PParasitic infections pose challenges to the development of effective treatments because these microorganisms are eukaryotes, like the humans and animals they infect. In addition, species such as toxoplasma gondii They live inside cells, making them more difficult to study and harder to develop treatments for.
“To [discover] “We need to take a closer look at the changes this parasite causes in host cells to better target it.” Gina Gallego Lopeza postdoctoral fellow and parasitologist at the Morgridge Institute and the University of Wisconsin-Madison. Many of the amino acids and lipids are T. Gondi Understanding how parasites manipulate host metabolites as they are necessary for survival host metabolic pathway It may suggest new strategies for defeating this invader.1
Recently, Gallego-López and her colleagues developed a new approach to noninvasively study intracellular infections using two-photon microscopy. Measuring metabolic changes in T. Gondi-infected cells.2 This research m bio, demonstrated that T. Gondi Changes in metabolic activity of human fibroblasts shed light on parasite-induced metabolic rewiring.
“It’s very difficult to distinguish between host cell metabolism and parasite metabolism,” he said. Laura Knolla parasitologist at the University of Wisconsin-Madison and co-author of the study. To overcome this, the team used T. Gondi The red fluorescent dye mCherry is expressed to track the location of the parasite. We then utilized natural fluorescence from cellular respiratory metabolites to monitor changes in the abundance of these products during infection.
The research team started with a less virulent strain of the virus. T. Gondi Because it grows more slowly, we were able to study metabolic changes over time. They did this by measuring nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate (collectively referred to as NAD(P)H), two metabolites that accept or donate electrons during cellular respiration. , gained insight into cellular metabolism. Therefore, changes in the ratio of protein-bound NAD(P)H to free enzyme served as a reliable indicator of cellular metabolism. they observed that T. Gondi Infection increased the proportion of bound enzymes and produced a more oxidized intracellular environment. Both indicate increased metabolism.
The researchers used two-photon microscopy to track the amount of NAD(P)H in host cells during the infection process by capturing the autofluorescence of metabolites. The concentration of NAD(P)H is inferred by the color gradient, with blue being less metabolites and red being more metabolites.
Gina Gallego Lopez
“We had no idea about the redox changes caused by substances such as: toxoplasma gondii host,” Gallego-Lopez said. “This is the first time we’ve been able to measure it in living cells.”
To further investigate metabolic effects T. Gondi In relation to infectious diseases, the research team studied changes in glucose and lactate concentrations. They showed that blood sugar levels gradually increased during the first 9 hours after infection, then decreased during the remaining 48 hours. Meanwhile, cellular lactate concentration began to decrease 6 h after infection. This corresponds to an increase in glycolysis early in infection and a subsequent decrease in glycolysis 24 hours later, paralleling increased intracellular oxidation and suggesting that the parasite alters glucose metabolism for growth. Suggests.
The team compared these findings with previous findings RNA sequencing results.3 They found that increases in gene expression previously observed in host cells corresponded to enzymes involved in cellular respiration. Additionally, they observed increased expression of reactive oxygen species metabolizing enzymes in the body. T. Gondi The same goes for other metabolically important enzymes.
The agreement between this study and the team’s previous gene expression data shows that: T. Gondi Changes cellular metabolism. Knoll’s team suspects this may provide clues about viable treatment strategies. The group previously Anticancer drug candidate decreased T. Gondi Intracellular growth.4 “Cancer is caused by rapidly replicating eukaryotic cells that evade the immune response.” [intracellular parasites] The same goes for it,” Knoll said. “So we need to rethink the drugs we already have, some of which could be very useful drugs.” [against T. gondii]”
Du Sichenga molecular geneticist who studies T. Gondi Ph.D. from Clemson University and was not involved in this research, said the study is interesting and that more labs will be applying this imaging technique and more models will demonstrate its effectiveness. If developed, he said, this imaging technology would be useful in the field. He is also interested in further exploring the mechanisms behind metabolic changes.
“This is probably something we need to understand in the future,” Dou said, adding that the field could investigate where these changes are coming from. “Host cells can change their metabolism to resist infection.”
