Discovery of Novel Macrocyclic MERTK/AXL Dual Inhibitors.

MERTK and AXL are members of the TAM (TYRO3, AXL, MERTK) family of receptor tyrosine kinases that are aberrantly expressed and have been implicated as therapeutic targets in a wide variety of human tumors. Dual MERTK and AXL inhibition could provide antitumor action mediated by both direct tumor cell killing and modulation of the innate immune response in some tumors such as nonsmall cell lung cancer. We utilized our knowledge of MERTK inhibitors and a structure-based drug design approach to discover a novel class of macrocyclic dual MERTK/AXL inhibitors. The lead compound 43 had low-nanomolar activity against both MERTK and AXL and good selectivity over TYRO3 and FLT3. Its target engagement and selectivity were also confirmed by NanoBRET and cell-based MERTK and AXL phosphorylation assays. Compound 43 had excellent pharmacokinetic properties (large AUC and long half-life) and mediated antitumor activity against lung cancer cell lines, indicating its potential as a therapeutic agent.

A Biotinylated cpFIT-PNA Platform for the Facile Detection of Drug Resistance to Artemisinin in Plasmodium falciparum.

The evolution of drug resistance to many antimalarial drugs in the lethal strain of malaria (Plasmodium falciparum) has been a great concern over the past 50 years. Among these drugs, artemisinin has become less effective for treating malaria. Indeed, several P. falciparum variants have become resistant to this drug, as elucidated by specific mutations in the pfK13 gene. This study presents the development of a diagnostic kit for the detection of a common point mutation in the pfK13 gene of P. falciparum, namely, the C580Y point mutation. FIT-PNAs (forced-intercalation peptide nucleic acid) are DNA mimics that serve as RNA sensors that fluoresce upon hybridization to their complementary RNA. Herein, FIT-PNAs were designed to sense the C580Y single nucleotide polymorphism (SNP) and were conjugated to biotin in order to bind these molecules to streptavidin-coated plates. Initial studies with synthetic RNA were conducted to optimize the sensing system. In addition, cyclopentane-modified PNA monomers (cpPNAs) were introduced to improve FIT-PNA sensing. Lastly, total RNA was isolated from red blood cells infected with P. falciparum (WT strain - NF54-WT or mutant strain - NF54-C580Y). Streptavidin plates loaded with either FIT-PNA or cpFIT-PNA were incubated with the total RNA. A significant difference in fluorescence for mutant vs WT total RNA was found only for the cpFIT-PNA probe. In summary, this study paves the way for a simple diagnostic kit for monitoring artemisinin drug resistance that may be easily adapted to malaria endemic regions.

Exploration of the Potential Biomarker FNDC5 for Discriminating Heart Failure in Patients with Coronary Atherosclerosis.

Coronary atherosclerosis leading to ischemic artery disease is one of the etiological factors to develop heart failure (HF). This study aimed to investigate potential biomarkers for discriminating HF in atherosclerotic patients. This study included 40 consecutive atherosclerotic patients who underwent angiography. Concentrations of B-type natriuretic peptide (BNP), fibronectin type III domain containing 5 (FNDC5), and Phosphodiesterase 9A (PDE9A) were measured in 20 atherosclerotic patients with HF symptoms/signs and 20 without HF symptoms/signs. Circulating BNP levels were elevated, while FNDC5 levels were reduced in atherosclerotic patients with HF symptoms/signs compared to those without HF symptoms/signs. Pearson correlation analysis showed a significant correlation between FNDC5 and BNP. Receiver Operating Characteristics analysis indicated that both FNDC5 and BNP were able to discriminate HF in atherosclerotic patients. Our findings suggest that FNDC5, along with BNP, has independent value as a biomarker for discriminating HF in patients with coronary atherosclerosis.

GTF2H4 regulates partial EndMT via NF-κB activation through NCOA3 phosphorylation in ischemic diseases.

