Up-regulation of Dyrk1b promote astrocyte activation following lipopolysaccharide-induced neuroinflammation

Mirk/Dyrk1B Kinase Inhibitors in Targeted Cancer Therapy

During the last years, there has been an increased effort in the discovery of selective and potent kinase inhibitors for targeted cancer therapy. Kinase inhibitors exhibit less toxicity compared to conventional chemotherapy, and several have entered the market. Mirk/Dyrk1B kinase is a promising pharmacological target in cancer since it is overexpressed in many tumors, and its overexpression is correlated with patients' poor prognosis. Mirk/Dyrk1B acts as a negative cell cycle regulator, maintaining the survival of quiescent cancer cells and conferring their resistance to chemotherapies. Many studies have demonstrated the valuable therapeutic effect of Mirk/Dyrk1B inhibitors in cancer cell lines, mouse xenografts, and patient-derived 3D-organoids, providing a perspective for entering clinical trials. Since the majority of Mirk/Dyrk1B inhibitors target the highly conserved ATP-binding site, they exhibit off-target effects with other kinases, especially with the highly similar Dyrk1A. In this review, apart from summarizing the data establishing Dyrk1B as a therapeutic target in cancer, we highlight the most potent Mirk/Dyrk1B inhibitors recently reported. We also discuss the limitations and perspectives for the structure-based design of Mirk/Dyrk1B potent and highly selective inhibitors based on the accumulated structural data of Dyrk1A and the recent crystal structure of Dyrk1B with AZ191 inhibitor.

Novel Therapeutic Avenues for Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a complicated, heterogeneous genetic condition that causes left ventricular hypertrophy, fibrosis, hypercontractility, and decreased compliance. Despite the advances made over the past 3 decades in understanding the molecular and cellular mechanisms aggravating HCM, the relationship between pathophysiological stress stimuli and distinctive myocyte growth profiles is still imprecise. Currently, mavacamten, a selective and reversible inhibitor of cardiac myosin ATPase, is the only drug approved by the US FDA for the treatment of HCM. Thus, there is an unmet need for developing novel disease-specific therapeutic approaches. This article provides an overview of emerging therapeutic targets for the treatment of HCM based on various molecular pathways and novel developments that are hopefully soon to enter the clinical study. These newly discovered targets include the dual specificity tyrosine-phosphorylation-regulated kinase 1B, the absence of the melanoma 1 inflammasome, the leucine-rich repeat kinase 2 enzyme, and the cluster of differentiation 147.

Salmonella Enteritidis GalE Protein Inhibits LPS-Induced NLRP3 Inflammasome Activation

Microbial infection can trigger the assembly of inflammasomes and promote secretion of cytokines, such as IL-1β and IL-18. It is well-known that Salmonella modulates the activation of NLRC4 (NLR family CARD domain-containing protein 4) and NLRP3 (NLR family pyrin domain-containing 3) inflammasomes, however the mechanisms whereby Salmonella avoids or delays inflammasome activation remain largely unknown. Therefore, we used Salmonella Enteritidis C50336ΔfliC transposon library to screen for genes involved in modulating inflammasomes activation. The screen revealed the galactose metabolism-related gene galE to be essential for inflammasome activation. Here, we found that inflammasome activation was significantly increased in J774A.1 cells or wild-type bone marrow-derived macrophages (BMDMs) during infection by ΔfliCΔgalE compared to cells infected with ΔfliC. Importantly, we found that secretion of IL-1β was Caspase-1-dependent, consistent with canonical NLRP3 inflammasome activation. Furthermore, the virulence of ΔfliCΔgalE was significantly decreased compared to ΔfliC in a mouse model. Finally, RNA-seq analysis showed that multiple signaling pathways related to the inflammasome were subject to regulation by GalE. Taken together, our results suggest that GalE plays an important role in the regulatory network of Salmonella evasion of inflammasome activation.

Study of DYRK1B gene expression and its association with metabolic syndrome in a small cohort of Egyptians

BACKGROUND

A cluster of many risk factors for type 2 diabetes and cardiovascular disease is used to describe the metabolic syndrome (MetS). Moreover, genetic differences associated with metabolic syndrome play a key role in its prevalence and side effects. This study aims to investigate the expression of DYRK1B and its association with metabolic syndrome in a small cohort of Egyptian.

MATERIALS AND METHODS

A total of 100 adult Egyptians (50 with MetS and 50 healthy control subjects) were included to this study. Clinical, biochemical and anthropometric analysis were assessed. Relative gene expressions of DYRK1B were compared between two groups of subjects using real time PCR.

RESULTS

We observed marked overexpression in DYRK1B (p < 0.05) in MetS subjects when compared with the healthy control subjects.

CONCLUSION

This is the first study to provide evidence that DYRK1B is highly expressed among the MetS subjects.

X-ray Structure-Guided Discovery of a Potent, Orally Bioavailable, Dual Human Indoleamine/Tryptophan 2,3-Dioxygenase (hIDO/hTDO) Inhibitor That Shows Activity in a Mouse Model of Parkinson's Disease

Human indoleamine 2,3-dioxygenase 1 (hIDO1) and tryptophan 2,3-dioxygenase (hTDO) have been closely linked to the pathogenesis of Parkinson's disease (PD); nevertheless, development of dual hIDO1 and hTDO inhibitors to evaluate their potential efficacy against PD is still lacking. Here, we report biochemical, biophysical, and computational analyses revealing that 1H-indazole-4-amines inhibit both hIDO1 and hTDO by a mechanism involving direct coordination with the heme ferrous and ferric states. Crystal structure-guided optimization led to 23, which manifested IC50 values of 0.64 and 0.04 μM to hIDO1 and hTDO, respectively, and had good pharmacokinetic properties and brain penetration in mice. 23 showed efficacy against the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse motor coordination deficits, comparable to Madopar, an anti-PD medicine. Further studies revealed that different from Madopar, 23 likely has specific anti-PD mechanisms involving lowering IDO1 expression, alleviating dopaminergic neurodegeneration, reducing inflammatory cytokines and quinolinic acid in mouse brain, and increasing kynurenic acid in mouse blood.

