Cascading Detection of Hydrogen Sulfide and N-Acetyltransferase 2 in Hepatocellular Carcinoma Cells Using a Two-Photon Fluorescent Probe.

Hydrogen sulfide (H2S), a critical gas signaling molecule, and N-acetyltransferase 2 (NAT2), a key enzyme in drug metabolism, are both known active biomarkers for liver function. However, the interactions and effects of H2S and NAT2 in living cells or lesion sites remain unknown due to the lack of imaging tools to achieve simultaneous detection of these two substances, making it challenging to implement real-time imaging and precise tracking. Herein, we report an activity-based two-photon fluorescent probe, TPSP-1, for the cascade detection of H2S and NAT2 in living liver cells. Continuous conversion from TPSP-1 to TPSP-3 was achieved in liver cells and tissues. Significantly, leveraging the outstanding optical properties of this two-photon fluorescent probe, TPSP-1, has been effectively used to identify pathological tissue samples directly from clinical liver cancer patients. This work provides us with this novel sensing and two-photon imaging probe, which can be used as a powerful tool to study the physiological functions of H2S and NAT2 and will help facilitate rapid and accurate diagnosis and therapeutic evaluation of hepatocellular carcinoma.

Activity-Based Imaging of Macrophage Migration Inhibitory Factor with a Two-Photon Fluorescent Probe.

Macrophage migration inhibitory factor (MIF), as a cytokine, plays an important role in the pathogenesis of cancer and some other diseases, and it is also one of the potential drug targets for disease treatment. However, due to the lack of simple and effective MIF imaging detection tools, the fluctuation and distribution of MIF in living cells or at lesion sites remain difficult to track precisely and in real time. Here, we report activity-based fluorescent probes, named MIFP1-MIFP3, which are used for real-time imaging and tracking of intracellular MIF, thus establishing a relationship between the fluctuation of MIF and the change of fluorescence signal during the cancer disease process. With the excellent optical properties of two-photon probe imaging, we can easily distinguish multiple cancer cells from normal cells with the representative probe, MIFP3. Moreover, MIFP3 has also been successfully used to directly identify the pathological tissues of patients with clinical liver cancer. These potential MIF probes could provide powerful tools for further study of the physiological function of MIF and will be helpful to promote the accurate diagnosis and therapeutic evaluation of MIF-associated malignancies.

3D two-photon brain imaging reveals dihydroartemisinin exerts antiepileptic effects by modulating iron homeostasis.

Imbalanced iron homeostasis plays a crucial role in neurological diseases, yet direct imaging evidence revealing the distribution of active ferrous iron (Fe2+) in the living brain remains scarce. Here, we present a near-infrared excited two-photon fluorescent probe (FeP) for imaging changes of Fe2+ flux in the living epileptic mouse brain. In vivo 3D two-photon brain imaging with FeP directly revealed abnormal elevation of Fe2+ in the epileptic mouse brain. Moreover, we found that dihydroartemisinin (DHA), a lead compound discovered through probe-based high-throughput screening, plays a critical role in modulating iron homeostasis. In addition, we revealed that DHA might exert its antiepileptic effects by modulating iron homeostasis in the brain and finally inhibiting ferroptosis. This work provides a reliable chemical tool for assessing the status of ferrous iron in the living epileptic mouse brain and may aid the rapid discovery of antiepileptic drug candidates.

Imaging of formaldehyde fluxes in epileptic brains with a two-photon fluorescence probe.

A two-photon (TP) fluorescence probe has been developed for imaging endogenous FA fluxes during metabolic and epigenetic processes in animal models, especially in live brains.