Chemotherapeutics for Toxoplasma gondii: Molecular Biotargets, Binding Modes, and Structure-Activity Relationship Investigations.

Toxoplasmosis, an infectious zoonotic disease caused by the apicomplexan parasite Toxoplasma gondii (T. gondii), is a major worldwide health problem. However, there are currently no effective options (chemotherapeutic drugs or prophylactic vaccines) for treating chronic latent toxoplasmosis infection. Accordingly, seeking more effective and safer chemotherapeutics for combating this disease remains a long-term and challenging objective. In this paper, we summarize possible molecular biotargets, with an emphasis on those that are druggable and promising, including, without limitation, calcium-dependent protein kinase 1, bifunctional thymidylate synthase-dihydrofolate reductase, and farnesyl diphosphate synthase. Meanwhile, as important components of medicinal chemistry, the binding modes and structure-activity relationship profiles of the corresponding inhibitors were also illuminated. We anticipate that this information will be helpful for further identification of more effective chemotherapeutic interventions to prevent and treat zoonotic infections caused by T. gondii.

High-dose dexamethasone injection disordered metabolism and multiple protein kinases expression in the mouse kidney.

Glucocorticoids (GCs) have been widely used in clinical treatment as anti-inflammatory, anti-shock and immunosuppressive medicines. However, the effect of excessive GCs on immune response and metabolism of kidney remains unclear. Here, we profiled the gene expression of kidney from mice with high-dose dexamethasone (DEX) treatment. A total of 1193 differentially expressed genes (DEGs) were screened in DEX treatment group compared with the saline group, including 715 down- regulated and 478 up-regulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of these DEGs showed extracellular matrix (ECM)-receptor interaction, cell adhesion molecules signaling pathway were significantly enriched, and that the vast majority of DEGs were involved in monocarboxylic acid metabolism, leukocyte cell-cell adhesion and fatty acid metabolism. Gene set enrichment analysis (GSEA) revealed that DEGs were strongly associated with immune-response and cell adhesion gene sets, such as Fc γ R-mediated phagocytosis, leukocyte transendothelial migration, T-cell receptor signaling pathway, cell adhesion, ECM-receptor interaction and focal adhesion-associated pathways. KEGG pathway analysis of differentially expressed kinases (DEKs) showed T-cell receptor and forkhead box class O signaling pathway were enriched. Furthermore, we found multiple protein kinases expression were dysregulated greatly after dexamethasone treatment, including classical effector of GCs stimulation-serum and GC-regulated kinase. These protein kinases are involved in multiple signaling pathways in mice kidney, such as mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. We profiled the gene expression of the kidney from high-dose dexamethasone-treated mice and provided important information for further study the mechanism of side effects of GCs in clinical therapy.

Targeting PINK1 Using Natural Products for the Treatment of Human Diseases.

PINK1, also known as PARK6, is a PTEN-induced putative kinase 1 that is encoded by nuclear genes. PINK1 is ubiquitously expressed and regulates mitochondrial function and mitophagy in a range of cell types. The dysregulation of PINK1 is associated with the pathogenesis and development of mitochondrial-associated disorders. Many natural products could regulate PINK1 to relieve PINK1-associated diseases. Here, we review the structure and function of PINK1, its relationship to human diseases, and the regulation of natural products to PINK1. We further highlight that the discovery of natural PINK1 regulators represents an attractive strategy for the treatment of PINK1-related diseases, including liver and heart diseases, cancer, and Parkinson's disease. Moreover, investigating PINK1 regulation of natural products can enhance the in-depth comprehension of the mechanism of action of natural products.

Fatty acids can inhibit Staphylococcus aureus SaeS activity at the membrane independent of alterations in respiration.

