Andrew Want

Background: Western diet (WD) is a type of nourishment based on ultra‐processed foods, rich in simple sugars and saturated fats. Long‐term consumption of WD may lead to disruption of insulin signaling and development of insulin resistance. It is supposed that insulin resistance is a probable risk factors for Alzheimer’s disease (AD). The aim of this study was to verify this hypothesis in wild type mice by checking the WD effect on initiation and propagation of main neuropathological AD features such as amyloid‐β (Aβ) plaques and neurofibrillary tangles, which start from the entorhinal cortex in the temporal area, and progresses to the hippocampus, resulting in the loss of memory and cognition.Method: Males of wild type C57BL/6J mice were fed WD diet or standard diet (SD; CTR). Mice experimental groups (WD and CTR) were divided into age subgroups 4‐, 8‐, 12‐ and 16‐month‐old. In the first step, the WD‐diet dependent insulin signaling was analyzed, and the levels of the insulin pathway components: p‐IRS‐1(Ser616), p‐Akt(473), p‐GSK‐3β(Ser9) in the entorhinal cortex and hippocampus were assessed. To analyze further whether WD‐derived impairments in insulin signaling may induce neuropathological AD features, p‐Tau(Thr231) and APP/Aβ were analyzed by immunoblotting and immunofluorescence of mouse brain tissue sections from entorhinal cortex and the hippocampus.Result: Entorhinal cortex proved to be more sensitive to WD‐dependent insulin impairments than the hippocampus: immunoblotting analysis of mouse entorhinal cortex brain lysates revealed an increase in p‐IRS‐1(Ser616) levels, indicating the development of insulin resistance under WD diet. Moreover, a change in the localization of p‐Tau(Thr231) in cellular compartments from fibers to nerve cell bodies indicated a progressive tauopathy. In addition, we also observed an age‐dependent decrease in APP protein levels correlating with the appearance of Aβ peptides in the cytoplasm of neurons under the WD diet.Conclusion: Obtained results suggest that the WD diet, by inducing abnormalities in insulin signaling in the brain, promotes the development of AD, and may be consider as a significant modifiable risk factor for AD, additional to the genetic risk factors.

The search is ongoing for new anticancer therapeutics that would overcome resistance to chemotherapy. This includes chronic myeloid leukemia, particularly suitable for the studies of novel anticancer compounds due to its homogenous and well-known genetic background. Here we show anticancer efficacy of novel dicarboximide denoted BK124.1 (C₃₁H₃₇ClN₂O₄) in a mouse CML xenograft model and in vitro in two types of chemoresistant CML cells: MDR1 blasts and in CD34⁺ patients’ stem cells (N = 8) using immunoblotting and flow cytometry. Intraperitoneal administration of BK124.1 showed anti-CML efficacy in the xenograft mouse model (N = 6) comparable to the commonly used imatinib and hydroxyurea. In K562 blasts, BK124.1 decreased the protein levels of BCR-ABL1 kinase and its downstream effectors, resulting in G2/M cell cycle arrest and apoptosis associated with FOXO3a/p21^waf1/cip1 upregulation in the nucleus. Additionally, BK124.1 evoked massive apoptosis in multidrug resistant K562-MDR1 cells (IC₅₀ = 2.16 μM), in CD34⁺ cells from CML patients (IC₅₀ = 1.5 µM), and in the CD34⁺/CD38⁻ subpopulation consisting of rare, drug-resistant cancer initiating stem cells. Given the advantages of BK124.1 as a potential chemotherapeutic and its unique ability to overcome BCR-ABL1 dependent and independent multidrug resistance mechanisms, future development of BK124.1 could offer a cure for CML and other cancers resistant to present drugs.

The term Western diet (WD) describes the consumption of large amounts of highly processed foods, rich in simple sugars and saturated fats. Long-term WD feeding leads to insulin resistance, postulated as a risk factor for Alzheimer’s disease (AD). AD is the main cause of progressive dementia characterized by the deposition of amyloid-β (Aβ) plaques and neurofibrillary tangles consisting of the hyperphosphorylated tau (p-Tau) protein in the brain, starting from the entorhinal cortex and the hippocampus. In this study, we report that WD-derived impairment in insulin signaling induces tau and Aβ brain pathology in wild-type C57BL/6 mice, and that the entorhinal cortex is more sensitive than the hippocampus to the impairment of brain insulin signaling. In the brain areas developing WD-induced insulin resistance, we observed changes in p-Tau(Thr231) localization in neuronal subcellular compartments, indicating progressive tauopathy, and a decrease in amyloid precursor protein levels correlating with the appearance of Aβ peptides. These results suggest that WD promotes the development of AD and may be considered not only a risk factor, but also a modifiable trigger of AD.

