (SciFinder, Web of Science, Scopus, Google Scholar, and PubMed) using “SIRT”, “sirtuin”, and “sirtuin inhibitors” as keywords.

Structures and Acetylcholinesterase Inhibition Abilities of some Derivatives Bearing (Pyridin-2-yl)tetrazole Scaffold

Tetrazole derivatives are a prominent class of heterocycles that hold significant value in medicinal chemistry and drug design. Their importance stems from their bioisosteric resemblance to carboxylic acid and amide moieties and their favorable metabolic stability and other beneficial physicochemical properties. In light of this, novel derivatives bearing the (pyridine-2-yl)tetrazol scaffold were synthesized with the presence of acid, ester and amide moieties and evaluated for their inhibitory effects on the enzyme acetylcholinesterase (AChE). Through a three-step synthesis reaction initiated with 2-pyridine carbonitrile, compound IV was successfully obtained with II and III as the intermediates. All substances II - III - IV demonstrated inhibitory activity against the enzyme acetylcholinesterase. Notably, substance IV exhibited the highest percentage of inhibition, achieving 23,7 % at a concentration of 75 µM. Based on molecular docking simulations, compounds containing stronger nucleophilic substituents exhibit more robust AChE enzyme inhibitory activity due to a greater abundance of hydrogen bonds. This drug-likeness simulation and ADME prediction highlight the potential of tetrazole derivatives as a promising treatment for Alzheimer's disease.

The clinical effectiveness and safety of Zone III REBOA for resection of sacropelvic tumors in patients older than 70 years

BackgroundREBOA is a method used to manage bleeding during surgery involving sacropelvic tumors. Nevertheless, studies on the use of REBOA among elderly people are lacking. The aim of this research was to investigate the efficacy and safety of Zone III REBOA in patients aged more than 70 years.MethodsA comparative study was conducted using case-control methods. A group of patients, referred to as Group A, who were younger than 70 years was identified and paired with a comparable group of patients, known as Group B, who were older than 70 years. Continuous monitoring of physiological parameters was conducted, and blood samples were collected at consistent intervals.ResultsTotally, 188 participants were enrolled and received REBOA. Among the 188 patients, seventeen were aged more than 70 years. By implementing REBOA, the average amount of blood loss was only 1427 ml. Experiments were also conducted to compare Group A and Group B. No notable differences were observed in terms of demographic variables, systolic blood pressure (SBP), arterial pH, lactate levels, blood creatinine levels, potassium levels, or calcium levels at baseline. Additionally, after the deflation of the REBOA, laboratory test results, which included arterial pH, lactate, potassium concentration, calcium concentration, and blood creatinine concentration, were not significantly different (P > 0.05).ConclusionThis study indicated that in selected patients aged more than 70 years can achieve satisfactory hemodynamic and metabolic stability with Zone III REBOA.Level of evidenceTherapeutic study, Level III.

Triazoles in Medicinal Chemistry: Physicochemical Properties, Bioisosterism, and Application.

Triazole demonstrates distinctive physicochemical properties, characterized by weak basicity, various dipole moments, and significant dual hydrogen bond acceptor and donor capabilities. These features are poised to play a pivotal role in drug-target interactions. The inherent polarity of triazole contributes to its lower logP, suggesting the potential improvement in water solubility. The metabolic stability of triazole adds additional value to drug discovery. Moreover, the metal-binding capacity of the nitrogen atom lone pair electrons of triazole has broad applications in the development of metal chelators and antifungal agents. This Perspective aims to underscore the unique physicochemical attributes of triazole and its application. A comparative analysis involving triazole isomers and other heterocycles provides guiding insights for the subsequent design of triazoles, with the hope of offering valuable considerations for designing other heterocycles in medicinal chemistry.

Synthesis and Evaluation of diaryl ether modulators of the leukotriene A4 hydrolase aminopeptidase activity

Activation of the aminopeptidase (AP) activity of leukotriene A4 hydrolase (LTA4H) presents a potential therapeutic strategy for resolving chronic inflammation. Previously, ARM1 and derivatives were found to activate the AP activity using the alanine-p-nitroanilide (Ala-pNA) as a reporter group in an enzyme kinetics assay. As an extension of this previous work, novel ARM1 derivatives were synthesized using a palladium-catalyzed Ullmann coupling reaction and screened using the same assay. Analogue 5, an aminopyrazole (AMP) analogue of ARM1, was found to be a potent AP activator with an AC50 of 0.12 μM. An X-ray crystal structure of LTA4H in complex with AMP was refined at 2.7 Å. Despite its AP activity with Ala-pNA substrate, AMP did not affect hydrolysis of the previously proposed natural ligand of LTA4H, Pro-Gly-Pro (PGP). This result highlights a discrepancy between the hydrolysis of more conveniently monitored chromogenic synthetic peptides typically employed in assays and endogenous peptides. The epoxide hydrolase (EH) activity of AMP was measured in vivo and the compound significantly reduced leukotriene B4 (LTB4) levels in a murine bacterial pneumonia model. However, AMP did not enhance survival in the murine pneumonia model over a 14-day period. A liver microsome stability assay showed metabolic stability of AMP. The results suggested that accelerated Ala-pNA cleavage is not sufficient for predicting therapeutic potential, even when the full mechanism of activation is known.

