Empagliflozin, a sodium-glucose co-transporter 2 inhibitor developed, has been shown to reduce cardiovascular events in patients with type 2 diabetes and established cardiovascular disease. Several studies have suggested that empagliflozin improves the cardiac energy state which is a partial cause of its potency. However, the detailed mechanism remains unclear. To address this issue, we used a mouse model that enabled direct measurement of cytosolic and mitochondrial ATP levels. Empagliflozin treatment significantly increased cytosolic and mitochondrial ATP levels in the hearts of db/db mice. Empagliflozin also enhanced cardiac robustness by maintaining intracellular ATP levels and the recovery capacity in the infarcted area during ischemic-reperfusion. Our findings suggest that empagliflozin enters cardiac mitochondria and directly causes these effects by increasing mitochondrial ATP via inhibition of NHE1 and Nav1.5 or their common downstream sites. These cardioprotective effects may be involved in the beneficial effects on heart failure seen in clinical trials.

The single-molecular conductance between two πconjugated wires with and without a radical substituent has been compared. Specifically, methyl-and iminonitroxidesubstituted 4-(biphenyl-4-yl)pyridine wires bound onto a porphyrin template were subjected to scanning tunneling microscopy (STM) apparent-height measurement at the interface between highly oriented pyrolytic graphite (HOPG) and octan-1-oic acid. Statistical analysis of the STM images revealed that the radical-substituted wire has 3.2 � 1.7-fold higher conductance than the methyl-substituted reference. Although density functional theory (DFT) calculation suggests that only 17 % of the SOMO is distributed on the wire moiety, the effect was significant. This study presents the potential of radical substituents to achieve high conductivity in molecular wires.

43Analysis of the dynamics of adenosine triphosphate (ATP) is vital to quantitatively 44 define the actual roles of ATP in biological activities. Here, we applied a genetically 45 encoded Förster resonance energy transfer biosensor "GO-ATeam" and created a 46 transgenic mouse model that allows systemic ATP levels to be quantitatively, 47 sensitively, noninvasively, and spatiotemporally measured under physiological and 48 pathological conditions. We used this model to readily conduct intravital imaging of 49 ATP dynamics under three different conditions: during exercise, in all organs and cells; 50 during myocardial infarction progression; and in response to the application of 51 cardiotoxic drugs. These findings provide compelling evidence that the GO-ATeam 52 mouse model is a powerful tool to investigate the multifarious functions of cellular ATP 53 in vivo with unprecedented spatiotemporal resolution in real-time. This will inform 54 predictions of molecular and morphological responses to perturbations of ATP levels, as 55 well as the elucidation of physiological mechanisms that control ATP homeostasis. 56 57 One Sentence Summary: 58 Intravital real-time imaging of ATP dynamics in multiple organs using GO-ATeam 59 mice, can be used to quantitatively, sensitively, noninvasively, and spatiotemporally 60 measure systemic ATP levels and provide a platform for preclinical pharmacological 61 studies. 62 63 64 67 MAIN TEXT 68 69 maintenance of energy homeostasis in physiology and possibly preclinical 116 pharmacological studies. 117 118 119 RESULTS 120 121 Generation of Transgenic Mice to Determine ATP Dynamics In Vivo 122We chose to employ the GO-ATeam strategy (Nakano et al., 2011) to observe ATP 123 dynamics in live mice. As noted above, this system employs GFP and OFP as the FRET 124 pair, which can be readily detected and is minimally sensitive to pH, an important 125 advantage because metabolic stress can cause a drop in intracellular pH. After several 126 failed attempts to generate GO-ATeam transgenic mice, we obtained stable GO-ATeam 127 knock-in mice with the FRET reporter cassette (Figs. 1A-1H). The knock-in mice 128 yielded homozygous and heterozygous offspring consistent with Mendelian inheritance. 129 Importantly, body weight, morphology and size, as well as the weights and functions of 130 the organs, were normal. Moreover, the mice were phenotypically normal throughout 131 their expected lifespan of approximately three years (data not shown). 132The FRET/GFP Ratio Reliably Reflects Cytosolic ATP Concentrations in GO-133 ATeam Mice 134To examine whether the GO-ATeam probe can effectively measure cytosolic ATP 135 concentrations in GO-ATeam knock-in mice, we first investigated the fluorescence 136 signals in mouse embryonic fibroblasts (MEFs) obtained from GO-ATeam knock-in 137 mice. After permeabilization of the plasma membrane of MEFs (n = 37), we recorded 138 FRET/GFP ratios in the cells with a two-photon microscope while stepwise increasing 139

The molecular conductance of radical‐substituted molecular wire was evaluated by STM apparent‐height measurement compared with a non‐radical‐substituted wire. Statistical analysis of the STM images revealed that the radical‐substituted wire has a 3.2‐fold larger conductance. Although only 17 % of the SOMO is calculated to exist on the wire moiety, the effect was significant. This study presents the potential of radical substituents to achieve high conductivity in molecular wires. More information can be found in the Research Article by K. Matsuda and co‐workers (DOI: 10.1002/chem.202104242).

What is the most significant result of this study?Substitution with an iminonitroxide radical increases the conductance of a molecular wire by 3.2 times, whereas the typical nonradical substituent effect is rather small (< 1.2 times). This work demonstrates that even fractional delocalization of a half-filled orbital boosts the single molecular conductance of a molecular wire.