SIRT3 regulates mitophagy in liver fibrosis through deacetylation of PINK1/NIPSNAP1.

Damaged mitochondria, a key factor in liver fibrosis, can be removed by the mitophagy pathway to maintain homeostasis of the intracellular environment to alleviate the development of fibrosis. PINK1 (PTEN-induced kinase 1) and NIPSNAP1 (nonneuronal SNAP25-like protein 1), which cooperatively regulate mitophagy, have been predicted to include the sites of lysine acetylation related to SIRT3 (mitochondrial deacetylase sirtuin 3). Our study aimed to discuss whether SIRT3 deacetylates PINK1 and NIPSNAP1 to regulate mitophagy in liver fibrosis. Carbon tetrachloride (CCl4 )-induced liver fibrosis as an in vivo model and LX-2 cells as activated cells were used to simulate liver fibrosis. SIRT3 expression was significantly decreased in mice in response to CCl4 , and SIRT3 knockout in vivo significantly deepened the severity of liver fibrosis, as indicated by increased α-SMA and Col1a1 levels both in vivo and in vitro. SIRT3 overexpression decreased α-SMA and Col1a1 levels. Furthermore, SIRT3 significantly regulated mitophagy in liver fibrosis, as demonstrated by LC3-Ⅱ/Ⅰ and p62 expression and colocalization between TOM20 and LAMP1. Importantly, PINK1 and NIPSNAP1 expression was also decreased in liver fibrosis, and PINK1 and NIPSNAP1 overexpression significantly improved mitophagy and attenuated ECM production. Furthermore, after simultaneously interfering with PINK1 or NIPSNAP1 and overexpressing SIRT3, the effect of SIRT3 on improving mitophagy and alleviating liver fibrosis was disrupted. Mechanistically, we show that SIRT3, as a mitochondrial deacetylase, specifically regulates the acetylation of PINK1 and NIPSNAP1 to mediate the mitophagy pathway in liver fibrosis. SIRT3-mediated PINK1 and NIPSNAP1 deacetylation is a novel molecular mechanism in liver fibrosis.

Publisher Correction: Single-DNA electron spin resonance spectroscopy in aqueous solutions.

In the version of this paper originally published online, the ORCID ID for Peter Z. Qin was incorrectly assigned to Zhuoyang Qin. In addition, the ORCID for Fazhan Shi was omitted. These errors have been corrected in the print, PDF, and HTML versions of the paper.

Single-DNA electron spin resonance spectroscopy in aqueous solutions.

Magnetic resonance spectroscopy of single biomolecules under near-physiological conditions could substantially advance understanding of their biological function, but this approach remains very challenging. Here we used nitrogen-vacancy centers in diamonds to detect electron spin resonance spectra of individual, tethered DNA duplexes labeled with a nitroxide spin label in aqueous buffer solutions at ambient temperatures. This work paves the way for magnetic resonance studies on single biomolecules and their intermolecular interactions in native-like environments.

Carnosol alleviates nonalcoholic fatty liver disease by inhibiting mitochondrial dysfunction and apoptosis through targeting of PRDX3.

Mitochondrial dysfunction is a major factor in nonalcoholic fatty liver disease (NAFLD), preceding insulin resistance and hepatic steatosis. Carnosol (CAR) is a kind of diterpenoid with antioxidant, anti-inflammatory and antitumor activities. Peroxiredoxin 3 (PRDX3), a mitochondrial H2O2-eliminating enzyme, undergoes overoxidation and subsequent inactivation under oxidative stress. The purpose of this study was to investigate the protective effect of the natural phenolic compound CAR on NAFLD via PRDX3. Mice fed a high-fat diet (HFD) and AML-12 cells treated with palmitic acid (PA) were used to detect the molecular mechanism of CAR in NAFLD. We found that pharmacological treatment with CAR notably moderated HFD- and PA- induced steatosis and liver injury, as shown by biochemical assays, Oil Red O and Nile Red staining. Further mechanistic investigations revealed that CAR exerted anti-NAFLD effects by inhibiting mitochondrial oxidative stress, perturbation of mitochondrial dynamics, and apoptosis in vivo and in vitro. The decreased protein and mRNA levels of PRDX3 were accompanied by intense oxidative stress after PA intervention. Interestingly, CAR specifically bound PRDX3, as shown by molecular docking assays, and increased the expression of PRDX3. However, the hepatoprotection of CAR in NAFLD was largely abolished by specific PRDX3 siRNA, which increased mitochondrial dysfunction and exacerbated apoptosis in vitro. In conclusion, CAR suppressed lipid accumulation, mitochondrial dysfunction and hepatocyte apoptosis by activating PRDX3, mitigating the progression of NAFLD, and thus, CAR may represent a promising candidate for clinical treatment of steatosis.