Abstract PO3-06-13: A novel stable 6-aryl-2-benzoyl-pyridine colchicine-binding site inhibitor targeting microtubules (60c) is effective against taxane-resistant, metastatic breast cancer

Abstract Background: Improving survival for patients diagnosed with metastatic disease and treating spontaneous chemoresistance remain major clinical challenges in treating breast cancer. Triple negative breast cancer (TNBC), characterized by a lack of therapeutically targetable receptors (ER/PR/HER2), is an aggressive subtype of breast cancer. TNBC therapy relies on a combination of systemically administered chemotherapies, including microtubule-targeting agents (MTAs) like paclitaxel (taxane class) or eribulin (vinca class); however, there are currently no FDA approved MTAs that bind to the colchicine-binding site. Approximately 70% of patients who initially respond to paclitaxel, a first-line MTA, will develop taxane resistance (TxR) within 6 months. We have previously reported that an orally bioavailable colchicine-binding site inhibitor (CBSI), sabizabulin (formerly known as Veru-111), not only inhibits TNBC tumor progression but also treats pre-established metastatic disease in a taxane-refractory PDX model, HCI-10-Luc2. Sabizabulin is currently in phase II/III trials for advanced prostate cancer. To further improve potency and metabolic stability, we created next-generation derivatives of the sabizabulin scaffold, including 60c. Results: 60c shows improved potency compared to sabizabulin against taxane-sensitive and TxR TNBC models, inhibiting proliferation and clonogenicity at low nanomolar concentrations, and inducing apoptosis in a dose-dependent manner. In vivo, 60c therapy significantly suppressed primary tumor growth and lung metastasis in an orthotopic MDA-MB-231-TxR xenograft model without gross toxicity, and with equivalent efficacy to combrestatin A4 phosphate (CA-4P), another CBSI in clinical trials. In the taxane-refractory HCI-10-Luc2 PDX model, 60c significantly suppressed both the growth of the primary tumor (by ~3.5 fold) and the expansion of pre-established axillary metastases (by ~26 fold) whereas paclitaxel had no effect. Analysis of total photon flux of organs excised at study endpoint showed that 60c had distinct anti-metastatic tropism as compared to sabizabulin. Whereas 60c completely suppressed metastases to the spleen (0/9 mice had signal), and significantly reduced metastatic burden in the leg bones (only 3/9 mice had signal) and in the kidney (only 2/9 mice had signal), 60c had no statistically significant effect on liver metastases. In contrast, we had previously reported that sabizabulin strongly repressed liver metastases in the same PDX model (0 mice with detectable liver metastases), with less potent effects on bone. Unlike 60c, sabizabulin showed no improvement relative to the vehicle control for spleen and kidney metastases. Together, our data positions 60c as a promising candidate for TNBC therapy, particularly for patients with TxR disease. Our results also suggest that different CBSI scaffolds may preferentially inhibit metastasis to specific organs, which requires further investigation. Citation Format: Damilola Oluwalana, Kelli Hartman, Raisa Krutilina, Hao Chen, Hilaire Playa, Shanshan Deng, Deanna Parke, Duane Miller, Tiffany Seagroves, Wei Li. A novel stable 6-aryl-2-benzoyl-pyridine colchicine-binding site inhibitor targeting microtubules (60c) is effective against taxane-resistant, metastatic breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-06-13.

