Nutrition and liver diseases

Research Progress of Circular RNA in Gastrointestinal Tumors

circular RNA (circRNA) is a closed ring structure formed by cyclic covalent bonds connecting the 5’-end and 3’-end of pre-mRNA. circRNA is widely distributed in eukaryotic cells. Recent studies have shown that circRNA is involved in the pathogenesis and development of multiple types of diseases, including tumors. circRNA is specifically expressed in tissues. And the stability of circRNA is higher than that of linear RNA, which can play biological roles through sponge adsorption of miRNA, interaction with RNA binding protein, regulation of gene transcription, the mRNA and protein translation brake, and translation of protein and peptides. These characteristics render circRNAs as biomarkers and therapeutic targets of tumors. Gastrointestinal tumors are common malignancies worldwide, which seriously threaten human health. In this review, we summarize the generation and biological characteristics of circRNA, molecular regulation mechanism and related effects of circRNA in gastrointestinal tumors.

Pathophysiology of Acute Liver Failure

Acute liver failure (ALF) is a rare syndrome resulting from an acute insult to the liver in patients without known underlying chronic liver disease. It is characterized by loss of synthetic function in the form of jaundice and coagulopathy and development of hepatic encephalopathy. Multiorgan failure (MOF) eventually develops, leading to death. Many different etiologies have been identified, with acetaminophen (APAP) overdose and viral hepatitis being the most common causes worldwide. The pathophysiology of ALF can be divided into cause-specific liver injury pathophysiologies and pathophysiology related to occurrence of secondary MOF. In terms of liver injury pathophysiology, APAP toxicity is the most well known. Secondary MOF is often a result of the initial massive proinflammatory response generating a systemic inflammatory response syndrome followed by a compensatory anti-inflammatory response leading to immune cell dysfunction and sepsis. As the liver is a tremendously important metabolic organ involved in energy metabolism, protein synthesis, fat metabolism, and glycemic control, multiple aspects of nutrition also need to be considered as part of the overall pathophysiology of ALF.

Role of liver transplantation in severe alcoholic hepatitis

Severe alcoholic hepatitis has very high short term mortality and corticosteroids have been the mainstay of treatment for decades. Patients with Lille score >0.45 are considered non-responders to steroids and have poor outcome. Recently Orthotopic Liver Transplantation (OLT) is being increasingly used as rescue treatment for these patients, without waiting for 6 months of abstinence. Liver transplant is the only rescue treatment which can potentially provide long term benefit for patients who are steroid non-responders. However, with scarcity of organs being a concern, all patients of severe alcoholic hepatitis cannot be chosen for transplantation in an arbitrary way. There is a need for development of predictive tools and objective protocols to select patients who can justify the use of precious liver grafts. With a stringent criteria for selection of patients receiving the graft, liver transplantation in severe alcoholic hepatitis can become a viable rescue therapeutic option conferring significant survival advantage of both short- and long-term basis. The optimal criteria for selection will also prevent misuse of the liver donor pool as well as to prevent mortality in salvageable patients. Further research needs to be done to identify subset of patients which are at low risk of recidivism and also cannot be managed with pharmacotherapy alone. We reviewed the current knowledge on role of OLT in patient with acute severe alcoholic hepatitis in the present review.

Modulatory role of Co-enzyme Q10 on methionine and choline deficient diet-induced non-alcoholic steatohepatitis (NASH) in albino rats

