👤 Michael Bloch

BackgroundDrug repurposing offers a rapid, cost-effective approach for discovering therapies against multiple targets.ObjectiveHere, we screen virtual ligand libraries consisting of 3468 approved drugs against 11 protein targets associated with Alzheimer's disease (AD).MethodsWe employ blind molecular docking, and target amyloid-β (Aβ), microtubule-associated protein tau (MAPT), Apolipoprotein E4 (APOE4), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), amyloid-β protein precursor (AβPP), β-secretase (BACE1), brain-derived neurotrophic factor (BDNF), presenilin 1 (PSEN1) and 2 (PSEN2), and α-synuclein (SNCA) proteins using AutoDock Vina.ResultsNotably, multitarget binding recurs among the top-10 ligands with Ergotamine and Dihydroergotamine potentially binding 8; Dutasteride 7; Drospirenone and Nilotinib 6; Adapalene and Conivaptan 5; Bromocriptine 4; and Rolapitant, Irinotecan, Plerixafor, Saquinavir, and Telmisartan 3, out of 11 protein targets. As such, we reveal potential binding sites for ergot alkaloids, steroids, retinoids, antivirals, angiotensin receptor blockers, and Neurokinin 1 (NK1) receptor antagonists on multiple AD targets. Importantly, the therapeutic potential of the top-scoring ligands is confounded by pharmacokinetics and adverse-effects. For example, poor blood-brain barrier (BBB) penetration, and vasoconstriction, discount ergot-alkaloid use in AD. Likewise, potential toxicity limits prolonged use of steroids, Nilotinib, Adapalene, and Irinotecan. Conversely, BBB penetration, neuronal protection, oral availability, anti-inflammation, and anti-hypertension, admit Angiotensin receptor blockers (ARB), (Telmisartan/Candesartan); Antidiuretic hormone (ADH) inhibitors (Conivaptan/Tolvaptan); and of the NK1 receptors antagonists (Rolapitant/Netupitant) use in AD.ConclusionsOur multitarget screening identifies selective synergistic AD modulators, such as ARB, ADH and NK1 receptor inhibitors, and simplifies drug discovery by focusing on the most promising candidates for experimental validation. Show less

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by brain aggregates of amyloid-β (Aβ) plaques and Tau tangles. Despite extensive research, effective therapy for AD remains elusive. Polyoxometalates (POMs), a class of inorganic compounds with diverse chemical structures and properties, are emerging as potential candidates for AD treatment due to their ability to target key molecular players implicated in disease pathogenesis, such as Aβ, acetylcholinesterase (AChE) and butyryl acetylcholinesterase (BChE). Here, we use molecular docking to predict the binding pose and affinities of POMs to 10 top targets associated with AD. First, we validate our method by replicating experimentally known binding of POMs to Aβ (ΔG = - 9.67 kcal/mol), AChE (ΔG = - 9.39 kcal/mol) and BChE (ΔG = - 10.86 kcal/mol). Then, using this method, we show that POM can also bind β-secretase 1 (BACE1, ΔG = - 10.14 kcal/mol), presenilin 1 (PSEN1, ΔG = - 10.65 kcal/mol), presenilin 2 (PSEN2, ΔG = - 7.94 kcal/mol), Amyloid Precursor Protein (APP, ΔG = - 7.26 kcal/mol), Apolipoprotein E (APOE4, ΔG = - 10.05 kcal/mol), Microtubule-Associated Protein Tau (MAPT, ΔG = - 5.28 kcal/mol) depending on phosphorylation, and α-synuclein (SNCA, ΔG = - 7.64 kcal/mol). Through such binding, POMs offer the potential to mitigate APP cleavage, Aβ oligomer neurotoxicity, Aβ aggregation, thereby attenuating disease progression. Overall, our molecular docking study represents a powerful tool in the discovery of POM-based therapeutics for AD, facilitating the development of novel treatments for AD. Show less

Interleukin-27 (IL-27) uniquely assembles p28 and EBI3 subunits to a heterodimeric cytokine that signals via IL-27Rα and gp130. To provide the structural framework for receptor activation by IL-27 and its emerging therapeutic targeting, we report here crystal structures of mouse IL-27 in complex with IL-27Rα and of human IL-27 in complex with SRF388, a monoclonal antibody undergoing clinical trials with oncology indications. One face of the helical p28 subunit interacts with EBI3, while the opposite face nestles into the interdomain elbow of IL-27Rα to juxtapose IL-27Rα to EBI3. This orients IL-27Rα for paired signaling with gp130, which only uses its immunoglobulin domain to bind to IL-27. Such a signaling complex is distinct from those mediated by IL-12 and IL-23. The SRF388 binding epitope on IL-27 overlaps with the IL-27Rα interaction site explaining its potent antagonistic properties. Collectively, our findings will facilitate the mechanistic interrogation, engineering, and therapeutic targeting of IL-27. Show less