Discovery of a SUCNR1 antagonist for potential treatment of diabetic nephropathy: In silico and in vitro studies

Diabetic nephropathy (DN) is one of the most severe complications of diabetes mellitus. Succinate Receptor 1 (SUCNR1), a member of the G-protein-coupled receptor (GPCR) family, represents a potential target for treatment of DN. Here, utilizing multi-strategy in silico virtual screening methods containing AlphaFold2 modelling, molecular dynamics (MD) simulation, ligand-based pharmacophore screening, molecular docking and machine learning-based similarity clustering, we successfully identified a novel antagonist of SUCNR1, AK-968/12117473 (Cpd3). Through extensive in vitro experiments, including dual-luciferase reporter assay, cellular thermal shift assay, immunofluorescence, and western blotting, we substantiated that Cpd3 could specifically target SUCNR1, inhibit the activation of NF-κB pathway, and ameliorate epithelial-mesenchymal transition (EMT) and extracellular matrix (ECM) deposition in renal tubular epithelial cells (NRK-52E) under high glucose conditions. Further in silico simulations revealed the molecular basis of the SUCNR1-Cpd3 interaction, and the in vitro metabolic stability assay indicated favorable drug-like pharmacokinetic properties of Cpd3. This work not only successfully pinpointed Cpd3 as a specific antagonist of SUCNR1 to serve as a promising candidate in the realm of therapeutic interventions for DN, but also provides a paradigm of dry-wet combined discovery strategies for GPCR-based therapeutics.

Discovery of 3-trifluoromethyl-substituted pyrazoles as selective phosphodiesterase 10A inhibitors for orally attenuating isoprenaline-induced cardiac hypertrophy

Recently, MP-10, a previous drug candidate with potent inhibition of phosphodiesterase 10A (PDE10A) in clinical phase II trials for schizophrenia or Alzheimer's disease, has shown significant potential in preventing and treating cardiovascular diseases. However, its poor metabolic stability and high permeability across the blood-brain barrier (BBB) make it unsuitable for preventing and treating peripheral cardiovascular diseases. Herein, the hit-to-lead optimization was performed to discover novel 3-trifluoromethyl-substituted pyrazole derivatives as potent and selective PDE10A inhibitors. The structure-activity relationships, biological characterization, molecular mechanism, and drug-like evaluation were discussed to identify compound C7 which showed potent inhibition against PDE10A (half maximal inhibitory concentration, IC50 = 11.9 nmol/L), more than 840-fold selectivity over other PDE subtypes, enhanced liver microsomes stability (T1/2 = 239 min) compared to MP-10 and low BBB permeability. Importantly, oral pretreatment with C7·3HCl at a dose of 5.0 mg/kg significantly attenuated the pathological and functional changes induced by isoprenaline (ISO)-induced pathological cardiac hypertrophy in mice, particularly suppressing increase of cardiac weight, atrial natriuretic peptide (ANP) and β-myosin heavy chain (β-MHC) hypertrophic markers along with cardiac fibrosis. These findings further support that targeting PDE10A provides an innovative therapeutic approach for preventing and treating cardiac diseases.

Novel Isoalantolactone-Based Derivatives as Potent NLRP3 Inflammasome Inhibitors: Design, Synthesis, and Biological Characterization.

The NLRP3 inflammasome has been recognized as a promising therapeutic target in drug discovery for inflammatory diseases. Our initial research identified a natural sesquiterpene isoalantolactone (IAL) as the active scaffold targeting NLRP3 inflammasome. To improve its activity and metabolic stability, a total of 64 IAL derivatives were designed and synthesized. Among them, compound 49 emerged as the optimal lead, displaying the most potent inhibitory efficacy on nigericin-induced IL-1β release in THP-1 cells, with an IC50 value of 0.29 μM, approximately 27-fold more potent than that of IAL (IC50: 7.86 μM), and exhibiting higher metabolic stability. Importantly, 49 remarkably improved DSS-induced ulcerative colitis in vivo. Mechanistically, we demonstrated that 49 covalently bound to cysteine 279 in the NACHT domain of NLRP3, thereby inhibiting the assembly and activation of NLRP3 inflammasome. These results provided compelling evidence to further advance the development of more potent NLRP3 inhibitors based on this scaffold.

Discovery of 4-benzylpiperazinequinoline BChE inhibitor that suppresses neuroinflammation for the treatment of Alzheimer's disease

Butyrylcholinesterase (BChE) has attracted wide interest as a promising target in Alzheimer's disease (AD) investigation. BChE is considered to play a compensable role of hydrolyzing acetylcholine (ACh), and its positive correlation with β-amyloid (Aβ) deposition also promotes disease progression. Herein, we uncovered a selective potent BChE inhibitor S21–1011 (eqBChE IC50 = 0.059 ± 0.006 μM, hBChE IC50 = 0.162 ± 0.069 μM), which presented satisfactory druggability and therapeutic efficacy in AD models. In pharmacokinetics (PK) studies, S21–1011 showed excellent blood-brain barrier (BBB) permeability, metabolism stability and high oral-bioavailability. In pharmacodynamic (PD) studies, it protected neural cells from toxicity and inflammation stimulation in vitro. Besides, it also exerted anti-inflammatory effect and alleviated cognitive impairment in mice models induced by lipopolysaccharides (LPS) and Aβ. Generally, this compound has been confirmed to function as a neuroprotector and cognition improver in various AD pathology-like models. Therefore, S21–1011, a novel potent BChE inhibitor, could be considered as a potential anti-AD candidate worthy of more profound investigation.

