Metabolic syndrome and non-alcoholic fatty liver disease in liver surgery: The new scourges?

Dysregulation of autophagy acts as a pathogenic mechanism of non-alcoholic fatty liver disease (NAFLD) induced by common environmental pollutants

Non-alcoholic fatty liver disease (NAFLD) has been the most common chronic liver disease in the world, including the developing countries. NAFLD is metabolic disease with significant lipid deposition in the hepatocytes of the liver, which is usually associated with oxidative stress, inflammation and fibrogenesis, and insulin resistance. Progressive NAFLD can develop into non-alcoholic steatohepatitis (NASH) or hepatocellular carcinoma. The current evidence proposes that environmental pollutants promote development and progression of NAFLD, and autophagy plays a vital role but is multifactorial affected in NAFLD. In this review, we analyzed on the regulations of common environmental pollutants on autophagy in NAFLD. To clarify the involved roles of autophagy, we discussed the dysregulation of autophagy by environmental pollutants in adipose tissue and gut, and their interactions with liver, as well as epigenetic regulation on autophagy by environmental pollutants. Furthermore, protective roles of potential therapeutic treatments on the multiple-hits of autophagy in NAFLD were descripted.

Metabolic syndrome and liver disease in the era of bariatric surgery: What you need to know!

Metabolic syndrome (MS) is defined as the constellation of obesity, insulin resistance, high serum triglycerides, low high-density lipoprotein cholesterol, and high blood pressure. It increasingly affects more and more people and progressively evolves into a serious issue with widespread healthcare, cost, and quality of life associated consequences. MS is associated with increased morbidity and mortality due to cardiovascular or chronic liver disease. Conservative treatment, which includes diet, exercise, and antidiabetic agents, is the mainstay of treatment, but depends on patient compliance to medical treatment and adherence to lifestyle modification recommendations. Bariatric surgery has recently emerged as an appropriate alternative treatment with promising long-term results. Sleeve gastrectomy and Roux-en-Y gastric bypass constitute the most commonly performed procedures and have been proven both cost-effective and safe with low complication rates. Liver transplantation is the only definitive treatment for end-stage liver disease and its utilization in patients with non-alcoholic steatohepatitis has increased more than fivefold over the past 15 years. In this review, we summarize current state of evidence on the surgical treatment of MS.

TLR4 knockout upregulates the expression of Mfn2 and PGC-1α in a high-fat diet and ischemia-reperfusion mice model of liver injury

AIMS

Patients with nonalcoholic fatty liver disease (NAFLD) have less tolerance to ischemia-reperfusion injury (IRI) of the liver than those with the healthy liver; hence have a higher incidence of severe complications after surgery. This study aimed to investigate the dynamics of the liver and mitochondrial damage and the impact of TLR4 knockout (TLR4KO) on Mfn2 expression in the composite model of NAFLD and IRI.

MAIN METHODS

We performed high-fat diet (HFD) feeding and ischemia reperfusion (IR) on wild type (WT) and TLR4 knockout TLR4KO mice.

KEY FINDINGS

The degree of structural and functional injuries to the liver and mitochondria (NAFLD and IRI) is greater than that caused by a single factor (NAFLD or IRI) or a simple superposition of both. The IL-6 and TNF-α expressions were significantly suppressed (P < .05), while PGC-1α and Mfn2 expressions were up-regulated considerably (P < .05) after TLR4KO. Furthermore, mitochondrial fusion increased, while ATP consumption and ROS production decreased significantly after TLR4KO (P < .05). The degree of reduction of compound injury by TLR4KO is more significant than the reduction degree of single factor injury. Also, TNF-α and IL-6 levels can be used predictive markers for mitochondrial damage and liver tolerance to NAFLD and IRI.

SIGNIFICANCE

TLR4KO upregulates the expression of Mfn2 and PGC-1α in the composite model of NAFLD and IRI. This pathway may be related to IL-6 and TNF-α. This evidence provides theoretical and experimental basis for the subsequent Toll-like receptor 4 (TLR4) receptor targeted therapy.

Metabolic syndrome and hepatic surgery

In Europe, the prevalence of metabolic syndrome (MS) has reached the endemic rate of 25%. Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of MS. Its definition is histological, bringing together the different lesions associated with hepatic steatosis (fat deposits on more than 5% of hepatocytes) without alcohol consumption and following exclusion of other causes. MS and NAFLD are implicated in the carcinogenesis of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). At present, HCC and ICC involving MS represent 15-20% and 20-30% respectively of indications for hepatic resection in HCC and ICC. Moreover, in the industrialized nations NAFLD is tending to become the most frequent indication for liver transplantation. MS patients combine the operative risk associated with their general condition and comorbidities and the risk associated with the presence and/or severity of NAFLD. Following hepatic resection in cases of HCC and ICC complicating MS, the morbidity rate ranges from 20 to 30%, and due to cardiovascular and infectious complications, post-transplantation mortality is heightened. The operative risk incurred by MS patients necessitates appropriate management including: (i) precise characterization of the subjacent liver; (ii) an accurately targeted approach privileging detection and optimization of treatment taking into account the relevant cardiovascular risk factors; (iii) a surgical strategy adapted to the histology of the underlying liver, with optimization of the volume of the remaining (postoperative) liver.

