Inferring COVID-19 testing and vaccination behavior from New Jersey testing data.

Characterizing the relationship between disease testing behaviors and infectious disease dynamics is of great importance for public health. Tests for both current and past infection can influence disease-related behaviors at the individual level, while population-level knowledge of an epidemic's course may feed back to affect one's likelihood of taking a test. The COVID-19 pandemic has generated testing data on an unprecedented scale for tests detecting both current infection (PCR, antigen) and past infection (serology); this opens the way to characterizing the complex relationship between testing behavior and infection dynamics. Leveraging a rich database of individualized COVID-19 testing histories in New Jersey, we analyze the behavioral relationships between PCR and serology tests, infection, and vaccination. We quantify interactions between individuals' test-taking tendencies and their past testing and infection histories, finding that PCR tests were disproportionately taken by people currently infected, and serology tests were disproportionately taken by people with past infection or vaccination. The effects of previous positive test results on testing behavior are less consistent, as individuals with past PCR positives were more likely to take subsequent PCR and serology tests at some periods of the epidemic time course and less likely at others. Lastly, we fit a model to the titer values collected from serology tests to infer vaccination trends, finding a marked decrease in vaccination rates among individuals who had previously received a positive PCR test. These results exemplify the utility of individualized testing histories in uncovering hidden behavioral variables affecting testing and vaccination.

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.

MAPK1 Mediates MAM Disruption and Mitochondrial Dysfunction in Diabetic Kidney Disease via the PACS-2-Dependent Mechanism.

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease (ESRD). Mitochondrial dysfunction in renal tubules, occurring early in the disease, is linked to the development of DKD, although the underlying pathways remain unclear. Here, we examine diabetic human and mouse kidneys, and HK-2 cells exposed to high glucose, to show that high glucose disrupts mitochondria-associated endoplasmic reticulum membrane (MAM) and causes mitochondrial fragmentation. We find that high glucose conditions increase mitogen-activated protein kinase 1(MAPK1), a member of the MAP kinase signal transduction pathway, which in turn lowers the level of phosphofurin acidic cluster sorting protein 2 (PACS-2), a key component of MAM that tethers mitochondria to the ER. MAPK1-induced disruption of MAM leads to mitochondrial fragmentation but this can be rescued in HK-2 cells by increasing PACS-2 levels. Functional studies in diabetic mice show that inhibition of MAPK1 increases PACS-2 and protects against the loss of MAM and the mitochondrial fragmentation. Taken together, these results identify the MAPK1-PACS-2 axis as a key pathway to therapeutically target as well as provide new insights into the pathogenesis of DKD.

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.

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.

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.

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.

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.

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.

Peroxiredoxin 3 Inhibits Acetaminophen-Induced Liver Pyroptosis Through the Regulation of Mitochondrial ROS.

Pyroptosis is a newly discovered form of cell death. Peroxiredoxin 3 (PRX3) plays a crucial role in scavenging reactive oxygen species (ROS), but its hepatoprotective capacity in acetaminophen (APAP)-induced liver disease remains unclear. The aim of this study was to assess the role of PRX3 in the regulation of pyroptosis during APAP-mediated hepatotoxicity. We demonstrated that pyroptosis occurs in APAP-induced liver injury accompanied by intense oxidative stress and inflammation, and liver specific PRX3 silencing aggravated the initiation of pyroptosis and liver injury after APAP intervention. Notably, excessive mitochondrial ROS (mtROS) was observed to trigger pyroptosis by activating the NLRP3 inflammasome, which was ameliorated by Mito-TEMPO treatment, indicating that the anti-pyroptotic role of PRX3 relies on its powerful ability to regulate mtROS. Overall, PRX3 regulates NLRP3-dependent pyroptosis in APAP-induced liver injury by targeting mitochondrial oxidative stress.