In Staphylococcus aureus, the two-component system SaeRS is responsible for regulating various virulence factors essential for the success of this pathogen. SaeRS can be stimulated by neutrophil-derived products but has also recently been shown to be inactivated by the presence of free fatty acids. A mechanism for how fatty acids negatively impacts SaeRS has not been described. We found that unsaturated fatty acids, as well as fatty acids not commonly found in Staphylococcal membranes, prevent the activation of SaeRS at a lower concentration than their saturated counterparts. These fatty acids can negatively impact SaeRS without altering the respiratory capacity of the bacterium. To uncover a potential mechanism for how fatty acids impact SaeRS function/activity, we utilized a naturally occurring point mutation found in S. aureus as well as chimeric SaeS proteins. Using these tools, we identified that the native transmembrane domains of SaeS dictate the transcriptional response to fatty acids in S. aureus. Our data support a model where free fatty acids alter the activity of the two-component system SaeRS directly through the sensor kinase SaeS and is dependent on the transmembrane domains of the protein.

Chronic Ouabain Prevents Na,K-ATPase Dysfunction and Targets AMPK and IL-6 in Disused Rat Soleus Muscle.

Sustained sarcolemma depolarization due to loss of the Na,K-ATPase function is characteristic for skeletal muscle motor dysfunction. Ouabain, a specific ligand of the Na,K-ATPase, has a circulating endogenous analogue. We hypothesized that the Na,K-ATPase targeted by the elevated level of circulating ouabain modulates skeletal muscle electrogenesis and prevents its disuse-induced disturbances. Isolated soleus muscles from rats intraperitoneally injected with ouabain alone or subsequently exposed to muscle disuse by 6-h hindlimb suspension (HS) were studied. Conventional electrophysiology, Western blotting, and confocal microscopy with cytochemistry were used. Acutely applied 10 nM ouabain hyperpolarized the membrane. However, a single injection of ouabain (1 µg/kg) prior HS was unable to prevent the HS-induced membrane depolarization. Chronic administration of ouabain for four days did not change the α1 and α2 Na,K-ATPase protein content, however it partially prevented the HS-induced loss of the Na,K-ATPase electrogenic activity and sarcolemma depolarization. These changes were associated with increased phosphorylation levels of AMP-activated protein kinase (AMPK), its substrate acetyl-CoA carboxylase and p70 protein, accompanied with increased mRNA expression of interleikin-6 (IL-6) and IL-6 receptor. Considering the role of AMPK in regulation of the Na,K-ATPase, we suggest an IL-6/AMPK contribution to prevent the effects of chronic ouabain under skeletal muscle disuse.

Acacetin and pinostrobin as a promising inhibitor of cancer-associated protein kinases.

Protein kinases associated with cancer genes play vital role in angiogenesis, invasion, motility, proliferation, and survival. Therefore, cancer prevention/treatment, targeting kinases with phytochemicals could be a promising approach. Given potential of phytochemicals in modulating cancer-associated kinases, present study aims to find inhibitory prospects of selected flavonoids for cancer-chemoprevention/treatment. The molecular docking interaction analysis was done by exploring binding potential of flavonoids with kinases (PI3K, Akt, mTOR, EGFR, MAPK, MKK4, Fyn, ZAP-70, B-Raf, JAK-2, STAT-1, STAT-3, STAT-4, STAT-5, and VEGF) involved in various carcinogenesis phases. Among flavonoids acacetin showed highest binding-energy against JAK-2 following Fyn > VEGF > PI3K > MKK4 > MAPK > BRaf > STAT-5 > STAT-1 > STAT-4 whereas pinostrobin depicts higher binding-energy with JAK-2 followed by B-Raf > MKK4 > VEGF > PI3K > MAPK > STAT-1 > STAT-4 > STAT-5. Further, molecular-dynamic simulation revealed that pinostrobin interacted with JAK-2 protein with binding-energy of -25.068 ± 1.08 kJ/mol whereas acacetin interacted with both JAK-2 and Fyn with binding-energies of -23.466 ± 0.9508 kJ/mol and-8.935 ± 1.3108 kJ/mol respectively. High binding-energy, low inhibition-constant, and drug-likeness of acacetin and pinostrobin provide a clue for their usage as a JAK-2 inhibitor which could be useful for molecular/cell-target based in-vitro and in-vivo investigations.

Metformin alleviates cisplatin-induced ototoxicity by autophagy induction possibly via the AMPK/FOXO3a pathway.

