miR-194 ameliorates hepatic ischemia/reperfusion injury via targeting PHLDA1 in a TRAF6-dependent manner

HSP110 aggravates ischemia-reperfusion injury after liver transplantation by promoting NF-κB pathway

BACKGROUND

Ischemia-reperfusion injury (IRI) poses a significant challenge to liver transplantation (LT). The underlying mechanism primarily involves overactivation of the immune system. Heat shock protein 110 (HSP110) functions as a molecular chaperone that helps stabilize protein structures.

METHODS

An IRI model was established by performing LT on Sprague-Dawley rats, and HSP110 was silenced using siRNA. Hematoxylin-eosin staining, TUNEL, immunohistochemistry, ELISA and liver enzyme analysis were performed to assess IRI following LT. Western blotting and quantitative reverse transcription-polymerase chain reaction were conducted to investigate the pertinent molecular changes.

RESULTS

Our findings revealed a significant increase in the expression of HSP110 at both the mRNA and protein levels in the rat liver following LT (P < 0.05). However, when rats were injected with siRNA-HSP110, IRI subsequent to LT was notably reduced (P < 0.05). Additionally, the levels of liver enzymes and inflammatory chemokines in rat serum were significantly reduced (P < 0.05). Silencing HSP110 with siRNA resulted in a marked decrease in M1-type polarization of Kupffer cells in the liver and downregulated the NF-κB pathway in the liver (P < 0.05).

CONCLUSIONS

HSP110 in the liver promotes IRI after LT in rats by activating the NF-κB pathway and inducing M1-type polarization of Kupffer cells. Targeting HSP110 to prevent IRI after LT may represent a promising new approach for the treatment of LT-associated IRI.

Targeting NF-κB in Hepatic Ischemia-Reperfusion Alleviation: from Signaling Networks to Therapeutic Targeting

Hepatic ischemia-reperfusion injury (HIRI) is a major complication of liver trauma, resection, and transplantation that can lead to liver dysfunction and failure. Scholars have proposed a variety of liver protection methods aimed at reducing ischemia-reperfusion damage, but there is still a lack of effective treatment methods, which urgently needs to find new effective treatment methods for patients. Many studies have reported that signaling pathway plays a key role in HIRI pathological process and liver function recovery mechanism, among which nuclear transfer factor-κB (NF-κB) signaling pathway is one of the signal transduction closely related to disease. NF-κB pathway is closely related to HIRI pathologic process, and inhibition of this pathway can delay oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction. In addition, NF-κB can also interact with PI3K/Akt, MAPK, and Nrf2 signaling pathways to participate in HIRI regulation. Based on the role of NF-κB pathway in HIRI, it may be a potential target pathway for HIRI. This review emphasizes the role of inhibiting the NF-κB signaling pathway in oxidative stress, inflammatory response, cell death, and mitochondrial dysfunction in HIRI, as well as the effects of related drugs or inhibitors targeting NF-κB on HIRI. The objective of this review is to elucidate the role and mechanism of NF-κB pathway in HIRI, emphasize the important role of NF-κB pathway in the prevention and treatment of HIRI, and provide a theoretical basis for the target NF-κB pathway as a therapy for HIRI.

Circulating microRNA Profiles Identify a Patient Subgroup with High Inflammation and Severe Symptoms in Schizophrenia Experiencing Acute Psychosis

Schizophrenia is a complex and heterogenous psychiatric disorder. This study aimed to demonstrate the potential of circulating microRNAs (miRNAs) as a clinical biomarker to stratify schizophrenia patients and to enhance understandings of their heterogenous pathophysiology. We measured levels of 179 miRNA and 378 proteins in plasma samples of schizophrenia patients experiencing acute psychosis and obtained their Positive and Negative Syndrome Scale (PANSS) scores. The plasma miRNA profile revealed three subgroups of schizophrenia patients, where one subgroup tended to have higher scores of all the PANSS subscales compared to the other subgroups. The subgroup with high PANSS scores had four distinctively downregulated miRNAs, which enriched 'Immune Response' according to miRNA set enrichment analysis and were reported to negatively regulate IL-1β, IL-6, and TNFα. The same subgroup had 22 distinctively upregulated proteins, which enriched 'Cytokine-cytokine receptor interaction' according to protein set enrichment analysis, and all the mapped proteins were pro-inflammatory cytokines. Hence, the subgroup is inferred to have comparatively high inflammation within schizophrenia. In conclusion, miRNAs are a potential biomarker that reflects both disease symptoms and molecular pathophysiology, and identify a patient subgroup with high inflammation. These findings provide insights for the precision medicinal strategies for anti-inflammatory treatments in the high-inflammation subgroup of schizophrenia.

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.

