Research

19 pages, 3953 KiB

Open AccessArticle

UV-B Filter Octylmethoxycinnamate Alters the Vascular Contractility Patterns in Pregnant Women with Hypothyroidism

by Margarida Lorigo, Carla Quintaneiro, Luiza Breitenfeld and Elisa Cairrao

Biomedicines 2021, 9(2), 115; https://doi.org/10.3390/biomedicines9020115 - 26 Jan 2021

Cited by 7 | Viewed by 2548

Increasing evidence relating the exposure and/or bioaccumulation of endocrine-disrupting compounds (EDCs) with cardiovascular system are arising. Octylmethoxycinnamate (OMC) is the most widely used UV-B filter and as EDC interacts with TH receptors. However, their effects on thyroid diseases during pregnancy remain unknown. The [...] Read more.

Increasing evidence relating the exposure and/or bioaccumulation of endocrine-disrupting compounds (EDCs) with cardiovascular system are arising. Octylmethoxycinnamate (OMC) is the most widely used UV-B filter and as EDC interacts with TH receptors. However, their effects on thyroid diseases during pregnancy remain unknown. The purpose of this work was to assess the short- and long-term effects of OMC on arterial tonus of pregnant women with hypothyroidism. To elucidate this, human umbilical artery (HUA) rings without endothelium were used to explore the vascular effects of OMC by arterial and cellular experiments. The binding energy and the modes of interaction of the OMC into the active center of the TSHR and THRα were analyzed by molecular docking studies. Our results indicated that OMC altered the contractility patterns of HUA contracted with serotonin, histamine and KCl, possibly due to an interference with serotonin and histamine receptors or an involvement of the Ca²⁺ channels. The molecular docking analysis show that OMC compete with T₃ for the binding center of THRα. Taken together, these findings pointed out to alterations in HUA reactivity as result of OMC-exposure, which may be involved in the development and increased risk of cardiovascular diseases. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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22 pages, 8141 KiB

Open AccessArticle

Pharmacoinformatics and Preclinical Studies of NSC765690 and NSC765599, Potential STAT3/CDK2/4/6 Inhibitors with Antitumor Activities against NCI60 Human Tumor Cell Lines

by Bashir Lawal, Yen-Lin Liu, Ntlotlang Mokgautsi, Harshita Khedkar, Maryam Rachmawati Sumitra, Alexander T. H. Wu and Hsu-Shan Huang

Biomedicines 2021, 9(1), 92; https://doi.org/10.3390/biomedicines9010092 - 19 Jan 2021

Cited by 44 | Viewed by 3851

Abstract

Signal transducer and activator of transcription 3 (STAT3) is a transcriptional regulator of a number of biological processes including cell differentiation, proliferation, survival, and angiogenesis, while cyclin-dependent kinases (CDKs) are a critical regulator of cell cycle progression. These proteins appear to play central [...] Read more.

Signal transducer and activator of transcription 3 (STAT3) is a transcriptional regulator of a number of biological processes including cell differentiation, proliferation, survival, and angiogenesis, while cyclin-dependent kinases (CDKs) are a critical regulator of cell cycle progression. These proteins appear to play central roles in angiogenesis and cell survival and are widely implicated in tumor progression. In this study, we used the well-characterized US National Cancer Institute 60 (NCI60) human tumor cell lines to screen the in vitro anti-cancer activities of our novel small molecule derivatives (NSC765690 and NSC765599) of salicylanilide. Furthermore, we used the DTP-COMPARE algorithm and in silico drug target prediction to identify the potential molecular targets, and finally, we used molecular docking to assess the interaction between the compounds and prominent potential targets. We found that NSC765690 and NSC765599 exhibited an anti-proliferative effect against the 60 panels of NCI human cancer cell lines, and dose-dependent cytotoxic preference for NSCLC, melanoma, renal, and breast cancer cell lines. Protein–ligand interactions studies revealed that NSC765690 and NSC765599 were favored ligands for STAT3/CDK2/4/6. Moreover, cyclization of the salicylanilide core scaffold of NSC765690 mediated its higher anti-cancer activities and had greater potential to interact with STAT3/CDK2/4/6 than did NSC765599 with an open-ring structure. NSC765690 and NSC765599 met the required safety and criteria of a good drug candidate, and are thus worthy of further in-vitro and in-vivo investigations in tumor-bearing mice to assess their full therapeutic efficacy. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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17 pages, 2103 KiB