Partial endothelial-to-mesenchymal transition (EndMT) is an intermediate phenotype observed in endothelial cells (ECs) undergoing a transition toward a mesenchymal state to support neovascularization during (patho)physiological angiogenesis. Here, we investigated the occurrence of partial EndMT in ECs under hypoxic/ischemic conditions and identified general transcription factor IIH subunit 4 (GTF2H4) as a positive regulator of this process. In addition, we discovered that GTF2H4 collaborates with its target protein excision repair cross-complementation group 3 (ERCC3) to co-regulate partial EndMT. Furthermore, by using phosphorylation proteomics and site-directed mutagenesis, we demonstrated that GTF2H4 was involved in the phosphorylation of receptor coactivator 3 (NCOA3) at serine 1330, which promoted the interaction between NCOA3 and p65, resulting in the transcriptional activation of NF-κB and the NF-κB/Snail signaling axis during partial EndMT. In vivo experiments confirmed that GTF2H4 significantly promoted partial EndMT and angiogenesis after ischemic injury. Collectively, our findings reveal that targeting GTF2H4 is promising for tissue repair and offers potential opportunities for treating hypoxic/ischemic diseases.

Correction: Cyclopentane FIT-PNAs: bright RNA sensors.

Correction for 'Cyclopentane FIT-PNAs: bright RNA sensors' by Odelia Tepper et al., Chem. Commun., 2021, 57, 540-543, https://doi.org/10.1039/D0CC07400D.

Variation of Tetrahydrofurans in Thyclotides Enhances Oligonucleotide Binding and Cellular Uptake of Peptide Nucleic Acids.

Selective incorporation of conformational constraints into thyclotides can be used to modulate their binding to complementary oligonucleotides, increase polarity, and optimize uptake into HCT116 cells without assistance from moieties known to promote cell uptake. The X-ray structure and biophysical studies of a thyclotide-DNA duplex reveal that incorporation of tetrahydrofurans into an aegPNA backbone promotes a helical conformation that enhances binding to complementary DNA and RNA. Selective incorporation of tetrahydrofurans into the aegPNA backbone allows polarity to be increased incrementally so that uptake into HCT116 cells can be optimized. The enhanced binding, polarity, and cellular uptake properties of thyclotides were used to demonstrate effective inhibition of microRNA-21 in HCT116 cells.

Thyclotides, tetrahydrofuran-modified peptide nucleic acids that efficiently penetrate cells and inhibit microRNA-21.

Peptide nucleic acids (PNAs) are promising therapeutic molecules for gene modulation; however, they suffer from poor cell uptake. Delivery of PNAs into cells requires conjugation of the PNA to another large molecule, typically a cell-penetrating peptide or nanoparticle. In this study, we describe a new PNA-based molecule with cyclic tetrahydrofuran (THF) backbone modifications that in some cases considerably improve cell uptake. We refer to these THF-PNA oligomers as thyclotides. With THF groups at every position of the oligomer, the cell uptake of thyclotides targeted to miR-21 is enhanced compared with the corresponding unmodified PNA based on an aminoethylglycine backbone. An optimized thyclotide can efficiently enter cells without the use of cell-penetrating peptides, bind miR-21, its designated microRNA target, decrease expression of miR-21 and increase expression of three downstream targets (PTEN, Cdc25a and KRIT1). Using a plasmid with the PTEN-3'UTR coupled with luciferase, we further confirmed that a miR-21-targeted thyclotide prevents miR-21 from binding to its target RNA. Additionally, the thyclotide shows no cytotoxicity when administered at 200 times its active concentration. We propose that thyclotides be further explored as therapeutic candidates to modulate miRNA levels.

Alkyl-substituted N-methylaryl-N'-aryl-4-aminobenzamides: A new series of small molecule inhibitors for Wip1 phosphatase.

