Growth hormone-stimulated IGF-1 generation in cirrhosis reflects hepatocellular dysfunction

Insulin-like growth factor-1 in cirrhosis is linked to hepatic dysfunction and fibrogenesis and predicts liver-related mortality

BACKGROUND AND AIMS

We aimed to characterise insulin-like growth factor-1 (IGF-1) signalling in patients with advanced chronic liver disease (ACLD).

METHODS

Consecutive patients undergoing hepatic venous pressure gradient [HVPG] measurement were prospectively included. Clinical stages were defined as follows: probable ACLD (pACLD): liver stiffness ≥10 kPa and HVPG ≤5 mmHg, S0: mild PH (HVPG 6-9 mmHg), S1: clinically significant PH (CSPH), S2: CSPH with varices, S3: past variceal bleeding, S4: past/current non-bleeding hepatic decompensation and S5: further decompensation.

RESULTS

In total, 269 patients were included; 105 were compensated (pACLD: n = 18; S0: n = 30; S1: n = 20; S2: n = 37), and 164 were decompensated (S3: n = 11; S4: n = 89; S5: n = 64). Median levels of IGF-1 decreased with progressive cirrhosis (from pACLD: 88.5 ng/mL to S5: 51.0 ng/mL; p < 0.001). Patients with CSPH had significantly lower IGF-1 levels (63.5 ng/mL vs. 81.0 ng/mL; p = 0.001). IGF-1 showed an independent negative association with body mass index (BMI; aB: -1.56; p < 0.001), enhanced liver fibrosis (ELF) test (aB: -8.43; p < 0.001), MELD (aB: -1.13; p = 0.042) and age (per 10 years; aB: -6.87; p < 0.001). IGF-1 exhibited an excellent AUROC (0.856) for the prediction of liver-related death at 6 months of follow-up. Lower IGF-1 (per 10 ng/mL) was linked to higher risk of (further) decompensation (0.90; 95% CI: 0.83-0.98; p = 0.016), acute-on-chronic liver failure (ACLF; asHR: 0.80; 95% CI: 0.68-0.93; p = 0.004) and liver-related death (asHR: 0.76; 95% CI: 0.63-0.91; p = 0.004).

CONCLUSION

Decreased levels of IGF-1 reflect impaired hepatic function and fibrogenesis in patients with cirrhosis, which seems particularly relevant in obesity since low IGF-1 was independently linked to high BMI. Lower IGF-1 in cirrhosis predicts decompensation, ACLF and liver-related death.

Association of chronic liver disease with bone diseases and muscle weakness

The liver is a vital organ involved in nutrient metabolism, hormone regulation, immunity, cytokine production, and gut homeostasis. Impairment in liver function can result in malnutrition, chronic inflammation, decreased anabolic hormone levels, and dysbiosis. These conditions eventually cause an imbalance in osteoblast and osteoclast activities, resulting in bone loss. Osteoporosis is a frequent complication of chronic liver disease (CLD) that adversely affects quality of life and increases early mortality. Sarcopenia is another common complication of CLD characterized by progressive loss of skeletal muscle mass and function. Assessment criteria for sarcopenia specific to liver disease have been established, and sarcopenia has been reported to be associated with an increase in the risk of liver disease-related events and mortality in patients with CLD. Owing to their similar risk factors and underlying pathophysiological mechanisms, osteoporosis and sarcopenia often coexist (termed osteosarcopenia), progress in parallel, and further exacerbate the conditions mentioned above. Therefore, comprehensive management of these musculoskeletal disorders is imperative. This review summarizes the clinical implications and characteristics of osteoporosis, extending to sarcopenia and osteosarcopenia, in patients with CLD caused by different etiologies.

The oncogenic mechanisms of the Janus kinase-signal transducer and activator of transcription pathway in digestive tract tumors

Digestive tract tumors are heterogeneous and involve the dysregulation of multiple signaling pathways. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway plays a notable role in the oncogenesis of digestive tract tumors. Typically activated by pro-inflammatory cytokines, it regulates important biological processes, such as cell growth, differentiation, apoptosis, immune responses, and inflammation. The aberrant activation of this pathway manifests in different forms, including mutations in JAKs, overexpression of cytokine receptors, and sustained STAT activation, and contributes to promoting the malignant characteristics of cancer cells, including uncontrolled proliferation, resistance to apoptosis, enhanced invasion and metastasis, angiogenesis, acquisition of stem-like properties, and drug resistance. Numerous studies have shown that aberrant activation of the JAK-STAT pathway is closely related to the development and progression of digestive tract tumors, contributing to tumor survival, angiogenesis, changes in the tumor microenvironment, and even immune escape processes. In addition, this signaling pathway also affects the sensitivity of digestive tract tumors to chemotherapy and targeted therapy. Therefore, it is crucial to comprehensively understand the oncogenic mechanisms underlying the JAK-STAT pathway in order to develop effective therapeutic strategies against digestive tract tumors. Currently, several JAK-STAT inhibitors are undergoing clinical and preclinical trials as potential treatments for various human diseases. However, further investigation is required to determine the role of this pathway, as well as the effectiveness and safety of its inhibitors, especially in the context of digestive tract tumors. In this review, we provide an overview of the structure, classic activation, and negative regulation of the JAK-STAT pathway. Furthermore, we discuss the pathogenic mechanisms of JAK-STAT signaling in different digestive tract tumors, with the aim of identifying potential novel therapeutic targets. Video Abstract.