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.

circ-CBFB upregulates p66Shc to perturb mitochondrial dynamics in APAP-induced liver injury.

p66Shc, a master regulator of mitochondrial reactive oxygen species (mtROS), is a crucial mediator of hepatocyte oxidative stress. However, its functional contribution to acetaminophen (APAP)-induced liver injury and the mechanism by which it is modulated remain unknown. Here, we aimed to assess the effect of p66Shc on APAP-induced liver injury and to evaluate if circular RNA (circRNA) functions as a competitive endogenous RNA (ceRNA) to mediate p66Shc in APAP-induced liver injury. p66Shc-, miR-185-5p-, and circ-CBFB-silenced mice were injected with APAP. AML12 cells were transfected with p66Shc, miR-185-5p, and circ-CBFB silencing or overexpression plasmids or siRNAs prior to APAP stimulation. p66Shc was upregulated in liver tissues in response to APAP, and p66Shc silencing in vivo protected mice from APAP-induced mitochondrial dynamics perturbation and liver injury. p66Shc knockdown in vitro attenuated mitochondrial dynamics and APAP-induced hepatocyte injury. Mechanically, p66Shc perturbs mitochondrial dynamics partially by inhibiting OMA1 ubiquitination. miR-185-5p, which directly suppressed p66Shc translation, was identified by microarray and bioinformatics analyses, and its overexpression attenuated mitochondrial dynamics and hepatocyte injury in vitro. Furthermore, luciferase, pull-down and RNA immunoprecipitation assays demonstrated that circ-CBFB acts as a miRNA sponge of miR-185-5p to mediate p66Shc in APAP-induced liver injury. circ-CBFB knockdown also alleviated APAP-induced mitochondrial dynamics perturbation and hepatocyte injury. More importantly, we found that the protective effects of circ-CBFB knockdown on p66Shc, mitochondrial dynamics and liver injury were abolished by miR-185-5p inhibition both in vivo and in vitro. In conclusion, p66Shc is a key regulator of APAP-induced liver injury that acts by triggering mitochondrial dynamics perturbation. circ-CBFB functions as a ceRNA to regulate p66Shc during APAP-induced liver injury, which may provide a potential therapeutic target.

Author Correction: Potent effects of dioscin against obesity in mice.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

circ-PRKCB acts as a ceRNA to regulate p66Shc-mediated oxidative stress in intestinal ischemia/reperfusion.

Background: Oxidative stress has emerged as an essential factor in the pathogenesis of intestinal ischemia/reperfusion (I/R) injury. The adaptor protein p66Shc is a key regulator of reactive oxygen species (ROS) generation and a mediator of I/R damage in the intestine, but the upstream mechanisms that directly regulate p66Shc expression during intestinal I/R remain largely unknown. Recent studies have suggested that noncoding RNAs, such as circular RNAs (circRNAs), are important players in physiological and pathological processes based on their versatile regulatory roles in gene expression. The aim of this study was to elucidate the contribution of p66Shc to oxidative damage in intestinal I/R and to investigate the regulation of p66Shc by circRNA sponges. Methods: Intestinal I/R was induced in mice via superior mesenteric artery (SMA) occlusion. A miR-339-5p agomir or circ-protein kinase C beta (PRKCB) siRNA was injected intravenously before I/R challenge. In addition, Caco-2 cells were subjected to hypoxia/reoxygenation (H/R) in vitro to simulate an in vivo I/R model. Results:In vitro, p66Shc deficiency significantly reduced H/R-induced ROS overproduction by attenuating mitochondrial superoxide anion (O2-) levels, suppressing NADPH oxidase activity and enhancing antioxidant enzyme expression. Moreover, miR-339-5p was identified to directly regulate p66Shc expression in the intestine. Furthermore, we found that a circRNA transcribed from the PRKCB gene, named circ-PRKCB, acted as an endogenous miR-339-5p sponge to regulate p66Shc expression. circ-PRKCB silencing or miR-339-5p overexpression significantly downregulated p66Shc expression and attenuated oxidative stress levels and I/R injury in vivo and in vitro. Notably, the increased circ-PRKCB levels and decreased miR-339-5p levels associated with murine intestinal I/R were consistent with those in patients with intestinal infarction. Conclusions: Our findings reveal a crucial role for the circ-PRKCB/miR-339-5p/p66Shc signaling pathway in regulating oxidative stress in the I/R intestine. This pathway may be a potential therapeutic target for intestinal I/R injury.

