Silencing lncRNA KCNQ1OT1 reduced hepatic ischemia reperfusion injury-induced pyroptosis by regulating miR-142a-3p/HMGB1 axis

Effects of Adipose-Derived Mesenchymal Stem Cell-Secretome on Pyroptosis of Laparoscopic Hepatic Ischemia Reperfusion Injury in a Porcine Model

Extensive research has been conducted on mesenchymal stem cells (MSCs) regarding their ability to modify the immune response and reduce tissue damage. Many researchers have found that the regulatory capacity of MSCs primarily comes from their secretome. As a result, there has been much interest in utilizing "cell-free" therapies as alternatives to stem cell treatments. In this study, the secretome from adipose mesenchymal stem cells (ADSC-secretome) was extracted and injected into minipigs with established liver injury models. Blood and liver tissue samples were obtained prior to the procedure, as well as on days 1, 3, and 7 after surgery. It was found that ADSC-secretome effectively suppressed the synthesis of the NOD-like receptor protein 3 (NLRP3) inflammasome, leading to a downregulation of gasdermin-D (GSDMD) expression, and demonstrated a more prominent anti-pyroptosis effect compared to ADSCs. Furthermore, ADSC-secretome inhibited the high mobility group box 1 (HMGB1)/toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) inflammatory pathway. In summary, both ADSC-secretome and ADSCs inhibited pyroptosis in right hemihepatic ischemia-reperfusion combined with left hemihepatectomy injury, and ADSC-secretome exhibited a stronger therapeutic effect. ADSC-secretome exerted these therapeutic effects through the inhibition of the HMGB1/TLR4/NF-κB inflammatory pathway. In the future, "cell-free" therapy is expected to replace cell-based methods.

Mechanism of action of the nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome and its regulation in liver injury

ABSTRACT

Nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) is a cytosolic pattern recognition receptor that recognizes multiple pathogen-associated molecular patterns and damage-associated molecular patterns. It is a cytoplasmic immune factor that responds to cellular stress signals, and it is usually activated after infection or inflammation, forming an NLRP3 inflammasome to protect the body. Aberrant NLRP3 inflammasome activation is reportedly associated with some inflammatory diseases and metabolic diseases. Recently, there have been mounting indications that NLRP3 inflammasomes play an important role in liver injuries caused by a variety of diseases, specifically hepatic ischemia/reperfusion injury, hepatitis, and liver failure. Herein, we summarize new research pertaining to NLRP3 inflammasomes in hepatic injury, hepatitis, and liver failure. The review addresses the potential mechanisms of action of the NLRP3 inflammasome, and its regulation in these liver diseases.

Current status and perspective on molecular targets and therapeutic intervention strategy in hepatic ischemia-reperfusion injury

Hepatic ischemia‒reperfusion injury (HIRI) is a common and inevitable complication of hepatic trauma, liver resection, or liver transplantation. It contributes to postoperative organ failure or tissue rejection, eventually affecting patient prognosis and overall survival. The pathological mechanism of HIRI is highly complex and has not yet been fully elucidated. The proposed underlying mechanisms include mitochondrial damage, oxidative stress imbalance, abnormal cell death, immune cell hyperactivation, intracellular inflammatory disorders and other complex events. In addition to serious clinical limitations, available antagonistic drugs and specific treatment regimens are still lacking. Therefore, there is an urgent need to not only clarify the exact etiology of HIRI but also reveal the possible reactions and bottlenecks of existing drugs, helping to reduce morbidity and shorten hospitalizations. We analyzed the possible underlying mechanism of HIRI, discussed various outcomes among different animal models and explored neglected potential therapeutic strategies for HIRI treatment. By thoroughly reviewing and analyzing the literature on HIRI, we gained a comprehensive understanding of the current research status in related fields and identified valuable references for future clinical and scientific investigations.

Dexmedetomidine alleviates Hypoxia/reoxygenation-induced mitochondrial dysfunction in cardiomyocytes via activation of Sirt3/Prdx3 pathway

BACKGROUND

Myocardial ischemia/reperfusion injury (MIRI) seriously threatens the health of people. The mitochondrial dysfunction in cardiomyocytes can promote the progression of MIRI. Dexmedetomidine (Dex) could alleviate the myocardial injury, which was known to reverse mitochondrial dysfunction in lung injury. However, the function of Dex in mitochondrial dysfunction during MIRI remains unclear.

OBJECTIVE

To assess the function of Dex in mitochondrial dysfunction during MIRI.

METHODS

To investigate the function of Dex in MIRI, H9C2 cells were placed in condition of hypoxia/reoxygenation (H/R). CCK8 assay was performed to test the cell viability, and the mitochondrial membrane potential was evaluated by JC-1 staining. In addition, the binding relationship between Sirt3 and Prdx3 was explored by Co-IP assay. Furthermore, the protein expressions were examined using western blot.

RESULTS

Dex could abolish H/R-induced mitochondrial dysfunction in H9C2 cells. In addition, H/R treatment significantly inhibited the expression of Sirt3, while Dex partially restored this phenomenon. Knockdown of Sirt3 or Prdx3 obviously reduced the protective effect of Dex on H/R-induced mitochondrial injury. Meanwhile, Sirt3 could enhance the function of Prdx3 via deacetylation of Prdx3.

