-
International Journal of Molecular... Mar 2016The Aquilaria malaccensis (Thymelaeaceae) tree is a source of precious fragrant resin, called agarwood, which is widely used in traditional medicines in East Asia...
The Aquilaria malaccensis (Thymelaeaceae) tree is a source of precious fragrant resin, called agarwood, which is widely used in traditional medicines in East Asia against diseases such as asthma. In our continuous search for active natural products, A. malaccensis seeds ethanolic extract demonstrated antiallergic effect with an IC50 value less than 1 µg/mL. Therefore, the present research aimed to purify and identify the antiallergic principle of A. malaccensis through a bioactivity-guided fractionation approach. We found that phorbol ester-rich fraction was responsible for the antiallergic activity of A. malaccensis seeds. One new active phorbol ester, 12-O-(2Z,4E,6E)-tetradeca-2,4,6-trienoylphorbol-13-acetate, aquimavitalin (1) was isolated. The structure of 1 was assigned by means of 1D and 2D NMR data and high-resolution mass spectrometry (HR-MS). Aquimavitalin (1) showed strong inhibitory activity in A23187- and antigen-induced degranulation assay with IC50 values of 1.7 and 11 nM, respectively, with a therapeutic index up to 71,000. The antiallergic activities of A. malaccensis seeds and aquimavitalin (1) have never been revealed before. The results indicated that A. malaccensis seeds and the pure compound have the potential for use in the treatment of allergy.
Topics: Animals; Anti-Allergic Agents; Cell Line, Tumor; Phorbol Esters; Plant Extracts; Rats; Seeds; Thymelaeaceae
PubMed: 27007372
DOI: 10.3390/ijms17030398 -
Journal of Biomolecular Structure &... 2022Munc13-1 is a presynaptic active zone protein that plays a critical role in priming the synaptic vesicle and releasing neurotransmitters in the brain. Munc13-1 acts as a...
Munc13-1 is a presynaptic active zone protein that plays a critical role in priming the synaptic vesicle and releasing neurotransmitters in the brain. Munc13-1 acts as a scaffold and is activated when diacylglycerol (DAG)/phorbol ester binds to its C1 domain in the plasma membrane. Our previous studies showed that bryostatin 1 activated the Munc13-1, but resveratrol inhibited the phorbol ester-induced Munc13-1 activity. To gain structural insights into the binding of the ligand into Munc13-1 C1 in the membrane, we conducted 1.0 μs molecular dynamics (MD) simulation on Munc13-1 C1-ligand-lipid ternary system using phorbol 13-acetate, bryostatin 1 and resveratrol as ligands. Munc13-1 C1 shows higher conformational stability and less mobility along membrane with phorbol 13-acetate and bryostatin 1 than with resveratrol. Bryostatin 1 and phorbol ester remained in the protein active site, but resveratrol moved out of Munc13-1 C1 during the MD simulation. While bryostatin 1-bound Munc13-1 C1 showed two different positioning in the membrane, phorbol 13-acetate and resveratrol-bound Munc13-1 C1 only showed one positioning. Phorbol 13-acetate formed hydrogen bond with Ala-574 and Gly-589. Bryostatin 1 had more hydrogen bonds with Trp-588 and Arg-592 than with other residues. Resveratrol formed hydrogen bond with Ile-590. This study suggests that different ligands control Munc13-1 C1's mobility and positioning in the membrane differently. Ligand also has a critical role in the interaction between Munc13-1 C1 and lipid membrane. Our results provide structural basis of the pharmacological activity of the ligands and highlight the importance of membrane in Munc13-1 activity.Communicated by Ramaswamy H. Sarma.
Topics: Molecular Dynamics Simulation; Ligands; Resveratrol; Phorbol Esters; Lipids
PubMed: 34779746
DOI: 10.1080/07391102.2021.2001375 -
Journal of Biomolecular Structure &... 2023C1 domains are lipid-binding structural units of about 50 residues. Typical C1 domains associate with the plasma membrane and bind to diacylglycerol/phorbol ester during...