Cisplatin is an antitumor drug that is widely used for the treatment of various solid tumors. Unfortunately, patients are often troubled by serious side effects, especially hearing loss. Up to now, there have been no clear and effective measures to prevent cisplatin-induced ototoxicity in clinical use. We explored the role of autophagy and the efficacy of metformin in cisplatin-induced ototoxicity in cells, zebrafish, and mice. Furthermore, the underlying molecular mechanism of how metformin affects cisplatin-induced ototoxicity was examined. In in vitro experiments, autophagy levels in HEI-OC1 cells were assessed using fluorescence and Western blot analyses. In in vivo experiments, whether metformin had a protective effect against cisplatin ototoxicity was validated in zebrafish and C57BL/6 mice. The results showed that cisplatin induced autophagy activation in HEI-OC1 cells. Metformin exerted antagonistic effects against cisplatin ototoxicity in HEI-OC1 cells, zebrafish, and mice. Notably, metformin activated autophagy and increased the expression levels of the adenosine monophosphate-activated protein kinase (AMPK) and the transcription factor Forkhead box protein O3 (FOXO3a), whereas cells with AMPK silencing displayed otherwise. Our findings indicate that metformin alleviates cisplatin-induced ototoxicity possibly through AMPK/FOXO3a-mediated autophagy machinery. This study underpins further researches on the prevention and treatment of cisplatin ototoxicity.NEW & NOTEWORTHY Cisplatin is an antitumor drug that is widely used for the treatment of various solid tumors. Up to now, there have been no clear and effective measures to prevent cisplatin-induced ototoxicity in clinical use. We investigated the protective effect of metformin on cisplatin ototoxicity in vitro and in vivo. Our findings indicate that metformin alleviates cisplatin-induced ototoxicity possibly through AMPK/FOXO3a-mediated autophagy machinery. This study underpins further researches on the prevention and treatment of cisplatin ototoxicity.

An innovative kinome platform to accelerate small-molecule inhibitor discovery and optimization from hits to leads.

Kinases, accounting for 20% of the human genome, have been the focus of pharmaceutical drug discovery efforts for over three decades. Despite concerns surrounding the tractability of kinases as drug targets, it is evident that kinase drug discovery offers great potential, underscored by the US Food and Drug Administration (FDA) approval of 48 small-molecule kinase inhibitors. Despite these successes, it is challenging to identify novel kinome selective inhibitors with good pharmacokinetic/pharmacodynamic (PK/PD) properties, and resistance to kinase inhibitor treatment frequently arises. A new era of kinase drug discovery predicates the need for diverse and powerful tools to discover the next generation of kinase inhibitors. Here, we outline key tenets of the Bristol Meyers Squibb (BMS) kinase platform, to enable efficient generation of highly optimized kinase inhibitors.

Acrylamide treatment alters the level of Ca2+ and Ca2+-related protein kinase in spinal cords of rats.

This study aimed to analyze the neurological changes induced by acrylamide (ACR) poisoning and their underlying mechanisms within the spinal cords of male adult Wistar rats. The rats were randomly divided into three groups (n = 9 rats per group). ACR was intraperitoneally injected to produce axonopathy according to the daily dosing schedules of 20 or 40 mg/kg/day of ACR for eight continuous weeks (three times per week). During the exposure period, body weights and gait scores were assessed, and the concentration of Ca2+ was calculated in 27 mice. Protein kinase A (PKA), protein kinase C (PKC), cyclin-dependent protein kinase 5 (CDK5), and P35 were assessed by electrophoretic resolution and Western blotting. The contents of 3'-cyclic adenosine monophosphate (cAMP) and calmodulin (CaM) were determined using ELISA kits, and the activities of calcium/calmodulin-dependent protein kinase II (CaMKII), PKA, and PKC were determined using the commercial Signa TECTPKAassay kits. Compared with control rats, treatment with 20 and 40 mg/kg of ACR decreased body weight and increased gait scores at 8 weeks. Intracellular Ca2+ levels increased significantly in treated rats; CaM, PKC, CDK5, and P35 levels were significantly decreased; and PKA and cAMP levels remained unchanged. CaMKII, PKA, and PKC activities increased significantly. The results indicated that ACR can damage neurofilaments by affecting the contents and activities of CaM, CaMKII, PKA, cAMP, PKC, CDK5, and P35, which could result in ACR toxic neuropathy.