Minor laparoscopic liver resection as day-case surgery (without overnight hospitalisation): a pilot study

BACKGROUND

Day-case surgery (DCS) has become increasingly popular over recent years, as has laparoscopic liver resection (LLR) for the treatment of benign or malignant liver tumours. The purpose of this prospective study was to demonstrate the feasibility of minor LLR as DCS.

METHODS

Prospective, intention-to-treat, non-randomised study of patients undergoing minor LLR between July 2015 and December 2017. Exclusion criteria were resection by laparotomy, major LLR, difficult locations for minor LLR, history of major abdominal surgery, hepatobiliary procedures without liver parenchyma resection, cirrhosis with Child > A and/or portal hypertension, significant medical history and exclusion criteria for DCS. The primary endpoint was the unplanned overnight admission rate. Secondary endpoints were the reason for exclusion, complication data, criteria for DCS evaluation, satisfaction and compliance with the protocol.

RESULTS

One hundred sixty-seven patients underwent liver resection during the study period. LLR was performed in 92 patients (55%), as DCS in 23 patients (25%). Reasons for minor LLR were liver metastasis (n = 9), hepatic adenoma (n = 5), hepatocellular carcinoma (n = 4), ciliated hepatic foregut cyst (n = 2) and other benign tumours (n = 3). All day-case minor LLR, except two patients, consisted of single wedge resection, while one patient underwent left lateral sectionectomy. There were four unplanned overnight admissions (17.4%), one unscheduled consultation (4.3%), two hospital readmissions (8.6%) and no major complications/mortality. Compliance with the protocol was 69.5%. Satisfaction rate was 91%.

CONCLUSION

In selected patients, day-case minor LLR is feasible with acceptable complication and readmission rates. Day-case minor LLR can therefore be legitimately proposed in selected patients.

Surgical Management of Intrahepatic Cholangiocarcinoma in Patients with Cirrhosis: Impact of Lymphadenectomy on Peri-Operative Outcomes

BACKGROUND

The consequences of lymphadenectomy (LND) on cirrhotic patients undergoing hepatectomy for intrahepatic cholangiocarcinoma (ICC) have not been investigated. We sought to analyze the impact of LND on morbidity among patients undergoing resection for ICC.

METHODS

A total of 1005 patients who underwent hepatectomy for ICC at one of the 14 participating institutions between 1990 and 2015 were identified. A propensity score match analysis was performed to reduce confounding biases between cirrhosis and non-cirrhosis groups.

RESULTS

Cirrhosis was diagnosed in 118 (11.7%) patients. Among non-cirrhotic patients, 63% underwent major liver resection versus only 20% among patients with cirrhosis (p < 0.001). LND was also less common among cirrhotic versus non-cirrhotic patients (19 vs. 50%, p < 0.001). The incidence of complications was 41 and 30% among patients who did not and did have cirrhosis, respectively (p = 0.022). The propensity-matched cohort included 150 patients. The incidence of complications was 71% among patients who underwent lymphadenectomy versus 23% among patients who did not undergo lymphadenectomy (OR 8.39) (p < 0.001). In the propensity-matched analysis, the median HLN was comparable among patients independent of cirrhosis status (median HLN: non-cirrhosis, 2.5 vs. cirrhosis, 2) (p = 0.95). While lymphadenectomy was associated with a higher risk of infections (non-cirrhosis, 0% vs. cirrhosis, 21%, p < 0.001) among patients with cirrhosis, infections were not associated with lymphadenectomy among non-cirrhotic patients (p = 0.19).

CONCLUSION

Lymphadenectomy was associated with an increased risk of complications among patients with cirrhosis undergoing surgery for ICC. The benefit of lymphadenectomy in cirrhotic patients should be considered in light of the higher risk of postoperative complications compared with non-cirrhotic patients.

Prevalence of Metabolic Syndrome in Liver Transplant Recipients in Iran

BACKGROUND

Metabolic syndrome (MetSx) is common among liver transplant recipients. It contributes to morbidity and mortality.