Ubiquitin-specific protease 22 ameliorates chronic alcohol-associated liver disease by regulating BRD4.

Alcohol-associated liver disease (ALD) is a liver system disease caused by alcohol abuse, and it involves complex processes ranging from steatosis to fibrosis, cirrhosis and hepatocellular carcinoma. Steatosis and inflammation are the main phenomena involved in ALD. Ubiquitin-specific protease 22 (USP22) plays an important role in liver steatosis; however, its functional contribution to ALD remains unclear. USP22-silenced mice were fed a Lieber-DeCarli liquid diet. AML-12 and HEK293T cells were used to detect the interaction between USP22 and BRD4. Here, we report that hepatic USP22 expression was dramatically upregulated in mice with ALD. Inflammation and steatosis were significantly ameliorated following USP22 silencing in vivo, as indicated by decreased IL-6 and IL-1ß levels. We further showed that the overexpression of USP22 increased inflammation, while knocking down BRD4 suppressed the inflammatory response in AML-12 cells. Notably, USP22 functioned as a BRD4 deubiquitinase to facilitate BRD4 inflammatory functions. More importantly, the expression levels of USP22 and BRD4 in patients with ALD were significantly increased. In conclusion, USP22 acts a key pathogenic factor in ALD by deubiquitinating BRD4, which facilitates the inflammatory response and aggravates ALD.

LncRNA Mical2/miR-203a-3p sponge participates in epithelial-mesenchymal transition by targeting p66Shc in liver fibrosis.

Epithelial-mesenchymal transition (EMT) is regulated by reactive oxygen species (ROS) in liver fibrosis. p66Shc is a redox enzyme, but its role of EMT is unclear in liver fibrosis. Long noncoding RNAs (lncRNAs) have been implicated as important regulators in numerous physiological and pathological processes and generally acting as a microRNA (miRNA) sponge to regulate gene expression. The aim of the current study was to evaluate the contribution of p66Shc to EMT in liver fibrosis and the regulation of p66Shc by lncRNA sponge. In vivo, p66Shc silencing prevented carbon tetrachloride (CCl4)-induced EMT as evidenced by the upregulation of E-cadherin, downregulation of Vimentin and N-cadherin, and inhibition of oxidative stress and extracellular matrix (ECM) components. Moreover, in vitro, TGF-ß1 significantly enhanced ECM components, as well as the development of the EMT phenotype. These effects were abrogated by p66Shc downregulation and aggravated by p66Shc overexpression. Mechanistically, p66Shc contributed to EMT via mediating ROS, as evidenced by p66Shc downregulation inhibiting EMT under exogenous hydrogen peroxide (H2O2) stimulation. Furthermore, we found that molecule interacting with CasL2 (Mical2) lncRNA functioned as an endogenous miR-203a-3p sponge to regulate p66Shc expression. Both Mical2 silencing and miR-203a-3p agomiR treatment downregulated p66Shc expression, thus suppressing EMT in vivo and in vitro. Notably, the increased p66Shc and Mical2 levels and decreased miR-203a-3p levels in murine fibrosis were consistent with those in patients with liver fibrosis. In sum, our study reveals that p66Shc is critical for liver fibrosis and that Mical2, miR-203a-3p and p66Shc compose a novel regulatory pathway in liver fibrosis.

miR-103a-3p regulates mitophagy in Parkinson's disease through Parkin/Ambra1 signaling.