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.

Inhibition of p66Shc Oxidative Signaling via CA-Induced Upregulation of miR-203a-3p Alleviates Liver Fibrosis Progression.

We previously found that inhibition of p66Shc confers protection against hepatic stellate cell (HSC) activation during liver fibrosis. However, the effect of p66Shc on HSC proliferation, as well as the mechanism by which p66Shc is modulated, remains unknown. Here, we elucidated the effect of p66Shc on HSC proliferation and evaluated microRNA (miRNA)-p66Shc-mediated reactive oxidative species (ROS) generation in liver fibrosis. An in vivo model of carbon tetrachloride (CCl4)-induced liver fibrosis in rats and an LX-2 cell model were developed. p66Shc expression was significantly upregulated in rats with CCl4-induced liver fibrosis and in human fibrotic livers. Additionally, p66Shc knockdown in vitro attenuated mitochondrial ROS generation and HSC proliferation. Interestingly, p66Shc promoted HSC proliferation via ß-catenin dephosphorylation in vitro. MicroRNA (miR)-203a-3p, which was identified by microarray and bioinformatics analyses, directly inhibited p66Shc translation and attenuated HSC proliferation in vitro. Importantly, p66Shc was found to play an indispensable role in the protective effect of miR-203a-3p. Furthermore, carnosic acid (CA), the major antioxidant compound extracted from rosemary leaves, protected against CCl4-induced liver fibrosis through the miR-203a-3p/p66Shc axis. Collectively, these results suggest that p66Shc, which is directly suppressed by miR-203a-3p, is a key regulator of liver fibrosis. This finding may lead to the development of therapeutic targets for liver fibrosis.

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.

Sirtuin 3-mediated deacetylation of acyl-CoA synthetase family member 3 by protocatechuic acid attenuates non-alcoholic fatty liver disease.

BACKGROUND AND PURPOSE: Hepatic fatty acid metabolism disorder, a key pathogenic mechanism underlying non-alcoholic fatty liver disease (NAFLD), is associated with the hyperacetylation of mitochondrial enzymes. Acyl-CoA synthetase family member 3 (ACSF3), which is involved in the regulation of fatty acid metabolism, was predicted to contain lysine acetylation sites related to the mitochondrial deacetylase sirtuin 3 (SIRT3). The purpose of this study was to explore the underlying mechanism by which SIRT3 deacetylates ACSF3 in NAFLD and the protective effect of the natural phenolic compound protocatechuic acid (PCA) against fatty acid metabolism disorder via the SIRT3/ACSF3 pathway. EXPERIMENTAL APPROACH: The role of protocatechuic acid and its molecular mechanism in NAFLD were detected in rats and SIRT3-knockout mice fed a high-fat diet (HFD) and in AML-12 cells treated with palmitic acid (PA). KEY RESULTS: Pharmacological treatment with protocatechuic acid significantly attenuated high-fat diet-induced fatty acid metabolism disorder in NAFLD. Molecular docking assays showed that protocatechuic acid specifically bound SIRT3 as a substrate and increased SIRT3 protein expression. However, the protective role of protocatechuic acid was abolished by SIRT3 knockdown, which increased ACSF3 expression and exacerbated fatty acid metabolism disorder. Mechanistically, SIRT3 was shown to specifically regulate the acetylation and degradation of ACSF3, which govern the capacity of ACSF3 to mediate fatty acid metabolism disorder during NAFLD. CONCLUSION AND IMPLICATIONS: SIRT3-mediated ACSF3 deacetylation is a novel molecular mechanism in NAFLD therapy and protocatechuic acid confers protection against high-fat diet- and palmitic acid-induced hepatic fatty acid metabolism disorder through the SIRT3/ACSF3 pathway.