The wild-type p53 induced phosphatase 1 (Wip1), a member of the serine/threonine-specific PP2C family, is overexpressed in numerous human cancers. Wip1 dephosphorylates p53 as well as several kinases (such as p38 MAPK, ATM, Chk1, and Chk2) in the DNA damage response pathway that are responsible for maintaining genomic stability and preventing oncogenic transformation. As a result, Wip1 is an attractive target for synthetic inhibitors that could be further developed into therapeutics to treat some cancers. In this study, we report a series of alkyl-substituted N-methylaryl-N'-aryl-4-aminobenzamides and their inhibitory activity of the Wip1 phosphatase. A straightforward synthetic route was developed to synthesize the target compounds from commercially available starting materials. Three different portions (R1, R2, R3) of the core scaffold were extensively modified to examine structure-activity relationships. This study revealed interesting trends about a new molecular scaffold to inhibit Wip1.

Foam Cells in Atherosclerosis: Novel Insights Into Its Origins, Consequences, and Molecular Mechanisms.

Foam cells play a vital role in the initiation and development of atherosclerosis. This review aims to summarize the novel insights into the origins, consequences, and molecular mechanisms of foam cells in atherosclerotic plaques. Foam cells are originated from monocytes as well as from vascular smooth muscle cells (VSMC), stem/progenitor cells, and endothelium cells. Novel technologies including lineage tracing and single-cell RNA sequencing (scRNA-seq) have revolutionized our understanding of subtypes of monocyte- and VSMC-derived foam cells. By using scRNA-seq, three main clusters including resident-like, inflammatory, and triggering receptor expressed on myeloid cells-2 (Trem2 hi ) are identified as the major subtypes of monocyte-derived foam cells in atherosclerotic plaques. Foam cells undergo diverse pathways of programmed cell death including apoptosis, autophagy, necroptosis, and pyroptosis, contributing to the necrotic cores of atherosclerotic plaques. The formation of foam cells is affected by cholesterol uptake, efflux, and esterification. Novel mechanisms including nuclear receptors, non-coding RNAs, and gut microbiota have been discovered and investigated. Although the heterogeneity of monocytes and the complexity of non-coding RNAs make obstacles for targeting foam cells, further in-depth research and therapeutic exploration are needed for the better management of atherosclerosis.

Low-density lipoprotein receptor and apolipoprotein A 5, myocardial infarction biomarkers in plasma-derived exosomes.

OBJECTIVES: Myocardial infarction (MI), a leading cause of death around the world, displays a complex pattern of inheritance. Previously, rare mutations in low-density lipoprotein receptor (LDLR) genes and apolipoprotein A V (APOA5) have been shown to contribute to MI risk in individual families. Exosomes provide a potential source of biomarkers for MI. This study is to determine the role of LDLR and APOA5 as biomarkers for early diagnosis of MI. METHODS: In this study, we detected the levels of LDLR, APOA5, and cardiac troponin T in plasma-derived exosomes in MI patients and age-matched healthy people by enzyme linked immunosorbent assay and observed the morphology and number of exosomes using transmission electron microscope and nanoparticle tracking analysis. Oxygen-glucose deprivation (OGD) method was used to induce MI in H9C2 cardiomyocytes to explore the effect of exosomes. RESULTS: We found that the levels of LDLR and APOA5 in plasma-derived exosomes in MI patients were significantly decreased. Furthermore, exosomes of MI patients were significantly larger in size and the concentration of exosomes was higher than that of age-matched non-MI people. In vitro experiments showed that OGD treatment induced apoptosis of myocardial cells and decreased the expression of LDLR and APOA5, while addition of exosomes isolated from healthy people rescued these phenotypes. CONCLUSION: Exosomal APOA5 and LDLR are intimately associated with MI, and thereby have the potential to function as diagnostic markers of MI.

Berberine on the Prevention and Management of Cardiometabolic Disease: Clinical Applications and Mechanisms of Action.