Parkin is a crucial protein that promotes the clearance of damaged mitochondria via mitophagy in neuron, and parkin mutations result in autosomal-recessive Parkinson's disease (AR-PD). However, the exact mechanisms underlying the regulation of Parkin-mediated mitophagy in PD remain unclear. In this study, PD models were generated through incubation of SH-SY5Y cells with 1-methyl-4-phenylpyridinium ion (MPP+, 1.5 mM for 24 h) and intraperitoneal injections of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg for five consecutive days) in mice. A Bioinformatics database was used to identify Parkin-targeting microRNAs (miRNAs). Then, miR-103a-3p agomir, miR-103a-3p antagomir and Parkin siRNA were used to assess the effects of miR-103a-3p/Parkin/Ambra1 signaling-mediated mitophagy in PD in vitro and in vivo. The protein and mRNA levels of Parkin and Ambra1 were significantly decreased, while miR-103a-3p, which is a highly expressed miRNA in the human brain, was obviously increased in PD mouse and SH-SY5Y cell models. Moreover, miR-103a-3p suppressed Parkin expression by targeting a conserved binding site in the 3'-untranslated region (UTR) of Parkin mRNA. Importantly, miR-103a-3p inhibition resulted in neuroprotective effects and improved mitophagy in vitro and in vivo, whereas Parkin siRNA strongly abolished these effects. These findings suggested that miR-103a-3p inhibition has neuroprotective effects in PD, which may be involved in regulating mitophagy through the Parkin/Ambra1 pathway. Modulating miR-103a-3p levels may be an applicable therapeutic strategy for PD.

Salvianolic acid A alleviates chronic ethanol-induced liver injury via promotion of ß-catenin nuclear accumulation by restoring SIRT1 in rats.

In recent years, alcoholic liver disease (ALD) has emerged as a growing public health problem worldwide. ß-catenin plays an important role in the growth, development, regeneration and metabolic activity of the liver. Salvianolic acid A (SalA) is a water-soluble component from the root extract of Salvia miltiorrhiza Bunge, and its effect on ALD has not yet been investigated. This study aimed to investigate the effect of SalA on chronic alcohol-induced liver injury and to explore the role of SIRT1-mediated ß-catenin deacetylation in such an effect. In this study, SalA treatment significantly alleviated the accumulation of lipid droplets and reduced the plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), alcohol and ammonia levels in rats. SalA enhanced ethanol and ammonia metabolism and maintained mitochondrial homeostasis. Moreover, SalA restored the activity of the major ethanol-metabolizing enzymes and oxidative stress functions in the liver. Importantly, we found that SalA treatment effectively inhibited the ethanol-mediated decrease in nuclear ß-catenin by upregulating SIRT1 in the liver. SIRT1 then deacetylated ß-catenin to promote its accumulation in the nucleus, thereby preventing alcohol-induced liver injury. The results demonstrate that the SIRT1/ß-catenin pathway is a key therapeutic target in liver injury caused by chronic alcohol exposure and that SalA protects against alcohol-induced liver injury via the SIRT1-mediated deacetylation of ß-catenin.

Carnosol-mediated Sirtuin 1 activation inhibits Enhancer of Zeste Homolog 2 to attenuate liver fibrosis.

