Foxo1 transcription factor is an evolutionarily conserved regulator of cell metabolism, oxidative stress, inflammation, and apoptosis. Activation of Hedgehog/Gli signaling is known to regulate cell growth, differentiation, and immune function. However, the molecular mechanisms by which interactive cell signaling networks restrain oxidative stress response and necroptosis are still poorly understood. Here, we report that myeloid-specific Foxo1 knockout (Foxo1M-KO) mice were resistant to oxidative stress-induced hepatocellular damage with reduced macrophage/neutrophil infiltration, and proinflammatory mediators in liver ischemia/reperfusion injury (IRI). Foxo1M-KO enhanced β-catenin-mediated Gli1/Snail activity, and reduced receptor-interacting protein kinase 3 (RIPK3) and NIMA-related kinase 7 (NEK7)/NLRP3 expression in IR-stressed livers. Disruption of Gli1 in Foxo1M-KO livers deteriorated liver function, diminished Snail, and augmented RIPK3 and NEK7/NLRP3. Mechanistically, macrophage Foxo1 and β-catenin colocalized in the nucleus, whereby the Foxo1 competed with T-cell factor (TCF) for interaction with β-catenin under inflammatory conditions. Disruption of the Foxo1–β-catenin axis by Foxo1 deletion enhanced β-catenin/TCF binding, activated Gli1/Snail signaling, leading to inhibited RIPK3 and NEK7/NLRP3. Furthermore, macrophage Gli1 or Snail knockout activated RIPK3 and increased hepatocyte necroptosis, while macrophage RIPK3 ablation diminished NEK7/NLRP3-driven inflammatory response. Our findings underscore a novel molecular mechanism of the myeloid Foxo1–β-catenin axis in regulating Hedgehog/Gli1 function that is key in oxidative stress-induced liver inflammation and necroptosis.

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Regulatory T cells (Tregs) are crucial mediators of immune control. The characteristic gene expression and suppressive functions of Tregs depend considerably on the stable expression and activity of the transcription factor FOXP3. Transcriptional regulation of the Foxp3 gene has been studied in depth, but both the expression and function of this factor are also modulated at the protein level. However, the molecular players involved in posttranslational FOXP3 regulation are just beginning to be elucidated. Here, we found that TRAF6‐deficient Tregs were dysfunctional in vivo; mice with Treg‐restricted deletion of TRAF6 were resistant to implanted tumors and displayed enhanced anti‐tumor immunity. We further determined that FOXP3 undergoes K63‐linked ubiquitination at lysine 262 mediated by the E3 ligase TRAF6. In the absence of TRAF6 activity or upon mutation of the ubiquitination site, FOXP3 displayed aberrant, perinuclear accumulation and disrupted regulatory function. Thus, K63‐linked ubiquitination by TRAF6 ensures proper localization of FOXP3 and facilitates the transcription factor's gene‐regulating activity in Tregs. These results implicate TRAF6 as a key posttranslational, Treg‐stabilizing regulator that may be targeted in novel tolerance‐breaking therapies.

Liver diseases represent a major global health burden accounting for approximately 2 million deaths per year worldwide. The liver functions as a primary immune organ that is largely enriched with various innate immune cells, including macrophages, dendritic cells, neutrophils, NK cells, and NKT cells. Activation of these cells orchestrates the innate immune response and initiates liver inflammation in response to the danger signal from pathogens or injured cells and tissues. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway is a crucial signaling cascade of the innate immune system activated by cytosol DNA. Recognizing DNA as an immune-stimulatory molecule is an evolutionarily preserved mechanism in initiating rapid innate immune responses against microbial pathogens. The cGAS is a cytosolic DNA sensor eliciting robust immunity via the production of cyclic GMP-AMPs that bind and activate STING. Although the cGAS-STING pathway has been previously considered to have essential roles in innate immunity and host defense, recent advances have extended the role of the cGAS-STING pathway to liver diseases. Emerging evidence indicates that overactivation of cGAS-STING may contribute to the development of liver disorders, implying that the cGAS-STING pathway is a promising therapeutic target. Here, we review and discuss the role of the cGAS-STING DNA-sensing signaling pathway in a variety of liver diseases, including viral hepatitis, nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), primary hepatocellular cancer (HCC), and hepatic ischemia-reperfusion injury (IRI), with highlights on currently available therapeutic options.

Background: Cancer-associated fibroblasts (CAFs) are a major component of hepatocellular carcinoma (HCC) stroma that are critically involved in HCC cancer chemoresistance, but the mechanism has not been elucidated. Previous studies have reported CD73 exerted an immunosuppressive function in cancer. Here, we explored the mechanism by which CAFs regulates CD73 + HCC cells and clarified whether CAFs promote chemoresistance of CD73 + cells.Methods: We used the co-culture method to study the relationship between CAFs and HCC cells.Immunohistochemistry was applied to evaluate the correlation between α-smooth-muscle actin (α-SMA) and CD73. CD73 mRNA and protein were determined by real-time polymerase chain reaction (RT-PCR) and western blotting, and hepatocyte growth factor (HGF) was assayed by enzyme-linked immunosorbent assay (ELISA). Western blotting was used to explore the regulated pathway of CD73 + HCC. We then knocked down CD73 in cells, and then assessed the effect of CD73 on the apoptosis by flow cytometry. Finally, a sphere formation assay was applied to investigate the stemness of cancer cells, and xenograft tumors in nude mice were built to investigate the tumorigenicity.Results: We found that the proportion of CAFs was positively correlated with CD73 expression in HCC cells. Mechanistically, c-Met and the MEK-ERK1/2 pathway were activated by HGF from CAFs which upregulated CD73 expression in HCC cells. Also, we found that CD73 promote sorafenib and cisplatin resistance in HCC, and CD73 + HCC cells indicated the higher capability of tumorigenicity compared to CD73 − HCC cells in vivo. Furthermore, HGF further enhanced the chemoresistant characteristics of CD73 + tumor cells.Conclusions: Our findings collectively suggest that CD73 is a vital HCC-chemoresistance force controlled by cross-talking between CAFs and HCC cells, thereby establishing CD73 as a potential new therapeutic target for HCC.