Insulin-like growth factor 1 predicts decompensation and long-term prognosis in patients with compensated cirrhosis

AIM

Insulin-like growth factor 1 (IGF-1), which is primarily produced in hepatocytes and is associated with liver functional reserve, plays a crucial role in the pathological condition of cirrhosis. This study aimed to investigate the usefulness of serum IGF-1 levels for predicting the long-term prognosis and decompensation development in patients with cirrhosis.

METHODS

We retrospectively evaluated 148 patients with cirrhosis and divided them into three groups according to baseline IGF-1 levels: low (L)-, intermediate (I)-, and high (H)-IGF-1 groups. The cumulative survival rates were compared among these groups in compensated and decompensated cirrhosis, respectively. Significant and independent factors associated with mortality and decompensation development were identified using Cox proportional hazards regression analysis.

RESULTS

The median observation period was 57.1 (41.7-63.2) months. Thirty (20.3%) patients died of liver disease-related events and 21 (22.3%) patients with compensated cirrhosis developed decompensation. Multivariate analysis identified low serum IGF-1 levels as a significant and independent factor associated with mortality (all patients: hazard ratio [HR], 0.967; p = 0.004; patients with compensated cirrhosis: HR, 0.927; p = 0.002). The cumulative survival rates were significantly lower in the L-IGF-1 group than in the H-IGF-1 and I-IGF-1 groups (all patients: p < 0.001 and = 0.009; patients with compensated cirrhosis: p = 0.012 and 0.003, respectively). However, in decompensated cirrhosis, the cumulative survival rates demonstrated no significant differences among the three groups. The cumulative decompensation incidence rates were significantly higher in the L-IGF-1 group than in the H-IGF-1 and I-IGF-1 groups (p < 0.001 and = 0.009, respectively). Low serum IGF-1 levels were significantly and independently associated with decompensation development (HR, 0.939; p < 0.001).

CONCLUSION

Low serum IGF-1 levels were significantly and independently associated with decompensation development and poor long-term prognosis in patients with compensated cirrhosis. Therefore, IGF-1 may be useful for predicting decompensation-related events and should be regularly monitored in the management of compensated phase.

The associations of gut microbiota, endocrine system and bone metabolism

Gut microbiota is of great importance in human health, and its roles in the maintenance of skeletal homeostasis have long been recognized as the "gut-bone axis." Recent evidence has indicated intercorrelations between gut microbiota, endocrine system and bone metabolism. This review article discussed the complex interactions between gut microbiota and bone metabolism-related hormones, including sex steroids, insulin-like growth factors, 5-hydroxytryptamine, parathyroid hormone, glucagon-like peptides, peptide YY, etc. Although the underlying mechanisms still need further investigation, the regulatory effect of gut microbiota on bone health via interplaying with endocrine system may provide a new paradigm for the better management of musculoskeletal disorders.

Insulin-like growth factor-1 (IGF-1) as predictor of cardiovascular mortality in heart failure patients: data from the T.O.S.CA. registry

INTRODUCTION

Data from the "Trattamento Ormonale nello Scompenso CArdiaco" (T.O.S.CA) registry showed that heart failure (HF) represents a complex clinical syndrome with different hormonal alterations. Renal failure represents a frequent complication in HF. We evaluated the relationship between renal function and insuline-like growth factor-1 (IGF-1) deficiency and its impact on cardiovascular mortality (CVM) in patients enrolled in the T.O.S.CA. registry.

METHODS

At the enrolment, all subjects underwent chemistry examinations, including circulating hormones and cardiovascular functional tests. COX regression analysis was used to evaluate factors related to CVM during the follow-up period in all populations, in high-risk patients and in the young-adult population. Also, we evaluate the effects of renal function on the CVM.