Dual-Specificity, Tyrosine Phosphorylation-Regulated Kinases (DYRKs) and cdc2-Like Kinases (CLKs) in Human Disease, an Overview

Dual-specificity tyrosine phosphorylation-regulated kinases (DYRK1A, 1B, 2-4) and cdc2-like kinases (CLK1-4) belong to the CMGC group of serine/threonine kinases. These protein kinases are involved in multiple cellular functions, including intracellular signaling, mRNA splicing, chromatin transcription, DNA damage repair, cell survival, cell cycle control, differentiation, homocysteine/methionine/folate regulation, body temperature regulation, endocytosis, neuronal development, synaptic plasticity, etc. Abnormal expression and/or activity of some of these kinases, DYRK1A in particular, is seen in many human nervous system diseases, such as cognitive deficits associated with Down syndrome, Alzheimer's disease and related diseases, tauopathies, dementia, Pick's disease, Parkinson's disease and other neurodegenerative diseases, Phelan-McDermid syndrome, autism, and CDKL5 deficiency disorder. DYRKs and CLKs are also involved in diabetes, abnormal folate/methionine metabolism, osteoarthritis, several solid cancers (glioblastoma, breast, and pancreatic cancers) and leukemias (acute lymphoblastic leukemia, acute megakaryoblastic leukemia), viral infections (influenza, HIV-1, HCMV, HCV, CMV, HPV), as well as infections caused by unicellular parasites (Leishmania, Trypanosoma, Plasmodium). This variety of pathological implications calls for (1) a better understanding of the regulations and substrates of DYRKs and CLKs and (2) the development of potent and selective inhibitors of these kinases and their evaluation as therapeutic drugs. This article briefly reviews the current knowledge about DYRK/CLK kinases and their implications in human disease.

Apelin-13 regulates LPS-induced N9 microglia polarization involving STAT3 signaling pathway

The process of neurodegenerative diseases has always been accompanied by neuroinflammatory response characterized by microglia activation. Two phenotypes of microglial polarization: the classically activated M1 type and the alternative activated M2 type, have been described. Although apelin-13 has been shown to have neuroprotective effects, its specific mechanism of anti-neuritis is still unclear. The aim of this study was to investigate whether apelin-13 can exert anti-neuroinflammatory effects by regulating the polarization of N9 microglia. MTT assay showed that 0.1 μM apelin-13 (24 h) and 2 μg/mL LPS (6 h) treatment had no significant effect on cell viability of N9 microglia. The combined treatment of Apelin-13 and LPS did not affect the viability of N9 microglia. N9 microglia were pretreated with 0.1 μM apelin-13 for 24 h, followed by incubation with LPS for 6 h. Morphological results indicated that apelin-13 (0.1 μM) inhibited LPS-induced N9 microglial activation as observed by smaller soma and slender process compared to LPS-treated group. Western blot confirmed that apelin-13 decreased the level of proinflammatory factor iNOS, IL-6 and up-regulated the level of anti-inflammatory factor arg-1 and IL-10 in N9 microglia. Flow cytometry revealed that apelin-13 inhibited the expression of M1 microglia activation marker CD86 and up-regulated the expression of M2 marker CD206. Furthermore, the data displayed that apelin-13 decreased the expression of p-STAT3 and the radio of p-STAT3/t-STAT3 in M1-type N9 microglia induced by LPS. In conclusion, our results indicated apelin-13 ameliorated neuroinflammation by shifting N9 microglial M1 polarization toward the M2 phenotype, the underlying mechanism of which may be related to STAT3 signals.

Development of novel amide-derivatized 2,4-bispyridyl thiophenes as highly potent and selective Dyrk1A inhibitors. Part II: Identification of the cyclopropylamide moiety as a key modification

Dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) is a potential target in Alzheimer's disease (AD) because of the established correlation between its over-expression and generation of neurofibrillary tangles (NFT) as well as the accumulation of amyloid plaques. However, the use of Dyrk1A inhibitors requires a high degree of selectivity over closely related kinases. In addition, the physicochemical properties of the Dyrk1A inhibitors need to be controlled to enable CNS permeability. In the present study, we optimized our previously published 2,4-bispyridyl thiophene class of Dyrk1A inhibitors by the synthesis of a small library of amide derivatives, carrying alkyl, cycloalkyl, as well as acidic and basic residues. Among this library, the cyclopropylamido modification (compound 4b) was identified as being highly beneficial for several crucial properties. 4b displayed high potency and selectivity against Dyrk1A over closely related kinases in cell-free assays (IC50: Dyrk1A = 3.2 nM; Dyrk1B = 72.9 nM and Clk1 = 270 nM) and inhibited the Dyrk1A activity in HeLa cells with high efficacy (IC50: 43 nM), while no significant cytotoxicity was observed. In addition, the cyclopropylamido group conferred high metabolic stability and maintained the calculated physicochemical properties in a range compatible with a potential CNS activity. Thus, based on its favourable properties, 4b can be considered as a candidate for further in vivo testing in animal models of AD.