Open AccessArticle

Identification of Key Phospholipids That Bind and Activate Atypical PKCs

by Suresh Velnati, Sara Centonze, Federico Girivetto, Daniela Capello, Ricardo M. Biondi, Alessandra Bertoni, Roberto Cantello, Beatrice Ragnoli, Mario Malerba, Andrea Graziani and Gianluca Baldanzi

Biomedicines 2021, 9(1), 45; https://doi.org/10.3390/biomedicines9010045 - 06 Jan 2021

Cited by 7 | Viewed by 3078

Abstract

PKCζ and PKCι/λ form the atypical protein kinase C subgroup, characterised by a lack of regulation by calcium and the neutral lipid diacylglycerol. To better understand the regulation of these kinases, we systematically explored their interactions with various purified phospholipids using the lipid [...] Read more.

PKCζ and PKCι/λ form the atypical protein kinase C subgroup, characterised by a lack of regulation by calcium and the neutral lipid diacylglycerol. To better understand the regulation of these kinases, we systematically explored their interactions with various purified phospholipids using the lipid overlay assays, followed by kinase activity assays to evaluate the lipid effects on their enzymatic activity. We observed that both PKCζ and PKCι interact with phosphatidic acid and phosphatidylserine. Conversely, PKCι is unique in binding also to phosphatidylinositol-monophosphates (e.g., phosphatidylinositol 3-phosphate, 4-phosphate, and 5-phosphate). Moreover, we observed that phosphatidylinositol 4-phosphate specifically activates PKCι, while both isoforms are responsive to phosphatidic acid and phosphatidylserine. Overall, our results suggest that atypical Protein kinase C (PKC) localisation and activity are regulated by membrane lipids distinct from those involved in conventional PKCs and unveil a specific regulation of PKCι by phosphatidylinositol-monophosphates. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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20 pages, 5783 KiB

Open AccessArticle

Study of the Relationship between Sigma Receptor Expression Levels and Some Common Sigma Ligand Activity in Cancer Using Human Cancer Cell Lines of the NCI-60 Cell Line Panel

by Evangelia Sereti, Chrisiida Tsimplouli, Elisavet Kalaitsidou, Nikos Sakellaridis and Konstantinos Dimas

Biomedicines 2021, 9(1), 38; https://doi.org/10.3390/biomedicines9010038 - 05 Jan 2021

Cited by 11 | Viewed by 2504

Abstract

Sigma (σ) receptors have attracted great interest since they are implicated in various cellular functions and biological processes and diseases, including various types of cancer. The receptor family consists of two subtypes: sigma-1 (σ1) and sigma-2 (σ2). Both σ receptor subtypes have been [...] Read more.

Sigma (σ) receptors have attracted great interest since they are implicated in various cellular functions and biological processes and diseases, including various types of cancer. The receptor family consists of two subtypes: sigma-1 (σ1) and sigma-2 (σ2). Both σ receptor subtypes have been proposed as therapeutic targets for various types of cancers, and many studies have provided evidence that their selective ligands (agonists and antagonists) exhibit antiproliferative and cytotoxic activity. Still, the precise mechanism of action of both σ receptors and their ligands remains unclear and needs to be elucidated. In this study, we aimed to simultaneously determine the expression levels of both σ receptor subtypes in several human cancer cell lines. Additionally, we investigated the in vitro antiproliferative activity of some widely used σ1 and σ2 ligands against those cell lines to study the relationship between σ receptor expression levels and σ ligand activity. Finally, we ran the NCI60 COMPARE algorithm to further elucidate the cytotoxic mechanism of action of the selected σ ligands studied herein. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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16 pages, 20432 KiB

Open AccessArticle

Insights into the Interaction Mechanism of DTP3 with MKK7 by Using STD-NMR and Computational Approaches

by Annamaria Sandomenico, Lorenzo Di Rienzo, Luisa Calvanese, Emanuela Iaccarino, Gabriella D’Auria, Lucia Falcigno, Angela Chambery, Rosita Russo, Guido Franzoso, Laura Tornatore, Marco D’Abramo, Menotti Ruvo, Edoardo Milanetti and Domenico Raimondo

Biomedicines 2021, 9(1), 20; https://doi.org/10.3390/biomedicines9010020 - 30 Dec 2020

Cited by 9 | Viewed by 2955

Abstract

GADD45

β

/MKK7 complex is a non-redundant, cancer cell-restricted survival module downstream of the NF-kB survival pathway, and it has a pathogenically critical role in multiple myeloma, an incurable malignancy of plasma cells. The first-in-class GADD45

β

/MKK7 inhibitor DTP3 effectively [...] Read more.

