Diet and Risk of Non-Alcoholic Fatty Liver Disease, Cirrhosis, and Liver Cancer: A Large Prospective Cohort Study in UK Biobank.

Background and Aims: Epidemiological evidence has shown the association between nutritional habits and liver disease. However, results remain conflicting. This study investigated the influence of dietary factors on the risk of incident non-alcoholic fatty liver disease (NAFLD), cirrhosis, and liver cancer. Methods: Data from the UK Biobank database were analyzed (n = 372,492). According to baseline data from the food frequency questionnaire, two main dietary patterns (Western and prudent) were identified using principal component analysis. We used cox proportional hazards models to explore the associations of individual food groups and dietary patterns with NAFLD, cirrhosis, and liver cancer. Results: During a median follow-up of 12 years, 3527 hospitalized NAFLD, 1643 cirrhosis, and 669 liver cancer cases were recorded among 372,492 participants without prior history of cancer or chronic liver diseases at baseline. In multivariable adjusted analysis, participants in the high tertile of Western dietary pattern score had an 18% (95%CI = 1.09−1.29), 21% (95%CI = 1.07−1.37), and 24% (95%CI = 1.02−1.50) higher risk of incident NAFLD, liver cirrhosis, and liver cancer, respectively, compared with the low tertile. Participants in the high tertile of prudent scores had a 15% (95%CI = 0.75−0.96) lower risk of cirrhosis, as compared with those in the low tertile. In addition, the higher consumption of red meat and the lower consumption of fruit, cereal, tea, and dietary fiber were significantly associated with a higher risk of NAFLD, cirrhosis, and liver cancer (ptrend < 0.05). Conclusions: This large prospective cohort study showed that an increased intake of food from the Western dietary pattern could be correlated with an increased risk of chronic liver diseases, while the prudent pattern was only correlated with a reduced liver cirrhosis risk. These data may provide new insights into lifestyle interventions for the prevention of chronical liver diseases.

Healthy Lifestyle Is Associated with Reduced Mortality in Patients with Non-Alcoholic Fatty Liver Disease.

Background and Aims: It is unclear whether a healthy lifestyle impacts mortality in the presence of non-alcoholic fatty liver disease (NAFLD). The present study aimed to examine the joint association of several modifiable lifestyle factors with mortality risk for NAFLD patients. Methods: We collected lifestyle behavior data form the National Health and Nutrition Examination Survey (NHANES) III from 1988 to 1994 and follow-up data form NHANES III-linked mortality data through 2015. We estimated joint association between four healthy lifestyle factors (non-smoking, non-drinking, regular physical activity, a healthy diet) after NAFLD diagnosis and mortality using Cox proportional hazards regression models. Results: During a median of 22.83 years of follow-up, 2932 deaths occurred. The risk of all-cause mortality decreased significantly with the healthy lifestyle scores increasing (p < 0.001). NAFLD patients with a favorable lifestyle (3 or 4 healthy lifestyle factors) reduced 36% of all-cause mortality and 43% of cardiovascular disease (CVD) mortality compared with those with an unfavorable lifestyle (0 or 1 healthy lifestyle factor) (HR, 0.64 [95% CI, 0.50−0.81], 0.57 [95% CI, 0.37−0.88]). Compared with the non-NAFLD group, the number of NAFLD patients required to adhere to a favorable lifestyle to prevent one cardiovascular disease death in 20 years was fewer (77 vs. 125). Conclusions: For the NAFLD patients, adopting a healthy lifestyle could significantly reduce their risk of death.

ATF6 promotes liver fibrogenesis by regulating macrophage-derived interleukin-1α expression.

Macrophages contribute to liver fibrogenesis by the production of a large variety of cytokines. ATF6 is associated with the activation of macrophages. The present study aimed to investigate the role of ATF6 in the expression of macrophage-derived cytokines and liver fibrogenesis after acute liver injury. Following thioacetamide (TAA)-induced acute liver injury, the characteristics of the occurrence of liver fibrosis and the secretion of cytokines by macrophages were first described. Then, the role of various cytokines secreted by macrophages in activating hepatic stellate cells (HSCs) was tested in vitro. Finally, endoplasmic reticulum stress (ER-stress) signals in macrophages were detected following liver injury. siRNA was used to interfere with the expression of ATF6 in macrophages to verify the influence of ATF6 on cytokine expression and liver fibrogenesis after liver injury. A single intraperitoneal injection of TAA induced acute liver injury. The depletion of macrophages attenuated acute liver injury, while it inhibited liver fibrogenesis. During acute liver injury, macrophages secrete a variety of cytokines. Most of these cytokines promoted the activation of HSCs, but the effect of IL-1α was most significant. In the early stage of acute liver injury, ER-stress signals in macrophages were activated. Interference of ATF6 expression suppressed the secretion of cytokines by macrophages and attenuated liver fibrogenesis. Overall, in the early stage of acute liver injury, ATF6 signals promoted the expression of macrophage-derived cytokines to participate in liver fibrogenesis, and IL-1α exhibited the most significant role in promoting the activation of HSCs and liver fibrogenesis.