Quiescent hepatic stellate cell (HSC) activation and subsequent conversion into myofibroblasts is the central event in hepatic fibrosis pathogenesis. Epithelial-mesenchymal transition (EMT), another vital participant in liver fibrosis, has the potential to initiate HSC activation, which promotes abundant myofibroblast production. Previous studies suggest that Enhancer of Zeste Homolog 2 (EZH2) plays a significant role in myofibroblast transdifferentiation; however, the underlying mechanisms remain largely unaddressed. Carnosol (CS), a compound extracted from rosemary, displays multiple pharmacological activities. This study aimed to investigate the signaling mechanisms underlying EZH2 inhibition and the anti-fibrotic effect of CS in liver fibrosis. We found that CS significantly inhibited CCl4- and TGFß1-induced liver fibrosis and reduced both HSC activation and EMT. EZH2 knockdown also prevented these processes induced by TGFß1 in HSCs and AML-12 cells. Interestingly, the protective effect of CS was positively associated with Sirtuin 1 (SIRT1) activation and accompanied by EZH2 inhibition. SIRT1 knockdown attenuated the EZH2 inhibition induced by CS and increased EZH2 acetylation, which enhanced its stability. Conversely, upon TGFß1 exposure, SIRT1 activation significantly reduced the level of EZH2 acetylation; however, EZH2 overexpression prevented the SIRT1 activation that primed myofibroblast inhibition, indicating that EZH2 is a target of SIRT1. Thus, SIRT1/EZH2 regulation could be used as a new therapeutic strategy for fibrogenesis. Together, this study provides evidence of activation of the SIRT1/EZH2 pathway by CS that inhibits myofibroblast generation, and thus, CS may represent an attractive candidate for anti-fibrotic clinical therapy.

Sirtuin 5 Alleviates Liver Ischemia/Reperfusion Injury by Regulating Mitochondrial Succinylation and Oxidative Stress.

Aims: Mitochondrial dysfunction is the primary mechanism of liver ischemia/reperfusion (I/R) injury. The lysine desuccinylase sirtuin 5 (SIRT5) is a global regulator of the mitochondrial succinylome and has pivotal roles in mitochondrial metabolism and function; however, its hepatoprotective capacity in liver I/R remains unclear. In this study, we established liver I/R model in SIRT5-silenced and SIRT5-overexpressed mice to examine the role and precise mechanisms of SIRT5 in liver I/R injury. Results: Succinylation was strongly enriched in liver mitochondria during I/R, and inhibiting mitochondrial succinylation significantly attenuated liver I/R injury. Importantly, the levels of the desuccinylase SIRT5 were notably decreased in liver transplant patients, as well as in mice subjected to I/R and in AML12 cells exposed to hypoxia/reoxygenation. Furthermore, SIRT5 significantly ameliorated liver I/R-induced oxidative injury, apoptosis, and inflammation by regulating mitochondrial oxidative stress and function. Intriguingly, the hepatoprotective effect of SIRT5 was mediated by PRDX3. Mechanistically, SIRT5 specifically desuccinylated PRDX3 at the K84 site, which enabled PRDX3 to alleviate mitochondrial oxidative stress during liver I/R. Innovation: This study denoted the new effect and mechanism of SIRT5 in regulating mitochondrial oxidative stress through lysine desuccinylation, thus preventing liver I/R injury. Conclusions: Our findings demonstrate for the first time that SIRT5 is a key mediator of liver I/R that regulates mitochondrial oxidative stress through the desuccinylation of PRDX3, which provides a novel strategy to prevent liver I/R injury. Antioxid. Redox Signal. 40, 616-631.

HRD1-induced TMEM2 ubiquitination promotes ER stress-mediated apoptosis through a non-canonical pathway in intestinal ischemia/reperfusion.