The present study aimed to evaluate the hepato-protective and neuro-protective activity of Co-enzyme Q10 (CoQ10) on non-alcoholic steatohepatitis (NASH) in albino rats induced by methionine and choline-deficient (MCD) diet. Rats were fed an MCD diet for 8 weeks to induce non-alcoholic steatohepatitis. CoQ10 (10 mg/(kg·day)−1) was orally administered for 2 consecutive weeks. Twenty-four hours after the last dose of the drug, the behavioral test, namely the activity cage test, was performed and the activity counts were recorded. Serum alanine transaminase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, total/direct bilirubin, and albumin were valued to assess liver function. Moreover, hepatic cytokines interleukin-6 as well as its modulator nuclear factor kappa-light-chain-enhancer of activated B cells were determined. In addition, brain biomarkers, viz ammonia, nitric oxide, and brain-derived neurotrophic factor (BDNF), were measured as they are reliable indices to assess brain damage. Histopathological and immunohistochemical examination of brain proliferating cell nuclear antigen in brain and liver tissues were also evaluated. Results revealed that MCD-induced NASH showed impairment in the liver functions with an increase in the liver inflammatory markers. Moreover, NASH resulted in pronounced brain dysfunction as evidenced by hyper-locomotor activity, a decrease in the BDNF level, as well as an increase in the brain nitric oxide and ammonia contents. Oral treatment of MCD-diet−fed rats with CoQ10 for 14 days showed a marked improvement in all the assigned parameters. Finally, it can be concluded that CoQ10 has a hepatoprotective and neuroprotective role in MCD-diet−induced NASH in rats.

Safety of an Immune-Enhancing Nutrition Supplement in Cirrhotic Patients With History of Encephalopathy

Malnutrition in advanced cirrhosis may worsen liver function and increase susceptibility to infections. Immune-enhancing nutrition supplements (IENS) may be of value, but their safety in patients with decompensated cirrhosis and history of encephalopathy is unknown. We assessed the safety of Impact Recover (Novartis, St. Louis Park, MN), an orally palatable IENS, in 12 men with hepatic cirrhosis of Child-Turcotte-Pugh (CTP) class B or C, ages 40-60. On day 0, patients were evaluated serially for 6 hours after ingestion of 2 packets of Impact Recover. Despite a transient doubling of the blood ammonia, no cognitive abnormalities were noted on clinical assessment or psychometric testing. Subsequently, patients were instructed to ingest 3 packets per day of Impact Recover for 56 days, after which supplements were stopped. Patients were evaluated in a fasting state on days 0 (baseline), 56 (end of treatment), and 112 (follow-up). One patient was transplanted on day 21, and another died after an urgent cholecystectomy on day 30. The remaining 10 patients completed the study. Mean value of CTP score was 9 (range, 7-11) and mean value of model for end-stage liver disease (MELD) score was 14 (7-21), and there was no change after 8 weeks of IENS. Only 1 experienced transient worsening of encephalopathy after omitting lactulose. Performances on psychometric tests did not change. Transferrin levels increased rapidly with IENS, then returned toward baseline after IENS was stopped. Fasting insulin and peptide YY (PYY) levels also increased, but fasting glucose and hemoglobin A1C did not change. Trends in other nutrition and immune parameters did not reach significance. We conclude that acute and chronic administration of Impact Recover was well tolerated in cirrhotic patients with controlled encephalopathy. Further studies are justified to assess potential efficacy of long-term IENS in preventing infection and slowing progression in advanced cirrhosis.

The management of hospitalized patients with cirrhosis: the Mount Sinai experience and a guide for hospitalists

BACKGROUND

Cirrhosis and chronic liver disease carry appreciable morbidity and mortality. Cirrhotic patients frequently require hospitalization and their care is both extremely complex and labor-intensive.

AIM

We seek to provide a review for gastroenterologists, hepatologists, internists, and hospitalists on the approach to care in patients hospitalized for complications related to end-stage liver disease.

METHODS

The Mount Sinai Medical Center's inpatient liver service has developed an integrated team approach for cirrhotic patients and throughout the years has educated fellows-in-training and medical house staff on both the treatment principles and "pearls" in managing the hospitalized cirrhotic patient. We reviewed the literature and provide recommendations on the management of complications of end-stage liver disease. Additionally, we provide a review of the protocols used at our institution in the care for cirrhotic patients.

RESULTS

Major complications of advanced liver disease include infection, ascites, spontaneous bacterial peritonitis, hepatic encephalopathy, portal hypertension, variceal hemorrhage, hepatorenal syndrome, and hepatocellular carcinoma. Management of these complications involves selecting the appropriate diagnostic studies and prompt administration of therapy.