TRIM37 exacerbates hepatic ischemia/reperfusion injury by facilitating IKKγ translocation

BACKGROUND

Hepatic ischemia/reperfusion (I/R) injury is one of the major pathological processes associated with various liver surgeries. However, there is still a lack of strategies to protect against hepatic I/R injury because of the unknown underlying mechanism. The present study aimed to identify a potential strategy and provide a fundamental experimental basis for treating hepatic I/R injury.

METHOD

A classic 70% ischemia/reperfusion injury was established. Immunoprecipitation was used to identify direct interactions between proteins. The expression of proteins from different subcellular localizations was detected by Western blotting. Cell translocation was directly observed by immunofluorescence. HE, TUNEL and ELISA were performed for function tests.

RESULT

We report that tripartite motif containing 37 (TRIM37) aggravates hepatic I/R injury through the reinforcement of IKK-induced inflammation following dual patterns. Mechanistically, TRIM37 directly interacts with tumor necrosis factor receptor-associated factor 6 (TRAF6), inducing K63 ubiquitination and eventually leading to the phosphorylation of IKKβ. TRIM37 enhances the translocation of IKKγ, a regulatory subunit of the IKK complex, from the nucleus to the cytoplasm, thereby stabilizing the cytoplasmic IKK complex and prolonging the duration of inflammation. Inhibition of IKK rescued the function of TRIM37 in vivo and in vitro.

CONCLUSION

Collectively, the present study discloses some potential function of TRIM37 in hepatic I/R injury. Targeting TRIM37 might be potential for treatment against hepatic I/R injury.Targeting TRIM37 might be a potential treatment strategy against hepatic I/R injury.

PHLDA1 knockdown alleviates mitochondrial dysfunction and endoplasmic reticulum stress-induced neuronal apoptosis via activating PPARγ in cerebral ischemia-reperfusion injury

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress occur in ischemic stroke. The disruption of these two organelles can directly lead to cell death through various signaling pathways. Thus, investigation of the associated molecular mechanisms in cerebral ischemia is a prerequisite for stroke treatment. Pleckstrin homology-like domain family A member 1 (PHLDA1) is a multifunctional protein that can modulate mitochondrial function and ER stress in cardiomyocyte and cancer cells. This work studied the role of PHLDA1 in cerebral ischemic/reperfusion (I/R) injury and explored the underlying mechanisms associated with mitochondrial functions and ER stress. Middle cerebral artery occlusion/reperfusion (MCAO/R)-treated mice and oxygen-glucose deprivation/reoxygenation (OGD/R)-stimulated neurons were used as I/R models in vivo and in vitro, respectively. PHLDA1 was upregulated in ischemic penumbra of MCAO/R-induced mice and OGD/R-exposed neurons. In vitro, PHLDA1 knockdown protected neurons from OGD/R-induced apoptosis. In vivo, PHLDA1 silencing facilitated functional recovery and reduced cerebral infarct volume. Mechanistically, PHLDA1 knockdown promoted PPARγ nuclear translocation, which may mediate the effects on reversion of mitochondrial functions and alleviation of ER stress. In summary, PHLDA1 knockdown alleviates neuronal ischemic injuries in mice. PPARγ activation and mitochondrial dysfunction and endoplasmic reticulum stress attenuation are involved in the underlying mechanisms.

Knockdown of PHLDA1 Alleviates Necrotizing Enterocolitis by Inhibiting NLRP3 Inflammasome Activation and Pyroptosis Through Enhancing Nrf2 Signaling

OBJECTIVE

Pleckstrin homology-like domain family A member 1 (PHLDA1) is involved in the progression of intestine-related diseases, but its role and related mechanisms in Necrotizing enterocolitis (NEC) are unclear. The aim of this study was to better understand the function of PHLDA1 in NEC and the underlying mechanisms.

METHODS

A neonatal mouse model of NEC was established by hypoxic hypothermia, and sh-PHLDA1 was transfected into mice to observe the mortality of each group within 4 days. The levels of IL-1β, IL-6, IL-18 and TNF-α were measured by PCR and ELISA. ROS, MDA, SOD, and GSH-Px levels were detected by Dihydroethidium (DHE) method and kit; expression of pyroptosis-related factors including NLRP3, ASC, cleaved-caspase1, GSDMD-N, IL-1β, IL-18, and Nrf2 were detected by western-blot; mechanistically, the effects of transfection of sh-PHLDA1 and ML385 (Nrf2 inhibitor) were investigated, and the expression of pyroptosis-related factors was detected again.

RESULTS

PHLDA1 was highly expressed in the intestinal tissues of NEC mice, and transfection of sh-PHLDA1 improved the survival rate, alleviated intestinal lesions, improved intestinal inflammation, oxidative stress and cellular scorching in NEC. In addition, sh-PHLDA1 was able to inhibit NLRP3 activation and pyroptosis by activating Nrf2.