Berberine is an alkaloid from several medicinal plants originally used to treat diarrhea and dysentery as a traditional Chinese herbal medicine. In recent years, berberine has been discovered to exhibit a wide spectrum of biological activities in the treatment of diverse diseases ranging from cancer and neurological dysfunctions to metabolic disorders and heart diseases. This review article summarizes the clinical practice and laboratory exploration of berberine for the treatment of cardiometabolic and heart diseases, with a focus on the novel insights and recent advances of the underlying mechanisms recognized in the past decade. Berberine was found to display pleiotropic therapeutic effects against dyslipidemia, hyperglycemia, hypertension, arrhythmia, and heart failure. The mechanisms of berberine for the treatment of cardiometabolic disease involve combating inflammation and oxidative stress such as inhibiting proprotein convertase subtilisin/kexin 9 (PCSK9) activation, regulating electrical signals and ionic channels such as targeting human ether-a-go-go related gene (hERG) currents, promoting energy metabolism such as activating adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, modifying gut microbiota to promote transforming of berberine into its intestine-absorbable form, and interacting with non-coding RNAs via targeting multiple signaling pathways such as AMPK, mechanistic target of rapamycin (mTOR), etc. Collectively, berberine appears to be safe and well-tolerated in clinical practice, especially for those who are intolerant to statins. Knowledge from this field may pave the way for future development of more effective pharmaceutical approaches for managing cardiometabolic risk factors and preventing heart diseases.

UNC5293, a potent, orally available and highly MERTK-selective inhibitor.

Inhibition of MER receptor tyrosine kinase (MERTK) causes direct tumor cell killing and stimulation of the innate immune response. Therefore, MERTK has been identified as a therapeutic target in a wide variety of human tumors. Clinical trials targeting MERTK have recently been initiated, however, none of these drugs are MERTK-specific. Herein, we present the discovery of a highly MERTK-selective inhibitor UNC5293 (24). UNC5293 has subnanomolar activity against MERTK with an excellent Ambit selectivity score (S50 (100 nM) = 0.041). It mediated potent and selective inhibition of MERTK in cell-based assays. Furthermore, it has excellent mouse PK properties (7.8 h half-life and 58% oral bioavailability) and was active in bone marrow leukemia cells in a murine model.

miR-33a-5p Suppresses ox-LDL-Stimulated Calcification of Vascular Smooth Muscle Cells by Targeting METTL3.

Oxidized low-density lipoprotein (ox-LDL) accumulation in the vascular wall plays a pivotal role in the development of atherosclerosis and vascular calcification. However, few studies focus on the regulatory roles of microRNAs in ox-LDL stimulated vascular calcification. The aim of the present study was to investigate how miR-33a-5p regulated vascular calcification stimulated by ox-LDL. In the present study, miR-33a-5p was downregulated during vascular smooth muscle cells (VSMCs) calcification and upon ox-LDL treatment. ox-LDL significantly stimulated VSMCs calcification, while miR-33a-5p overexpression by its mimics transfection inhibited alkaline phosphatase (ALP) activity, mineralization and marker genes associated with VSMCs calcification even in the presence of ox-LDL. Methyltransferase like 3 (METTL3) was the target gene of miR-33a-5p. METTL3 was upregulated during VSMCs calcification and upon ox-LDL treatment. When VSMCs were transfected with miR-33a-5p mimics, METTL3 was downregulated. METTL3 downregulation by siRNA method decreased VSMCs calcification even in the presence of ox-LDL. Taken together, these results suggest miR-33a-5p suppresses VSMCs calcification stimulated by ox-LDL via targeting METTL3, highlighting the critical role of miR-33a-5p/METTL3 in vascular calcification.

Discovery and Optimization of 2H-1λ2-Pyridin-2-one Inhibitors of Mutant Isocitrate Dehydrogenase 1 for the Treatment of Cancer.