Intratumoral regulatory T cells are associated with suppression of colorectal carcinoma metastasis after resection through overcoming IL-17 producing T cells.

With opposite immune activities, regulatory T cells (Tregs) and IL-17 producing T cells were accumulated in various malignant tumors and played critical roles in pathophysiologic course of these diseases. In this study, we investigated the mix-effect of the intratumoral Tregs and IL-17 producing T cells on metastasis of colorectal carcinoma (CRC) after resection. The frequency of intratumoral Tregs and IL-17A+ T cells, and the levels of FoxP3 and IL-17 mRNA were analyzed. The ratio of Tregs/IL-17A+T cells and the ratio of FoxP3 mRNA/IL-17 mRNA were calculated. The activities of matrix metalloproteases (MMPs) in tumor tissues were analyzed. Meanwhile, Tregs from patient's blood was co-cultured with human CRC cells in the presence of IL-17. MMPs protein and mRNA levels were determined after 48 or 24h incubation. We found that Tregs and IL-17A+T cells were accumulated in CRC. The ratio of Tregs/IL-17A+T cells was decreased in CRC tissues. More intratumoral Tregs and less IL-17A+T cells were associated with suppressed MMPs activities and decreased metastases score. In addition, vitro studies demonstrated that Tregs suppressed MMPs expression in the presence of IL-17. Our findings suggested the possibility that intratumoral Tregs protected against metastasis of CRC after resection through overcoming IL-17 producing T cells.

Adoptive transfer of hepatic stellate cells ameliorates liver ischemia reperfusion injury through enriching regulatory T cells.

Our previous study indicated that adoptive transferred regulatory T cells (Tregs) attenuated liver ischemia reperfusion injury (IRI). Recent studies demonstrated that hepatic stellate cells (HSCs) were producers of induced Tregs (iTregs) via retinoic acid. This study aimed to investigate the role of adoptive transferred HSCs in liver IRI. Mice were treated with gradient doses of HSCs before surgery at 24h or 72h. The levels of serum aminotransferases and hepatic cytokines were evaluated after reperfusion. Meanwhile, hepatic Tregs and their subsets were analyzed by flow cytometry. We found that adoptive transferred HSCs attenuated liver IRI. Administration of HSCs expanded the number of hepatic iTregs and natural Tregs (nTregs) after reperfusion. In addition, we found that the increased Tregs were almost Helios-Tregs before surgery. These Helios-Tregs were considered as iTregs and protected liver from IRI partially. Furthermore, adoptive transferred HSCs stabilized nTregs and prevented nTregs from reducing after reperfusion. These nTregs also attenuated liver IRI partially. Depletion of Tregs abolished the protective effect of HSCs. Thus, we conclude that adoptive transferred HSCs ameliorate liver IRI in Tregs-dependent manner.

Tumor necrosis factor-alpha preconditioning attenuates liver ischemia/reperfusion injury through preserving sarco/endoplasmic reticulum calcium-ATPase function.

BACKGROUND: Tumor necrosis factor-alpha (TNF-α) is a multifunctional cytokine. In this study, we investigated the role of TNF-α preconditioning in liver ischemia/reperfusion injury (IRI). METHODS: After IRI, serum alanine aminotransferase, protein levels of SERCA-3, and Caspase-3 in liver were analyzed. In vitro study, primary hepatocytes were isolated from mice and cultured in hypoxic media with or without TNF-α. The levels of SERCA-3, Caspase-3, and intracellular calcium were evaluated after 24-h incubation. In addition, protease inhibitors were adopted to determine the role of SERCA-3 in TNF-α preconditioning. RESULTS: Low dose of TNF-α preconditioning protected liver from IRI, which was described by reduced serum alanine aminotransferase, Capase-3, and elevated SERCA-3 compared with the animals without TNF-α treatment. The in vitro test confirmed the protective effect of TNF-α through maintaining homeostasis of intracellular calcium. However, the effect of TNF-α was deprived by protease inhibitors. CONCLUSIONS: In this study, we demonstrated that IRI reduced SERCA-3 expression in liver. Low dose of TNF-α preconditioning protected against SERCA-3 reducing, promoted intercellular calcium storage, and attenuated liver IRI.

