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Biochemical and Biophysical Research... Jul 2024In animal cells, vacuoles are absent, but can be induced by diseases and drugs. While phosphoinositides are critical for membrane trafficking, their role in the...
In animal cells, vacuoles are absent, but can be induced by diseases and drugs. While phosphoinositides are critical for membrane trafficking, their role in the formation of these vacuoles remains unclear. The immunosuppressive KRP203/Mocravimod, which antagonizes sphingosine-1-phosphate receptors, has been identified as having novel multimodal activity against phosphoinositide kinases. However, the impact of this novel KRP203 activity is unknown. Here, we show that KRP203 disrupts the spatial organization of phosphoinositides and induces extensive vacuolization in tumor cells and immortalized fibroblasts. The KRP203-induced vacuoles are primarily from endosomes, and augmented by inhibition of PIKFYVE and VPS34. Conversely, overexpression of PTEN decreased KRP203-induced vacuole formation. Furthermore, V-ATPase inhibition completely blunted KRP203-induced vacuolization, pointing to a critical requirement of the endosomal maturation process. Importantly, nearly a half of KRP203-induced vacuoles are significantly decorated with PI4P, a phosphoinositide typically enriched at the plasma membrane and Golgi. These results suggest a model that noncanonical spatial reorganization of phosphoinositides by KRP203 alters the endosomal maturation process, leading to vacuolization. Taken together, this study reveals a previously unrecognized bioactivity of KRP203 as a vacuole-inducing agent and its unique mechanism of phosphoinositide modulation, providing a new insight of phosphoinositide regulation into vacuolization-associated diseases and their molecular pathologies.
Topics: Vacuoles; Endosomes; Humans; Phosphatidylinositols; Animals; PTEN Phosphohydrolase; Phosphatidylinositol 3-Kinases; Class III Phosphatidylinositol 3-Kinases; Mice; Morpholines; Vacuolar Proton-Translocating ATPases; Cytoplasm; HeLa Cells; Aminopyridines; Heterocyclic Compounds, 3-Ring
PubMed: 38735134
DOI: 10.1016/j.bbrc.2024.149981 -
International Journal of Molecular... Apr 2024Numerous studies suggest the involvement of adenosine-5'-triphosphate (ATP) and similar nucleotides in the pathophysiology of asthma. Androgens, such as testosterone...
Numerous studies suggest the involvement of adenosine-5'-triphosphate (ATP) and similar nucleotides in the pathophysiology of asthma. Androgens, such as testosterone (TES), are proposed to alleviate asthma symptoms in young men. ATP and uridine-5'-triphosphate (UTP) relax the airway smooth muscle (ASM) via purinergic P2Y and P2Y receptors and K channel opening. We previously demonstrated that TES increased the expression of voltage-dependent K (K) channels in ASM. This study investigates how TES may potentiate ASM relaxation induced by ATP and UTP. Tracheal tissues treated with or without TES (control group) from young male guinea pigs were used. In organ baths, tracheas exposed to TES (40 nM for 48 h) showed enhanced ATP- and UTP-evoked relaxation. Tetraethylammonium, a K channel blocker, annulled this effect. Patch-clamp experiments in tracheal myocytes showed that TES also increased ATP- and UTP-induced K currents, and this effect was abolished with flutamide (an androgen receptor antagonist). K channels were involved in this phenomenon, which was demonstrated by inhibition with 4-aminopyridine. RB2 (an antagonist of almost all P2Y receptors except for P2Y), as well as N-ethylmaleimide and SQ 22,536 (inhibitors of G proteins and adenylyl cyclase, respectively), attenuated the enhancement of the K currents induced by TES. Immunofluorescence and immunohistochemistry studies revealed that TES did not modify the expression of P2Y receptors or COX-1 and COX-2, while we have demonstrated that this androgen augmented the expression of K1.2 and K1.5 channels in ASM. Thus, TES leads to the upregulation of P2Y signaling and K channels in guinea pig ASM, enhancing ATP and UTP relaxation responses, which likely limits the severity of bronchospasm in young males.