Neomorphic mutations in isocitrate dehydrogenase 1 (IDH1) are oncogenic for a number of malignancies, primarily low-grade gliomas and acute myeloid leukemia. We report a medicinal chemistry campaign around a 7,7-dimethyl-7,8-dihydro-2H-1λ2-quinoline-2,5(6H)-dione screening hit against the R132H and R132C mutant forms of isocitrate dehydrogenase (IDH1). Systematic SAR efforts produced a series of potent pyrid-2-one mIDH1 inhibitors, including the atropisomer (+)-119 (NCATS-SM5637, NSC 791985). In an engineered mIDH1-U87-xenograft mouse model, after a single oral dose of 30 mg/kg, 16 h post dose, between 16 and 48 h, (+)-119 showed higher tumoral concentrations that corresponded to lower 2-HG concentrations, when compared with the approved drug AG-120 (ivosidenib).

Conformational constraints of cyclopentane peptide nucleic acids facilitate tunable binding to DNA.

We report a series of synthetic, nucleic acid mimics with highly customizable thermodynamic binding to DNA. Incorporation of helix-promoting cyclopentanes into peptide nucleic acids (PNAs) increases the melting temperatures (Tm) of PNA+DNA duplexes by approximately +5°C per cyclopentane. Sequential addition of cyclopentanes allows the Tm of PNA + DNA duplexes to be systematically fine-tuned from +5 to +50°C compared with the unmodified PNA. Containing only nine nucleobases and an equal number of cyclopentanes, cpPNA-9 binds to complementary DNA with a Tm around 90°C. Additional experiments reveal that the cpPNA-9 sequence specifically binds to DNA duplexes containing its complementary sequence and functions as a PCR clamp. An X-ray crystal structure of the cpPNA-9-DNA duplex revealed that cyclopentanes likely induce a right-handed helix in the PNA with conformations that promote DNA binding.

The Effective Role of Natural Product Berberine in Modulating Oxidative Stress and Inflammation Related Atherosclerosis: Novel Insights Into the Gut-Heart Axis Evidenced by Genetic Sequencing Analysis.

The exacerbation of oxidative and inflammatory reactions has been involved in atherosclerotic cardiovascular diseases leading to morbidity and mortality worldwide. Discovering the underlying mechanisms and finding optimized curative approaches to control the global prevalence of cardiovascular diseases is needed. Growing evidence has demonstrated that gut microbiota is associated with the development of atherosclerosis, while berberine, a natural product exhibits antiatherogenic effects in clinical and pre-clinical studies, which implies a potential link between berberine and gut microbiota. In light of these novel discoveries, evidence of the role of berberine in modulating atherosclerosis with a specific focus on its interaction with gut microbiota is collected. This review synthesizes and summarizes antioxidant and anti-inflammatory effects of berberine on combating atherosclerosis experimentally and clinically, explores the interaction between berberine and intestinal microbiota comprehensively, and provides novel insights of berberine in managing atherosclerotic cardiovascular diseases via targeting the gut-heart axis mechanistically. The phenomenon of how berberine overcomes its weakness of poor bioavailability to conduct its antiatherogenic properties is also discussed and interpreted in this article. An in-depth understanding of this emerging area may contribute to identifying therapeutic potentials of medicinal plant and natural product derived pharmaceuticals for the prevention and treatment of atherosclerotic cardiovascular diseases in the future.

Cardiac Rehabilitation with Targeted Intensity Improves Cardiopulmonary Functions Accompanying with Reduced Copeptin Level in Patients with Coronary Artery Disease.

Cardiac rehabilitation (CR) plays an important role in cardiovascular disease prevention. Understanding the key component of CR such as training intensity and biomarkers reflecting cardiopulmonary functions may help to better target the rehabilitation program. Thirty-four consecutive patients with coronary artery disease after percutaneous coronary intervention participated in the CR program. The difference between intervention group and control group was mainly the training intensity. Cardiopulmonary exercise testing (CPET) and blood biomarker measurements were performed before and after CR. The results demonstrated that it was safe and feasible to perform CR, while sufficient training intensity was required to significantly ameliorate CPET parameters. Among numerous biomarkers tested, vasopressin surrogate marker copeptin (CPP) improved significantly after CR. Moreover, improved CPP was correlated with exercise intensity and peak oxygen uptake, two most important indicators of cardiopulmonary exercise capacities. Therefore, CR may have a novel role in maintaining plasma osmolality and cardiovascular homeostasis. Graphical Abstract Cardiac rehabilitation training improves cardiopulmonary exercise parameters El and PVO2 which are correlated with reduced CPP level. CPP, copeptin; El, exercise intensity; POV2, peak oxygen uptake.

