👤 Brian Rowan

Alzheimer's disease (AD) is one of the most common forms of neurodegenerative disorder characterized by extracellular Aβ accumulation and intracellular tau hyperphosphorylation. Currently, there are no effective therapeutic drugs available for AD. Regular exercise training has emerged as a promising physical intervention strategy for mitigating both the risk and progression of AD, but different types of exercise interventions show varied and conflicting results in AD treatment, with their differential effects and mechanisms still unelucidated. Using an Aβ oligomer-induced AD mouse model, we investigated therapeutic effects of voluntary wheel running, forced treadmill running, and combined exercise (voluntary combined with forced running) on AD pathologies. For depressive-like behavior, we conducted forced swimming test and tail suspension test; for cognition, Novel object recognition test (object recognition ability) and Morris water maze test (spatial learning and memory) was used respectively. We applied BrdU-DCX/NeuN/GFAP immunofluorescence co-staining to measure neurogenesis, Western blot to examine proteins associated with synapses, neurons, astrocytes, apoptosis, and BDNF signaling key components, serum metabolomics to identify exercise-induced metabolites. Furthermore, a clinical trial involving healthy subjects and patients with AD implemented an acute exercise intervention and utilized portable functional near-infrared spectroscopy to assess cortical activation and functional connectivity under conditions of both voluntary and forced exercise. Voluntary, forced, and combined exercise alleviated depressive-like phenotypes and short-term cognitive deficits in AD mice, while only forced exercise conferred sustained long-term memory benefit. All exercises boosted hippocampal neurogenesis by enhancing newborn cell (BrdU Our findings reveal distinct neuroprotective profiles of long-term voluntary, forced, and combined exercise interventions against Aβ oligomer neurotoxicity in an AD mouse model, and different acute exercise modalities also demonstrate distinct effects on cortical activation and functional connectivity in patients with AD. Our study provides novel insights into exercise modalities' therapeutic effects in ameliorating AD neuropathology. Show less

Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. Constitutive activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway has been linked to chemoresistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT) when cells adopt a motile and invasive phenotype through loss of epithelial markers (CDH1), and acquisition of mesenchymal markers (VIM, CDH2). Although MAPK/ERK1/2 kinase inhibitors (MEKi) are useful antitumor agents in a clinical setting, including the Food and Drug Administration (FDA)-approved MEK1,2 dual inhibitors cobimetinib and trametinib, there are limitations to their clinical utility, primarily adaptation of the BRAF pathway and ocular toxicities. The MEK5 (HGNC: MAP2K5) pathway has important roles in metastatic progression of various cancer types, including those of the prostate, colon, bone and breast, and elevated levels of ERK5 expression in breast carcinomas are linked to a worse prognoses in TNBC patients. The purpose of this study is to explore MEK5 regulation of the EMT axis and to evaluate a novel pan-MEK inhibitor on clinically aggressive TNBC cells. Our results show a distinction between the MEK1/2 and MEK5 cascades in maintenance of the mesenchymal phenotype, suggesting that the MEK5 pathway may be necessary and sufficient in EMT regulation while MEK1/2 signaling further sustains the mesenchymal state of TNBC cells. Furthermore, additive effects on MET induction are evident through the inhibition of both MEK1/2 and MEK5. Taken together, these data demonstrate the need for a better understanding of the individual roles of MEK1/2 and MEK5 signaling in breast cancer and provide a rationale for the combined targeting of these pathways to circumvent compensatory signaling and subsequent therapeutic resistance. Show less