Sorafenib reduces hepatic infiltrated regulatory T cells in hepatocellular carcinoma patients by suppressing TGF-beta signal.

BACKGROUND AND OBJECTIVES: Sorafenib has been shown to improve survival rate of hepatocellular carcinoma (HCC) patients significantly. Decline of tumor infiltrated regulatory T cells (TITs) may account for the activity of sorafenib partially. In this study, the underlying mechanism of sorafenib reducing TITs was investigated. METHODS: Tumor infiltrated mononuclear cells (TIMs), which were isolated form 19 HCC patients with or without sorafenib therapy, were analyzed by flow cytometry. TGF-ß signal pathways were analyzed by immunoblotting. In vitro test, naïve T cells were induced to regulatory T cells (Tregs) with or without sorafenib. After 3 days of culture, percentage of Tregs from CD4+ cells and TGF-ß signal pathways were analyzed. Meanwhile, TIMs from HCC patients without sorafenib treatment were cultured in the presence of sorafenib, and then the percentage of Foxp3 expressing cells from TIMs was analyzed. RESULTS: TITs were increased in HCC patients compared with controls. However, after sorafenib therapy, TITs were decreased significantly and TGF-ß signal pathways were down-regulated. Additionally, in the presence of sorafenib, induction of Tregs was inhibited and TGF-ß signal pathways in resulting cells were down-regulated. However, sorafenib treatment did not affect the percentage of Foxp3 expressing cells from TIMs in vitro. CONCLUSIONS: Sorafenib reducing TITs in HCC patients are associated with down-regulation of TGF-ß signal. This finding may help us for better understanding the activity of sorafenib in HCC patients.

Matrix metalloprotease 9 promotes liver recovery from ischemia and reperfusion injury.

BACKGROUND: Matrix metalloprotease (MMP) 9 has been always considered as a destructor of extracellular matrix, promoting liver injury and metastasis of carcinoma. In this study, we investigated the role of MMP-9 in liver wound healing from ischemia and reperfusion injury (IRI). METHODS: MMP9-/- mice were used to establish partial hepatic IRI model. Serum alanine aminotransferase and hepatic cytokines (tumor necrosis factor alpha, interleukin [IL]-1ß, IL-10, and transforming growth factor beta [TGF-ß]) levels were analyzed after IRI. Hepatic stellate cells were isolated from wild-type mice to determine the effect of MMP-9 on TGF-ß activation. In addition, the effect of TGF-ß on liver wound healing from IRI was determined. RESULTS: Liver recovery from IRI was impaired in MMP9-/- mice, which was described as elevated serum alanine aminotransferase, hepatic tumor necrosis factor alpha, and IL-1ß levels. Meanwhile, TGF-ß-active protein level was decreased in the liver of MMP9-/- mice. In vitro test, the activation of TGF-ß was suppressed in the presence of anti-MMP-9 monoclonal antibody. TGF-ß treatment promoted liver recovery from IRI in MMP9-/- mice. CONCLUSIONS: MMP-9 promoted liver recovery from IRI by activating TGF-ß. Thus, MMP-9 plays dual roles (bad and good) in liver IRI, depending on the timing.

Ex vivo induced regulatory T cells regulate inflammatory response of Kupffer cells by TGF-beta and attenuate liver ischemia reperfusion injury.

In the presence of TGF-ß, CD4+CD62L+T cells can be induced to CD4+CD25+FoxP3+ regulatory T cells (iTregs). In our previous work, we have shown that adoptive transfer of iTregs promoted liver recovery from ischemia reperfusion injury (IRI). In this study, we examined the molecular mechanism underlying the liver IRI attenuation by iTregs in a mouse partial hepatic IRI model. We found that the population of hepatic Tregs decreased significantly at 24 h after reperfusion. Adoptive transfer of iTregs before IRI markedly increased the numbers of hepatic Tregs and attenuated liver IRI as indicated by reduced serum aminotransferases and proinflammatory cytokines, such as interleukin-1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α). Ex vivo study indicated that iTregs suppressed IL-1ß and TNF-α expression, promoted transcription of interleukin-10 (IL-10), and elevated phosphorylation of SMAD3 in Kupffer cells (KCs). Furthermore, inhibition of TGF-ß signaling by anti-TGF-ß abolished the effects on KCs. Treatment with TGF-ß suppressed matrix metalloprotease (MMP9) production in KCs and protected liver from IRI. In conclusion, our results suggest that iTregs play a critical role in hepatic IRI by regulating pro-inflammatory and anti-inflammatory function of KCs through TGF-ß.