-
Journal of Medicinal Chemistry Jun 2024Structure-activity relationship studies of 2,8-disubstituted-1,5-naphthyridines, previously reported as potent inhibitors of () phosphatidylinositol-4-kinase β (PI4K),...
Structure-activity relationship studies of 2,8-disubstituted-1,5-naphthyridines, previously reported as potent inhibitors of () phosphatidylinositol-4-kinase β (PI4K), identified 1,5-naphthyridines with basic groups at 8-position, which retained PI4K inhibitory activity but switched primary mode of action to the host hemoglobin degradation pathway through inhibition of hemozoin formation. These compounds showed minimal off-target inhibitory activity against the human phosphoinositide kinases and MINK1 and MAP4K kinases, which were associated with the teratogenicity and testicular toxicity observed in rats for the PI4K inhibitor clinical candidate MMV390048. A representative compound from the series retained activity against field isolates and lab-raised drug-resistant strains of . It was efficacious in the humanized NSG mouse malaria infection model at a single oral dose of 32 mg/kg. This compound was nonteratogenic in the zebrafish embryo model of teratogenicity and has a low predicted human dose, indicating that this series has the potential to deliver a preclinical candidate for malaria.
PubMed: 38918002
DOI: 10.1021/acs.jmedchem.4c01154 -
Biochimica Et Biophysica Acta.... Jun 2024Phospholipase A's (PLA's) constitute a superfamily of enzymes that hydrolyze the sn-2 fatty acyl chain on glycerophospholipids. We have previously reported that each PLA...
Phospholipase A's (PLA's) constitute a superfamily of enzymes that hydrolyze the sn-2 fatty acyl chain on glycerophospholipids. We have previously reported that each PLA Type shows a unique substrate specificity for the molecular species it hydrolyzes, especially the acyl chain that is cleaved from the sn-2 position and to some extent the polar group. However, phosphatidylinositol (PI) and PI phosphates (PIPs) have not been as well studied as substrates as other phospholipids because the PIPs require adaptation of the standard analysis methods, but they are important in vivo. We determined the in vitro activity of the three major types of human PLA's, namely the cytosolic (c), calcium-independent (i), and secreted (s) PLAs toward PI, PI-4-phosphate (PI(4)P), and PI-4,5-bisphosphate (PI(4,5)P). The in vitro assay revealed that Group IVA cPLA (GIVA cPLA) showed relatively high activity toward PI and PI(4)P among the tested PLA's; nevertheless, the highly hydrophilic headgroup disrupted the interaction between the lipid surface and the enzyme. GIVA cPLA and GVIA iPLA showed detectable activity toward PI(4,5)P, but it appeared to be a poorer substrate for all of the PLA's tested. Furthermore, molecular dynamics (MD) simulations demonstrated that Thr416 and Glu418 of GIVA cPLA contribute significantly to accommodating the hydrophilic head groups of PI and PI(4)P, which could explain some selectivity for PI and PI(4)P. These results indicated that GIVA cPLA can accommodate PI and PI(4)P in its active site and hydrolyze them, suggesting that the GIVA cPLA may best account for the PI and PIP hydrolysis in living cells.
PubMed: 38917952
DOI: 10.1016/j.bbalip.2024.159527 -
ACS Infectious Diseases Jun 2024Human immunodeficiency virus (HIV) assembly at an infected cell's plasma membrane requires membrane deformation to organize the near-spherical shape of an immature...
Human immunodeficiency virus (HIV) assembly at an infected cell's plasma membrane requires membrane deformation to organize the near-spherical shape of an immature virus. While the cellular expression of HIV Gag is sufficient to initiate budding of virus-like particles, how Gag generates membrane curvature is not fully understood. Using highly curved lipid nanotubes, we have investigated the physicochemical basis of the membrane activity of recombinant nonmyristoylated Gag-Δp6. Gag protein, upon adsorption onto the membrane, resulted in the shape changes of both charged and uncharged nanotubes. This shape change was more pronounced in the presence of charged lipids, especially phosphatidylinositol bisphosphate (PI(4,5)P). We found that Gag modified the interfacial tension of phospholipid bilayer membranes, as judged by comparison with the effects of amphipathic peptides and nonionic detergent. Bioinformatic analysis demonstrated that a region of the capsid and SP1 domains junction of Gag is structurally similar to the amphipathic peptide magainin-1. This region accounts for integral changes in the physical properties of the membrane upon Gag adsorption, as we showed with the synthetic CA-SP1 junction peptide. Phenomenologically, membrane-adsorbed Gag could diminish the energetic cost of increasing the membrane area in a way similar to foam formation. We propose that Gag acts as a surface-active substance at the HIV budding site that softens the membrane at the place of Gag adsorption, lowering the energy for membrane bending. Finally, our experimental data and theoretical considerations give a lipid-centric view and common mechanism by which proteins could bend membranes, despite not having intrinsic curvature in their molecular surfaces or assemblies.