RESULTS

337 patients (41 deceased) were analyzed. CVM was related to severe renal dysfunction (HR stages IV-V = 4.86), high-risk conditions (HR 2.25), serum IGF-1 (HR 0.42), and HF etiology (HR 5.85 and HR 1.63 for valvular and ischemic etiology, respectively). In high-risk patients, CVM was related to IGF-1 levels, severe renal dysfunction and valvular etiology, whereas in young patients CMV was related to the high-risk pattern and serum IGF-1 levels.

CONCLUSIONS

Our study showed the clinical and prognostic utility of the IGF-1 assay in patients with HF.

Implications of pre-transplant sarcopenia and frailty in patients with non-alcoholic steatohepatitis and alcoholic liver disease

Frailty manifesting as sarcopenia is an independent risk factor for mortality in cirrhosis, and often presents in low model for end-stage liver disease (MELD) patients. Its etiology is multifactorial, but key physiologic changes culminate in altered energy utilization in the fasting state, preferentially utilizing muscle amino acids for gluconeogenesis thereby promoting sarcopenia. Hyperammonemia alters the circulating amino acid profile, diminishing pro-muscle branched-chain amino acids like leucine. The metabolic syndrome worsens sarcopenia through multi-tissue insulin resistance. Alcohol also exacerbates sarcopenia as a direct muscle toxin and inhibitor of growth signaling. Therapy is aimed at alcohol cessation, frequent high-protein meals, branched-chain amino acid supplementation, and diminished time spent fasting. Moderate exercise can improve muscle mass and muscle quality, though precise exercise regimens have not yet been explicitly determined. Studies are ongoing into the effects of myostatin antagonists and insulin sensitizers. The Liver Frailty Index can predict patients most at risk of poor outcome and should be considered in the management of all cirrhotic patients. Specialty testing like dual-energy X-ray absorptiometry (DEXA) scanning and cross-sectional estimates of muscle mass are areas of active research and may play a future role in clinical risk-stratification.

Disruption of the circadian clock component BMAL1 elicits an endocrine adaption impacting on insulin sensitivity and liver disease

SignificanceWhile increasing evidence associates the disruption of circadian rhythms with pathologic conditions, including obesity, type 2 diabetes, and nonalcoholic fatty liver diseases (NAFLD), the involved mechanisms are still poorly described. Here, we show that, in both humans and mice, the pathogenesis of NAFLD is associated with the disruption of the circadian clock combined with perturbations of the growth hormone and sex hormone pathways. However, while this condition protects mice from the development of fibrosis and insulin resistance, it correlates with increased fibrosis in humans. This suggests that the perturbation of the circadian clock and its associated disruption of the growth hormone and sex hormone pathways are critical for the pathogenesis of metabolic and liver diseases.

Cystic fibrosis related liver disease and endocrine considerations

Cystic fibrosis-liver disease (CFLD) is one of the most common non-pulmonary complications in the CF population, is associated with significant morbidity and represents the third leading cause of mortality in those with CF. CFLD encompasses a broad spectrum of hepatobiliary manifestations ranging from mild transaminitis, biliary disease, hepatic steatosis, focal biliary cirrhosis and multilobular biliary cirrhosis. The diagnosis of CFLD and prediction of disease progression remains a clinical challenge. The identification of novel CFLD biomarkers as well as the role of newer imaging techniques such as elastography to allow for early detection and intervention are active areas of research focus. Biliary cirrhosis with portal hypertension represents the most severe spectrum of CFLD, almost exclusively develops in the pediatric population, and is associated with a decline in pulmonary function, poor nutritional status, and greater risk of hospitalization. Furthermore, those with CFLD are at increased risk for vitamin deficiencies and endocrinopathies including CF-related diabetes, CF-related bone disease and hypogonadism, which can have further implications on disease outcomes and management. Effective treatment for CFLD remains limited and current interventions focus on optimization of nutritional status, identification and treatment of comorbid conditions, as well as early detection and management of CFLD specific sequelae such as portal hypertension or variceal bleeding. The extent to which highly effective modulator therapies may prevent the development or modify the progression of CFLD remains an active area of research. In this review, we discuss the challenges with defining and evaluating CFLD and the endocrine considerations and current management of CFLD.

