In Situ Observation of mtDNA Damage during Hepatic Ischemia-Reperfusion

Abstract

Hepatic ischemia-reperfusion (IR) injury is a severe pathophysiological event during liver surgery or transplantation and could lead to liver failure or even death. The energy supply of mitochondria plays an essential role in preventing IR injury. Mitochondrial DNA (mtDNA) is involved in maintaining the balance of energy by participating in an oxidative phosphorylation process. However, the exact relationship between IR and mtDNA remains unclear by reason of the lack of an accurate real-time analysis method. Herein, we fabricated a mitochondria-targeting fluorescent probe (mtDNA-BP) to explore mtDNA stability and supervise the changes in mtDNA in IR liver. By virtue of pyridinium electropositivity and suitable size, mtDNA-BP could accumulate in mitochondria and insert into the mtDNA groove, which made mtDNA-BP fluoresce strongly. This is attributed to the reduction of the intramolecular rotation energy loss that is restricted by DNA. By in situ fluorescence imaging, we observed in real time that mtDNA damage was aggravated by deteriorating IR injury, so the ROS-mtDNA-mediated IR damage signal pathway was speculated. Furthermore, on the basis of mtDNA-BP real-time response capability for mtDNA, we established a drug-screening method for inhibiting IR injury and found superior therapeutic performance of two potential drugs: pioglitazone and salidroside. This work contributes to our understanding of mtDNA-related disease and provides a new drug analysis method.

mtDNA-Specific Ultrasensitive Near-Infrared Fluorescent Probe Enables the Differentiation of Healthy and Apoptotic Cells

“…This result suggests that YON could replace Hochest 33258 due to stronger groove binding with DNA. According to eq , the number of binding sites ( n ) and binding constant ( K ) of YON and DNA were calculated to be 1.3 and 8.5 × 10 5 M –1 , respectively. The results confirmed that YON could sensitively and quantitatively detect DNA.…”

Reprogramming Exosomes to Escape from Immune Surveillance for Mitochondrial Protection in Hepatic Ischemia-Reperfusion Injury

“…In the initial stage of HIRI, mitochondrial dysfunction is characterized by the opening of mPTP and subsequent CytC release, which leads to consequent hepatocyte death 34 . In addition, a decrease in TFAM, a nuclear-encoded protein that facilitates the maintenance of mtDNA integrity and prevents mutation accumulation, is a characteristic of the early phase of HIRI and further aggravates respiratory chain dysfunction, leading to mitochondrial deficiencies 10 , 35 , 36 . Under these circumstances, suppressing mPTP opening and upregulating TFAM expression in dysfunctional mitochondria is crucial in the initial stage to prevent subsequent irreparable damage.…”

Inhibition of PLK3 Attenuates Tubular Epithelial Cell Apoptosis after Renal Ischemia–Reperfusion Injury by Blocking the ATM/P53-Mediated DNA Damage Response

“…To better characterize the molecular and 14 Oxidative Medicine and Cellular Longevity cellular events related to AKI, we used the TRAP-seq results in the GEO database to examine PLK3 expression in the translation profile of nephrons (tubules) exposed to IRI for 24 h. GO analysis showed that PLK3 was mainly involved in oxidative stress and DNA damage after renal I/R injury. DNA damage has been reported to be involved in I/R injury in a variety of vital organs, including the testicular, brain, liver, and heart [33][34][35][36]. During renal I/R injury, DNA fragmentation in the renal tubules after DNA damage occurs as early as 12 h after reperfusion and increases within 24 h [37].…”