Topics: Animals; Uridine Triphosphate; Guinea Pigs; Muscle Relaxation; Male; Adenosine Triphosphate; Trachea; Testosterone; Adenylyl Cyclases; Muscle, Smooth; Potassium Channels, Voltage-Gated; Signal Transduction; Receptors, Purinergic P2
PubMed: 38731872
DOI: 10.3390/ijms25094652 -
Acta Crystallographica Section B,... Jun 2024The molecule of anti-epileptic drug lamotrigine [LAM; 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine] is capable of the formation of multicomponent solids. Such an...
The molecule of anti-epileptic drug lamotrigine [LAM; 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine] is capable of the formation of multicomponent solids. Such an enhanced tendency is related to the diverse functionalities of the LAM chemical groups able to form hydrogen bonds. Two robust synthons are recognized in the supramolecular structure of LAM itself formed via N-H...N hydrogen bond: homosynthon, so-called aminopyridine dimer or synthon 1 [R(8)] and larger homosynthon 2 [R(8)]. The synthetic procedures for a new hydrate and 11 solvates of LAM (in the series: with acetone, ethanol: two polymorphs: form I and form II, 2-propanol, n-butanol, tert-butanol, n-pentanol, benzonitrile, acetonitrile, DMSO and dioxane) were performed. The comparative solid state structural analysis of a new hydrate and 11 solvates of LAM has been undertaken in order to establish robustness of the supramolecular synthons 1 and 2 found in the crystal structure of LAM itself as well as LAM susceptibility to build methodical solid state supramolecular architecture in the given competitive surrounding of potential hydrogen bonds. The aminopyridine dimer homosynthon 1 [R(8)] has been switched from para-para (P-P) topology to ortho-ortho (O-O) topology in all crystal structures, except in LAM:n-pentanol:water solvate where it remains P-P. Homosynthon 2 [R(8)] of the LAM crystal structure imitates in the LAM solvates as a heterosynthon by replacing the triazine nitrogen proton acceptor atoms of LAM with the proton acceptors of solvates molecules.
PubMed: 38728045
DOI: 10.1107/S2052520624002567 -
PloS One 2024Inhaled nitric oxide (iNO) has a beneficial effect on hypoxemic respiratory failure. The increased use of concurrent iNO and milrinone was observed. We aimed to report... (Comparative Study)
Comparative Study
First-year outcomes of very low birth weight preterm singleton infants with hypoxemic respiratory failure treated with milrinone and inhaled nitric oxide (iNO) compared to iNO alone: A nationwide retrospective study.
BACKGROUND
Inhaled nitric oxide (iNO) has a beneficial effect on hypoxemic respiratory failure. The increased use of concurrent iNO and milrinone was observed. We aimed to report the trends of iNO use in the past 15 years in Taiwan and compare the first-year outcomes of combining iNO and milrinone to the iNO alone in very low birth weight preterm (VLBWP) infants under mechanical ventilation.
METHODS
This nationwide cohort study enrolled preterm singleton infants with birth weight <1500g treated with iNO from 2004 to 2019. Infants were divided into two groups, with a combination of intravenous milrinone (Group 2, n = 166) and without milrinone (Group 1, n = 591). After propensity score matching (PSM), each group's sample size is 124. The primary outcomes were all-cause mortality and the respiratory condition, including ventilator use and duration. The secondary outcomes were preterm morbidities within one year after birth.
RESULTS
After PSM, more infants in Group 2 needed inotropes. The mortality rate was significantly higher in Group 2 than in Group 1 from one month after birth till 1 year of age (55.1% vs. 13.5%) with the adjusted hazard ratio of 4.25 (95%CI = 2.42-7.47, p <0.001). For infants who died before 36 weeks of postmenstrual age (PMA), Group 2 had longer hospital stays compared to Group 1. For infants who survived after 36 weeks PMA, the incidence of moderate and severe bronchopulmonary dysplasia (BPD) was significantly higher in Group 2 than in Group 1. For infants who survived until one year of age, the incidence of pneumonia was significantly higher in Group 2 (28.30%) compared to Group 1 (12.62%) (p = 0.0153).