The association between sarcopenia and endotoxin in patients with alcoholic cirrhosis

We aimed to prospectively identify the risk factors of sarcopenia in patients with cirrhosis.Patients (n = 193) included in a discovery cohort (January 2011 and December 2014) were categorized into alcoholic (A1; n = 55) and non-alcoholic cirrhosis (NA; n = 138) groups, and those (n = 235) in a validation cohort (January 2015 to December 2019) were categorized into alcoholic (n = 92), non-alcoholic steatohepatitis-related (n = 27), and hepatitis C virus-related cirrhosis groups (n = 116). Skeletal muscle mass index (SMI) was determined using computed tomography (SMI-CT) and bioelectrical impedance analysis (SMI-BIA). Endotoxin activity (EA) was measured with an EA assay.SMI-CT correlated with grip strength in all the groups but significantly correlated with SMI-BIA of the men in group A1 (R = 0.64, P < .0001) and both sexes in group NA (male: R = 0.44, P = .0001; female: R = 0.35, P = .003). SMI-CT inversely correlated with the EA levels of the men in group A1 (R = -0.67, P < .0001) and myostatin levels in group NA (R = -0.53, P < .0001). Lower extremity SMI had a strong negative correlation with the EA levels of the men in group A1 (R = -0.58, P < .001), whereas upper extremity SMI showed an inverse trend with EA levels (R = -0.28, P = .08). SMI-CT also inversely correlated with the EA levels in groups A2 (R = -0.52, P = .003) and N (R = -0.67, P < .0001) and myostatin levels in group C (R = -0.65, P < .0001). Moreover, SMI-CT correlated with nutritional factors, including cholinesterase (R = 0.50, P = .005), zinc (R = 0.45, P = .01), branched amino acid-to-tyrosine ratio (R = 0.39, P = .02), and triglyceride (R = 0.33, P = .03) in group N.Sarcopenia risk factors differ among cirrhosis etiologies. Alcohol-induced, intestine-mediated peripheral endotoxemia could participate in sarcopenia development in patients with alcoholic cirrhosis.

Post-surgery cholecystectomy, hepatectomy, and pancreatectomy patients increase the risk of osteoporotic vertebral fracture

INTRODUCTION

Data is currently lacking regarding association between the cholecystectomy/hepatectomy/pancreatectomy and the development of osteoporotic fracture. A retrospective cohort study was conducted to investigate the relationship between cholecystectomy/hepatectomy/pancreatectomy and the subsequent risk of developing osteoporotic fracture.

MATERIALS AND METHODS

Patients having undergone cholecystectomy, hepatectomy, or pancreatectomy between 2000 and 2012 were selected from the All Population Based Hospitalization File as the surgery cohort (n = 304,081), which was frequency matched with the control cohort (n = 304,081). The Cox proportional hazard model and Kaplan-Meier analysis were applied to measure the hazard ratios and the cumulative incidence of osteoporotic fracture.

RESULTS

A total of 1136 patients in the surgery cohort and 1179 patients in the control cohort were newly diagnosed with osteoporotic fracture. The overall osteoporotic fracture risk in the surgery cohort was 1.12-fold higher [95% confidence interval (CI), 1.03-1.21]. Specifically, surgery cohort had higher vertebral fracture risk than non-surgery cohort [adjusted hazard ratio (aHR) 1.12, Cl, 1.03-1.22]. In addition, patients underwent cholecystectomy (includes open and laparoscopic approaches), hepatectomy (only open approach), and pancreatectomy group (only open approach) were 1.10 (95% CI, 1.01-1.19), 1.49 (95% CI, 1.10-2.01), and 1.88 (95% CI, 1.23-2.87) times more likely to develop osteoporotic fracture, respectively. No significant difference of osteoporotic fracture risk was observed between open and laparoscopic cholecystectomy. The risk of osteoporotic fracture was significantly increased in females, patients aged ≥ 40 years old, and patients with some comorbidity.

CONCLUSIONS

Patients post cholecystectomy, hepatectomy, or pancreatectomy significantly increased risk of developing osteoporotic fracture, suggesting closer attention in post-operative care is needed.

Nutrition in Chronic Liver Disease: Consensus Statement of the Indian National Association for Study of the Liver

Malnutrition and sarcopenia are common in patients with chronic liver disease and are associated with increased risk of decompensation, infections, wait-list mortality and poorer outcomes after liver transplantation. Assessment of nutritional status and management of malnutrition are therefore essential to improve outcomes in patients with chronic liver disease. This consensus statement of the Indian National Association for Study of the Liver provides a comprehensive review of nutrition in chronic liver disease and gives recommendations for nutritional screening and treatment in specific clinical scenarios of malnutrition in cirrhosis in adults as well as children with chronic liver disease and metabolic disorders.