A Second-Generation Oral SARS-CoV-2 Main Protease Inhibitor Clinical Candidate for the Treatment of COVID-19.

Despite the record-breaking discovery, development and approval of vaccines and antiviral therapeutics such as Paxlovid, coronavirus disease 2019 (COVID-19) remained the fourth leading cause of death in the world and third highest in the United States in 2022. Here, we report the discovery and characterization of PF-07817883, a second-generation, orally bioavailable, SARS-CoV-2 main protease inhibitor with improved metabolic stability versus nirmatrelvir, the antiviral component of the ritonavir-boosted therapy Paxlovid. We demonstrate the in vitro pan-human coronavirus antiviral activity and off-target selectivity profile of PF-07817883. PF-07817883 also demonstrated oral efficacy in a mouse-adapted SARS-CoV-2 model at plasma concentrations equivalent to nirmatrelvir. The preclinical in vivo pharmacokinetics and metabolism studies in human matrices are suggestive of improved oral pharmacokinetics for PF-07817883 in humans, relative to nirmatrelvir. In vitro inhibition/induction studies against major human drug metabolizing enzymes/transporters suggest a low potential for perpetrator drug-drug interactions upon single-agent use of PF-07817883.

Radiosynthesis automation, non-human primate biodistribution and dosimetry of K+ channel tracer [11C]3MeO4AP

Background4-Aminopyridine (4AP) is a medication for the symptomatic treatment of multiple sclerosis. Several 4AP-based PET tracers have been developed for imaging demyelination. In preclinical studies, [11C]3MeO4AP has shown promise due to its high brain permeability, high metabolic stability, high plasma availability, and high in vivo binding affinity. To prepare for the translation to human studies, we developed a cGMP-compatible automated radiosynthesis protocol and evaluated the whole-body biodistribution and radiation dosimetry of [11C]3MeO4AP in non-human primates (NHPs).MethodsAutomated radiosynthesis was carried out using a GE TRACERlab FX-C Pro synthesis module. One male and one female adult rhesus macaques were used in the study. A high-resolution CT from cranial vertex to knee was acquired. PET data were collected using a dynamic acquisition protocol with four bed positions and 13 passes over a total scan time of ~ 150 min. Based on the CT and PET images, volumes of interest (VOIs) were manually drawn for selected organs. Non-decay corrected time-activity curves (TACs) were extracted for each VOI. Radiation dosimetry and effective dose were calculated from the integrated TACs using OLINDA software.ResultsFully automated radiosynthesis of [11C]3MeO4AP was achieved with 7.3 ± 1.2% (n = 4) of non-decay corrected radiochemical yield within 38 min of synthesis and purification time. [11C]3MeO4AP distributed quickly throughout the body and into the brain. The organs with highest dose were the kidneys. The average effective dose of [11C]3MeO4AP was 4.0 ± 0.6 μSv/MBq. No significant changes in vital signs were observed during the scan.ConclusionA cGMP-compatible automated radiosynthesis of [11C]3MeO4AP was developed. The whole-body biodistribution and radiation dosimetry of [11C]3MeO4AP was successfully evaluated in NHPs. [11C]3MeO4AP shows lower average effective dose than [18F]3F4AP and similar average effective dose as other carbon-11 tracers.

Development of a Decafluorobiphenyl Cyclized Peptide Targeting the NEMO-IKKα/β Interaction that Enhances Cell Penetration and Attenuates Lipopolysaccharide-Induced Acute Lung Injury.

Aberrant canonical NF-κB signaling has been implicated in diseases, such as autoimmune disorders and cancer. Direct disruption of the interaction of NEMO and IKKα/β has been developed as a novel way to inhibit the overactivation of NF-κB. Peptides are a potential solution for disrupting protein-protein interactions (PPIs); however, they typically suffer from poor stability in vivo and limited tissue penetration permeability, hampering their widespread use as new chemical biology tools and potential therapeutics. In this work, decafluorobiphenyl-cysteine SNAr chemistry, molecular modeling, and biological validation allowed the development of peptide PPI inhibitors. The resulting cyclic peptide specifically inhibited canonical NF-κB signaling in vitro and in vivo, and presented positive metabolic stability, anti-inflammatory effects, and low cytotoxicity. Importantly, our results also revealed that cyclic peptides had huge potential in acute lung injury (ALI) treatment, and confirmed the role of the decafluorobiphenyl-based cyclization strategy in enhancing the biological activity of peptide NEMO-IKKα/β inhibitors. Moreover, it provided a promising method for the development of peptide-PPI inhibitors.