The potential value of Copeptin and Pentraxin3 for evaluating the severity of coronary stenosis in patients with coronary artery disease.

INTRODUCTION: Coronary artery disease (CAD) is an ischemic heart disease due to the narrowing of the coronary arteries resulting from atherosclerosis. Blood biomarkers have been well utilized for the diagnosis and prognosis of CAD. However, the value of biomarkers for evaluating coronary atherosclerosis remains to be clarified. This clinical investigation aimed to explore the potential value of biomarkers for evaluating the severity of coronary stenosis in CAD patients. METHODS: The extent of coronary atherosclerosis was accessed by the angiography-based quantitative measurement Gensini score (GS). Blood levels of Brain natriuretic peptide, Copeptin (CPP), Phosphodiesterase 9A, and Pentraxin3 (PTX3) were measured in 56 patients divided into three levels as low GS (n = 17), intermediate GS (n = 19) and high GS (n = 20) based on GS tertiles. RESULTS: We found that plasma concentrations of CPP and PTX3 were significantly elevated in patients with high GS compared with the low GS group. In addition, Pearson correlation analysis showed that CPP and PTX3 were positively correlated with the GS. Furthermore, Receiver operating characteristics analysis demonstrated that both CPP and PTX3 exhibited discriminative capacities for evaluating the extent of coronary stenosis. CONCLUSIONS: Laboratory tests of CPP and PTX3 via non-invasive means may provide novel information for risk stratification and disease management in CAD patients before invasive angiographic approaches. This study opens the door for enormous opportunities to explore new biomarkers with better efficiency, sensitivity and specificity as alternative/additional methods for evaluating the severity of coronary atherosclerosis in CAD patients in future research.

Cyclopentane FIT-PNAs: bright RNA sensors.

Cyclopentane modified FIT-PNA (cpFIT-PNA) probes are reported as highly emissive RNA sensors with the highest reported brightness for FIT-PNAs. Compared to FIT-PNAs, cpFIT-PNAs have improved mismatch discrimination for several pyrimidine-pyrimidine single nucleotide variants (SNVs).

Berberine Promotes Cardiac Function by Upregulating PINK1/Parkin-Mediated Mitophagy in Heart Failure.

Berberine has been verified to protect cardiac function in patients with heart failure (HF). However, the mechanism(s) involved in berberine-mediated cardioprotective effects has not been clearly elucidated. The aim of this study was to further investigate the mechanism(s) involved in the beneficial effects of berberine on transverse aortic contraction (TAC)-induced chronic HF. Mice were randomly divided into four groups. Berberine was administered at a dose of 50 mg/kg/day for 4 weeks via oral gavage. Our findings showed that TAC-induced pressure overload (PO) prompted cardiac dysfunction, cardiac hypertrophy, interstitial fibrosis, cardiomyocyte apoptosis and mitochondrial injury, accompanied with suppressed mitophagy, the effects of which were attenuated by berberine. Furthermore, mitophagy regulators PINK1 and mito-Parkin were downregulated in TAC-induced HF, while berberine upregulated PINK1/Parkin-mediated mitophagy. Notably, knockdown of PINK1 by small interfering RNA significantly suppressed Parkin-mediated mitochondrial ubiquitination and nullified the beneficial actions on HF exerted by berberine. Taken together, our results indicated that berberine plays a critical role in attenuating cardiac hypertrophy and preserving cardiac function from PO induced HF. The potential underlying mechanism is the activation of mitochondrial autophagy via PINK1/Parkin/Ubiquitination pathway.