Low Serum Branched-Chain Amino Acid and Insulin-Like Growth Factor-1 Levels Are Associated with Sarcopenia and Slow Gait Speed in Patients with Liver Cirrhosis

Branched-chain amino acid (BCAA) and insulin-like growth factor 1 (IGF-1) are essential for muscle protein synthesis. We investigated the association of serum BCAA and IGF-1 levels with sarcopenia and gait speed in 192 patients with liver cirrhosis (LC). Sarcopenia was diagnosed according to the Japan Society of Hepatology criteria. Slow gait speed was defined as <1.0 m/s. Subjects were divided into three groups based on baseline BCAA or IGF-1 levels: low (L), intermediate (I), and high (H) groups. The L-BCAA group had the highest prevalence of sarcopenia (60.4%, p < 0.001) and slow gait speed (56.3%, p = 0.008), whereas the H-BCAA group had the lowest prevalence of sarcopenia (8.5%, p < 0.001). The L-IGF-1 group showed the highest prevalence of sarcopenia (46.9%, p < 0.001), whereas the H-IGF-1 group had the lowest prevalence of sarcopenia (10.0%, p < 0.001) and slow gait speed (18.0%, p = 0.003). Using the optimal BCAA and IGF-1 cutoff values for predicting sarcopenia (372 μmol/L and 48.5 ng/mL, respectively), the sensitivity and specificity were 0.709 and 0.759 for BCAA and 0.636 and 0.715 for IGF-1, respectively. Low serum BCAA and IGF-1 levels were associated with sarcopenia and slow gait speed in patients with LC.

Prognostic Significance of Serum Insulin-Like Growth Factor-1 in Hepatocellular Cancer Patients: A Validation Study

BACKGROUND

The Child-Turcotte-Pugh score (CTP) is the most commonly used tool to assess hepatic reserve and predict survival in hepatocellular cancer (HCC). The CTP stratification accuracy has been questioned and attempts have been made to improve the objectivity of the system. Serum insulin-like growth factor-1 (IGF-1)-CTP has been proposed to improve CTP prognostic accuracy. We aimed to validate the IGF-CTP score in our patient population.

PATIENTS AND METHODS

A total of 84 diagnosed HCC patients were enrolled prospectively. IGF-CTP scores in addition to CTP scores were calculated. C-index was used to compare the prognostic significance of the two scoring systems and overall survival (OS).

RESULTS

Cirrhosis was present in 48 (57.1%) patients, 35 (41.7%) patients were non-cirrhotic, 36 (42.8%) patients were hepatitis B (HBV) positive, and 8 (9.5%) patients were hepatitis C (HCV) positive. Serum IGF-1 levels were significantly lower in cirrhotic compared with non-cirrhotic patients (p=0.04). There was a significant difference in OS rates of patients with serum IGF-1 level <50 ng/mL and patients with serum IGF-1 levels ≥50 ng/mL (p=0.02); the OS rates were 6.5 and 14.8 months, respectively (p=0.02). The median OS of all patients was 7.38 months (95% CI: 5.89-13.79). The estimated C-index for CTP and IGF-CTP scores was 0.605 (95% CI: 0.538, 0.672) and 0.599 (95% CI: 0.543, 0.655), respectively. The U statistics indicated that the C-indices between two scoring systems are not statistically different (P= 0.91).

CONCLUSION

This study evaluated IGF-1 levels and the IGF-CTP classification in a predominantly HBV (+) cohort of HCC patients with 41.7% non-cirrhotic. Although the prognostic value was similar, among patients with CTP-A, class those reclassified as IGF-CTP B had shorter OS than those with IGF-CTP score A. Thus, further validations of IGF-CTP score in similar populations may add additional value as a stratification tool to predict HCC outcome.

Predictive value of insulin-like growth factor 1-Child-Turcotte-Pugh score for mortality in patients with decompensated cirrhosis

BACKGROUND

Previous studies have used a modified version of the Child-Turcotte-Pugh (CTP) score to include insulin-like growth factor 1 (IGF-1) concentrations, denoted the Insulin-like Growth Factor 1-Child-Turcotte-Pugh (IGF-CTP) system. We evaluated the predictive power of IGF-CTP for 1-year mortality in patients with decompensated cirrhosis (DC).

METHODS

A total of 386 patients with DC were retrospectively analyzed. Comparison of distribution of patients with decompensated cirrhosis according to Insulin-like Growth Factor-1-Child-Turcotte-Pugh and Child-Turcotte-Pugh scores were performed. Area under the receiver operating characteristic curves (AUROCs) for IGF-CTP, CTP and the Model for End-stage Liver Disease (MELD) scores were evaluated to compare predictive value. Univariate and multivariate analyses were carried out to determine potential risk factors for 1-y mortality.

RESULTS

During the 1-y follow-up, 94 patients died. Significantly more patients (both surviving and non-surviving) were classified as IGF-CTP stage C than CTP stage C. The AUROC of IGF-CTP was significantly higher than that of CTP and MELD in the training and validation cohorts. Multivariate analysis indicated IGF-CTP score and IGF-1 to be independently associated with mortality.