Kinome inhibition reveals a role for polo-like kinase 1 in targeting post-transcriptional control in cancer.

Dysfunctions in post-transcriptional control are observed in cancer and chronic inflammatory diseases. Here, we employed a kinome inhibitor library (n = 378) in a reporter system selective for 3'-untranslated region-AU-rich elements (ARE). Fifteen inhibitors reduced the ARE-reporter activity; among the targets is the polo-like kinase 1 (PLK1). RNA-seq experiments demonstrated that the PLK1 inhibitor, volasertib, reduces the expression of cytokine and cell growth ARE mRNAs. PLK1 inhibition caused accelerated mRNA decay in cancer cells and was associated with reduced phosphorylation and stability of the mRNA decay-promoting protein, tristetraprolin (ZFP36/TTP). Ectopic expression of PLK1 increased abundance and stability of high molecular weight of ZFP36/TTP likely of the phosphorylated form. PLK1 effect was associated with the MAPK-MK2 pathway, a major regulator of ARE-mRNA stability, as evident from MK2 inhibition, in vitro phosphorylation, and knockout experiments. Mutational analysis demonstrates that TTP serine 186 is a target for PLK1 effect. Treatment of mice with the PLK1 inhibitor reduced both ZFP36/TTP phosphorylation in xenograft tumor tissues, and the tumor size. In cancer patients' tissues, PLK1/ARE-regulated gene cluster was overexpressed in solid tumors and associated with poor survival. The data showed that PLK1-mediated post-transcriptional aberration could be a therapeutic target.

α1-Adrenergic receptors increase glucose oxidation under normal and ischemic conditions in adult mouse cardiomyocytes.

The role of catecholamine receptors in cardiac energy metabolism is unknown. α1-adrenergic receptors (α1-ARs) have been identified to play a role in whole body metabolism but its role in cardiac energy metabolism has not been explored. We used freshly prepared primary adult mouse cardiomyocytes and incubated with either 14C-palmitate or 14C-glucose tracers to measure oxidation rates in the presence or absence of phenylephrine, an α1-AR agonist (with ß and α2-AR blockers) under normal cell culture conditions. 14CO2 released was collected over a 10 min period in covered tissue culture plates using a 1 M hyamine hydroxide solution placed in well cups, counted by scintillation and converted into nmoles/hr. We found that phenylephrine stimulated glucose oxidation but not fatty acid oxidation in adult primary cardiomyocytes. α1-AR stimulated glucose oxidation was blocked by the AMPK inhibitor, dorsomorphin dihydrochloride, and the PKC inhibitor, rottlerin. Ischemic conditions were induced by lowering the glucose concentration from 22.5 mM to 1.375 mM. Under ischemic conditions, we found that phenylephrine also increased glucose oxidation. We report a direct role of α1-ARs in regulating glucose oxidation under normal and ischemic conditions that may lead to new therapeutic approaches in treating ischemia.

Sigma-1 receptor regulates mitophagy in dopaminergic neurons and contributes to dopaminergic protection.

Mitochondria are essential for neuronal survival and function, and mitochondrial dysfunction plays a critical role in the pathological development of Parkinson's disease (PD). Mitochondrial quality control is known to contribute to the survival of dopaminergic (DA) neurons, with mitophagy being a key regulator of the quality control system. In this study, we show that mitophagy is impaired in the substantia nigra pars compacta (SNc) of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD. Treatment with the sigma-1 receptor (Sig 1R) agonist 2-morpholin-4-ylethyl 1-phenylcyclohexane-1-carboxylate (PRE-084) reduced loss of DA neurons, restored motor ability and MPTP-induced damage to mitophagy activity in the SNc of PD-like mice. Additionally, knockdown of Sig 1R in SH-SY5Y DA cells inhibited mitophagy and enhanced 1-methyl-4-phenylpyridinium ion (MPP+) neurotoxicity, whereas application of the Sig 1R selective agonist SKF10047 promoted clearance of damaged mitochondria. Moreover, knockdown of Sig 1R in SH-SY5Y cells resulted in decreased levels of p-ULK1 (Unc-51 Like Autophagy Activating Kinase 1) (Ser555), p-TBK1 (TANK Binding Kinase 1) (Ser172), p-ubiquitin (Ub) (Ser65), Parkin recruitment, and stabilization of PTEN-induced putative kinase 1 (PINK1) in mitochondria. The present data provide the first evidence for potential roles of PINK1/Parkin in Sig 1R-modulated mitophagy in DA neurons.