C1 domains are lipid-binding structural units of about 50 residues. Typical C1 domains associate with the plasma membrane and bind to diacylglycerol/phorbol ester during the activation of the proteins containing these domains. Although the overall structure of the C1 domains are similar, there are differences in their primary sequence and in the orientation of the ligand/lipid binding residues. To gain structural insights into the ligand/lipid binding, we performed molecular docking of phorbol 13-acetate into the C1 domain and 1.0 μs molecular dynamics simulation on the C1 domain-ligand-lipid ternary system for PKCθ C1A, PKCδ C1B, PKCβII C1B, PKCθ C1B, Munc13-1 C1, and βII-Chimaerin C1. We divided these C1 domains into three types based on the orientations of Gln-27 and Trp/Tyr-22. In type 1, Trp/Tyr-22 is outside and Gln-27 is inside the ligand binding pocket. In type 2, both Trp/Tyr-22 and Gln-27 are outside the ligand binding pocket, and in type 3, Trp/Tyr-22 is inside and Gln-27 is outside the pocket. The type 1 C1 domains showed higher ligand binding and higher membrane binding with a shorter distance between the C1 domain and the membrane than the type 2 and type 3. For ligand binding, Pro-11 plays a major role in the type 1 and 2, and Gly-23 in the type 1 and type 3 C1 domains. This study elucidates the role of Gln-27, Trp-22, Pro-11 and Gly-23 in ligand/lipid binding in typical C1 domains and bears significance in developing selective modulators of C1 domain-containing proteins.Communicated by Ramaswamy H. Sarma.
Topics: Molecular Dynamics Simulation; Molecular Docking Simulation; Protein Structure, Tertiary; Ligands; Protein Binding; Binding Sites; Phorbol Esters; Lipids
PubMed: 36602779
DOI: 10.1080/07391102.2022.2163699 -
The Journal of Investigative Dermatology Jun 1991Previous studies have established that some phorbol compounds that are active in binding to protein kinase C (PKC) are also strong mitogens for human melanocytes in...
Previous studies have established that some phorbol compounds that are active in binding to protein kinase C (PKC) are also strong mitogens for human melanocytes in culture. Structure/activity studies on tigliane class phorbol compounds, which lack an oxygen at the 12 position, have shown that tumor-promoting activity can be diminished or abolished though retaining other biologic activities of phorbol compounds, including the ability to activate PKC. In this study, two tigliane class phorbol derivates [12 deoxyphorbol, 13 isobutyrate (DPIB) and 12 deoxyphorbol, 13 phenylacetate (DPPA)] were studied for their ability to stimulate melanocyte proliferation in a serum-free culture system based on MCDB 153 medium. Compared to the activity of phorbol 12-O-myristate, 13 acetate (PMA), a widely used tumor-promoting phorbol derivative, DPIB and DPPA were effective mitogens for human melanocytes. The importance of PKC activation in mitogenic modulation of human melanocytes is further supported by the stereospecific mitogenic activity of (-)Indolactam V, a PKC-activating compound structurally unrelated to phorbols. The use of the tigliane type phorbols DPIB and DPPA to stimulate growth of human melanocytes may provide safer compounds for laboratory or patient studies and may also provide further insights into the role of PKC activation in human melanocyte biology.
Topics: Cell Division; Cells, Cultured; Enzyme Activation; Humans; Indoles; Lactams; Melanocytes; Phorbol Esters; Protein Kinase C; Stimulation, Chemical; Tetradecanoylphorbol Acetate
PubMed: 2045687
DOI: 10.1111/1523-1747.ep12476565 -
The Journal of Clinical Investigation Apr 1990Induction of human erythroleukemia (HEL) cells with nanomolar tumor-promoting phorbol myristate acetate (PMA) diesters results in the synchronous acquisition of multiple...
Induction of human erythroleukemia (HEL) cells with nanomolar tumor-promoting phorbol myristate acetate (PMA) diesters results in the synchronous acquisition of multiple markers of the megakaryocyte phenotype. Induced cells markedly increase their content of cytoplasm and show features of morphological maturation. At the ultrastructural level, PMA-treated cells show increases in cytoplasm, nuclear lobulation and nucleolar content, and free ribosomes. Limited numbers of cells also express alpha-granules and nascent demarcation membrane systems. Functionally, PMA-stimulated HEL cells express increased amounts of the megakaryocyte/platelet proteins: glycoprotein IIb/IIIa, platelet factor 4, von Willebrand factor, glycoprotein Ib, and thrombospondin. No changes are observed in antigenic markers of the erythroid (glycophorin A) or macrophage lineages (MO-1 or MO-2). The increases in antigenic expression are rapid, reaching maximum levels within 3-4 d under serum-free conditions. Treatment with PMA also abruptly (within 1-2 d) inhibits cellular division in these cells. Washout studies indicate that phorbols exert their effect within 18-24 h, the approximate cell cycle time for these cells. Consistent with proliferative arrest, c-myc proto-oncogene transcripts begin to decline within 8 h of PMA treatment, although transcripts of c-myb are unaffected. Importantly, megakaryocyte differentiation is associated with endomitotic DNA synthesis (i.e., continued DNA synthesis in the absence of mitosis and cytokinesis), with HEL cells reaching a DNA content of 3-12 times that of unstimulated cells. Endomitosis is coordinately regulated with changes in antigenic expression and cell size such that those cells having the highest DNA content are the largest and also express the greatest levels of antigen.