Intestinal ischemia/reperfusion (I/R) injury is a typical pathological course in the clinic with a high morbidity rate. Recent research has pointed out the critical role of ubiquitination during the occurrence and development of intestinal I/R by precisely mediating protein quality control and function. Here, we conducted an integrated multiomic analysis to identify critical ubiquitination-associated molecules in intestinal I/R and identified endoplasmic reticulum-located HRD1 as a candidate molecule. During intestinal I/R, excessive ER stress plays a central role by causing apoptotic pathway activation. In particular, we found that ER stress-mediated apoptosis was mitigated by HRD1 knockdown in intestinal I/R mice. Mechanistically, TMEM2 was identified as a new substrate of HRD1 in intestinal I/R by mass spectrometry analysis, which has a crucial role in attenuating apoptosis and promoting non-canonical ER stress resistance. A strong negative correlation was found between the protein levels of HRD1 and TMEM2 in human intestinal ischemia samples. Specifically, HRD1 interacted with the lysine 42 residue of TMEM2 and reduced its stabilization by K48-linked polyubiquitination. Furthermore, KEGG pathway analysis revealed that TMEM2 regulated ER stress-mediated apoptosis in association with the PI3k/Akt signaling pathway rather than canonical ER stress pathways. In summary, HRD1 regulates ER stress-mediated apoptosis through a non-canonical pathway by ubiquitinating TMEM2 and inhibiting PI3k/Akt activation during intestinal I/R. The current study shows that HRD1 is an intestinal I/R critical regulator and that targeting the HRD1/TMEM2 axis may be a promising therapeutic approach.

Effects of Time Pressure, Reward, and Information Involvement on User Management of Fake News on a Social Media Platform.

This study examined the effects of time pressure, reward, and information involvement on individual fact-checking behavior within a social media platform. We used a four-factor mixed-design experiment to examine fact-checking performances of 144 participants for 36 ambiguous social platform statements, all of which were news statements of social events or of common-sense knowledge collected from the internet and selected through pre-test screening. We measured the participants' total number of fact-checked statements and their judgment accuracy of those statements. We also measured participants' decision time for making judgments, and their judgment confidence levels. Participants' social presence, time pressure, and information involvement were significantly related to the number of statements they fact-checked. Their perceived social presence on a social media platform reduced their fact-checking. Time pressure increased the frequency of fact-checking and weakened the impact of social presence. Participants were less likely to fact-check statements when they had high involvement with the information, due to overconfidence. Statements with high information involvement had longer decision-making times. These findings provide a basis for designing ways to display and push information to increase an individual's awareness of a need to fact-check ambiguous information in a new social media environment.

Geospatial mapping of distribution grid with machine learning and publicly-accessible multi-modal data.

Detailed and location-aware distribution grid information is a prerequisite for various power system applications such as renewable energy integration, wildfire risk assessment, and infrastructure planning. However, a generalizable and scalable approach to obtain such information is still lacking. In this work, we develop a machine-learning-based framework to map both overhead and underground distribution grids using widely-available multi-modal data including street view images, road networks, and building maps. Benchmarked against the utility-owned distribution grid map in California, our framework achieves > 80% precision and recall on average in the geospatial mapping of grids. The framework developed with the California data can be transferred to Sub-Saharan Africa and maintain the same level of precision without fine-tuning, demonstrating its generalizability. Furthermore, our framework achieves a R2 of 0.63 in measuring the fraction of underground power lines at the aggregate level for estimating grid exposure to wildfires. We offer the framework as an open tool for mapping and analyzing distribution grids solely based on publicly-accessible data to support the construction and maintenance of reliable and clean energy systems around the world.

Salvianolic Acid A Protects against Acetaminophen-Induced Hepatotoxicity via Regulation of the miR-485-3p/SIRT1 Pathway.

The vast majority of drug-induced liver injury is mainly attributed to acetaminophen (APAP) overdose. Salvianolic acid A (Sal A), a powerful water-soluble compound obtained from Salvia miltiorrhiza, has been confirmed to exert hepatoprotective effects. However, the beneficial effects and the exact mechanisms of Sal A on APAP-induced hepatotoxicity remain unclear. In this study, APAP-induced liver injury with or without Sal A treatment was examined in vitro and in vivo. The results showed that Sal A could alleviate oxidative stress and inflammation by regulating Sirtuin 1 (SIRT1). Furthermore, miR-485-3p could target SIRT1 after APAP hepatotoxicity and was regulated by Sal A. Importantly, inhibiting miR-485-3p had a hepatoprotective effect similar to that of Sal A on APAP-exposed AML12 cells. These findings suggest that regulating the miR-485-3p/SIRT1 pathway can alleviate oxidative stress and inflammation induced by APAP in the context of Sal A treatment.