CONCLUSIONS

There are many complications of cirrhosis. Management of these complications can be complex and are targeted at stabilizing the patient's clinical condition. Liver transplantation remains the only definitive treatment.

Total and acylated ghrelin in liver cirrhosis: correlation with clinical and nutritional status

OBJECTIVES

The pathogenesis of anorexia in cirrhotic patients is complex and the appetite-modulating hormone ghrelin could be involved. Acylated ghrelin is the biologically active form that modifies insulin sensitivity and body composition. The aim of the present study was to compare acylated and total ghrelin concentration in patients with liver cirrhosis and to investigate the possible relationship between ghrelin and clinical and nutritional parameters.

DESIGN AND METHODS

Sixty patients with viral liver cirrhosis who did not have hepatocellular carcinoma or acute infections were studied. Twenty healthy volunteers were recruited after matching for age, gender, and body mass index with the patients and served as controls. Fasting levels of total, acylated ghrelin, leptin, TNF-alpha and insulin were measured in all subjects, in addition, clinical and nutrition parameters were assessed.

RESULTS

In cirrhotic patients, plasma levels of both acylated and total ghrelin were significantly higher than those in the controls. The mean plasma acylated ghrelin levels were significantly higher in Child C cirrhosis compared to Child A and B. Ghrelin (total and acylated) were negatively correlated with leptin in cirrhotic patients confirming the fact that leptin acts as a physiological counterpart of ghrelin.

CONCLUSIONS

Nutritional and metabolic abnormalities in cirrhotic patients may be dependent on the changes in the ghrelin/leptin systems, mainly the acylated form of ghrelin.

Effects of low fat and babassu fat diets on nutritional status in obstructive cholestasis in young rats

PURPOSE: To test the effects of a low fat diet compared with a babassu fat diet on nutritional status in obstructive cholestasis in young rats. METHODS: We submitted 40 rats in 4 groups of 10 animals each from P21 (21st postnatal day) to P49 to two of the following treatments: bile duct ligation or sham operation and low fat diet (corn oil supplying 4.5% of the total amount of energy) or babassu fat diet (this fat supplying 32.7% and corn oil supplying 1.7% of the total amount of energy). Weight gain from P25 to P49 every 4 days was measured. The Verhulst's growth function was fitted to these values of weight gain. Growth velocity and acceleration at each moment were estimated using the same equation. Total food and energy intake from P21 to P49, energy utilization rate (EUR) from P25 to P49 and fat absorption rate (FAR) and nitrogen balance (NB) from P42 to P49 were measured. Two Way ANOVA and the S.N.K. test for multiple paired comparisons were employed to study the effects of cholestasis and those of the diets and their interaction (p<0.05) on those variables. RESULTS: In cholestatic animals, a higher growth velocity at P45, a higher growth acceleration at P41 and P45, a greater EUR, a greater FAR and a greater NB, were found with the low fat diet as compared with the babassu fat diet. CONCLUSION: A low fat diet lessens the growth restriction brought about by cholestasis and allows for an improved dietary energy utilization and a better protein balance than the babassu fat diet.

Altered expression of genes regulating skeletal muscle mass in the portacaval anastomosis rat