GADD45

β

/MKK7 complex is a non-redundant, cancer cell-restricted survival module downstream of the NF-kB survival pathway, and it has a pathogenically critical role in multiple myeloma, an incurable malignancy of plasma cells. The first-in-class GADD45

β

/MKK7 inhibitor DTP3 effectively kills MM cells expressing its molecular target, both in vitro and in vivo, by inducing MKK7/JNK-dependent apoptosis with no apparent toxicity to normal cells. DTP3 combines favorable drug-like properties, with on-target-specific pharmacology, resulting in a safe and cancer-selective therapeutic effect; however, its mode of action is only partially understood. In this work, we have investigated the molecular determinants underlying the MKK7 interaction with DTP3 by combining computational, NMR, and spectroscopic methods. Data gathered by fluorescence quenching and computational approaches consistently indicate that the N-terminal region of MKK7 is the optimal binding site explored by DTP3. These findings further the understanding of the selective mode of action of GADD45

β

/MKK7 inhibitors and inform potential mechanisms of drug resistance. Notably, upon validation of the safety and efficacy of DTP3 in human trials, our results could also facilitate the development of novel DTP3-like therapeutics with improved bioavailability or the capacity to bypass drug resistance. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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15 pages, 4015 KiB

Open AccessArticle

Detailed Characterization of the Cooperative Binding of Piperine with Heat Shock Protein 70 by Molecular Biophysical Approaches

by Gabriel Zazeri, Ana Paula Ribeiro Povinelli, Marcelo de Freitas Lima and Marinônio Lopes Cornélio

Biomedicines 2020, 8(12), 629; https://doi.org/10.3390/biomedicines8120629 - 18 Dec 2020

Cited by 3 | Viewed by 2423

Abstract

In this work, for the first time, details of the complex formed by heat shock protein 70 (HSP70) independent nucleotide binding domain (NBD) and piperine were characterized through experimental and computational molecular biophysical methods. Fluorescence spectroscopy results revealed positive cooperativity between the two [...] Read more.

In this work, for the first time, details of the complex formed by heat shock protein 70 (HSP70) independent nucleotide binding domain (NBD) and piperine were characterized through experimental and computational molecular biophysical methods. Fluorescence spectroscopy results revealed positive cooperativity between the two binding sites. Circular dichroism identified secondary conformational changes. Molecular dynamics along with molecular mechanics Poisson Boltzmann surface area (MM/PBSA) reinforced the positive cooperativity, showing that the affinity of piperine for NBD increased when piperine occupied both binding sites instead of one. The spontaneity of the complexation was demonstrated through the Gibbs free energy (∆G < 0 kJ/mol) for different temperatures obtained experimentally by van’t Hoff analysis and computationally by umbrella sampling with the potential of mean force profile. Furthermore, the mean forces which drove the complexation were disclosed by van’t Hoff and MM/PBSA as being the non-specific interactions. In conclusion, the work revealed characteristics of NBD and piperine interaction, which may support further drug discover studies. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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12 pages, 1125 KiB

Open AccessArticle

Brassicasterol with Dual Anti-Infective Properties against HSV-1 and Mycobacterium tuberculosis, and Cardiovascular Protective Effect: Nonclinical In Vitro and In Silico Assessments

by Sherif T. S. Hassan

Biomedicines 2020, 8(5), 132; https://doi.org/10.3390/biomedicines8050132 - 24 May 2020

Cited by 10 | Viewed by 2984

Abstract

While few studies have revealed the biological properties of brassicasterol, a phytosterol, against some biological and molecular targets, it is believed that there are still many activities yet to be studied. In this work, brassicasterol exerts a therapeutic utility in an in vitro [...] Read more.

