The Neurotrophic Function of Glucagon-Like Peptide-1 Promotes Human Neuroblastoma Differentiation via the PI3K-AKT Axis.

 Background: Neurons are terminally-differentiated cells that generally develop from neuronal stem cells stimulated by various neurotrophic factors such as NGF, BDNF, NT3, and NT-4. Neurotrophic factors have multiple functions for neurons, including enabling neuronal development, growth, and protection. Glucagon-like peptide-1 (GLP-1) is an intestinal-secreted incretin that enhances cellular glucose up-take to decrease blood sugar levels. However, many studies suggest that the function of GLP-1 is not limited to the regulation of blood sugar levels. Instead, it may also act as a neurotrophic factor with a role in ensuring neuronal survival and neurite outgrowth, as well as protecting synaptic plasticity and memory formation. Methods: The SH-SY5Y cells were differentiated by sequential treatments of retinoic acid and GLP-1 treatment within polyethylenimine-coated dishes under serum-free Neurobasal medium. PI3K inhibitor (LY294002) and MEK inhibitor (U0126) were used to determine the signaling pathway in regulation of neuronal differentiation. Neuronal marker (TUJ1) and synaptic markers (synapsin 1, synaptophysin, and PSD95) as well as single cell patch-clamp were applied to determine maturity of neurons. Antibodies of AMPA receptor, NMDA receptor subunit 2A, dopamine receptor D1, muscarinic acetylcholine receptor 2, and nicotinic acetylcholine receptor α4 were used to examine the types of differentiated neurons. Results: Our study's results demonstrated that the treatment with GLP-1 of SH-SY5Y human neuroblastoma cells increased the expression of AMPA receptors, NMDA receptors, dopamine receptors, synaptic proteins-synapsin 1, synaptophysin, and postsynaptic density protein 95, but not muscular and nicotinic acetylcholine receptors. In addition, the biomarker of dividing neuronal cells, vimentin, was decreased after treatment with GLP-1. Tuj1 immunostaining images showed that GLP-1 induced neurite processes and the development of neuronal morphologies. The GLP-1-differentiated neurons were able to be induced to generate action potentials by single cell patch-clamp. Our study also suggested that the PI3K-AKT axis is the dominant signaling pathway promoting the differentiation of SH-SY5Y cells into mature and functional neurons in response to GLP-1 receptor activation. Conclusions: The sequential treatment of retinoic acid and GLP-1 within a serum-free medium is able to trigger the differentiation of SH-SY5Y cells into morphologically and physiologically mature glutamatergic and dopaminergic neurons.

The potential of drug repurposing combined with reperfusion therapy in cerebral ischemic stroke: A supplementary strategy to endovascular thrombectomy.

Stroke is the major cause of adult disability and the second or third leading cause of death in developed countries. The treatment options for stroke (thrombolysis or thrombectomy) are restricted to a small subset of patients with acute ischemic stroke because of the limited time for an efficacious response and the strict criteria applied to minimize the risk of cerebral hemorrhage. Attempts to develop new treatments, such as neuroprotectants, for acute ischemic stroke have been costly and time-consuming and to date have yielded disappointing results. The repurposing approved drugs known to be relatively safe, such as statins and minocycline, may provide a less costly and more rapid alternative to new drug discovery in this clinical condition. Because adequate perfusion is thought to be vital for a neuroprotectant to be effective, endovascular thrombectomy (EVT) with advanced imaging modalities offers the possibility of documenting reperfusion in occluded large cerebral vessels. An examination of established medications that possess neuroprotective characters using in a large-vessel occlusive disorder with EVT may speed the identification of new and more broadly efficacious medications for the treatment of ischemic stroke. These approaches are highlighted in this review along with a critical assessment of drug repurposing combined with reperfusion therapy as a supplementary means for halting or mitigating stroke-induced brain damage.

Sulforaphane induced cell cycle arrest in the G2/M phase via the blockade of cyclin B1/CDC2 in human ovarian cancer cells.

BACKGROUND: Malignant tumors are the single most common cause of death and the mortality rate of ovarian cancer is the highest among gynecological disorders. The excision of benign tumors is generally followed by complete recovery; however, the activity of cancer cells often results in rapid proliferation even after the tumor has been excised completely. Thus, clinical treatment must be supplemented by auxiliary chemotherapy or radiotherapy. Sulforaphane (SFN) is an extract from the mustard family recognized for its anti-oxidation abilities, phase 2 enzyme induction, and anti-tumor activity. METHODS: This study investigated the cell cycle arrest in G2/M by SFN and the expression of cyclin B1, Cdc2, and the cyclin B1/CDC2 complex in PA-1 cells using western blotting and co-IP western blotting. RESULTS: This study investigated the anticancer effects of dietary isothiocyanate SFN on ovarian cancer, using cancer cells line PA-1. SFN-treated cells accumulated in metaphase by CDC2 down-regulation and dissociation of the cyclin B1/CDC2 complex. CONCLUSION: Our findings suggest that, in addition to the known effects on cancer prevention, SFN may also provide antitumor activity in established ovarian cancer.

Effect of sulforaphane on growth inhibition in human brain malignant glioma GBM 8401 cells by means of mitochondrial- and MEK/ERK-mediated apoptosis pathway.

In recent studies, sulforaphane (SFN) has been seen to demonstrate antioxidant and anti-tumor activities as well as potent chemopreventive action against cancer. The present study investigates the anti-proliferation (using MTT assay, SFN demonstrated cytotoxic activity against GBM 8401 cell with IC(50) values at 35.52 µM) and induced apoptosis of SFN 24-h treatment in the cells of human brain malignant glioma GBM 8401 cells. We studied the MMP, caspase, MEK/ERK activation, and NF-κB transcription factor activity. Our results indicate that SFN inhibits cell proliferation as well as the activation of apoptosis in GBM 8401 cells. Both effects increased in proportion to the dosage of SFN, and apoptosis was induced via mitochondria- and caspase-dependent pathways. Daily s.c. injections of SFN for 3 weeks in severe combined immunodeficient mice (SCID) with GBM8401 s.c. tumors resulted in a decrease in mean tumor weight of 69-75 % compared with vehicle-treated controls. Our findings suggest that, in addition to the known effects on cancer prevention, SFN may provide antitumor activity in established malignant glioma.