CONCLUSION

Dex was found to attenuate H/R-induced mitochondrial dysfunction in cardiomyocytes via activation of Sirt3/Prdx3 pathway. Thus, this study might shed new lights on exploring new strategies for the treatment of MIRI.

NcRNA Regulated Pyroptosis in Liver Diseases and Traditional Chinese Medicine Intervention: A Narrative Review

Pyroptosis is a novel pro-inflammatory mode of programmed cell death that differs from ferroptosis, necrosis, and apoptosis in terms of its onset and regulatory mechanisms. Pyroptosis is dependent on cysteine aspartate protein hydrolase (caspase)-mediated activation of GSDMD, NLRP3, and the release of pro-inflammatory cytokines, interleukin-1 (IL-1β), and interleukin-18 (IL-18), ultimately leading to cell death. Non-coding RNA (ncRNA) is a type of RNA that does not encode proteins in gene transcription but plays an important regulatory role in other post-transcriptional links. NcRNA mediates pyroptosis by regulating various related pyroptosis factors, which we termed the pyroptosis signaling pathway. Previous researches have manifested that pyroptosis is closely related to the development of liver diseases, and is essential for liver injury, alcoholic fatty liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), liver fibrosis, and liver cancer. In this review, we attempt to address the role of the ncRNA-mediated pyroptosis pathway in the above liver diseases and their pathogenesis in recent years, and briefly outline that TCM (Traditional Chinese Medicine) intervene in liver diseases by modulating ncRNA-mediated pyroptosis, which will provide a strategy to find new therapeutic targets for the prevention and treatment of liver diseases in the future.

ALKBH5-mediated m6A demethylation of pri-miR-199a-5p exacerbates myocardial ischemia/reperfusion injury by regulating TRAF3-mediated pyroptosis

Myocardial ischemia‒reperfusion injury (MI/RI) is closely related to pyroptosis. alkB homolog 5 (ALKBH5) is abnormally expressed in the MI/RI models. However, the detailed molecular mechanism of ALKBH5 in MI/RI has not been elucidated. In this study, rats and H9C2 cells served as experimental subjects and received MI/R induction and H/R induction, respectively. The abundance of the targeted molecules was evaluated using RT-qPCR, Western blotting, immunohistochemistry, immunofluorescence, and enzyme-linked immunosorbent assay. The heart functions of the rats were evaluated using echocardiography, and heart injury was evaluated. Cell viability and pyroptosis were determined using cell counting Kit-8 and flow cytometry, respectively. Total m6A modification was measured using a commercial kit, and pri-miR-199a-5p m6A modification was detected by Me-RNA immunoprecipitation (RIP) assay. The interactions among the molecules were validated using RIP and luciferase experiments. ALKBH5 was abnormally highly expressed in H/R-induced H9C2 cells and MI/RI rats. ALKBH5 silencing improved injury and inhibited pyroptosis. ALKBH5 reduced pri-miR-199a-5p m6A methylation to block miR-199a-5p maturation and inhibit its expression. TNF receptor-associated Factor 3 (TRAF3) is a downstream gene of miR-199a-5p. Furthermore, in H/R-induced H9C2 cells, the miR-199a-5p inhibitor-mediated promotion of pyroptosis was reversed by ALKBH5 silencing, and the TRAF3 overexpression-mediated promotion of pyroptosis was offset by miR-199a-5p upregulation. ALKBH5 silencing inhibited pri-miR-199a-5p expression and enhanced pri-miR-199a-5p m6A modification to promote miR-199a-5p maturation and enhance its expression, thereby suppressing pyroptosis to alleviate MI/RI through decreasing TRAF3 expression.

Non-coding RNAs: The potential biomarker or therapeutic target in hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is the major complication of liver surgery and liver transplantation, that may increase the postoperative morbidity, mortality, tumor progression, and metastasis. The underlying mechanisms have been extensively investigated in recent years. Among these, oxidative stress, inflammatory responses, immunoreactions, and cell death are the most studied. Non-coding RNAs (ncRNAs) are defined as the RNAs that do not encode proteins, but can regulate gene expressions. In recent years, ncRNAs have emerged as research hotspots for various diseases. During the progression of HIRI, ncRNAs are differentially expressed, while these dysregulations of ncRNAs, in turn, have been verified to be related to the above pathological processes involved in HIRI. ncRNAs mainly contain microRNAs, long ncRNAs, and circular RNAs, some of which have been reported as biomarkers for early diagnosis or assessment of liver damage severity, and as therapeutic targets to attenuate HIRI. Here, we briefly summarize the common pathophysiology of HIRI, describe the current knowledge of ncRNAs involved in HIRI in animal and human studies, and discuss the potential of ncRNA-targeted therapeutic strategies. Given the scarcity of clinical trials, there is still a long way to go from pre-clinical to clinical application, and further studies are needed to uncover their potential as therapeutic targets.