Critical role of caveolin-1 in intestinal ischemia reperfusion by inhibiting protein kinase C ßII.

Intestinal ischemia reperfusion (I/R) is a common clinical pathological process. We previously reported that pharmacological inhibition of protein kinase C (PKC) ßII with a specific inhibitor attenuated gut I/R injury. However, the endogenous regulatory mechanism of PKCßII inactivation is still unclear. Here, we explored the critical role of caveolin-1 (Cav1) in protecting against intestinal I/R injury by regulating PKCßII inactivation. PKCßII translocated to caveolae and bound with Cav1 after intestinal I/R. Cav1 was highly expressed in the intestine of mice with I/R and IEC-6 cells stimulated with hypoxia/reoxygenation (H/R). Cav1-knockout (KO) mice suffered from worse intestinal injury after I/R than wild-type (WT) mice and showed extremely low survival due to exacerbated systemic inflammatory response syndrome (SIRS) and remote organ (lung and liver) injury. Cav1 deficiency resulted in excessive PKCßII activation and increased oxidative stress and apoptosis after intestinal I/R. Full-length Cav1 scaffolding domain peptide (CSP) suppressed excessive PKCßII activation and protected the gut against oxidative stress and apoptosis due to I/R injury. In summary, Cav1 could regulate PKCßII endogenous inactivation to alleviate intestinal I/R injury. This finding may represent a novel therapeutic strategy for the prevention and treatment of intestinal I/R injury.

In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors.

An ultimate goal of electron paramagnetic resonance (EPR) spectroscopy is to analyze molecular dynamics in place where it occurs, such as in a living cell. The nanodiamond (ND) hosting nitrogen-vacancy (NV) centers will be a promising EPR sensor to achieve this goal. However, ND-based EPR spectroscopy remains elusive, due to the challenge of controlling NV centers without well-defined orientations inside a flexible ND. Here, we show a generalized zero-field EPR technique with spectra robust to the sensor's orientation. The key is applying an amplitude modulation on the control field, which generates a series of equidistant Floquet states with energy splitting being the orientation-independent modulation frequency. We acquire the zero-field EPR spectrum of vanadyl ions in aqueous glycerol solution with embedded single NDs, paving the way towards in vivo EPR.

Picotesla magnetometry of microwave fields with diamond sensors.

Developing robust microwave-field sensors is both fundamentally and practically important with a wide range of applications from astronomy to communication engineering. The nitrogen vacancy (NV) center in diamond is an attractive candidate for such purpose because of its magnetometric sensitivity, stability, and compatibility with ambient conditions. However, the existing NV center-based magnetometers have limited sensitivity in the microwave band. Here, we present a continuous heterodyne detection scheme that can enhance the sensor's response to weak microwaves, even in the absence of spin controls. Experimentally, we achieve a sensitivity of 8.9 pT Hz-1/2 for microwaves of 2.9 GHz by simultaneously using an ensemble of nNV ~ 2.8 × 1013 NV centers within a sensor volume of 4 × 10-2 mm3. Besides, we also achieve 1/t scaling of frequency resolution up to measurement time t of 10,000 s. Our scheme removes control pulses and thus will greatly benefit practical applications of diamond-based microwave sensors.

The m6A reader YTHDF3-mediated PRDX3 translation alleviates liver fibrosis.