CONCLUSION

Knockdown of PHLDA1 attenuated necrotizing small intestinal colitis by enhancing Nrf2 expression to inhibit NLRP3 inflammasome activation and pyroptosis.

DUSP9 alleviates hepatic ischemia/reperfusion injury by restraining both mitogen-activated protein kinase and IKK in an apoptosis signal-regulating kinase 1-dependent manner

Hepatic ischemia/reperfusion (I/R) injury occurs frequently in various liver operations and diseases, but its effective treatment remains inadequate because the key switch that leads to hepatic explosive inflammation has not been well disclosed. Dual specificity phosphatase 9 (DUSP9) is widely involved in the innate immune response of solid organs and is sometimes regulated by ubiquitin. In the present study, we find that DUSP9 is reduced in mouse hepatic I/R injury. DUSP9 enrichment attenuates hepatic inflammation both in vivo and in vitro as revealed by western blot analysis and qRT-PCR. In contrast, DUSP9 depletion leads to more severe I/R injury. Mechanistically, DUSP9 inhibits the phosphorylation of apoptosis signal-regulating kinase 1 (ASK1) by directly binding to ASK1, thereby decreasing tumor necrosis factor receptor-associated factor 6 (TRAF6), K63 ubiquitin and the phosphorylation of p38/JNK1 instead of ERK1. The present study documents a novel role of DUSP9 in hepatic I/R injury and implies the potential of targeting the DUSP9/ASK1 axis towards mitogen-activated protein kinase and TRAF6/inhibitor of κB kinase pathways.

TDAG51 deficiency attenuates dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a group of chronic inflammatory diseases of the gastrointestinal tract. Although the multifactorial etiology of IBD pathogenesis is relatively well documented, the regulatory factors that confer a risk of IBD pathogenesis remain less explored. In this study, we report that T-cell death-associated gene 51 (TDAG51/PHLDA1) is a novel regulator of the development of dextran sulfate sodium (DSS)-induced colitis in mice. TDAG51 expression was elevated in the colon tissues of DSS-induced experimental colitis mice. TDAG51 deficiency protected mice against acute DSS-induced lethality and body weight changes and disease severity. DSS-induced structural damage and mucus secretion in colon tissues were significantly reduced in TDAG51-deficient mice compared with wild-type mice. We observed similar results in a DSS-induced chronic colitis mouse model. Finally, we showed that the production of inflammatory mediators, including proinflammatory enzymes, molecules and cytokines, was decreased in DSS-treated TDAG51-deficient mice compared with DSS-treated wild-type mice. Thus, we demonstrated that TDAG51 deficiency plays a protective role against DSS-induced colitis by decreasing the production of inflammatory mediators in mice. These findings suggest that TDAG51 is a novel regulator of the development of DSS-induced colitis and is a potential therapeutic target for IBD.

Rye Bread Crust as an Inducer of Antioxidant Genes and Suppressor of NF-κB Pathway In Vivo

Heat-processed food, like bread, containing high amounts of advanced glycation end products (AGEs), is controversially discussed regarding the effects on health and disease. In in vitro and in vivo experiments, AGEs can induce proinflammatory NF-κB and/or the anti-inflammatory NRF2 pathways. The aim of this study was to investigate how gene expression is influenced in vivo upon short as well as long-term feeding of mice with control and bread crust-food (BC). For that, the liver, kidney and heart from two days- and eight days-fed mice were isolated and gene arrays were performed. Fewer genes were affected in terms of expression after two days of BC feeding than after eight days. We observed, especially in the heart and to lesser extent in the liver, an induction of antioxidant response by BC. Among the significantly up-regulated genes identified in the heart were transcripts encoding for cardioprotective and antioxidative proteins like metallothionein 2, uncoupling protein 3 and pyruvate dehydrogenase kinase 4. In contrast, in the liver, genes encoding for inflammatory drivers like thioredoxin-interacting protein, lncRNA Mtss1 and ubiquitin-specific protease 2 were down-modulated. However, an increased expression of immunoglobulins was observed in the kidney. Furthermore, in vivo imaging analyses with NF-κB-luciferase-reporter mice uncovered a rather anti-inflammatory response, especially after three and seven days of the feeding study. Our results suggest that bread crust exerts antioxidant and anti-inflammatory effects in the model organism mouse in an organ-specific manner.