δ-opioid receptor activation protects against Parkinson's disease-related mitochondrial dysfunction by enhancing PINK1/Parkin-dependent mitophagy.

Our previous studies have shown that the δ-opioid receptor (DOR) is an important neuroprotector via the regulation of PTEN-induced kinase 1 (PINK1), a mitochondria-related molecule, under hypoxic and MPP+ insults. Since mitochondrial dysfunctions are observed in both hypoxia and MPP+ insults, this study further investigated whether DOR is cytoprotective against these insults by targeting mitochondria. Through comparing DOR-induced responses to hypoxia versus MPP+-induced parkinsonian insult in PC12 cells, we found that both hypoxia and MPP+ caused a collapse of mitochondrial membrane potential and severe mitochondrial dysfunction. In sharp contrast to its inappreciable effect on mitochondria in hypoxic conditions, DOR activation with UFP-512, a specific agonist, significantly attenuated the MPP+-induced mitochondrial injury. Mechanistically, DOR activation effectively upregulated PINK1 expression and promoted Parkin's mitochondrial translocation and modification, thus enhancing the PINK1-Parkin mediated mitophagy. Either PINK1 knockdown or DOR knockdown largely interfered with the DOR-mediated mitoprotection in MPP+ conditions. Moreover, there was a major difference between hypoxia versus MPP+ in terms of the regulation of mitophagy with hypoxia-induced mitophagy being independent from DOR-PINK1 signaling. Taken together, our novel data suggest that DOR activation is neuroprotective against parkinsonian injury by specifically promoting mitophagy in a PINK1-dependent pathway and thus attenuating mitochondrial damage.

Structure, function, and inhibitor targeting of HIV-1 Nef-effector kinase complexes.

Antiretroviral therapy has revolutionized the treatment of AIDS, turning a deadly disease into a manageable chronic condition. Life-long treatment is required because existing drugs do not eradicate HIV-infected cells. The emergence of drug-resistant viral strains and uncertain vaccine prospects highlight the pressing need for new therapeutic approaches with the potential to clear the virus. The HIV-1 accessory protein Nef is essential for viral pathogenesis, making it a promising target for antiretroviral drug discovery. Nef enhances viral replication and promotes immune escape of HIV-infected cells but lacks intrinsic enzymatic activity. Instead, Nef works through diverse interactions with host cell proteins primarily related to kinase signaling pathways and endosomal trafficking. This review emphasizes the structure, function, and biological relevance of Nef interactions with host cell protein-tyrosine kinases in the broader context of Nef functions related to enhancement of the viral life cycle and immune escape. Drug discovery targeting Nef-mediated kinase activation has allowed identification of promising inhibitors of multiple Nef functions. Pharmacological inhibitors of Nef-induced MHC-I down-regulation restore the adaptive immune response to HIV-infected cells in vitro and have the potential to enhance immune recognition of latent viral reservoirs as part of a strategy for HIV clearance.

Comparative assessment of the effects of bumped kinase inhibitors on early zebrafish embryo development and pregnancy in mice.