We examined the temporal relationship between portacaval anastomosis (PCA), weight gain, changes in skeletal muscle mass and molecular markers of protein synthesis, protein breakdown, and satellite cell proliferation and differentiation. Male Sprague-Dawley rats with end to side PCA (n=24) were compared with sham-operated pair-fed rats (n=24). Whole body weight, lean body mass, and forelimb grip strength were determined at weekly intervals. The skeletal muscle expression of the ubiquitin proteasome system, myostatin, its receptor (the activin 2B receptor) and its signal, cyclin-dependent kinase inhibitor (CDKI) p21, insulin-like growth factor (IGF)-I and its receptor (IGF-I receptor-alpha), and markers of satellite cell proliferation and differentiation were quantified. PCA rats did not gain body weight and had lower lean body mass, forelimb grip strength, and gastrocnemius muscle weight. The skeletal muscle expression of the mRNA of ubiquitin proteasome components was higher in PCA rats in the first 2 wk followed by a lower expression in the subsequent 2 wk (P<0.01). The mRNA and protein of myostatin, activin 2B receptor, and CDKI p21 were higher, whereas IGF-I and its receptor as well as markers of satellite cell function (proliferating nuclear cell antigen, myoD, myf5, and myogenin) were lower at weeks 3 and 4 following PCA (P < 0.05). We conclude that PCA resulted in uninhibited proteolysis in the initial 2 wk. This was followed by an adaptive response in the later 2 wk consisting of an increased expression of myostatin that may have contributed to reduced muscle protein synthesis, impaired satellite cell function, and lower skeletal muscle mass.

The influence of Enteral Nutrition in postoperative patients with poor liver function

AIM: To investigate the safety, rationality and the practicality of enteral nutritional (EN) support in the postoperative patients with damaged liver function and the protective effect of EN on the gut barrier.

METHODS: 135 patients with liver function of Child B or C grade were randomly allocated to enteral nutrition group (EN, 65 cases), total parenteral nutrition group (TPN, 40 cases) and control group (CON, 30 cases). Nutritional parameters, hepatic and kidney function indexes were measured at the day before operation, 5th and 10th day after the operation respectively. Comparison was made to evaluate the efficacy of different nutritional support. Urinary concentrations of lactulose (L) and mannitol (M) were measured by pulsed electrochemical detection (HPLC-PED) and the L/M ratio calculated to evaluate their effectiveness on protection of gut barrier.

RESULTS: No significant damages in hepatic and kidney function were observed in both EN and TPN groups between pre- and postoperatively. EN group was the earliest one reaching the positive nitrogen balance after operation and with the lowest loss of body weight and there was no change in L/M ratio after the operation (0.026 ± 0.004) at the day 1 before operation, 0.030 ± 0.004 at the day 5 postoperative and 0.027 ± 0.005 at the day 10 postoperative), but the change in TPN group was significant at the day 5 postoperative (0.027 ± 0.003 vs 0.038 ± 0.009, P < 0.01).

CONCLUSION: EN is a rational and effective method in patients with hepatic dysfunction after operation and has significant protection effect on the gut barrier.

Ghrelin in chronic liver disease

BACKGROUND/AIMS

Ghrelin is a novel endogenous ligand for the growth hormone (GH) secretagogue receptor involved in energy metabolism, glucose homeostasis and food intake. We investigated the role of ghrelin and insulin-like growth factor-1 (IGF-1), the mediator of the GH axis, in patients with chronic liver diseases (CLD).

METHODS

Ghrelin and IGF-1 serum levels were determined in 105 CLD patients and 97 healthy controls and correlated with clinical and biochemical parameters.

RESULTS

Ghrelin was significantly elevated and IGF-1 reduced in CLD patients compared with healthy controls. IGF-1 serum levels inversely correlated with Child's classification. Ghrelin levels were significantly elevated in Child C cirrhosis patients independent of the aetiology of liver disease. Ghrelin levels did not correlate with liver function. In contrast, there was a correlation of ghrelin with clinical (gastrointestinal bleeding, ascites, encephalopathy) and biochemical (anaemia, inflammatory markers, hypoglycaemia, renal dysfunction) parameters. In a subgroup of patients with CLD and hepatocellular carcinoma (HCC), we observed a strong inverse correlation between alpha-fetoprotein (AFP) and ghrelin levels.

CONCLUSIONS

Unlike IGF-1, ghrelin is not correlated with liver function, but increases in Child C cirrhosis and with complications of CLD. The inverse correlation with AFP in HCC patients requires further studies on the potential impact of ghrelin on the pathogenesis of anorexia-cachexia syndrome.