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Nakahara, M.

Publications and source records attributed to Nakahara, M..

2 recordsLinked to original sources

Membrane potential modulates ERK activity and cell proliferation

Plasma membrane potential has been linked to cell proliferation for over 40 years. In this study, we experimentally demonstrated that membrane depolarization promotes mitosis and that this process depends on the voltage-dependent activation of extracellular signal-regulated kinase (ERK). Notably, ERK activity showed a clear dependence on the membrane potential, independent of growth factor stimulation. This voltage dependence was observed even near the resting membrane potential, indicating that small shifts in the resting potential can influence proliferative activity. Voltage-dependent ERK activity is derived from the altered dynamics of phosphatidylserine and is not mediated by calcium influx from the extracellular space. These findings suggest that fundamental biological processes such as cell proliferation are regulated by the physicochemical properties of membrane lipids. This study highlights the broader physiological roles of membrane potentials beyond action potentials, which are well-established in neural systems.

cell biology↗

miR-10b Deficiency Affords Atherosclerosis Resistance

Human vascular endothelial cells (ECs) are categorized into two groups; pro-stenotic (Type-I) and anti-stenotic (Type-II) ECs, and one of the master genes for a stress-induced \"Type-II-to-Type-I\" degeneration is Regulator of G-protein signaling 5 (RGS5). Here we show that miR-10b is a crucial downstream mediator in RGS5-dependent degeneration. We also demonstrated the miR-10bhigh Type-I EC exosome has a trans effect which suppresses anti-proliferative abilities of Type-II ECs. Moreover, we found miR-10b-deficient mice showed a resistance to experimental atherosclerosis, where high-fat-high-cholesterol-diet-fed mice were subjected to partial carotid ligation. Furthermore, we determined the key target of miR-10b was Latent transforming growth factor-{beta} binding protein 1 (LTBP1), which is a regulator of TGF-{beta} signaling. Compatible with a commonly accepted view that TGF-{beta} creates the major growth-inhibitory signal against vascular smooth muscle cells, TGF-{beta} inhibitor treatments abolished anti-proliferative functions of Type-II ECs. Therefore, RGS5/miR-10b/LTBP1/TGF-{beta} axis plays a leading role in quality control of ECs.

cell biology↗