PubMed: 38917054
DOI: 10.1021/acsinfecdis.4c00251 -
International Journal of Clinical... Jun 2024The therapeutic impact of the Wenyang Huoxue (WYXH) formula on coronary atherosclerotic heart disease (CHD) is well established, yet the precise mechanisms are currently...
BACKGROUND
The therapeutic impact of the Wenyang Huoxue (WYXH) formula on coronary atherosclerotic heart disease (CHD) is well established, yet the precise mechanisms are currently not fully understood. This study provides preliminary insights into the potential mechanisms underlying the therapeutic effects of the formula on CHD by utilizing network pharmacology and molecular docking technology.
MATERIALS AND METHODS
The primary active constituents and their corresponding action targets for the formula were retrieved from the TCMSP database. Utilizing Cytoscape 3.9.1 software, a network linking the components of the formula to their respective targets was constructed. Information was collected from Genecards, OMIM, TTD, and DrugBank databases to identify targets related to CHD. The common targets shared by the formula and CHD were then imported into the STRING database to create a protein-protein interaction (PPI) network. Following this, enrichment analyses were performed on the shared targets using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, molecular docking was conducted on the primary active compounds and the core targets.
RESULTS
The network encompassing the components and targets of the formula comprises a total of 311 nodes and 895 edges. Compounds exhibiting higher degree centrality consist of quercetin, β-sitosterol, and kaempferol. In the PPI network, proteins with elevated degree centrality are protein kinase B (AKT1), epidermal growth factor receptor (EGFR), and mitogen-activated protein kinase 3 (MAPK3). The results of GO and KEGG enrichment analyses reveal that the biological processes associated with the efficacy of the formula in treating CHD primarily involve positive regulation of gene expression, hypoxia response, and lipopolysaccharide response, among others. The signaling pathways primarily involved include phosphatidylinositol 3-kinase and protein kinase B (PI3K-AKT), MAPK3, tumor necrosis factor (TNF), and so on. Molecular docking results demonstrate a strong affinity between quercetin, β-sitosterol, and kaempferol with AKT1, EGFR, and MAPK3.
CONCLUSION
We showed for the first time that AKT1, EGFR, and MAPK3 are potential targets influenced by the WYHX formula in CHD treatment. The therapeutic effects could possibly involve signaling pathways such as the PI3K-AKT, MAPK, TNF, and AGE-RAGE pathways.
PubMed: 38916485
DOI: 10.5414/CP204575 -
Frontiers in Neuroscience 2024Alzheimer's disease (AD) is the most common form of dementia and is characterized by the accumulation of amyloid-beta (Aβ) plaques and neurofibrillary Tau tangles in...
Alzheimer's disease (AD) is the most common form of dementia and is characterized by the accumulation of amyloid-beta (Aβ) plaques and neurofibrillary Tau tangles in the brain. We previously identified a set of candidate AD microRNAs (miRNAs) in human cerebrospinal fluid (CSF) and used a target prediction pipeline to identify mRNAs and pathways that could potentially be regulated by the miRNAs. Of these pathways, clathrin mediated endocytosis (CME) was selected for further investigation. CME is altered in multiple brain cell types in AD and is implicated in early cellular phenotypes such as enlarged early endosomes and pathogenic processing of Aβ. However, a comprehensive evaluation of major CME hub proteins in humans with AD across multiple brain regions is lacking. Thus, we used immunoblots to evaluate human post-mortem AD and control (CTL) frontal cortex (FC; AD = 22, CTL = 23) and hippocampus (HP; AD = 34, CTL = 22) for changes in Intersectin 1 (ITSN1), Phosphatidylinositol Binding Clathrin Assembly Protein gene (PICALM), Clathrin Light Chain (CLT), FCH and Mu Domain Containing Endocytic Adaptor 1 (FCHO1), Adaptor Related Protein Complex 2 (AP2) Subunit Alpha 1 (AP2A1), and Dynamin 2 (DNM2). Of these, we found that in AD, ITSN1-long (ITSN1-L) was decreased in the FC of males and HP of females, while ITSN1-short was increased in the HP of both males and females. We further evaluated ITSN1-L levels in cortex (CTX) and HP of the 5xFAD mouse model of Aβ pathology at different timepoints during aging and disease progression by immunoblot ( = 5-8 per group). At 3 months, female 5xFAD exhibited an increase of ITSN1-L in CTX but a decrease at 6 and 9 months. Additionally, immunofluorescent staining of 5xFAD primary HP neurons showed an increase of ITSN1-L in matured 5xFAD neurons at 21 and 28 days . Together, our studies show that in AD, isoforms of ITSN1 change in a brain region-and sex-dependent manner. Further, changes in ITSN1-L are transient with levels increasing during early Aβ accumulation and decreasing during later progression. These findings suggest that ITSN1 expression, and consequently CME activity, may change depending on the stage of disease progression.
