Physiological Expression of Ion Channel Receptors in Human Periodontal Ligament Stem Cells

Non-proliferative neurogenesis in human periodontal ligament stem cells

Understanding the sequence of events from undifferentiated stem cells to neuron is not only important for the basic knowledge of stem cell biology, but also for therapeutic applications. In this study we examined the sequence of biological events during neural differentiation of human periodontal ligament stem cells (hPDLSCs). Here, we show that hPDLSCs-derived neural-like cells display a sequence of morphologic development highly similar to those reported before in primary neuronal cultures derived from rodent brains. We observed that cell proliferation is not present through neurogenesis from hPDLSCs. Futhermore, we may have discovered micronuclei movement and transient cell nuclei lobulation coincident to in vitro neurogenesis. Morphological analysis also reveals that neurogenic niches in the adult mouse brain contain cells with nuclear shapes highly similar to those observed during in vitro neurogenesis from hPDLSCs. Our results provide additional evidence that it is possible to differentiate hPDLSCs to neuron-like cells and suggest the possibility that the sequence of events from stem cell to neuron does not necessarily requires cell division from stem cell.

α-Tocopherol Modulates Non-Amyloidogenic Pathway and Autophagy in an In Vitro Model of Alzheimer's Disease: A Transcriptional Study

Alzheimer's disease (AD) is the most common form of dementia worldwide. The hallmarks of AD are the extracellular amyloid plaques, which are formed by amyloid β (Aβ) aggregates derived from the processing of the amyloid precursor protein (APP), and the intraneuronal neurofibrillary tangles, which are formed by the hyperphosphorylated tau protein. The aim of this work was to study the effects of α-tocopherol in retinoic acid differentiated SH-SY5Y neuroblastoma cells exposed to Aβ1-42 evaluating the transcriptional profile by next-generation sequencing. We observed that α-tocopherol was able to reduce the cytotoxicity induced by Aβ treatment, as demonstrated by Thiazolyl Blue Tetrazolium Bromide (MTT) assay. Moreover, the transcriptomic analysis evidenced that α-tocopherol treatment upregulated genes involved in the non-amyloidogenic processing of APP, while it downregulated the amyloidogenic pathway. Moreover, α-tocopherol modulated the expression of the genes involved in autophagy and the cell cycle, which are both known to be altered in AD. The treatment with α-tocopherol was also able to reduce oxidative stress, restoring nuclear factor erythroid-derived 2-like 2 (Nrf2) and decreasing inducible nitric oxide synthase (iNOS) levels, as demonstrated by immunocytochemistry.

Transcriptomic Analysis of MAPK Signaling in NSC-34 Motor Neurons Treated with Vitamin E

Vitamin E family is composed of different tocopherols and tocotrienols that are well-known as antioxidants but that exert also non-antioxidant effects. Oxidative stress may be involved in the progression of neurodegenerative disorders including amyotrophic lateral sclerosis (ALS), characterized by motor neuron death. The aim of the study was the evaluation of the changes induced in the transcriptional profile of NSC-34 motor neurons treated with α-tocopherol. In particular, cells were treated for 24 h with 10 µM α-tocopherol, RNA was extracted and transcriptomic analysis was performed using Next Generation Sequencing. Vitamin E treatment modulated MAPK signaling pathway. The evaluation revealed that 34 and 12 genes, respectively belonging to “Classical MAP kinase pathway” and “JNK and p38 MAP kinase pathway”, were involved. In particular, a downregulation of the genes encoding for p38 (Log₂ fold change −0.87 and −0.67) and JNK (Log₂ fold change −0.16) was found. On the contrary, the gene encoding for ERK showed a higher expression in cells treated with vitamin E (Log₂ fold change 0.30). Since p38 and JNK seem more involved in cell death, while ERK in cell survival, the data suggested that vitamin E treatment may exert a protective role in NSC-34 motor neurons. Moreover, Vitamin E treatment reduced the expression of the genes which encode proteins involved in mitophagy. These results indicate that vitamin E may be an efficacious therapy in preventing motor neuron death, opening new strategies for those diseases that involve motor neurons, including ALS.