A deep understanding of the roles of redox metabolites and pathways in physiology and pathology requires molecular tools that enable both visualization of these processes and their selective modulation. Over the last two decades, a number of genetically encoded fluorescent biosensors for key redox metabolites have been developed, allowing real-time detection in living systems of varying complexity. Recent developments in this area include the ultrasensitive probe HyPer7 and a new fluorogenic probe, HyPerFAST, which enables even more sensitive H2O2 detection across any chosen optical range, from blue to near-infrared. Complementary to imaging with biosensors, chemogenetics offers tunable substrate-dependent modulation of metabolic pathways, allowing the study of normal cell functioning and modeling dysfunctions caused by abnormal pathway activity and/or metabolite levels. We will present recent developments in this area that include insights on oxidative stress brought about by the use of D-amino acid oxidase (DAO) and intriguing details of the Warburg effect brought about by a new mitochondrial "booster," Grubraw, based on bacterial D-amino acid dehydrogenase.

Human extravillous trophoblasts play a key role in implantation, placentation, and successful pregnancy outcomes due to their ability to migrate and invade through the uterine spiral arteries. Abnormalities in the trophoblasts' migratory and invasive abilities may result in insufficient remodeling of the uterine spiral arteries. This leads to the development of preeclampsia, a syndrome in pregnancy. Neuropeptide Y (NPY) is a sympathetic neurotransmitter that plays a significant role in the adaptive stress response as well as in the regulation of body energy balance. This study was designed with the aim of investigating whether preeclampsia is associated with NPY-induced disruption of trophoblast migration and redox balance. For this purpose, the concentration of NPY was determined in the plasma of 20 healthy and 20 preeclamptic pregnant women. The obtained results demonstrated that in preeclampsia, the concentration of NPY is significantly lower (190 pg/mL) than in a healthy pregnancy (260 pg/mL). After that, NPY in concentrations of 190 pg/mL and 260 pg/mL was used to treat the human extravillous trophoblast cell line HTR-8/SVneo for ten weeks. The effect of NPY on trophoblast proliferation was determined by counting cells during each passage. After the end of the treatment, the effect of NPY on migration and intracellular concentrations of superoxide anion radical (O2.-), hydrogen peroxide (H2O2), and nitric oxide (NO) were examined. The obtained results show that NPY induces changes in trophoblast proliferation and reduces their migration at both applied doses. In addition, both doses of NPY induce a decrease in intracellular concentrations of O2.-, H2O2, and NO. The NPY concentration of 190 pg/mL significantly decreased O2.- in trophoblasts in comparison to the concentration of 260 pg/mL. This study demonstrates that NPY affects the migration and redox balance regulation of trophoblasts. It also disrupts the trophoblast redox balance at a level characteristic of preeclamptic pregnancy.

Canine hyperadrenocorticism (HAC) or Cushing’s syndrome is a multisystemic clinical condition caused by chronic exposure to elevated concentrations of glucocorticoids. It has been considered that oxidative stress is implicated in pathophysiology of HAC. The exact impact of uric acid (UA) on oxidative stress in hyperadrenocorticism remains unclear, given its ability to act as both an antioxidant and a pro-oxidant. In addition, increased UA levels are related to the development of hypertension, dyslipidemia, and type II diabetes in humans with HAC. For this purpose, we aimed to investigate the association of UA with the components of oxidative stress in dogs with HAC. This study included 12 dogs with newly diagnosed HAC and 12 healthy controls. The oxidative stress in serum samples was assessed by advanced oxidation protein product (AOPP) and thiobarbituric acid–reactive substances (TBARS), and antioxidative status by total antioxidant capacity (TAC), reduced glutathione (GSH) and paraoxonase-1 (PON-1). Uric acid was compared between two groups and correlated with oxidative stress parameters. The results showed that dogs with HAC exerted markedly higher level of UA compared to healthy controls (p<0.001). Additionally, higher levels of AOPP and TBARS (p=0.001; p =0.043) were observed in the HAC group, indicating oxidative damage compared to the controls. Among antioxidants, only GSH exhibited a difference between groups (p=0.001). Correlation analysis of UA revealed strong association with TBARS (r=0.615; p=0.037), which implies that UA is linked to an increase of oxidative stress in canine Cushing’s syndrome. The results of this study indicate a possible pro-oxidant role of UA in dogs with HAC.