MicroRNAs have been demonstrated as key regulators of gene expression in the etiology of a range of diseases including Alzheimer’s disease (AD). Recently, we identified miR-483-5p as the most upregulated miRNA amongst a panel of miRNAs in blood plasma specific to prodromal, early-stage Alzheimer’s disease patients. Here, we investigated the functional role of miR-483-5p in AD pathology. Using TargetScan and miRTarBase, we identified the microtubule-associated protein MAPT, often referred to as TAU, and the extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2), known to phosphorylate TAU, as predicted direct targets of miR-483-5p. Employing several functional assays, we found that miR-483-5p regulates ERK1 and ERK2 at both mRNA and protein levels, resulting in lower levels of phosphorylated forms of both kinases. Moreover, miR-483-5p-mediated repression of ERK1/2 resulted in reduced phosphorylation of TAU protein at epitopes associated with TAU neurofibrillary pathology in AD. These results indicate that upregulation of miR-483-5p can decrease phosphorylation of TAU via ERK pathway, representing a compensatory neuroprotective mechanism in AD pathology. This miR-483-5p/ERK1/TAU axis thus represents a novel target for intervention in AD.

Induction of mitotic catastrophe through the disruption of microtubules is an established target in cancer therapy. However, the molecular mechanisms determining the mitotic catastrophe and the following apoptotic or non-apoptotic cell death remain poorly understood. Moreover, many existing drugs targeting tubulin, such as vincristine, have reduced efficacy, resulting from poor solubility in physiological conditions. Here, we introduce a novel small molecule 2-aminoimidazoline derivative—OAT-449, a synthetic water-soluble tubulin inhibitor. OAT-449 in a concentration range from 6 to 30 nM causes cell death of eight different cancer cell lines in vitro, and significantly inhibits tumor development in such xenograft models as HT-29 (colorectal adenocarcinoma) and SK-N-MC (neuroepithelioma) in vivo. Mechanistic studies showed that OAT-449, like vincristine, inhibited tubulin polymerization and induced profound multi-nucleation and mitotic catastrophe in cancer cells. HeLa and HT-29 cells within 24 h of treatment arrested in G2/M cell cycle phase, presenting mitotic catastrophe features, and 24 h later died by non-apoptotic cell death. In HT-29 cells, both agents altered phosphorylation status of Cdk1 and of spindle assembly checkpoint proteins NuMa and Aurora B, while G2/M arrest and apoptosis blocking was consistent with p53-independent accumulation in the nucleus and largely in the cytoplasm of p21/waf1/cip1, a key determinant of cell fate programs. This is the first common mechanism for the two microtubule-dissociating agents, vincristine and OAT-449, determining the cell death pathway following mitotic catastrophe demonstrated in HT-29 cells.

The sorting of specific cell populations is an established tool in biological research, with new applications demanding greater cell throughput, sterility and elimination of cross-contamination. Here we report ‘vortex-actuated cell sorting’ (VACS), a new technique that deflects cells individually, via the generation of a transient microfluidic vortex by a thermal vapour bubble: a novel mechanism, which is able to sort cells based on fluorescently-labelled molecular markers. Using in silico simulation and experiments on beads, an immortal cell line and human peripheral blood mononuclear cells (PBMCs), we demonstrate high-purity and high-recovery sorting with input rates up to 10⁴ cells per s and switching speeds comparable to existing techniques (>40 kHz). A tiny footprint (1 × 0.25 mm) affords miniaturization and the potential to achieve multiplexing: a crucial step in increasing processing rate. Simple construction using biocompatible materials potentially minimizes cost of fabrication and permits single-use sterile cartridges. We believe VACS potentially enables parallel sorting at throughputs relevant to cell therapy, liquid biopsy and phenotypic screening.