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Changes in adenosine triphosphate (ATP) and peroxynitrite (ONOO - ) concentrations have been correlated in a number of diseases including ischemia-reperfusion injury and drug-induced liver injury. Herein, we report the development of a fluorescent probe ATP-LW, which enables the simultaneous detection of ONOO - and ATP. ONOO - selectively oxidizes the boronate pinacol ester of ATP-LW to afford the fluorescent 4-hydroxy-1,8-naphthalimide product NA-OH (λ ex = 450 nm, λ em = 562 nm or λ ex = 488 nm, λ em = 568 nm). In contrast, the binding of ATP to ATP-LW induces the spirolactam ring opening of rhodamine to afford a highly emissive product (λ ex = 520 nm, λ em = 587 nm). Due to the differences in emission between the ONOO - and ATP products, ATP-LW allows ONOO - levels to be monitored in the green channel (λ ex = 488 nm, λ em = 500-575 nm) and ATP concentrations in the red channel (λ ex = 514 nm, λ em = 575-650 nm). The use of ATP-LW as a combined ONOO - and ATP probe was demonstrated using hepatocytes (HL-7702 cells) in cellular imaging experiments. Treatment of HL-7702 cells with oligomycin A (an inhibitor of ATP synthase) resulted in a reduction of signal intensity in the red channel and an increase in that of the green channel as expected for a reduction in ATP concentrations. Similar fluorescence changes were seen in the presence of SIN-1 (an exogenous ONOO - donor).

Liver fibrosis has accounted for liver diseases and overall mortality, but no relevant drug has been developed. Filamentous fungi are important resources of natural products for pharmaceutical development. Calcarisporium arbuscula is a mushroom endophytic fungus, which primarily produces aurovertins. Here, in an aurovertin null-production mutant, one silent gene cluster ( mca17 ) was activated by overexpression of a pathway-specific zinc finger transcriptional regulator, and a tetramic acid-type compound ( 1 , MCA17-1) was identified. Along with detailed structural characterization, its biosynthesis was proposed to be produced from the core PKS-NRPS hybrid enzyme. Moreover, 1 suppressed the activation of LX-2 upon transforming growth factor-β (TGF-β) challenge and had stronger bioactivity than the positive control obeticholic acid (OCA) against liver fibrosis. Our work suggested that this engineered fungus could be a producer of 1 for promising pharmaceutical development, and alternatively, it would be developed as a mushroom ingredient in dietary therapy to prevent liver fibrosis.

Acidic fibroblast growth factor (FGF1) regulates a wide array of important biological phenomena such as angiogenesis, cell differentiation, tumor growth, and neurogenesis. Generally, FGFs are known for their strong affinity for the glycosaminoglycan heparin, as a prerequisite for recognition of a specific tyrosine kinase on the cell surface and are responsible for the cell signal transduction cascade. Inositol hexaphosphate (IP6) is a natural antioxidant and is known for its antiangiogenic role, in addition to its ability to control tumor growth. In the present study, we investigated the interaction of IP6 with the acidic fibroblast growth factor (FGF1) using various biophysical techniques including isothermal calorimetry, circular dichroism, and multidimensional NMR spectroscopy. Herein, we have reported the three-dimensional solution structure of the FGF1-IP6 complex. These data show that IP6 binds FGF1 and enhances its thermal stability. In addition, we also demonstrate that IP6 acts as an antagonist to acidic fibroblast growth factor by inhibiting its receptor binding and subsequently decreasing the mitogenic activity. The inhibition likely results in the ability of IP6 to antagonize the angiogenic and mitogenic activity of FGF1.