LncRNA KCNQ1OT1 ameliorates the liver injury induced by acetaminophen through the regulation of miR-122-5p/CES2 axis

A human liver organoid screening platform for DILI risk prediction

BACKGROUND & AIMS

Drug-induced liver injury (DILI), both intrinsic and idiosyncratic, causes frequent morbidity, mortality, clinical trial failures and post-approval withdrawal. This suggests an unmet need for improved in vitro models for DILI risk prediction that can account for diverse host genetics and other clinical factors. In this study, we evaluated the utility of human liver organoids (HLOs) for high-throughput DILI risk prediction and in an organ-on-chip system.

METHODS

HLOs were derived from three separate iPSC lines and benchmarked on two platforms for their ability to model in vitro liver function and identify hepatotoxic compounds using biochemical assays for albumin, ALT, AST, microscopy-based morphological profiling, and single-cell transcriptomics: i) HLOs dispersed in 384-well-formatted plates and exposed to a library of compounds; ii) HLOs adapted to a liver-on-chip system.

RESULTS

Dispersed HLOs derived from the three iPSC lines had similar DILI predictive capacity as intact HLOs in a high-throughput screening format, allowing for measurable IC50 values of compound cytotoxicity. Distinct morphological differences were observed in cells treated with drugs exerting differing mechanisms of toxicity. On-chip HLOs significantly increased albumin production, CYP450 expression, and ALT/AST release when treated with known hepatoxic drugs compared to dispersed HLOs and primary human hepatocytes. On-chip HLOs were able to predict the synergistic hepatotoxicity of tenofovir-inarigivir and displayed steatosis and mitochondrial perturbation, via phenotypic and transcriptomic analysis, on exposure to fialuridine and acetaminophen, respectively.

CONCLUSIONS

The high-throughput and liver-on-chip systems exhibit enhanced in vivo-like functions and demonstrate the potential utility of these platforms for DILI risk assessment. Tenofovir-inarigivr-associated hepatotoxicity was observed and correlates with the clinical manifestation of DILI observed in patients.

IMPACT AND IMPLICATIONS

Idiosyncratic (spontaneous, patient-specific) drug-induced liver injury (DILI) is difficult to study due to the lack of liver models that function as human liver tissue and are adaptable for large-scale drug screening. Human liver organoids grown from patient stem cells respond to known DILI-causing drugs in both a high-throughput and on a physiological "chip" culture system. These platforms show promise for researchers in their use as predictive models for novel drugs before entering clinical trials and as a potential in vitro diagnostic tool. Our findings support further development of patient-derived liver organoid lines and their use in the context of DILI research.

Potential of long non-coding RNA KCNQ1OT1 as a biomarker reflecting systemic inflammation, multiple organ dysfunction, and mortality risk in sepsis patients

Background

Long non‐coding RNA potassium voltage‐gated channel subfamily Q member 1 opposite strand 1 (lnc‐KCNQ1OT1) represses inflammation and multiple organ dysfunction, whereas its clinical value in sepsis is unclear. Thus, this study aimed to explore this issue.

Methods

Lnc‐KCNQ1OT1 from peripheral blood mononuclear cells were detected by RT‐qPCR in 116 sepsis patients and 60 healthy controls (HCs). Moreover, sepsis patients were followed‐up until death or up to 28 days.

Results

Lnc‐KCNQ1OT1 decreased in patients with sepsis than in HCs (p < 0.001). In sepsis patients, lnc‐KCNQ1OT1 was negatively correlated with sequential organ failure assessment (SOFA) scores (r = −0.344, p < 0.001) and several SOFA subscale scores (including respiratory system, coagulation, liver, and renal systems) (all r < 0, p < 0.05). Furthermore, lnc‐KCNQ1OT1 was negatively correlated with CRP (r = −0.386, p < 0.001), TNF‐α (r = −0.332, p < 0.001), IL‐1β (r = −0.319, p < 0.001), and IL‐6 (r = −0.255, p = 0.006). Additionally, lnc‐KCNQ1OT1 levels were lower in sepsis deaths than in sepsis survivors (p < 0.001), and the receiver operating characteristic curve showed that lnc‐KCNQ1OT1 had an acceptable ability to predict 28‐day mortality (area under the curve: 0.780, 95% confidence interval: 0.678–0.882). Meanwhile, its ability to predict 28‐day mortality risk was higher than that of CRP, TNF‐α, IL‐1β, and IL‐6, but slightly lower than the SOFA score and acute physiology and chronic health evaluation II score.

Conclusion

Lnc‐KCNQ1OT1 serves as a potential biomarker for monitoring disease severity and prognosis in patients with sepsis.

Targeting epigenetics and lncRNAs in liver disease: From mechanisms to therapeutics

Early onset and progression of liver diseases can be driven by aberrant transcriptional regulation. Different transcriptional regulation processes, such as RNA/DNA methylation, histone modification, and ncRNA-mediated targeting, can regulate biological processes in healthy cells, as well also under various pathological conditions, especially liver disease. Numerous studies over the past decades have demonstrated that liver disease has a strong epigenetic component. Therefore, the epigenetic basis of liver disease has challenged our knowledge of epigenetics, and epigenetics field has undergone an important transformation: from a biological phenomenon to an emerging focus of disease research. Furthermore, inhibitors of different epigenetic regulators, such as m⁶A-related factors, are being explored as potential candidates for preventing and treating liver diseases. In the present review, we summarize and discuss the current knowledge of five distinct but interconnected and interdependent epigenetic processes in the context of hepatic diseases: RNA methylation, DNA methylation, histone methylation, miRNAs, and lncRNAs. Finally, we discuss the potential therapeutic implications and future challenges and ongoing research in the field. Our review also provides a perspective for identifying therapeutic targets and new hepatic biomarkers of liver disease, bringing precision research and disease therapy to the modern era of epigenetics.

Role of Noncoding RNAs in Acetaminophen-Induced Liver Injury

Genomic and transcriptomic analyses have well established that the major fraction of the mammalian genome is transcribed into different classes of RNAs ranging in size from a few nucleotides to hundreds of thousands of nucleotides, which do not encode any protein. Some of these noncoding RNAs (ncRNAs) are directly or indirectly linked to the regulation of expression or functions of 25,000 proteins coded by <2% of the human genome. Among these regulatory RNAs, microRNAs are small (2125 nucleotides) RNAs that are processed from precursor RNAs that have stemloop structure, whereas noncoding RNAs >200 nucleotides are termed long noncoding RNAs (lncRNAs). Circular RNAs (circRNAs) are newly identified lncRNA members that are generated by back-splicing of primary transcripts. The functions of ncRNAs in modulating liver toxicity of xenobiotics are emerging only recently. Acetaminophen (N-acetyl-para-aminophenol, paracetamol or APAP) is a safe analgesic and antipyretic drug at the therapeutic dose. However, it can cause severe liver toxicity that may lead to liver failure if overdosed or combined with alcohol, herbs, or other xenobiotics. This review discusses the role of ncRNAs in acetaminophen metabolism, toxicity, and liver regeneration after APAP-induced liver injury (AILI).