Serum mitochondrial biomarkers and damage-associated molecular patterns are higher in acetaminophen overdose patients with poor outcome

Abstract

Acetaminophen (APAP) overdose is a major cause of acute liver failure (ALF). Numerous studies have shown that APAP hepatotoxicity in mice involves mitochondrial dysfunction, and recent data suggest this is also the case in humans. We have previously shown that glutamate dehydrogenase (GDH), mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) fragments can be measured in circulation of overdose patients as mechanistic biomarkers of mitochondrial damage and damage-associated molecular patterns. In the present study, our goal was to determine if these biomarkers are higher in serum from non-survivors of APAP-induced ALF (AALF) compared with survivors. GDH, mtDNA and nDNA fragments were measured in serum from AALF patients who did (n = 34) or did not (n = 35) recover. Importantly, all three were significantly increased in patients who died compared with those who survived (GDH: 450±73 vs. 930±145 U/L; mtDNA: 21±6 vs. 48±13 and 33±10 vs. 43±7 ng/mL for two different genes; nDNA fragments: 148±13 vs. 210±13 % of control). Receiver operating characteristic (ROC) curve analyses revealed that nDNA fragments, GDH and mtDNA were predictive of outcome (AUC, study admission: 0.73, 0.70 and 0.71 or 0.76, respectively, p < 0.05; AUC, time of peak ALT: 0.78, 0.71 and 0.71 or 0.76, respectively, p < 0.05) and the results were similar to those from the model for end-stage liver disease (MELD) (AUC, peak MELD: 0.77, p < 0.05). Conclusions Our data suggest that patients with more mitochondrial damage are less likely to survive, demonstrating that mitochondria are central in the mechanisms of APAP hepatotoxicity in humans. Clinically, serum nDNA fragments, GDH and mtDNA could be useful as part of a panel of biomarkers to predict patient outcome.

An Oligodeoxynucleotide with AAAG Repeats Significantly Attenuates Burn-induced Systemic inflammatory Responses by inhibiting interferon Regulatory Factor 5 Pathway

“…tissue as described above were homogenized in 1 ml Trizol reagent (CWBIO, CW0580S) and reverse transcribed using cDNA Synthesis Kit (TransGen Biotech, Beijing, China), respectively. Quantitative real-time polymerase chain reaction (RT-PCR) was performed using two-step SYBR green qPCR assays, and the target mRNA was identified by the specific primers as follows (forward and reverse primers, respectively): TLR9: The mtDNA level was measured by absolute quantification RT-PCR, as previously described (18). The DNA was isolated from plasma using the DNeasy Blood and Tissue Kit (Qiagen, Hilden, Germany), according to the manufacturer's instructions.…”

Novel circulating- and imaging-based biomarkers to enhance the mechanistic understanding of human drug-induced liver injury

“…GLDH, mtDNA and nDNA fragments were in fact all shown to be significantly increased in serum from ALF patients that died in comparison to those that survived.Importantly, ALT values were found to be similar between the two groups [26]. Circulating mtDNA levels have also been researched in other fields and found to be increased in response to stimuli such as trauma, improving risk prediction beyond commonly used biomarkers and having involvement in the development of inflammatory response syndromes [76,77].…”

“…By contrast, our understanding of these mechanisms in humans is limited [69]. There is evidence for a stress on GSH levels after APAP exposure and APAP protein adducts are measurable in serum after overdose indicating that metabolic activation and protein adduct formation do occur in humans in a manner similar to that described in rodent models [26,69].…”

“…Primarily, by informing on the pathophysiology of injury and identifying an exact mechanism, biomarkers of this kind could by their nature be extremely useful in directing appropriate therapeutic interventions to specific targets and hereby allowing treatment in a stratified and personalised manner [25,26]. In addition, it is logical that mechanistic biomarkers will coincide with the earlier detection of liver injury as the mechanisms induced will inherently preside injury itself and any successive clinical symptoms [25,27].…”

Mitochondrial dysfunction as a mechanism of drug-induced hepatotoxicity: current understanding and future perspectives

“…Thus, these biomarkers reflect more an injury mechanism than just cell death. Interestingly, when comparing a large group of patients who survived an APAP overdose with patients who did either not survive or needed a liver transplant, the surviving patients showed on average less mitochondrial damage as indicated by biomarkers GLDH, mtDNA and nuclear DNA fragments than the non-surviving patients despite the fact that both groups had similar peak ALT values [259]. These data suggest that mitochondrial injury does not just occur after APAP but is critically involved in the injury process [260].…”