CONCLUSION
Combined treatment of iNO and milrinone is increasingly applied in VLBWP infants in Taiwan. This retrospective study did not support the benefits of combining iNO and milrinone on one-year survival and BPD prevention. A future prospective study is warranted.
Topics: Humans; Milrinone; Infant, Newborn; Nitric Oxide; Male; Administration, Inhalation; Female; Retrospective Studies; Infant, Very Low Birth Weight; Taiwan; Infant, Premature; Respiratory Insufficiency; Infant; Respiration, Artificial; Treatment Outcome; Hypoxia
PubMed: 38722851
DOI: 10.1371/journal.pone.0297137 -
Scientific Reports May 2024Thromboembolic events are complications in cancer patients and hypercoagulability has been linked to the tissue factor (TF) pathway, making this an attractive target....
Thromboembolic events are complications in cancer patients and hypercoagulability has been linked to the tissue factor (TF) pathway, making this an attractive target. Here, we investigated the effects of chemotherapeutics and CDK inhibitors (CDKI) abemaciclib/palbociclib (CDK4/6), THZ-1 (CDK7/12/13), and dinaciclib (CDK1/2/5/9) alone and in combination regimens on TF abundance and coagulation. The human colorectal cancer (CRC) cell line HROC173 was treated with 5-FU or gemcitabine to stimulate TF expression. TF cells were sorted, recultured, and re-analyzed. The effect of treatment alone or in combination was assessed by functional assays. Low-dose chemotherapy induced a hypercoagulable state and significantly upregulated TF, even after reculture without treatment. Cells exhibited characteristics of epithelial-mesenchymal transition, including high expression of vimentin and mucin. Dinaciclib and THZ-1 also upregulated TF, while abemaciclib and palbociclib downregulated it. Similar results were observed in coagulation assays. The same anticoagulant activity of abemaciclib was seen after incubation with peripheral immune cells from healthy donors and CRC patients. Abemaciclib reversed 5-FU-induced TF upregulation and prolonged clotting times in second-line treatment. Effects were independent of cytotoxicity, senescence, and p27 induction. TF-antibody blocking experiments confirmed the importance of TF in plasma coagulation, with Factor XII playing a minor role. Short-term abemaciclib counteracts 5-FU-induced hypercoagulation and eventually even prevents thromboembolic events.
Topics: Humans; Thromboplastin; Cell Line, Tumor; Fluorouracil; Colonic Neoplasms; Up-Regulation; Cyclin-Dependent Kinases; Protein Kinase Inhibitors; Aminopyridines; Benzimidazoles; Pyridinium Compounds; Cyclic N-Oxides; Indolizines; Epithelial-Mesenchymal Transition
PubMed: 38719932
DOI: 10.1038/s41598-024-61076-5 -
Drug Metabolism and Disposition: the... Jun 2024Brepocitinib is an oral once-daily Janus kinase 1 and Tyrosine kinase 2 selective inhibitor currently in development for the treatment of several autoimmune disorders....
Brepocitinib is an oral once-daily Janus kinase 1 and Tyrosine kinase 2 selective inhibitor currently in development for the treatment of several autoimmune disorders. Mass balance and metabolic profiles were determined using accelerator mass spectrometry in six healthy male participants following a single oral 60 mg dose of C-brepocitinib (∼300 nCi). The average mass balance recovery was 96.7% ± 6.3%, with the majority of dose (88.0% ± 8.0%) recovered in urine and 8.7% ± 2.1% of the dose recovered in feces. Absorption of brepocitinib was rapid, with maximal plasma concentrations of total radioactivity and brepocitinib achieved within 0.5 hours after dosing. Circulating radioactivity consisted primarily of brepocitinib (47.8%) and metabolite M1 (37.1%) derived from hydroxylation at the C5' position of the pyrazole ring. Fractional contributions to metabolism via cytochrome P450 enzymes were determined to be 0.77 for CYP3A4/5 and 0.14 for CYP1A2 based on phenotyping studies in human liver microsomes. However, additional clinical studies are required to understand the potential contribution of CYP1A1. Approximately 83% of the dose was eliminated as N-methylpyrazolyl oxidative metabolites, with 52.1% of the dose excreted as M1 alone. Notably, M1 was not observed as a circulating metabolite in earlier metabolic profiling of human plasma from a multiple ascending dose study with unlabeled brepocitinib. Mechanistic studies revealed that M1 was highly unstable in human plasma and phosphate buffer, undergoing chemical oxidation leading to loss of the 5-hydroxy-1-methylpyrazole moiety and formation of aminopyrimidine cleavage product M2. Time-dependent inhibition and trapping studies with M1 yielded insights into the mechanism of this unusual and unexpected instability. SIGNIFICANCE STATEMENT: This study provides a detailed understanding of the disposition and metabolism of brepocitinib, a JAK1/TYK2 inhibitor for atopic dermatitis, in humans as well as characterization of clearance pathways and pharmacokinetics of brepocitinib and its metabolites.