OBJECTIVE

To determine the prevalence of MetSx in patients undergoing liver transplantation (LTx) in Iran.

METHODS

202 liver transplant recipients of both sexes completed this study. Relevant information including age, sex, the underlying disease, systolic and diastolic blood pressure, waist circumference, fasting serum levels of blood sugar (FBS), triglyceride (TG), and HDL-cholesterol were measured. The prevalence of MetSx was evaluated at 1, 3, 6, 9, and 12 months after LTx.

RESULTS

The prevalence of MetSx was 36.6% after 1 month that decreased to 28.2% after 12 months of follow-up. The lowest prevalence of MetSx (27.7%) was observed 9 months after LTx. Our data showed a decrease in TG and an increase in HDL-C level and no significant changes in blood pressure, waist circumference and FBS during the study period.

CONCLUSION

The prevalence of MetSx after LTx is high when compared to the normal population. It seems that a change in diet after transplantation may affect the prevalence of MetSx.

The influence of steatosis on the short- and long-term results of resection of liver metastases from colorectal carcinoma

We aimed to establish whether the presence of hepatic steatosis influences outcome after resection of colorectal liver metastases (CLM).

PATIENTS AND METHODS

Patients operated between 1990 and 2014 were divided into four groups based on the degree of hepatic steatosis. The association between hepatic steatosis and outcome was analyzed, using a multivariate and a propensity score case-match analysis.

RESULTS

No significant differences were observed between patients with and without steatosis in either mortality or morbidity in the complete series or after matching (3.2% vs. 3.5%/p = 0.845) (32.3% vs 31.4%/p = 0.802). Five-year survival in patients with and without steatosis were 56.5% and 46.5% respectively (p = 0.046). The steatosis had a significant protective effect in the univariate analysis (HR (95% CI) = 0.78 (0.62-0.99) p = 0.048), and was close to significance in the multivariate analysis (HR (95%) = 0.81 (0.63-1.03) p = 0.089). No significant differences were seen with regard to liver recurrence.

CONCLUSIONS

The presence of steatosis does not predict short-outcome after resection of CLM, but appears to be a favorable prognostic factor for survival. This protective effect does not depend on a decrease in liver recurrence.

Preoperative selection of patients with colorectal cancer liver metastasis for hepatic resection

Surgical resection of colorectal liver metastases (CRLM) has a well-documented improvement in survival. To benefit from this intervention, proper selection of patients who would be adequate surgical candidates becomes vital. A combination of imaging techniques may be utilized in the detection of the lesions. The criteria for resection are continuously evolving; currently, the requirements that need be met to undergo resection of CRLM are: the anticipation of attaining a negative margin (R0 resection), whilst maintaining an adequate functioning future liver remnant. The timing of hepatectomy in regards to resection of the primary remains controversial; before, after, or simultaneously. This depends mainly on the tumor burden and symptoms from the primary tumor. The role of chemotherapy differs according to the resectability of the liver lesion(s); no evidence of improved survival was shown in patients with resectable disease who received preoperative chemotherapy. Presence of extrahepatic disease in itself is no longer considered a reason to preclude patients from resection of their CRLM, providing limited extra-hepatic disease, although this currently is an area of active investigations. In conclusion, we review the indications, the adequate selection of patients and perioperative factors to be considered for resection of colorectal liver metastasis.

Crude triterpenoid saponins from Ilex latifolia (Da Ye Dong Qing) ameliorate lipid accumulation by inhibiting SREBP expression via activation of AMPK in a non-alcoholic fatty liver disease model

BACKGROUND

Ilex latifolia Thunb. (Da Ye Dong Qing) is used for weight loss and for its antidiabetic effects. This study aims to investigate the beneficial effects and potential mechanisms of action of crude triterpenoid saponins (CTS) from I. latifolia in a mouse model of high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD).

METHODS

Male C57BL/6 mice (n = 50), were arbitrarily divided into five groups (n = 10 in each group): a control group, HFD group, simvastatin group (10 mg/kg/day), and two CTS treatment groups (100 and 200 mg/kg/day). All mice except those in the control group were fed an HFD for 4 weeks. Animals in the treatment groups were orally administered simvastatin or CTS for 8 weeks. Oral glucose tolerance tests and insulin tolerance tests were performed. At the end of treatment, plasma lipid levels, and oxidative parameters in the liver were measured using commercial test kits. Western blotting was used to evaluate whether CTS induced AMP-activated protein kinase (AMPK) and acetyl CoA carboxylase activation, and the expression of transcription factors and their target genes was evaluated in a quantitative PCR assay.

