The ATF6β-calreticulin axis promotes neuronal survival under endoplasmic reticulum stress and excitotoxicity

While ATF6α plays a central role in the endoplasmic reticulum (ER) stress response, the function of its paralogue ATF6β remains elusive, especially in the central nervous system (CNS). Here, we demonstrate that ATF6β is highly expressed in the hippocampus of the brain, and specifically regulates the expression of calreticulin (CRT), a molecular chaperone in the ER with a high Ca2+-binding capacity. CRT expression was reduced to ~ 50% in the CNS of Atf6b−/− mice under both normal and ER stress conditions. Analysis using cultured hippocampal neurons revealed that ATF6β deficiency reduced Ca2+ stores in the ER and enhanced ER stress-induced death. The higher levels of death in Atf6b−/− neurons were recovered by ATF6β and CRT overexpressions, or by treatment with Ca2+-modulating reagents such as BAPTA-AM and 2-APB, and with an ER stress inhibitor salubrinal. In vivo, kainate-induced neuronal death was enhanced in the hippocampi of Atf6b−/− and Calr+/− mice, and restored by administration of 2-APB and salubrinal. These results suggest that the ATF6β-CRT axis promotes neuronal survival under ER stress and excitotoxity by improving intracellular Ca2+ homeostasis

The ATF6β-calreticulin axis promotes neuronal survival under endoplasmic reticulum stress and excitotoxicity

神経細胞死を抑制する新たな分子を発見 --脳卒中やアルツハイマー病への応用に期待--. 京都大学プレスリリース. 2021-06-30.While ATF6α plays a central role in the endoplasmic reticulum (ER) stress response, the function of its paralogue ATF6β remains elusive, especially in the central nervous system (CNS). Here, we demonstrate that ATF6β is highly expressed in the hippocampus of the brain, and specifically regulates the expression of calreticulin (CRT), a molecular chaperone in the ER with a high Ca²⁺-binding capacity. CRT expression was reduced to ~ 50% in the CNS of Atf6b⁻/⁻ mice under both normal and ER stress conditions. Analysis using cultured hippocampal neurons revealed that ATF6β deficiency reduced Ca²⁺ stores in the ER and enhanced ER stress-induced death. The higher levels of death in Atf6b⁻/⁻ neurons were recovered by ATF6β and CRT overexpressions, or by treatment with Ca²⁺-modulating reagents such as BAPTA-AM and 2-APB, and with an ER stress inhibitor salubrinal. In vivo, kainate-induced neuronal death was enhanced in the hippocampi of Atf6b⁻/⁻ and Calr⁺/⁻ mice, and restored by administration of 2-APB and salubrinal. These results suggest that the ATF6β-CRT axis promotes neuronal survival under ER stress and excitotoxity by improving intracellular Ca²⁺ homeostasis

Low Temperature Gasification of Coconut Shell with CO2 and KOH: Effects of Temperature, Chemical Loading, and Introduced Carbonization Step on the Properties of Syngas and Porous Carbon Product

Effect of KOH, reaction temperature and time, and introduced carbonization step on the amount and composition of syngas as well as porous properties of the carbon products for CO2 gasification of coconut shell at low temperatures (300–700°C) was investigated. Results showed that the presence of potassium hydroxide and gasification temperature had a significant effect on the amount and composition of syngas product and facilitated the rate of hydrogen and carbon monoxide formation. It was also found that carbonization step could promote the generation of hydrogen gas as well as increasing the gas heating value per kg of gas. Furthermore, the porosity development of carbon product was found to be influenced by the chemical ratio and gasification temperature. The optimal conditions for achieving high hydrogen composition and specific surface area were to gasify coconut shell under CO2 at 600°C for 60 min with carbonization step and with chemical weight ratio of 3.0. This condition gave the hydrogen composition as high as 29.70 %weight of produced syngas with heating value of 41.4 MJ/kg of gas and specific surface area of 2650 m2/g of the carbon product

Development of low-CO2-emission vehicles and utilization of local renewable energy for the vitalization of rural areas in Japan

Most of Japan's energy supply depends on imports from foreign countries, making the independence ratio of energy in Japan very low. The Fukushima nuclear power plant accident triggered by the Great East Japan Earthquake and Tsunami led to a mass shutdown of all the nuclear plants in Japan, a stoppage that is still in effect. In this paper, we review the energy supply situation and some social problems faced by rural areas in Japan. Given that lifestyles in rural Japan are reliant on automobiles, there is significant demand for the establishment of a sustainable mobility society. Furthermore, Japan is now entering an aging society ahead of other countries. In order to enhance the vitalization of rural areas and accelerate the establishment of sustainable society, our project developed low-CO2-emission vehicles (i.e., a single-driver EV [micro-EV] and a low-speed E-bus) for elderly people and tourists through the cooperation of regional industries, a local university, and a city office. This paper also reports some trial test results on renewable energy utilization as the driving energy supply for these low-emission vehicles