A Tiny Pocket Packs a Punch: Leveraging Pyridones for the Discovery of CNS-Penetrant Aza-indazole IRAK4 Inhibitors.

We herein report the discovery, synthesis, and evolution of a series of indazoles and azaindazoles as CNS-penetrant IRAK4 inhibitors. Described is the use of structure-based and property-based drug design strategically leveraged to guide the property profile of a key series into a favorable property space while maintaining potency and selectivity. Our rationale that led toward functionalities with potency improvements, CNS-penetration, solubility, and favorable drug-like properties is portrayed. In vivo evaluation of an advanced analogue showed significant, dose-dependent modulation of inflammatory cytokines in a mouse model. In pursuit of incorporating a highly engineered bridged ether that was crucial to metabolic stability in this series, significant synthetic challenges were overcome to enable the preparation of the analogues.

Deletion of Impdh2 in adipocyte precursors limits the expansion of white adipose tissue and enhances metabolic health with overnutrition

The equilibrium between the hypertrophic growth of existing adipocytes and adipogenesis is vital in managing metabolic stability in white adipocytes when faced with overnutrition. Adipogenesis has been established as a key player in combating metabolic irregularities caused by various factors. However, the benefits of increasing adipogenesis-mediated white adipose tissue (WAT) expansion for metabolic health regulation remain uncertain. Our findings reveal an increase in Impdh2 expression during the adipogenesis phase, both in vivo and in vitro. Xmp enhances adipogenic potential by fostering mitotic clonal expansion (MCE). The conditional knockout of Impdh2 in adipocyte progenitor cells(APCs) in adult and aged mice effectively curbs white adipose tissue expansion, ameliorates glucose tolerance, and augments energy expenditure under high-fat diet (HFD). However, no significant difference is observed under normal chow diet (NCD). Concurrently, the knockout of Impdh2 in APCs significantly reduces the count of new adipocytes induced by HFD, without affecting adipocyte size. Mechanistically, Impdh2 regulates the proliferation of APCs during the MCE phase via Xmp. Exogenous Xmp can significantly offset the reduction in adipogenic abilities of APCs due to Impdh2 deficiency. In summary, we discovered that adipogenesis-mediated WAT expansion, induced by overnutrition, also contributes to metabolic abnormalities. Moreover, the pivotal role of Impdh2 in regulating adipogenesis in APCs offers a novel therapeutic approach to combat obesity.

Structure–Activity Relationship of Synthetic Linear KTS-Peptides Containing Meta-Aminobenzoic Acid as Antagonists of α1β1 Integrin with Anti-Angiogenic and Melanoma Anti-Tumor Activities

To develop peptide drugs targeting integrin receptors, synthetic peptide ligands endowed with well-defined selective binding motifs are necessary. The snake venom KTS-containing disintegrins, which selectively block collagen α1β1 integrin, were used as lead compounds for the synthesis and structure–activity relationship of a series of linear peptides containing the KTS-pharmacophore and alternating natural amino acids and 3-aminobenzoic acid (MABA). To ensure a better stiffness and metabolic stability, one, two and three MABA residues, were introduced around the KTS pharmacophore motif. Molecular dynamics simulations determined that the solution conformation of MABA peptide 4 is more compact, underwent larger conformational changes until convergence, and spent most of the time in a single cluster. The peptides’ binding affinity has been characterized by an enzyme linked immunosorbent assay in which the most potent peptide 4 inhibited with IC50 of 324 ± 8 µM and 550 ± 45 µM the binding of GST-α1-A domain to collagen IV fragment CB3, and the cell adhesion to collagen IV using α1-overexpressor cells, respectively. Docking studies and MM-GBSA calculations confirmed that peptide 4 binds a smaller region of the integrin near the collagen-binding site and penetrated deeper into the binding site near Trp1. Peptide 4 inhibited tube formation by endothelial cell migration in the Matrigel angiogenesis in vitro assay. Peptide 4 was acutely tolerated by mice, showed stability in human serum, decreased tumor volume and angiogenesis, and significantly increased the survival of mice injected with B16 melanoma cells. These findings propose that MABA-peptide 4 can further serve as an α1β1-integrin antagonist lead compound for further drug optimization in angiogenesis and cancer therapy.