Topics: Antigens; Cell Differentiation; Cell Division; Cell Fusion; Humans; Interphase; Leukemia, Erythroblastic, Acute; Megakaryocytes; Phenotype; Phorbol 12,13-Dibutyrate; Protein Kinase C; Proto-Oncogene Mas; Proto-Oncogenes; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured
PubMed: 2318965
DOI: 10.1172/JCI114538 -
British Journal of Cancer Oct 1985Epidermal tumourigenesis can be achieved in rodents by the application of a single subthreshold dose of a carcinogen (initiation) followed by repeated applications of a... (Review)
Review
Defective responses of transformed keratinocytes to terminal differentiation stimuli. Their role in epidermal tumour promotion by phorbol esters and by deep skin wounding.
Epidermal tumourigenesis can be achieved in rodents by the application of a single subthreshold dose of a carcinogen (initiation) followed by repeated applications of a tumour promoter such as 12-0-tetradecanoyl phorbol, 13-acetate (TPA). TPA induces terminal differentiation in the majority of epidermal keratinocytes in vitro. However, transformed keratinocytes respond weakly to this terminal differentiation signal, and it is suggested that this property allows initiated cells and their progeny to obtain a selective advantage over their normal counterparts during promotion of papilloma formation by TPA. New data are reviewed which suggest that a putative wound hormone TGF-beta has similar differential effects on normal and transformed epithelial cells to those of TPA. It is proposed that the release of TGF-beta from platelets following deep skin wounding may be an explanation as to why wounding is a promoting stimulus but milder forms of epidermal injury are not. Weakly promoting hyperplasiogenic agents are also discussed within the context of a selection theory of tumour promotion.
Topics: Animals; Carcinogens; Cell Differentiation; Cell Transformation, Neoplastic; Epidermis; In Vitro Techniques; Keratins; Mice; Mitosis; Oncogenes; Papilloma; Peptides; Phenotype; Phorbols; Protein Kinase C; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Transforming Growth Factors
PubMed: 2415144
DOI: 10.1038/bjc.1985.219 -
Experimental and Molecular Pathology Apr 2022Neutrophils stand sentinel over infection and possess diverse antimicrobial weapons, including neutrophil extracellular traps (NETs). NETs are composed of web-like...
Neutrophils stand sentinel over infection and possess diverse antimicrobial weapons, including neutrophil extracellular traps (NETs). NETs are composed of web-like extracellular DNA decorated with antimicrobial substances and can trap and eliminate invading microorganisms. Although phorbol 12-myristate 13-acetate (PMA) is a potent NET inducer, previous studies have demonstrated that not all neutrophils exhibit NET formation even if stimulated by PMA at high concentrations. This study first showed that some neutrophils stimulated by PMA displayed a swollen nucleus but not NET formation and that hypoxic environments suppressed the NET release. Next, characterization of PMA-stimulated neutrophils with a swollen nucleus was accomplished by differentiating between suicidal-type NETosis and apoptosis. Furthermore, the significance of the phenomenon was examined using formalin-fixed, paraffin-embedded human lung disease tissues with and without pneumonia. As a result, histone H3 citrullination, DNA outflow, propidium iodide labeling, resistance to DNase I, and suspended actin rearrangement were characteristics of PMA-stimulated neutrophils with a swollen nucleus distinct from neutrophils that underwent either suicidal-type NETosis or apoptosis. Neutrophils stimulated by PMA under hypoxic conditions secreted matrix metalloproteinase-9 cytotoxic to human lung-derived fibroblasts. Further, deposition of neutrophil-derived citrullinated histone H3 chromatin substances in pulmonary lesions was greater in patients with pneumonia than in patients without pneumonia and positively correlated with hypoxia-inducible factor-1α expression. The collective findings suggested that neutrophils activated under hypoxic conditions could be putative modulators of hypoxia-related disease manifestations.
Topics: Acetates; DNA; Extracellular Traps; Histones; Humans; Hypoxia; Lung Diseases; Myristic Acid; Neutrophils; Phorbols; Tetradecanoylphorbol Acetate
PubMed: 35259405
DOI: 10.1016/j.yexmp.2022.104754 -
Chemical & Pharmaceutical Bulletin 2022Five new crotofolanes, named crotocascarins R-V (1-5), one rearranged trinorcrotofolane, crotocascarin δ, and one phorbol derivative were isolated from the...