RESULTS

Compared with the HFD group, the CTS (200 mg/kg/day) treatment group showed significantly decreased plasma lipid parameters (P < 0.001, P = 0.018, and P = 0.005 for triglycerides, total cholesterol and low-density lipoprotein cholesterol, respectively), and improved insulin resistance (P = 0.006). CTS (100 and 200 mg/kg/day) supplementation also reduced hepatic lipids and protected the liver from oxidative stress by attenuating malondialdehyde content (P < 0.001 and P < 0.001, respectively) and restoring aspartate aminotransferase levels (P < 0.001 and P < 0.001, respectively). Moreover, CTS (200 mg/kg/day) reduced lipid accumulation by enhancing AMPK phosphorylation and inhibiting expression of sterol regulatory element-binding proteins (SREBPs) and their target genes SREBP-1c, SREBP-2, fatty acid synthase, and stearoyl-CoA desaturase (P = 0.013, P = 0.007, P = 0.011, and P = 0.014, respectively).

CONCLUSION

CTS from I. latifolia improved insulin resistance and liver injury in HFD-fed mice, and attenuated NAFLD via the activation of AMPK and inhibition of the gene expression of SREBPs and some of their target molecules.

Effects on Liver Lipid Metabolism of the Naturally Occurring Dietary Flavone Luteolin-7-glucoside

Disruptions in whole-body lipid metabolism can lead to the onset of several pathologies such as nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs). The present study aimed at elucidating the molecular mechanisms behind the lipid-lowering effects of the flavone luteolin-7-glucoside (L7G) which we previously showed to improve plasma lipid profile in rats. L7G is abundant in plant foods of Mediterranean diet such as aromatic plants used as herbs. Results show that dietary supplementation with L7G for one week induced the expression of peroxisome proliferator-activated receptor-alpha (PPAR-α) and of its target gene carnitine palmitoyl transferase 1 (CPT-1) in rat liver. L7G showed a tendency to decrease the hepatic expression of sterol regulatory element-binding protein-1 (SREBP-1), without affecting fatty acid synthase (FAS) protein levels. Although SREBP-2 and LDLr mRNA levels did not change, the expression of HMG CoA reductase (HMGCR) was significantly repressed by L7G. L7G also inhibited this enzyme's in vitro activity in a dose dependent manner, but only at high and not physiologically relevant concentrations. These results add new evidence that the flavone luteolin-7-glucoside may help in preventing metabolic diseases and clarify the mechanisms underlying the beneficial health effects of diets rich in fruits and vegetables.

The multiple universes of estrogen-related receptor α and γ in metabolic control and related diseases

The identification of the estrogen-related receptors (ERRs) as the first orphan nuclear receptors ignited a new era in molecular endocrinology, which led to the discovery of new ligand-dependent response systems. Although ERR subfamily members have yet to be associated with a natural ligand, the characterization of these orphan receptors has demonstrated that they occupy a strategic node in the transcriptional control of cellular energy metabolism. In particular, ERRs are required for the response to various environmental challenges that require high energy levels by the organism. As central regulators of energy homeostasis, ERRs may also be implicated in the etiology of metabolic disorders, such as type 2 diabetes and metabolic syndrome. Here, we review the recent evidence that further highlights the role of ERRs in metabolic control, particularly in liver and skeletal muscle, and their likely involvement in metabolic diseases. Consequently, we also explore the promises and pitfalls of ERRs as potential therapeutic targets.

Potential protection of vitamin C against liver-lesioned mice

Pathologically, liver injury can result from sustained trauma to hepatocytes, including acute damage. Thus, attenuation of hepatocellular lesion may help improve liver functions. The purpose of this study was to explore the potential advantages of vitamin C (VC) intake on acutely intralesional liver in carbon tetrachloride (CCl4)-exposed mice. Here our data showed that VC supplementation contributed to ameliorated vital signs of CCl4-lesioned mice, resulting in dose-dependent reduction of hepatomegaly. VC lowered the levels of liver functional enzymes including alanine aminotransferase (ALT) and glutamic-oxaloacetic transaminase (AST) in serum, while concentration of lactic acid concentration in blood plasma was decreased. VC-administered CCl4-lesioned mice manifested increased activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), while the malondialdehyde (MDA) content was reduced in liver tissue. Moreover, VC consumption attenuated hepatotoxic injuries of CCl4-lesioned mice, in which the number of TNF-α positive cells was dose-dependently reduced. Furthermore, intrahepatic expression of TRL-4 mRNA, a vital inflammation-regulator, was down-regulated in VC-administered mice. Overall, we conclude that VC has the potentiality of anti-hepatotoxicity that is capable of ameliorating liver functions, speculating that therapeutic mechanism relates to normalizing metabolism and blocking inflammatory stress in the liver.