PubMed: 38915309
DOI: 10.3389/fnins.2024.1426180 -
American Journal of Physiology.... Jun 2024FATP4 was thought to mediate intestinal lipid absorption which was disputed by a study using keratinocyte-Fatp4-rescued Fatp4 mice. These knockouts when fed with a...
FATP4 was thought to mediate intestinal lipid absorption which was disputed by a study using keratinocyte-Fatp4-rescued Fatp4 mice. These knockouts when fed with a western diet showed elevated intestinal triglyceride (TG) and fatty-acid levels. To investigate a possible role of FATP4 on intestinal lipid processing, (KO) mice were generated by -specific inactivation of the Fatp4 gene. We aimed to measure circulating and intestinal lipids in control and KO mice after acute or chronic fat intake or during ageing. Remarkably, mice displayed a ~30% decrease in ileal behenic, lignoceric, and nervonic acids, ceramides containing these FA, as well as, ileal sphingomyelin, phosphatidylcholine, and phosphatidylinositol levels. Such decreases were concomitant with an increase in jejunal cholesterol ester. After 2-week recovery from high lipid overload by tyloxapol and oral-lipid treatment, mice showed an increase in plasma TG and chylomicrons. Upon overnight fasting followed by an oral fat meal, mice showed an increase in plasma TG-rich lipoproteins and particle number of chylomicrons and very low-density lipoproteins. During ageing or after feeding with a high-fat high-cholesterol (HFHC) diet, mice showed an increase in plasma TG, fatty acids, glycerol, and lipoproteins as well as intestinal lipids. HFHC-fed KO mice displayed an increase in body weights, the numbers of lipid droplets with larger sizes in the ileum concomitant with a decrease in ileal ceramides and phosphatidylcholine. Thus, enterocyte FATP4 deficiency led to a metabolic shift from polar to neutral lipids in distal intestine rendering an increase in plasma lipids and lipoproteins.
PubMed: 38915276
DOI: 10.1152/ajpgi.00109.2024 -
Journal of Neurogenetics Jun 2024The neurogenetics and vision community recently mourned William L. Pak, PhD, whose pioneering work spearheaded the genetic, electrophysiological, and molecular bases of...
Personal essay of a rookie's journey with Bill Pak and his legacy: tales and perspectives on PI-PLC, NorpA and cyclophilin, NinaA - William L. Pak, PhD., 1932-2023: in memoriam.
The neurogenetics and vision community recently mourned William L. Pak, PhD, whose pioneering work spearheaded the genetic, electrophysiological, and molecular bases of biological processes underpinning vision. This essay provides a historical background to the daunting challenges and personal experiences that carved the path to seminal findings. It also reflects on the intellectual framework, mentoring philosophy, and inspirational legacy of Bill Pak's research. An emphasis and perspectives are placed on the discoveries and implications to date of the phosphatidylinositol-specific phospholipase C (P IP LC), NorpA, and the cyclophilin, NinaA of the fruit fly, Drosophila melanogaster, and their respective mammalian homologues, P I-P LCβ4, and cyclophilin-related protein, Ran-binding protein 2 (Ranbp2) in critical biological processes and diseases of photoreceptors and other neurons.
PubMed: 38913811
DOI: 10.1080/01677063.2024.2366455 -
PeerJ 2024(Thunb.) Makino, a well-known edible and medicinal plant, has anti-aging properties and is used to treataging-associated conditions such as diabetes, metabolic...
BACKGROUND
(Thunb.) Makino, a well-known edible and medicinal plant, has anti-aging properties and is used to treataging-associated conditions such as diabetes, metabolic syndrome, and cardiovascular diseases. Gypenosides (GYPs) are the primary constituents of . Increasing evidence indicates that GYPs are effective at preserving mitochondrial homeostasis and preventing heart failure (HF). This study aimed to uncover the cardioprotective mechanisms of GYPs related to mitochondrial regulation.