CONCLUSION

The IGF-CTP score is independently associated with mortality for patients with DC, and offers more accurate prediction of 1-y mortality than either CTP or MELD score for these patients.

Sarcopenia in nonalcoholic fatty liver disease: new challenges for clinical practice

Introduction: Sarcopenia is increasingly recognized in patients with nonalcoholic liver disease (NAFLD). Initially recognized as a consequence of advanced liver disease, there is now emerging evidence that sarcopenia may be a novel risk factor for the development of NAFLD, with a role in fibrosis and disease progression.Areas covered: This review examines the epidemiology, pathogenesis, and complex interplay between NAFLD and sarcopenia. Furthermore, the authors discuss the challenges with diagnosis of sarcopenia in the clinic and the evidence-based management of sarcopenia in patients with NAFLD. A MEDLINE and PubMed search was undertaken using the terms; 'sarcopenia,' 'frailty,' 'muscle,' 'obesity,' 'non-alcoholic fatty liver disease,' 'non-alcoholic steatohepatitis', and 'cirrhosis' up to 31 September 2019.Expert opinion: Sarcopenia may be masked by the co-existence of morbid obesity, which is most notable in patients with NAFLD. Sarcopenia is a key indicator of adverse outcomes in patients with cirrhosis, such as hepatic decompensation, poor quality of life and premature mortality. Patients with NAFLD and advanced fibrosis/cirrhosis should undergo anthropometric measures (handgrip strength), dry body mass index, and measures of physical frailty (including muscle function, not just mass) to enable targeted early interventions of nutrition (low fat, 1.5 g/kg/day protein intake, 2-3 hourly food intake) and exercise (combined resistance and aerobic).

Preoperative Serum Insulin-Like Growth Factor 1 Level as a Prognostic Factor in Patients Undergoing Hepatic Resection for Hepatocellular Carcinoma

In this study, preoperative serum levels of insulin-like growth factor 1 (IGF-1) were determined in 216 hepatocellular carcinoma (HCC) patients who underwent hepatic resection to investigate a possible contribution of IGF-1 to the increased risk for HCC recurrence and mortality. During January 2010 and December 2013, 216 HCC patients receiving hepatectomy were recruited. The primary endpoint was the HCC recurrences within the 3-year follow-up. The secondary endpoint was all-cause mortality. The multivariate analyses with Cox regression model were applied to explore the clinical significance of IGF-1 serum levels and associated parameters on death and recurrence of HCC patients. The IGF-1 levels of included patients were determined, with a median value of 75.5 ng/mL (IQR, 40.3-93.0 ng/mL). The preoperative serum level of IGF-1 was negatively correlated with tumor size, Child-Pugh class, or tumor stage (P < 0.001 for all). In multivariate models comparing the first, second, and third quartiles with the fourth quartile of IGF-1, the levels of IGF-1 in Q1 and Q2 were associated with HCC recurrence, with an increased risk of 216% [hazard ratios (HR) = 3.16 (95% CI: 1.79-4.28)] and 106% [3.02 (1.36-3.11)]. Similarly, concentrations of IGF-1 in Q1 and Q2 were also related to all-cause mortality, with an increased recurrence risk of 238% [HR = 3.38 (95% CI: 1.85-4.36)] and 117% [3.02 (1.40-3.21)], respectively. Poor prognosis in HCC patients receiving hepatectomy could be indicated by low preoperative serum levels of IGF-1, which would be applied as a predictor.

Validation of insulin-like growth factor-1 as a prognostic parameter in patients with hepatocellular carcinoma in a European cohort

Background

In hepatocellular carcinoma (HCC), the third leading cause of cancer-related mortality worldwide, the Child-Turcotte-Pugh score (CTP) is one of the most established tools to assess hepatic reserve and determine survival. Serum levels of insulin-like growth factor-1 (IGF-1) are decreased in patients with chronic liver disease or HCC. A modified score combining circulating IGF-1 with the CTP score (IGF-CTP) was recently proposed.

Methods

IGF-CTP scoring was evaluated in 216 patients diagnosed with HCC between 2007 and 2017 to assess the predictive value of serum IGF-1 levels for patient risk stratification and overall survival (OS).

Results

Liver cirrhosis was identified in 80.1% of the study cohort, and alcohol-induced liver disease was the most frequent underlying cause of HCC (44.4%). Serum IGF-1 levels were significantly lower in patients with HCC in cirrhosis compared with non-cirrhotic HCC (p < 0.01). A lower serum level of IGF-1 was associated with more advanced stages of liver cirrhosis (p < 0.05) and cancer stages (p < 0.001). Median OS in the cohort was 11.4 months (range 0.5–118.2 months). OS was significantly higher (10.9 vs. 7.9 months; p < 0.05) in patients with a serum IGF-1 level above the median of 43.4 ng/mL. Patient reassignment using IGF-CTP scoring reclassified 35.6% of patients. Through reassignment, stratification regarding OS was comparable to CTP.