BaCKgRoUND aND aIMS:The cluster of differentiation 47 (CD47)-signal regulatory protein alpha (SIRPα) signaling pathway plays important roles in immune homeostasis and tissue inflammatory response. Activation of the Hedgehog/ smoothened (SMO)/GLI family zinc finger 1 (Gli1) pathway regulates cell growth, differentiation, and immune function. However, it remains unknown whether and how the CD47-SIRPα interaction may regulate Hedgehog/SMO/Gli1 signaling in mesenchymal stem cell (MSC)-mediated immune regulation during sterile inflammatory liver injury. appRoaCH aND ReSUltS: In a mouse model of ischemia/reperfusion (IR)-induced sterile inflammatory liver injury, we found that adoptive transfer of MSCs increased CD47 expression and ameliorated liver IR injury. However, deletion of CD47 in MSCs exacerbated IR-induced liver damage, with increased serum ALT levels, macrophage/neutrophil infiltration, and pro-inflammatory mediators. MSC treatment augmented SIRPα, Hedgehog/SMO/Gli1, and Notch1 intracellular domain (NICD), whereas CD47-deficient MSC treatment reduced these gene expressions in IR-stressed livers. Moreover, disruption of myeloid SMO or Notch1 increased IR-triggered liver inflammation with diminished Gli1 and NICD, but enhanced NIMA related kinase 7 (NEK7) and NLR family pyrin domain containing 3 (NLRP3) activation in MSC-transferred mice. Using a MSC/macrophage co-culture system, we found that MSC CD47 and macrophage SIRPα expression were increased after LPS stimulation. The CD47-SIRPα interaction increased macrophage Gli1 and NICD nuclear translocation, whereby NICD interacted with Gli1 and regulated its target gene Dvl2 (dishevelled segment polarity protein 2), which in turn inhibited NEK7/NLRP3 activity. CoNClUSIoNS:The CD47-SIRPα signaling activates the Hedgehog/SMO/Gli1 pathway, which controls NEK7/NLRP3 activity through a direct interaction between Gli1 and NICD. NICD is a coactivator of Gli1, and the target gene Dvl2 regulated by the NICD-Gli1 complex is crucial for the modulation of NLRP3-driven inflammatory response in MSCmediated immune regulation. Our findings provide potential therapeutic targets in MSC-mediated immunotherapy of sterile inflammatory liver injury. (Hepatology 2021;0:1-18). M esenchymal stem cells (MSCs) are multipotent cells capable of differentiation into mesenchymal lineages. They have become the most frequently used cell type for tissue repair and regeneration because of their remarkable immunoregulatory properties. MSCs exert extensive immunomodulation through interaction with immune cells

Highlights Kupffer cells Nrf2 was downregulated in both human and mouse NASH livers Myeloid Nrf2 deficiency aggravates liver steatosis and inflammation in HFDinduced NASH Nrf2 controls the NLRP3 activation in a ROSmediated Hippo-YAP signaling manner

Objective Handgrip strength (HGS) exercise has been reported to reduce blood pressure in both hypertensive and normotensive patients. In this study, we evaluated the association of HGS with hypertension in a Chinese Han Population. Methods A total of 11,151 subjects mainly consisting of a rural population were recruited with a multi-stage sampling method in Jurong city, Jiangsu Province, China. Besides hypertension and diabetes, major chronic diseases were excluded. HGS was categorized into tertiles by age and gender. Logistic regression was used to estimate the association of HGS and hypertension with the odds ratio ( OR ) and 95% confidence interval ( CI ). Results From low to high tertiles of HGS, diastolic blood pressure (DBP) was significantly increased (74.52 ± 7.39, 74.70 ± 7.03, and 75.54 ± 7.01 mmHg, respectively; P trend = 0.001), as well as in females ( P trend = 0.003). The differences in DBP among the tertiles of HGS were still significant in females even after adjusting for covariates ( P trend = 0.048). No significant differences in systolic blood pressure (SBP) were observed among the tertiles of HGS ( P >0.05). Compared to low HGS, high HGS was significantly associated with hypertension after adjustment for age and gender (adjusted OR , 1.19; 95% CI , 1.06–1.34; P =0.004). A stratified analysis showed that the significant association of high HGS and hypertension was also observed with the following factors even after adjusting for age and gender: female gender (adjusted OR , 1.25; 95% CI, 1.08–1.46; P =0.004), ages of 60–69 years (adjusted OR , 1.29; 95% CI, 1.06–1.57; P =0.011), and married (adjusted OR , 1.20; 95% CI, 1.06–1.37; P =0.005). However, no significant associations were found after adjusting for age, gender, smoking status, drinking status, body mass index, physical activity level, glucose, high- and low-density lipoprotein cholesterol, total cholesterol, and triglyceride ( P >0.05). Conclusion The findings of the current study suggest that HGS was positively correlated with DBP in a rural population, and high HGS was associated with hypertension in females; however, the association may be modified by smoking status, drinking status, body mass index, physical activity, cholesterol level, and glucose level. Further utilization of HGS exercises to intervene in the development and prognosis of hypertension ...