Leucine-rich repeat and immunoglobin-domain containing (LRRIG) proteins that are commonly involved in protein-protein interactions play important roles in nervous system development and maintenance. LINGO-1, one of this family members, is characterized as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte precursor cell (OPC) differentiation into mature myelinating oligodendrocytes. Three LINGO-1 homologs named LINGO-2, LINGO-3, and LINGO-4 have been described. However, their relative expression and functions remain unexplored. Here, we show by in situ hybridization and quantitative polymerase chain reaction that the transcripts of LINGO homologs are differentially expressed in the central nervous system. The immunostaining of brain slices confirmed this observation and showed the co-expression of LINGO-1 with its homologs. Using BRET (bioluminescence resonance energy transfer) analysis, we demonstrate that LINGO proteins can physically interact with each of the other ones with comparable affinities and thus form the oligomeric states. Furthermore, co-immunoprecipitation experiments indicate that LINGO proteins form heterocomplexes in both heterologous systems and cortical neurons. Since LINGO-1 is a promising target for the treatment of demyelinating diseases, its ability to form heteromeric complexes reveals a new level of complexity in its functioning and opens the way for new strategies to achieve diverse and nuanced LINGO-1 regulation. Show less

Despite intensive study of the mechanisms of chemotherapeutic drug resistance in human breast cancer, few reports have systematically investigated the mechanisms that underlie resistance to the chemotherapy-sensitizing agent tumor necrosis factor (TNF)-alpha. Additionally, the relationship between TNF-alpha resistance mediated by MEK5/Erk5 signaling and epithelial-mesenchymal transition (EMT), a process associated with promotion of invasion, metastasis, and recurrence in breast cancer, has not previously been investigated. To compare differences in the proteome of the TNF-alpha resistant MCF-7 breast cancer cell line MCF-7-MEK5 (in which TNF-alpha resistance is mediated by MEK5/Erk5 signaling) and its parental TNF-a sensitive MCF-7 cell line MCF-7-VEC, two-dimensional gel electrophoresis and high performance capillary liquid chromatography coupled with tandem mass spectrometry approaches were used. Differential protein expression was verified at the transcriptional level using RT-PCR assays. An EMT phenotype was confirmed using immunofluorescence staining and gene expression analyses. A short hairpin RNA strategy targeting Erk5 was utilized to investigate the requirement for the MEK/Erk5 pathway in EMT. Proteomic analyses and PCR assays were used to identify and confirm differential expression of proteins. In MCF-7-MEK5 versus MCF-7-VEC cells, vimentin (VIM), glutathione-S-transferase P (GSTP1), and creatine kinase B-type (CKB) were upregulated, and keratin 8 (KRT8), keratin 19 (KRT19) and glutathione-S-transferase Mu 3 (GSTM3) were downregulated. Morphology and immunofluorescence staining for E-cadherin and vimentin revealed an EMT phenotype in the MCF-7-MEK5 cells. Furthermore, EMT regulatory genes SNAI2 (slug), ZEB1 (delta-EF1), and N-cadherin (CDH2) were upregulated, whereas E-cadherin (CDH1) was downregulated in MCF-7-MEK5 cells versus MCF-7-VEC cells. RNA interference targeting of Erk5 reversed MEK5-mediated EMT gene expression. This study demonstrates that MEK5 over-expression promotes a TNF-alpha resistance phenotype associated with distinct proteomic changes (upregulation of VIM/vim, GSTP1/gstp1, and CKB/ckb; and downregulation of KRT8/krt8, KRT19/krt19, and GSTM3/gstm3). We further demonstrate that MEK5-mediated progression to an EMT phenotype is dependent upon intact Erk5 and associated with upregulation of SNAI2 and ZEB1 expression. Show less

Hepatic undifferentiated (embryonal) sarcoma (HUS) is an exceptional hepatic malignant tumor in adults. Genetic studies were never reported in adult cases. In this study concerning three cases of HUS occurring in adult, we studied the three classical ways of carcinogenesis i.e. the TP53 (p53), Wnt (CTNNB1/beta-catenin and AXIN1) and telomerase (hTERT) pathways. We studied the expression of p53, beta-catenin and telomerase catalytic subunit hTERT by immunohistochemistry in the three cases; we determined TP53 gene mutation in two cases and the genome-wide allelotype, AXIN1, and CTNNB1/beta-catenin gene mutation in one case. Immunohistochemistry showed an overexpression of p53 in more than 80% of tumoral cells; furthermore, mutations of TP53 were observed in two cases, involving the sequence-specific DNA binding domain. In contrast, no mutation was found in CTNNB1/beta-catenin and AXIN1 genes. Tumoral cells did not show hTERT staining nor nuclear expression of beta-catenin. In addition, allelotype analysis in one case showed loss of heterozygosity of chromosome 7p, 11p, 17p, 22q, and allelic imbalance of 1p, 8p, 20q. In this report of HUS in three adult patients, we emphasize the role of TP53 pathway in carcinogenesis of this rare tumor. This point could be of interest for therapeutic strategies. Show less