Bumped kinase inhibitors (BKIs) are effective against a variety of apicomplexan parasites. Fifteen BKIs with promising in vitro efficacy against Neospora caninum tachyzoites, low cytotoxicity in mammalian cells, and no toxic effects in non-pregnant BALB/c mice were assessed in pregnant mice. Drugs were emulsified in corn oil and were applied by gavage for 5 days. Five BKIs did not affect pregnancy, five BKIs exhibited ~15-35% neonatal mortality and five compounds caused strong effects (infertility, abortion, stillbirth and pup mortality). Additionally, the impact of these compounds on zebrafish (Danio rerio) embryo development was assessed by exposing freshly fertilised eggs to 0.2-50 µM of BKIs and microscopic monitoring of embryo development in a blinded manner for 4 days. We propose an algorithm that includes quantification of malformations and embryo deaths, and established a scoring system that allows the calculation of an impact score (Si) indicating at which concentrations BKIs visibly affect zebrafish embryo development. Comparison of the two models showed that for nine compounds no clear correlation between Si and pregnancy outcome was observed. However, the three BKIs affecting zebrafish embryos only at high concentrations (≥40 µM) did not impair mouse pregnancy at all, and the three compounds that inhibited zebrafish embryo development already at 0.2 µM showed detrimental effects in the pregnancy model. Thus, the zebrafish embryo development test has limited predictive value to foresee pregnancy outcome in BKI-treated mice. We conclude that maternal health-related factors such as cardiovascular, pharmacokinetic and/or bioavailability properties also contribute to BKI-pregnancy effects.

Glucosamine regulates hepatic lipid accumulation by sensing glucose levels or feeding states of normal and excess.

Dose-dependent lipid accumulation was induced by glucose in HepG2 cells. GlcN also exerted a promotory effect on lipid accumulation in HepG2 cells under normal glucose conditions (NG, 5 mM) and liver of normal fed zebrafish larvae. High glucose (HG, 25 mM)-induced lipid accumulation was suppressed by l-glutamine-d-fructose 6-phosphate amidotransferase inhibitors. ER stress inhibitors did not suppress HG or GlcN-mediated lipid accumulation. HG and GlcN stimulated protein expression, DNA binding and O-GlcNAcylation of carbohydrate-responsive element-binding protein (ChREBP). Furthermore, both HG and GlcN increased nuclear sterol regulatory element-binding protein-1 (SREBP-1) levels in HepG2 cells. In contrast to its stimulatory effect under NG, GlcN suppressed lipid accumulation in HepG2 cells under HG conditions. Similarly, GlcN suppressed lipid accumulation in livers of overfed zebrafish. In addition, GlcN activity on DNA binding and O-GlcNAcylation of ChREBP was stimulatory under NG and inhibitory under HG conditions. Moreover, GlcN enhanced ChREBP, SREBP-1c, ACC, FAS, L-PK and SCD-1 mRNA expression under NG but inhibited HG-induced upregulation in HepG2 cells. The O-GlcNAc transferase inhibitor, alloxan, reduced lipid accumulation by HG or GlcN while the O-GlcNAcase inhibitor, PUGNAc, enhanced lipid accumulation in HepG2 cells and liver of zebrafish larvae. GlcN-induced lipid accumulation was inhibited by the AMPK activator, AICAR. Phosphorylation of AMPK (p-AMPK) was suppressed by GlcN under NG while increased by GlcN under HG. PUGNAc downregulated p-AMPK while alloxan restored GlcN- or HG-induced p-AMPK inhibition. Our results collectively suggest that GlcN regulates lipogenesis by sensing the glucose or energy states of normal and excess fuel through AMPK modulation.

Acute Nicotine Treatment Alleviates LPS-Induced Impairment of Fear Memory Reconsolidation Through AMPK Activation and CRTC1 Upregulation in Hippocampus.

BACKGROUND: Fear memory is a fundamental capability for animals and humans to survive. Its impairment results in the disability to avoid danger. When memory is reactivated, a reconsolidation process, which can be disrupted by various stimuli, including inflammation, is required to become permanent. Nicotine has been shown to improve cognitive deficits induced by inflammation and other stimuli. Therefore, in the present study, we investigated the effect of nicotine on lipopolysaccharide (LPS)-induced impairment of fear memory reconsolidation and the underlying mechanism. METHODS: Step-through inhibitory avoidance task was recruited to study fear memory of rat, i.p. LPS (0.5 mg/kg) treatment was used to induce inflammation, and western blot and immunostaining were applied to detect protein expression and distribution in medial prefrontal cortex and hippocampus. RESULTS: Our data showed that LPS induced fear memory reconsolidation impairment without affecting retrieval. In addition, LPS significantly increased inflammation factors tumor necrosis factor-α and interleukin-1 beta and decreased CREB-regulated transcription coactivator 1 (CRTC1) expression and adenosine monophosphate-activated protein kinase (AMPK) activation in hippocampus. More importantly, LPS significantly decreased CRTC1 expression and AMPK activation in neurons by activating microglia cells. Of note, either nicotine treatment or activation of AMPK by intracerebroventricular infusion of metformin reduced LPS-induced impairment of fear memory reconsolidation and ameliorated inflammation factor tumor necrosis factor-α and interleukin-1 beta as well as the expression of CRTC1. CONCLUSIONS: In conclusion, our results showed that acute nicotine treatment alleviates LPS-induced impairment of fear memory reconsolidation through activation of AMPK and upregulation of CRTC1 in hippocampus.