While few studies have revealed the biological properties of brassicasterol, a phytosterol, against some biological and molecular targets, it is believed that there are still many activities yet to be studied. In this work, brassicasterol exerts a therapeutic utility in an in vitro setting against herpes simplex virus type 1 (HSV-1) and Mycobacterium tuberculosis (Mtb) as well as a considerable inhibitory property against human angiotensin-converting enzyme (ACE) that plays a dynamic role in regulating blood pressure. The antireplicative effect of brassicasterol against HSV-1 is remarkably detected (50% inhibitory concentration (IC₅₀): 1.2 µM; selectivity index (SI): 41.7), while the potency of its effect is ameliorated through the combination with standard acyclovir with proper SI (IC₅₀: 0.7 µM; SI: 71.4). Moreover, the capacity of this compound to induce an adequate level of antituberculosis activity against all Mtb strains examined (minimum inhibitory concentration values ranging from 1.9 to 2.4 µM) is revealed. The anti-ACE effect (12.3 µg/mL; 91.2% inhibition) is also ascertained. Molecular docking analyses propose that the mechanisms by which brassicasterol induces anti-HSV-1 and anti-Mtb might be related to inhibiting vital enzymes involved in HSV-1 replication and Mtb cell wall biosynthesis. In summary, the obtained results suggest that brassicasterol might be promising for future anti-HSV-1, antituberculosis, and anti-ACE drug design. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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16 pages, 2283 KiB

Open AccessArticle

Structure–Activity Analysis and Molecular Docking Studies of Coumarins from Toddalia asiatica as Multifunctional Agents for Alzheimer’s Disease

by Pitchayakarn Takomthong, Pornthip Waiwut, Chavi Yenjai, Bungon Sripanidkulchai, Prasert Reubroycharoen, Ren Lai, Peter Kamau and Chantana Boonyarat

Biomedicines 2020, 8(5), 107; https://doi.org/10.3390/biomedicines8050107 - 02 May 2020

Cited by 18 | Viewed by 3459

Abstract

Coumarins, naturally occurring phytochemicals, display a wide spectrum of biological activities by acting on multiple targets. Herein, nine coumarins from the root of Toddalia asiatica were evaluated for activities related to pathogenesis of Alzheimer’s disease (AD). They were examined for acetylcholinesterase (AChE) and [...] Read more.

Coumarins, naturally occurring phytochemicals, display a wide spectrum of biological activities by acting on multiple targets. Herein, nine coumarins from the root of Toddalia asiatica were evaluated for activities related to pathogenesis of Alzheimer’s disease (AD). They were examined for acetylcholinesterase (AChE) and AChE- or self-induced amyloid beta (Aβ) aggregation inhibitory activities, as well as neuroprotection against H₂O₂- and Aβ_1–42-induced human neuroblastoma SH-SY5Y cell damage. Moreover, in order to understand the mechanism, the binding interactions between coumarins and their targets: (i) AChE and (ii) Aβ_1–42 peptide were investigated in silico. All coumarins exhibited mild to moderate AChE and self-induced Aβ aggregation inhibitory actions. In addition, the coumarins substituted with the long alkyl chain at position 6 or 8 illustrated ability to inhibit AChE-induced Aβ aggregation, resulting from their dual binding site at catalytic anionic site and peripheral active site in AChE. Moreover, the most potent multifunctional coumarin, phellopterin, could attenuate neuronal cell damage induced by H₂O₂ and Aβ_1–42 toxicity. Conclusively, seven out of nine coumarins were identified as multifunctional agents inhibiting the pathogenesis of AD. The structure–activity relationship information obtained might be applied for further optimization of coumarins into a useful drug which may combat AD. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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18 pages, 4202 KiB

Open AccessArticle

Efficaciousness of Low Affinity Compared to High Affinity TSPO Ligands in the Inhibition of Hypoxic Mitochondrial Cellular Damage Induced by Cobalt Chloride in Human Lung H1299 Cells

by Nidal Zeineh, Nunzio Denora, Valentino Laquintana, Massimo Franco, Abraham Weizman and Moshe Gavish

Biomedicines 2020, 8(5), 106; https://doi.org/10.3390/biomedicines8050106 - 02 May 2020

Cited by 6 | Viewed by 2432

Abstract

The 18 kDa translocator protein (TSPO) plays an important role in apoptotic cell death, including apoptosis induced by the hypoxia mimicking agent cobalt chloride (CoCl₂). In this study, the protective effects of a high (CB86; Ki = 1.6 nM) and a [...] Read more.