Five new crotofolanes, named crotocascarins R-V (1-5), one rearranged trinorcrotofolane, crotocascarin δ, and one phorbol derivative were isolated from the EtOAc-soluble fraction of the MeOH extract of the leaves of Croton cascarilloides. Crotocascarins R (1), T (3), and U (4) possessed isobutyric acid as an acyl moiety and crotocascarin B (2) an acetyl group, whereas crotocascarin V (5) was elucidated to be a hydroxylated compound of crotocascarin K at the 9-position. Crotocascarin δ (6) was a trinor rearranged crotofolane with a tertiary hemiketal functional group at the 8-position. The absolute configuration of the 8-position was determined by the comparison of the experimental electronic circular dichroism (ECD) spectrum and calculated ECD spectra. Compound 7 was a phorbol ester derivative with a peroxide functional group. The fatty acid attached at the 12-position was found to be a single species-i.e., lauric acid (C-12)-from the evidence of the mass spectral data.
Topics: Circular Dichroism; Croton; Diterpenes; Phorbols; Plant Leaves
PubMed: 35370206
DOI: 10.1248/cpb.c21-01034 -
International Journal of Molecular... Feb 2024Angiotensin-converting enzyme (ACE) plays a crucial role in the pathogenesis of hypertension. Roxb., an herb known for its antihypertensive effect, lacks a...
Angiotensin-converting enzyme (ACE) plays a crucial role in the pathogenesis of hypertension. Roxb., an herb known for its antihypertensive effect, lacks a comprehensive understanding of the mechanism underlying its antihypertensive action. This study aimed to elucidate the antihypertensive mechanism of aqueous extract of leaves (AEPS) via its modulation of the ACE pathway in phorbol 12-myristate-13-acetate (PMA)-induced human umbilical vein endothelial cells (HUVECs). HUVECs were divided into five groups: control, treatment with 200 µg/mL AEPS, induction 200 nM PMA, concomitant treatment with 200 nM PMA and 200 µg/mL AEPS, and treatment with 200 nM PMA and 0.06 μM captopril. Subsequently, ACE mRNA expression, protein level and activity, angiotensin II (Ang II) levels, and angiotensin II type 1 receptor (AT1R) and angiotensin II type 2 receptor (AT2R) mRNA expression in HUVECs were determined. AEPS successfully inhibited ACE mRNA expression, protein and activity, and angiotensin II levels in PMA-induced HUVECs. Additionally, AT1R expression was downregulated, whereas AT2R expression was upregulated. In conclusion, AEPS reduces the levels of ACE mRNA, protein and activity, Ang II, and AT1R expression in PMA-induced HUVECs. Thus, AEPS has the potential to be developed as an ACE inhibitor in the future.
Topics: Humans; Antihypertensive Agents; Myristates; Angiotensin II; Endothelial Cells; Piper; Cells, Cultured; Peptidyl-Dipeptidase A; Receptor, Angiotensin, Type 1; RNA, Messenger; Acetates; Phorbols
PubMed: 38474055
DOI: 10.3390/ijms25052806 -
International Journal of Molecular... Apr 2022Megakaryocytes are large hematopoietic cells present in the bone marrow cavity, comprising less than 0.1% of all bone marrow cells. Despite their small number,...
Megakaryocytes are large hematopoietic cells present in the bone marrow cavity, comprising less than 0.1% of all bone marrow cells. Despite their small number, megakaryocytes play important roles in blood coagulation, inflammatory responses, and platelet production. However, little is known about changes in gene expression during megakaryocyte maturation. Here we identified the genes whose expression was changed during K562 leukemia cell differentiation into megakaryocytes using an Affymetrix GeneChip microarray to determine the multifunctionality of megakaryocytes. K562 cells were differentiated into mature megakaryocytes by treatment for 7 days with phorbol 12-myristate 13-acetate, and a microarray was performed using RNA obtained from both types of cells. The expression of 44,629 genes was compared between K562 cells and mature megakaryocytes, and 954 differentially expressed genes (DEGs) were selected based on a p-value < 0.05 and a fold change >2. The DEGs was further functionally classified using five major megakaryocyte function-associated clusters—inflammatory response, angiogenesis, cell migration, extracellular matrix, and secretion. Furthermore, interaction analysis based on the STRING database was used to generate interactions between the proteins translated from the DEGs. This study provides information on the bioinformatics of the DEGs in mature megakaryocytes after K562 cell differentiation.
Topics: Acetates; Cell Differentiation; Computational Biology; Humans; K562 Cells; Megakaryocytes; Microarray Analysis; Myristic Acid; Phorbols; Tetradecanoylphorbol Acetate; Thrombopoiesis
PubMed: 35457039
DOI: 10.3390/ijms23084221