Conclusions

This study is the first to investigate IGF-1 and the IGF-CTP classification in a European cohort of HCC patients. Serum IGF-1 correlates with OS in patients with HCC. However, the IGF-CTP classification was not superior compared to CTP score regarding OS.

Loss of skeletal muscle mass in patients with chronic liver disease is related to decrease in bone mineral density and exercise tolerance

AIM

This study aimed to identify the relationship between loss of skeletal muscle mass and clinical factors such as osteoporosis in patients with chronic liver disease.

METHODS

The subjects were 112 patients (85 men and 27 women) with hepatocellular carcinoma who were scheduled to undergo hepatectomy. Skeletal muscle reduction was diagnosed according to the cut-off level of the skeletal mass index (SMI) for Asians (men <7.0 kg/m² , women <5.4 kg/m² ). Osteoporosis was diagnosed according to T-score ≤-2.5 standard deviation. The SMI and T-score were assessed using the results of dual-energy X-ray absorption. Peak oxygen consumption (PeakVO₂ ), an index of exercise tolerance, was evaluated using the cardiopulmonary exercise test. The characteristics of patients with low SMI (low SMI group) were compared with those of patients whose SMI was not low (control group). Outcomes are presented as median (interquartile range).

RESULTS

The T-score was significantly lower in the low SMI group (control vs. low SMI -1.1 [1.8] vs. -1.6 [1.9], P = 0.049). T-score positively correlated with SMI (r = 0.409, P < 0.0001). PeakVO₂ was significantly decreased in the low SMI group (17.7 [6.3] vs. 14.4 [4.5], P = 0.006). In multivariate logistic regression analysis, T-score (odds ratio [OR], 3.508; 95% confidence interval [CI], 1.074-11.456; P = 0.038) and PeakVO₂ (OR, 3.512; 95% CI, 1.114-11.066; P = 0.032) were significantly related to SMI, independent of age and sex.

CONCLUSIONS

Skeletal muscle reduction in chronic liver disease is closely related to exercise tolerance and osteoporosis, and these factors are believed to be associated with physical inactivity in daily life.

Sarcopenia in hiding: The risk and consequence of underestimating muscle dysfunction in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Up to one third of individuals with NAFLD will develop nonalcoholic steatohepatitis (NASH), which is associated with progression to cirrhosis and is rapidly becoming the leading indication for liver transplantation. Sarcopenia is defined as a progressive and generalized loss of skeletal muscle mass, strength, and function. It is observed in up to 60% of patients with end-stage liver disease and portends a poor prognosis. Recent studies have shown that sarcopenia is a novel risk factor for developing NAFLD. Pathophysiological mechanisms relating sarcopenia and NASH may include insulin resistance (IR) and increased inflammation. IR leads to accumulation of triglycerides in both muscle tissue and the liver. It also exacerbates proteolysis and leads to muscle depletion. Chronic inflammation leads to liver injury and progression of fibrosis. The inflammatory milieu also stimulates protein catabolism. Viewing skeletal muscle as an endocrine organ that secretes various salutary myokines may help us understand its role in the development of steatosis. A better understanding of the pathophysiology will aid in developing physical and pharmacological therapeutic interventions. In this review, we will explore the complex inter-relationships between sarcopenia and NASH. We will discuss the impact of sarcopenia in patients with NASH and therapeutic options for the management of sarcopenia. (Hepatology 2017;66:2055-2065).

The Long Winding Road to Transplant: How Sarcopenia and Debility Impact Morbidity and Mortality on the Waitlist

Frailty and sarcopenia are common complications of cirrhosis. Frailty has been described as an increased susceptibility to stressors secondary to a cumulative decline in physiologic reserve; this decline occurs with aging or is a result of the disease process, across multiple organ systems. Sarcopenia, a key component of frailty, is defined as progressive and generalized loss of skeletal muscle mass and strength. The presence of either of these complications is associated with increased morbidity and mortality, as these are tightly linked to decompensation and increased complication rates. Recognition of these entities is critical. Studies have shown improvement in muscle strength and function lead to reduced mortality, suggesting both frailty and sarcopenia are modifiable risk factors. In this review we outline the prevalence of frailty and sarcopenia in cirrhosis and the impact on clinical outcomes such as decompensation, hospitalization, and mortality. Existing and potential novel therapeutic approaches for frailty and sarcopenia are also reviewed.