Peroxiredoxin 3 (PRDX3) acts as a master regulator of mitochondrial oxidative stress and exerts hepatoprotective effects, but the role of PRDX3 in liver fibrosis is not well understood. N6-methyladenosine (m6A) is considered the most prevalent posttranscriptional modification of mRNA. This study aimed to elucidate the effect of PRDX3 on liver fibrosis and the potential mechanism through which the m6A modification regulates PRDX3. PRDX3 expression was found to be negatively correlated with liver fibrosis in both animal models and clinical specimens from patients. We performed adeno-associated virus 9 (AAV9)-PRDX3 knockdown and AAV9-PRDX3 HSC-specific overexpression in mice to clarify the role of PRDX3 in liver fibrosis. PRDX3 silencing exacerbated hepatic fibrogenesis and hepatic stellate cell (HSC) activation, whereas HSC-specific PRDX3 overexpression attenuated liver fibrosis. Mechanistically, PRDX3 suppressed HSC activation at least partially via the mitochondrial reactive oxygen species (ROS)/TGF-ß1/Smad2/3 pathway. Furthermore, PRDX3 mRNA was modified by m6A and interacted with the m6A readers YTH domain family proteins 1-3 (YTHDF1-3), as evidenced by RNA pull-down/mass spectrometry. More importantly, PRDX3 expression was suppressed when YTHDF3, but not YTHDF1/2, was knocked down. Moreover, PRDX3 translation was directly regulated by YTHDF3 in an m6A-dependent manner and thereby affected its function in liver fibrosis. Collectively, the results indicate that PRDX3 is a crucial regulator of liver fibrosis and that targeting the YTHDF3/PRDX3 axis in HSCs may be a promising therapeutic approach for liver fibrosis.

Activation of TAF9 via Danshensu-Induced Upregulation of HDAC1 Expression Alleviates Non-alcoholic Fatty Liver Disease.

Fatty acid ß-oxidation is an essential pathogenic mechanism in nonalcoholic fatty liver disease (NAFLD), and TATA-box binding protein associated factor 9 (TAF9) has been reported to be involved in the regulation of fatty acid ß-oxidation. However, the function of TAF9 in NAFLD, as well as the mechanism by which TAF9 is regulated, remains unclear. In this study, we aimed to investigate the signaling mechanism underlying the involvement of TAF9 in NAFLD and the protective effect of the natural phenolic compound Danshensu (DSS) against NAFLD via the HDAC1/TAF9 pathway. An in vivo model of high-fat diet (HFD)-induced NAFLD and a palmitic acid (PA)-treated AML-12 cell model were developed. Pharmacological treatment with DSS significantly increased fatty acid ß-oxidation and reduced lipid droplet (LD) accumulation in NAFLD. TAF9 overexpression had the same effects on these processes both in vivo and in vitro. Interestingly, the protective effect of DSS was markedly blocked by TAF9 knockdown. Mechanistically, TAF9 was shown to be deacetylated by HDAC1, which regulates the capacity of TAF9 to mediate fatty acid ß-oxidation and LD accumulation during NAFLD. In conclusion, TAF9 is a key regulator in the treatment of NAFLD that acts by increasing fatty acid ß-oxidation and reducing LD accumulation, and DSS confers protection against NAFLD through the HDAC1/TAF9 pathway.

Sinapic Acid Reduces Oxidative Stress and Pyroptosis via Inhibition of BRD4 in Alcoholic Liver Disease.

Alcoholic liver disease (ALD) is one of the main causes of death in chronic liver disease. Oxidative stress and pyroptosis are important factors leading to ALD. Bromodomain-containing protein 4 (BRD4) is a factor that we have confirmed to regulate ALD. As a phenolic acid compound, sinapic acid (SA) has significant effects in antioxidant, anti-inflammatory and liver protection. In this study, we explored whether SA regulates oxidative stress and pyroptosis through BRD4 to play a protective effect in ALD. Male C57BL/6 mice and AML-12 cells were used for experiments. We found that SA treatment largely abolished the up-regulation of BRD4 and key proteins of the canonical pyroptosis signalling in the liver of mice fed with alcohol, while conversely enhanced the antioxidant response. Consistantly, both SA pretreatment and BRD4 knockdown inhibited oxidative stress, pyroptosis, and liver cell damage in vitro. More importantly, the expression levels of BRD4 and pyroptosis indicators increased significantly in ALD patients. Molecule docking analysis revealed a potent binding of SA with BRD4. In conclusion, this study demonstrates that SA reduces ALD through BRD4, which is a valuable lead compound that prevents the ALD process.