Development of novel anti-malarial from structurally diverse library of molecules, targeting plant-like CDPK1, a multistage growth regulator of P. falciparum.

Upon Plasmodium falciparum merozoites exposure to low [K+] environment in blood plasma, there is escalation of cytosolic [Ca2+] which activates Ca2+-Dependent Protein Kinase 1 (CDPK1), a signaling hub of intra-erythrocytic proliferative stages of parasite. Given its high abundance and multidimensional attributes in parasite life-cycle, this is a lucrative target for designing antimalarials. Towards this, we have virtually screened MyriaScreenII diversity collection of 10,000 drug-like molecules, which resulted in 18 compounds complementing ATP-binding pocket of CDPK1. In vitro screening for toxicity in mammalian cells revealed that these compounds are non-toxic in nature. Furthermore, SPR analysis demonstrated differential binding affinity of these compounds towards recombinantly purified CDPK1 protein. Selection of lead compound 1 was performed by evaluating their inhibitory effects on phosphorylation and ATP binding activities of CDPK1. Furthermore, in vitro biophysical evaluations by ITC and FS revealed that binding of compound 1 is driven by formation of energetically favorable non-covalent interactions, with different binding constants in presence and absence of Ca2+, and TSA authenticated stability of compound 1 bound CDPK1 complex. Finally, compound 1 strongly inhibited intra-erythrocytic growth of P. falciparum in vitro. Conceivably, we propose a novel CDPK1-selective inhibitor, step towards developing pan-CDPK kinase inhibitors, prerequisite for cross-stage anti-malarial protection.

A newborn with a large NTRK fusion positive infantile fibrosarcoma successfully treated with larotrectinib.

Infantile fibrosarcoma (IFS) is a rare pediatric cancer that typically presents early in life. Surgical resection is commonly curative; however, resection is sometimes not possible requiring additional multimodal treatment. IFS commonly harbors a fusion in one of the neurotrophic receptor tyrosine kinase (NTRK) genes. Larotrectinib, a highly selective inhibitor of tropomyosin receptor kinase (TRK), has been shown to be well tolerated and effective in children as young as 1-month old. We report a case of IFS in a newborn treated with larotrectinib. The patient experienced a rapid clinical and radiographic response demonstrating the potential to treat newborns with larotrectinib.

In Search of Outliers. Mining for Protein Kinase Inhibitors Based on Their Anti-Proliferative NCI-60 Cell Lines Profile.

Protein kinases play a pivotal role in signal transduction, protein synthesis, cell growth and proliferation. Their deregulation represents the basis of pathogenesis for numerous diseases such as cancer and pathologies with cardiovascular, nervous and inflammatory components. Protein kinases are an important target in the pharmaceutical industry, with 48 protein kinase inhibitors (PKI) already approved on the market as treatments for different afflictions including several types of cancer. The present work focuses on facilitating the identification of new PKIs with antitumoral potential through the use of data-mining and basic statistics. The National Cancer Institute (NCI) granted access to the results of numerous previously tested compounds on 60 tumoral cell lines (NCI-60 panel). Our approach involved analyzing the NCI database to identify compounds that presented similar growth inhibition (GI) profiles to that of existing PKIs, but different from approved oncologic drugs with other mechanisms of action, using descriptive statistics and statistical outliers. Starting from 34,000 compounds present in the database, we filtered 400 which displayed selective inhibition on certain cancer cell lines similar to that of several already-approved PKIs.