The 18 kDa translocator protein (TSPO) plays an important role in apoptotic cell death, including apoptosis induced by the hypoxia mimicking agent cobalt chloride (CoCl₂). In this study, the protective effects of a high (CB86; Ki = 1.6 nM) and a low (CB204; Ki = 117.7 nM) affinity TSPO ligands were investigated in H1299 lung cancer cell line exposed to CoCl₂. The lung cell line H1299 was chosen in the present study since they express TSPO and able to undergo programmed cell death. The examined cell death markers included: ATP synthase reversal, reactive oxygen species (ROS) generation, mitochondrial membrane potential (Δψm) depolarization, cellular toxicity, and cellular viability. Pretreatment of the cells with the low affinity ligand CB204 at a concentration of 100 µM suppressed significantly (p < 0.05 for all) CoCl₂-induced cellular cytotoxicity (100%), ATP synthase reversal (67%), ROS generation (82%), Δψm depolarization (100%), reduction in cellular density (97%), and also increased cell viability (85%). Furthermore, the low affinity TSPO ligand CB204, was harmless when given by itself at 100 µM. In contrast, the high affinity ligand (CB86) was significantly effective only in the prevention of CoCl₂–induced ROS generation (39%, p < 0.001), and showed significant cytotoxic effects when given alone at 100 µM, as reflected in alterations in ADP/ATP ratio, oxidative stress, mitochondrial membrane potential depolarization and cell death. It appears that similar to previous studies on brain-derived cells, the relatively low affinity for the TSPO target enhances the potency of TSPO ligands in the protection from hypoxic cell death. Moreover, the high affinity TSPO ligand CB86, but not the low affinity ligand CB204, was lethal to the lung cells at high concentration (100 µM). The low affinity TSPO ligand CB204 may be a candidate for the treatment of pulmonary diseases related to hypoxia, such as pulmonary ischemia and chronic obstructive pulmonary disease COPD. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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11 pages, 1769 KiB

Open AccessArticle

The Minimal Effect of Linker Length for Fatty Acid Conjugation to a Small Protein on the Serum Half-Life Extension

by Jinhwan Cho, Junyong Park, Giyoong Tae, Mi Sun Jin and Inchan Kwon

Biomedicines 2020, 8(5), 96; https://doi.org/10.3390/biomedicines8050096 - 26 Apr 2020

Cited by 5 | Viewed by 3433

Abstract

Conjugation of serum albumin or one of its ligands (such as fatty acid) has been an effective strategy to prolong the serum half-lives of drugs via neonatal Fc receptor (FcRn)–mediated recycling of albumin. So far, fatty acid (FA) has been effective in prolonging [...] Read more.

Conjugation of serum albumin or one of its ligands (such as fatty acid) has been an effective strategy to prolong the serum half-lives of drugs via neonatal Fc receptor (FcRn)–mediated recycling of albumin. So far, fatty acid (FA) has been effective in prolonging the serum half-lives for therapeutic peptides and small proteins, but not for large therapeutic proteins. Very recently, it was reported a large protein conjugated to FA competes with the binding of FcRn with serum albumin, leading to limited serum half-life extension, because primary FA binding sites in serum albumin partially overlap with FcRn binding sites. In order to prevent such competition, longer linkers between FA and the large proteins were required. Herein, we hypothesized that small proteins do not cause substantial competition for FcRn binding to albumin, resulting in the extended serum half-life. Using a small protein (28 kDa), we investigated whether the intramolecular distance in FA-protein conjugate affects the FcRn binding with albumin and serum half-life using linkers with varying lengths. Unlike with the FA-conjugated large protein, all FA-conjugated small proteins with different linkers exhibited comparable the FcRn binding to albumin and extended serum half-life. Full article

(This article belongs to the Special Issue Protein–Ligand Interactions: Target Identification and Drug Discovery)

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