Cyclin Y-mediated transcript profiling reveals several important functional pathways regulated by Cyclin Y in hippocampal neurons.

Cyclin Y (CCNY), which is a cyclin protein known to play a role in cell division, is unexpectedly and thus interestingly expressed in non-proliferating neuronal cells. There have been only a few studies reporting the neuronal functions of CCNY in synapse remodeling and hippocampal long-term potentiation. Therefore, we here provide global and comprehensive information on the putative functions of CCNY in biological and functional pathways in neuronal systems. We adopted high-throughput RNA-sequencing technology for analyzing transcriptomes regulated by CCNY and utilized bioinformatics for identifying putative molecules, biological processes, and functional pathways that are possibly connected to CCNY functions in hippocampal neuronal cells of rats. We revealed that several enriched annotation terms and pathways associated with CCNY expression within neurons, including apoptosis, learning or memory, synaptic plasticity, actin cytoskeleton, focal adhesion, extracellular matrix-receptor interaction and chemokine signaling pathway are targeted by CCNY. In addition, the mRNA levels of some genes enriched for those annotation terms and pathways or genes reported to be altered in Alzheimer's disease mouse model were further validated by quantitative real-time PCR in hippocampal neuronal cells. The present study provides an excellent resource for future investigations of CCNY functions in neuronal systems.

Functional restoration of replicative senescent mesenchymal stem cells by the brown alga Undaria pinnatifida.

The brown alga Undaria pinnatifida, which is called Mi-Yoek in Korea, has been traditionally consumed as a health food in East Asian countries. Recent studies have reported that U. pinnatifida has beneficial effects on arteriosclerosis, inflammation, fat metabolism, and tumors. In this study, we examined the anti-senescence effects of ethanol extracts of U. pinnatifida (UP-Ex) in human bone marrow mesenchymal stem cells (hBM-MSCs). UP-Ex protected hBM-MSCs against oxidative injury, as determined by MTT assays. This effect was confirmed by immunoblot analysis of the oxidation-sensitive protein p53 and the apoptotic protein cleaved caspase-3. Excessive intracellular reactive oxygen species (ROS) accumulation induced by oxidative stress was moderated in UP-Ex-treated hBM-MSCs (UP-Ex-MSCs). Similarly, expression of the ROS-scavenging enzymes superoxide dismutase 1 (SOD1), SOD2, and catalase was recovered in UP-Ex-MSCs. Excessive ROS induced by long-term cell expansion (passage 17) was significantly decreased along with restoration of the senescence proteins p53, p21, and p16 in UP-Ex-MSCs. UP-Ex treatment also improved the ability of these replicative, senescent hBM-MSCs (passage 17) to differentiate into osteocytes or adipocytes, suggesting that UP-Ex ameliorates the functional decline of senescent stem cells and may provide better therapeutic efficacy in stem cell therapy. Abbreviations: hBM-MSCs: human bone marrow mesenchymal stem cells; DCF: 2',7'-dichlorodihydrofluorescein; DCFH-DA: 2',7'-dichlorofluorescein diacetate; MTT: 3-(4,5-dimethylthiazol-2-yl-)2,5-diphenyltetrazolium bromide; PBS: phosphate-buffered saline; PFA: paraformaldehyde; RIPA: radioimmunoprecipitation assay; ROS: reactive oxygen species; SOD1: superoxide dismutase 1; SOD2: superoxide dismutase 2.

PDE4 Inhibition by Rolipram Promotes Neuronal Differentiation in Human Bone Marrow Mesenchymal Stem Cells.

Increased intracellular cyclic adenosine monophosphate (cAMP) can promote axonal elongation and facilitate neuronal repair, while decreased cAMP is associated with losses in neuronal regenerative capacity. Rolipram, which upregulates intracellular cAMP by blocking phosphodiesterase-4 (PDE4) enzyme activity, can mitigate diverse neurological disorders. In this study, we investigated whether rolipram induces neuronal differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs). Rolipram-treated MSCs (Roli-MSCs) had significantly increased expression of the neuroprogenitor proteins Nestin, Musashi, GFAP, and Sox-2. When Roli-MSCs were differentiated with neuronal induction media (Roli-dMSCs), they exhibited cell body and dendritic morphologies similar to those of neurons. The neurite number and length of Roli-dMSCs were significantly increased compared to those of differentiated MSCs (dMSCs). Compared with undifferentiated hBM-MSCs, the Roli-dMSCs and dMSCs showed significantly increased expression of the neuronal-specific marker genes Nestin, Musashi, CD133, GFAP, NF-M, MAP-2, KCNH1, KCNH5, SCN3A, and CACNA1A, and decreased expression of other lineage-specific markers Adiponectin, ALP, FABP4, and MMP13. The Roli-dMSCs also showed a higher expression of the neuronal markers Nestin, Musashi, Sox-2, NF-M, and Tuj-1 compared to those of the undifferentiated hBM-MSCs, measured by immunocytochemistry and immunoblotting assay. Thus, we have shown that rolipram ameliorates neuronal differentiation by the regulation of neuroprogenitor expression in hBM-MSCs, and rolipram treatment of MSCs may improve the therapeutic efficacy of stem cell therapy for neurodegenerative disorders.

Resveratrol-induced SIRT1 activation promotes neuronal differentiation of human bone marrow mesenchymal stem cells.

Resveratrol-3,4',5-trihydroxy-trans-stillbene (resveratrol; RSV), a natural non-flavonoid polyphenol compound, provides protection against stress injury, excessive sunlight, ultraviolet radiation, infections, and invading fungi. There is increasing evidence that resveratrol, a sirtuin1 activator, plays a pivotal role in neuroprotection and neuronal differentiation. In this study, we investigated whether resveratrol induces neuronal differentiation of human bone marrow-mesenchymal stem cells (hBM-MSCs). Quantitative PCR results showed that resveratrol-treated MSCs (RSV-MSCs) had significantly increased expression of the neuroprogenitor markers Nestin, Musashi, CD133, and GFAP. When RSV-MSCs were differentiated with neuronal induction media (RSV-dMSCs), they exhibited a cell body and dendritic morphology similar to neurons. The number and neurite length of these RSV-dMSCs were significantly increased compared to differentiated MSCs (dMSCs). The RSV-dMSCs and dMSCs had significantly increased expression of the neuronal-specific marker genes Nestin, Musashi, CD133, GFAP, NF-M, MAP-2, and KCNH1. The RSV-dMSCs also showed a higher expression of the neuronal marker proteins, Nestin and NF-M, based on immunocytochemical staining and immunoblot analysis. This effect was abolished by the treatment of sirtuin1 inhibitor EX527. Therefore, we have shown that resveratrol treatment, along with the use of neuronal induction media, effectively stimulates neuronal cell differentiation of hBM-MSCs.