METHODS
The bioactive components in GYPs and the potential targets in treating HF were obtained and screened using the network pharmacology approach, followed by drug-disease target prediction and enrichment analyses. The pharmacological effects of GYPs in cardioprotection, mitochondrial function, mitochondrial quality control, and underlying mechanisms were further investigated in Doxorubicin (Dox)-stimulated H9c2 cardiomyocytes.
RESULTS
A total of 88 bioactive compounds of GYPs and their respective 71 drug-disease targets were identified. The hub targets covered MAPK, EGFR, PI3KCA, and Mcl-1. Enrichment analysis revealed that the pathways primarily contained PI3K/Akt, MAPK, and FoxO signalings, as well as calcium regulation, protein phosphorylation, apoptosis, and mitophagy process. In Dox-stimulated H9c2 rat cardiomyocytes, pretreatment with GYPs increased cell viability, enhanced cellular ATP content, restored basal oxygen consumption rate (OCR), and improved mitochondrial membrane potential (MMP). Furthermore, GYPs improved PINK1/parkin-mediated mitophagy without influencing mitochondrial fission/fusion proteins and the autophagic LC3 levels. Mechanistically, the phosphorylation of PI3K, Akt, GSK-3β, and the protein level of Mcl-1 was upregulated by GYP treatment.
CONCLUSION
Our findings reveal that GYPs exert cardioprotective effects by rescuing the defective mitophagy, and PI3K/Akt/GSK-3/Mcl-1 signaling is potentially involved in this process.
Topics: Gynostemma; Mitophagy; Glycogen Synthase Kinase 3 beta; Signal Transduction; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-akt; Cardiotonic Agents; Plant Extracts; Phosphatidylinositol 3-Kinases; Animals; Rats; Myocytes, Cardiac; Cell Line
PubMed: 38912051
DOI: 10.7717/peerj.17538 -
International Journal of Nanomedicine 2024Endometriosis (EM) is an estrogen-dependent benign gynecologic disease affecting approximately 10% of reproductive-age women with a high recurrence rate, but lacks...
INTRODUCTION
Endometriosis (EM) is an estrogen-dependent benign gynecologic disease affecting approximately 10% of reproductive-age women with a high recurrence rate, but lacks reliable biomarkers. No previous studies have investigated the possible use of extracellular vesicle (EV)-associated micro RNAs (miRNAs) from menstrual blood (MB) as candidate diagnostic or prognostic markers of EM.
METHODS
Specimens were obtained from endometriosis and non-endometriosis patients at the International Peace Maternity and Child Health Hospital in Shanghai. Microarray was used to screen differentially expressed miRNAs among peritoneal fluid (PF), fallopian tube fluid (FF), and MB. Dual-luciferase reporter gene assay was carried out to verify the relationship between miR-4443 and ACSS2. Cell proliferation and Transwell invasion assays were performed in vitro after intervention on miR-4443 and ACSS2 in hEM15A human endometrial stromal cells and primary human endometrial stromal cells (hESCs). Spearman correlation analysis, receiver operating characteristic (ROC) curve analysis, and survival analysis were applied to clinical data, including severity of symptoms and relapse of EM among EM patients.
RESULTS
EV-associated miR-4443 was abundant in MB of endometriosis patients. ACSS2 knockdown and miR-4443 overexpression promoted cell proliferation and migration via the PI3K/AKT pathway. miR-4443 levels in MB-EVs were positively correlated with the degree of dyspareunia (r=0.64; P<0.0001) and dysmenorrhea (r=0.42; P<0.01) in the endometriosis group. ROC curve analyses showed an area under the curve (AUC) of 0.741 (95% CI 0.624-0.858; P<0.05) for miR-4443 and an AUC of 0.929 (95% CI 0.880-0.978; P<0.05) for the combination of miR-4443 and dysmenorrhea.
CONCLUSION
MB-derived EV-associated miR-4443 might participate in endometriosis development, thus providing a new candidate biomarker for the noninvasive prediction of endometriosis recurrence.
Topics: Humans; Endometriosis; Female; MicroRNAs; Extracellular Vesicles; Proto-Oncogene Proteins c-akt; Adult; Cell Proliferation; Phosphatidylinositol 3-Kinases; Disease Progression; Cell Movement; Signal Transduction; Cell Line; Endometrium
PubMed: 38911502
DOI: 10.2147/IJN.S456594 -
RSC Medicinal Chemistry Jun 2024[This corrects the article DOI: 10.1039/D3MD00630A.].
[This corrects the article DOI: 10.1039/D3MD00630A.].
PubMed: 38911159
DOI: 10.1039/d4md90022g