Topics: Humans; Male; Adult; Protein Kinase Inhibitors; Young Adult; Pyrazoles; Janus Kinase 1; Administration, Oral; Cytochrome P-450 CYP3A; Healthy Volunteers; Microsomes, Liver; Janus Kinase 2; Feces; Hydroxylation; Cytochrome P-450 CYP1A2; Middle Aged
PubMed: 38719744
DOI: 10.1124/dmd.124.001750 -
ACS Infectious Diseases Jun 2024The current tuberculosis (TB) treatment is challenged by a complex first-line treatment for drug-sensitive (DS) TB. Additionally, the prevalence of multidrug (MDR)- and...
The current tuberculosis (TB) treatment is challenged by a complex first-line treatment for drug-sensitive (DS) TB. Additionally, the prevalence of multidrug (MDR)- and extensively drug (XDR)-resistant TB necessitates the search for new drug prototypes. We synthesized and screened 30 hybrid compounds containing aminopyridine and 2-chloro-3-formyl quinoline to arrive at a compound with potent antimycobacterial activity, UH-NIP-16. Subsequently, antimycobacterial activity against DS and MDR () strains were performed. It demonstrated an MIC value of 1.86 ± 0.21 μM for laboratory pathogenic strain H37Rv and 3.045 ± 0.813 μM for a clinical strain CDC1551. UH-NIP-16 also decreased the MIC values of streptomycin, isoniazid, ethambutol, and bedaquiline to about 45, 55, 68, and 76%, respectively, when used in combination, potentiating their activities. The molecule was active against a clinical MDR strain. Cytotoxicity on PBMCs from healthy donors and on human cell lines was found to be negligible. Further, blind docking of UH-NIP-16 using Auto Dock Vina and MGL tools onto diverse proteins showed high binding affinities with multiple proteins, the top five targets being metabolically critical proteins CelA1, DevS, MmaA4, lysine acetyltransferase, and immunity factor for tuberculosis necrotizing toxin. These bindings were confirmed by fluorescence spectroscopy using a representative protein, MmaA4. Envisaging that a pathogen will have a lower probability of developing resistance to a hybrid molecule with multiple targets, we propose that UH-NIP-16 can be further developed as a lead molecule with the bacteriostatic potential against , both alone and in combination with first-line drugs.
Topics: Mycobacterium tuberculosis; Antitubercular Agents; Humans; Microbial Sensitivity Tests; Quinolines; Molecular Docking Simulation; Isonicotinic Acids; Tuberculosis
PubMed: 38717380
DOI: 10.1021/acsinfecdis.4c00277 -
European Journal of Medicinal Chemistry Jun 2024Histone deacetylase 6 (HDAC6) is an emerging drug target to treat oncological and non-oncological conditions. Since highly selective HDAC6 inhibitors display limited...
Histone deacetylase 6 (HDAC6) is an emerging drug target to treat oncological and non-oncological conditions. Since highly selective HDAC6 inhibitors display limited anticancer activity when used as single agent, they usually require combination therapies with other chemotherapeutics. In this work, we synthesized a mini library of analogues of the preferential HDAC6 inhibitor HPOB in only two steps via an Ugi four-component reaction as the key step. Biochemical HDAC inhibition and cell viability assays led to the identification of 1g (highest antileukemic activity) and 2b (highest HDAC6 inhibition) as hit compounds. In subsequent combination screens, both 1g and especially 2b showed synergy with DNA methyltransferase inhibitor decitabine in acute myeloid leukemia (AML). Our findings highlight the potential of combining HDAC6 inhibitors with DNA methyltransferase inhibitors as a strategy to improve AML treatment outcomes.