Non-Coding RNA Related to MAPK Signaling Pathway in Liver Cancer

The advancement in high-throughput sequencing analysis and the evaluation of chromatin state maps have revealed that eukaryotic cells produce many non-coding transcripts/RNAs. Further, a strong association was observed between some non-coding RNAs and cancer development. The mitogen-activated protein kinases (MAPK) belong to the serine–threonine kinase family and are the primary signaling pathways involved in cell proliferation from the cell surface to the nucleus. They play an important role in various human diseases. A few non-coding RNAs associated with the MAPK signaling pathway play a significant role in the development of several malignancies, including liver cancer. In this review, we summarize the molecular mechanisms and interactions of microRNA, lncRNA, and other non-coding RNAs in the development of liver cancer that are associated with the MAPK signaling pathway. Further, we briefly discuss the therapeutic strategies for liver cancer related to ncRNA and the MAPK signaling pathway.

MicroRNAs: Novel Targets in Hepatic Ischemia–Reperfusion Injury

Hepatic ischemia–reperfusion injury (IRI) is one of the main factors for early allograft dysfunction (EAD), which may lead to graft rejection, graft loss, or shortened graft life in liver transplantation. Hepatic IRI appears to be inevitable during the majority of liver procurement and transportation of donor organs, resulting in a cascade of biological changes. The activation of signaling pathways during IRI results in the up- and downregulation of genes and microRNAs (miRNAs). miRNAs are ~21 nucleotides in length and well-characterized for their role in gene regulations; they have recently been used for therapeutic approaches in addition to their role as biomarkers for many diseases. miRNAs that are associated with hepatic IRI in in vitro and in vivo animal models are comprehensively summarized in this review. In those studies, the manipulation of miRNAs has been shown for the inhibition of aggravated immune response, reduction of apoptosis, stimulation of tissue repair, and enhancement of cell recovery to attenuate liver damage. Therefore, the utilization of liver-specific miRNA holds great potential as a therapeutic agent to improve early allograft dysfunction, hepatic injury, and patient outcome.

PHLDA1 Suppresses TLR4-Triggered Proinflammatory Cytokine Production by Interaction With Tollip

Pleckstrin homology-like domain, family A, member 1 (PHLDA1) has been reported to be expressed in many mammalian tissues and cells. However, the functions and exact mechanisms of PHLDA1 remain unclear. In this study, we found that PHLDA1 expression was significantly altered in macrophages after exposure to lipopolysaccharide (LPS) in vitro, suggesting that PHLDA1 may be involved in the regulation of TLR4 signaling pathway activated by LPS. PHLDA1 attenuated the production of LPS-stimulated proinflammatory cytokines (TNF-α, IL-6, and IL-1β). Further research showed that the phosphorylation levels of some important signal molecules in TLR4/MyD88-mediated MAPK and NF-κB signaling pathways were reduced by PHLDA1, which in turn impaired the transcription factors NF-κB and AP1 nuclear translocation and their responsive element activities. Furthermore, we found that PHLDA1 repressed LPS-induced proinflammatory cytokine production via binding to Tollip which restrained TLR4 signaling pathway. A mouse model of endotoxemia was established to confirm the above similar results. In brief, our findings demonstrate that PHLDA1 is a negative regulator of LPS-induced proinflammatory cytokine production by Tollip, suggesting that PHLDA1 plays an anti-inflammatory role through inhibiting the TLR4/MyD88 signaling pathway with the help of Tollip. PHLDA1 may be a novel therapeutic target in treating endotoxemia.

FBXW5 aggravates hepatic ischemia/reperfusion injury via promoting phosphorylation of ASK1 in a TRAF6-dependent manner

Liver ischemia/reperfusion injury (IRI) is an inevitable pathological process exacerbating the occurrence of rejection in liver transplantation. At present, there is still a lack of sufficient cognition for the mechanism as well as effective clinical strategies. F-box/WD repeat-containing protein 5 (FBXW5), a key modulator of stress signalling, was recently reported to participate in hepatic immunity. However, the role of FBXW5 in liver IRI is still unclear. In the present study, we found expression of FBXW5 was increased in liver IRI both in vivo and in vitro. Inhibition of FBXW5 significantly alleviated both mitogen-activated protein kinase (MAPK) and inhibitor of nuclear factor kappa-B kinase (IKK) pathways, thus resulting in cytokine release, hepatic pathological injury and apoptosis. Over-expression of FBXW5 achieved an opposite effect. Investigations on the mechanism showed that FBXW5 intensified hepatic inflammation by promoting phosphorylation of ASK1, while blockade of TRAF6 could abolish this process. Moreover, reinforce of mTOR amplified the anti-inflammatory efficacy derived from inhibition of FBXW5, indicating the function of FBXW5/ASK1/TRAF6 axis in hepatic IRI might be relatively independent of mTOR-guided M2 polarization of Kupffer cell. Taken together, FBXW5 could be a key accelerator in liver IRI by enhancing activation of ASK1 in a TRAF6-dependent manner. The joint intervention towards both FBXW5 and mTOR might be a promising strategy to protect liver from IRI.