Topics: Humans; Histone Deacetylase Inhibitors; Histone Deacetylase 6; Decitabine; Drug Synergism; Structure-Activity Relationship; Leukemia, Myeloid, Acute; Molecular Structure; Antineoplastic Agents; Drug Screening Assays, Antitumor; Cell Survival; Cell Proliferation; Dose-Response Relationship, Drug; Cell Line, Tumor; Peptoids; Aminopyridines; Benzamides
PubMed: 38714044
DOI: 10.1016/j.ejmech.2024.116447 -
Current Oncology Reports Jun 2024Update on the most recent clinical evidence on CDK4/6 inhibitors (CDK4/6i) in the treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor... (Review)
Review
PURPOSE OF REVIEW
Update on the most recent clinical evidence on CDK4/6 inhibitors (CDK4/6i) in the treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor (HER)2-negative breast cancer.
RECENT FINDINGS
Over the past decade, CDK4/6i have become part of the standard of care treatment of patients with both metastatic and high-risk early HR + /HER2- breast cancers. The three available CDK4/6i (palbociclib, ribociclib and abemaciclib) have been extensively studied in combination with endocrine therapy (ET) in metastatic breast cancer (mBC) with consistent prolongation of progression free survival; however, ribociclib has emerged as the preferred first line agent in mBC given overall survival benefit over endocrine monotherapy. In early BC, abemaciclib is the only currently approved agent while ribociclib has early positive clinical trial data. Toxicities and financial burden limit the use of CDK4/6i in all patients and resource-poor settings, and optimal timing of their use in mBC remains unclear. There is considerable evidence for the use of CDK4/6i in metastatic and early HR + /HER2- breast cancer, but knowledge gaps remain, and further research is necessary to better define their optimal use.
Topics: Humans; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Breast Neoplasms; Protein Kinase Inhibitors; Female; Aminopyridines; Purines; Benzimidazoles
PubMed: 38713311
DOI: 10.1007/s11912-024-01540-7 -
BioRxiv : the Preprint Server For... May 2024Spinal cord injuries (SCI) often lead to lifelong disability. Among the various types of injuries, incomplete and discomplete injuries, where some axons remain intact,...
Spinal cord injuries (SCI) often lead to lifelong disability. Among the various types of injuries, incomplete and discomplete injuries, where some axons remain intact, offer potential for recovery. However, demyelination of these spared axons can worsen disability. Demyelination is a reversible phenomenon, and drugs like 4-aminopyridine (4AP), which target K+ channels in demyelinated axons, show that conduction can be restored. Yet, accurately assessing and monitoring demyelination post-SCI remains challenging due to the lack of suitable imaging methods. In this study, we introduce a novel approach utilizing the positron emission tomography (PET) tracer, [ F]3F4AP, specifically targeting K+ channels in demyelinated axons for SCI imaging. Rats with incomplete contusion injuries were imaged up to one month post-injury, revealing [ F]3F4AP's exceptional sensitivity to injury and its ability to detect temporal changes. Further validation through autoradiography and immunohistochemistry confirmed [ F]3F4AP's targeting of demyelinated axons. In a proof-of-concept study involving human subjects, [ F]3F4AP differentiated between a severe and a largely recovered incomplete injury, indicating axonal loss and demyelination, respectively. Moreover, alterations in tracer delivery were evident on dynamic PET images, suggestive of differences in spinal cord blood flow between the injuries. In conclusion, [ F]3F4AP demonstrates efficacy in detecting incomplete SCI in both animal models and humans. The potential for monitoring post-SCI demyelination changes and response to therapy underscores the utility of [ F]3F4AP in advancing our understanding and management of spinal cord injuries.
PubMed: 38712041
DOI: 10.1101/2024.04.24.590984