Esculetin induces apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-mediated mitochondrial pathways

Esculetin (6,7-dihydroxycoumarin) is a coumarin derivative extracted from natural plants and has been reported to have anticancer activity. However, the mechanism by which esculetin prevents human hepatic cancer cell growth is still largely unknown. In this study, we investigated the effect of esculetin on human hepatocellular carcinoma (HCC) SMMC-7721 cells and explored the cell signal mechanism. Our data indicated that esculetin induced apoptosis in SMMC-7721 cells, which were supported by DAPI staining and Annexin V/PI staining. Meanwhile, esculetin increased the activities of caspase-3 and caspase-9, promoted bax expression, decreased bcl-2 expression, and triggered collapse of mitochondrial membrane potential, and increased cytochrome c release from mitochondria. In addition, the inactivation of IGF-1, PI3K, and Akt was observed after esculetin administration. Furthermore, pretreatment with IGF-1 before esculetin administration abrogated the pro-apoptotic effects of esculetin, while PI3K inhibitor increased the pro-apoptotic effects of esculetin. These results indicated that esculetin induced the apoptosis of SMMC-7721 cells through IGF-1/PI3K/Akt-regulated mitochondrial dysfunction.

Prognostic significance of insulin-like growth factor-I serum levels in acute decompensation of cirrhosis

CONTEXT

IGF-I serum levels are suppressed in cirrhosis, but its prognostic significance is unknown.

OBJECTIVES

To investigate the prognostic value of IGF-I in patients admitted for acute decompensation of cirrhosis.

MATERIALS AND METHODS

Cohort study that included 103 patients. IGF-I was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Ninety-day mortality was 26.2% and it was independently associated with MELD, age and IGF-I. The Kaplan-Meier survival probability at 90 days was 94.3% in patients with IGF-I ≥13 ng/mL and 63.2% for patients with IGF-I <13 ng/mL (p = .001).

DISCUSSION AND CONCLUSION

IGF-I levels are independently associated with mortality in acute decompensation of cirrhosis.

The Association Between IGF-1 Levels and the Histologic Severity of Nonalcoholic Fatty Liver Disease

Objectives:

The mechanisms responsible for the development of nonalcoholic fatty liver disease (NAFLD) and progression to nonalcoholic steatohepatitis (NASH) are incompletely understood. Growing evidence suggests that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) may have roles in the development and progression of NAFLD. We hypothesized that lower serum IGF-1 levels would be associated with increased liver fat accumulation, inflammation, and fibrosis in a group of meticulously phenotyped obese subjects with liver biopsies.

Methods:

A retrospective, cross-sectional study was performed at Massachusetts General Hospital, Boston, MA, USA and St. Mary's Hospital, Richmond, VA, USA. Liver biopsies were performed in 142 subjects during NAFLD work-up or bariatric surgery and were graded by a single, blinded pathologist. Main outcome measures included liver histology and serum IGF-1.

Results:

Mean age was 52±10 years and body mass index (BMI) was 43±9 kg/m². Mean serum IGF-1 was lower in subjects with lobular inflammation (112±47 vs. 136±57 ng/ml, P=0.01), hepatocyte ballooning (115±48 vs. 135±57 ng/ml, P=0.05), higher fibrosis stage (stage 2–4 vs. 0–1; 96±40 vs. 125±51 ng/ml, P=0.005), and NASH (109±45 vs. 136±57 ng/ml, P=0.002). All results remained significant after controlling for age, BMI, and a diagnosis of diabetes, and all but hepatocyte ballooning (trend, P=0.06) remained significant after excluding individuals with cirrhosis. Steatosis was not significantly associated with mean serum IGF-1 levels.

Conclusions:

Low serum IGF-1 levels are associated with increased histologic severity of NAFLD when rigorously controlled for age, BMI, the presence of diabetes, and after the exclusion of subjects with cirrhosis. Further investigation is warranted to determine the differential effects of GH and IGF-1 on the development and progression of NAFLD, which could further elucidate pathophysiology and identify therapeutic targets.

Validation of a Modified Child-Turcotte-Pugh Classification System Utilizing Insulin-Like Growth Factor-1 for Patients with Hepatocellular Carcinoma in an HBV Endemic Area

BACKGROUND

Recently, a modified insulin-like growth factor-1 (IGF)-Child-Turcotte-Pugh (CTP) classification was proposed to improve the original CTP classification. This study aimed to validate the new IGF-CTP classification system as a prognostic maker for patients with hepatocellular carcinoma (HCC) in a hepatitis B virus endemic area.

METHODS

We conducted a post-hoc analysis of a prospective cohort study. We used Harrell's C-index and U-statistics to compare the prognostic performance of both IGF-CTP and CTP classifications for overall survival. We evaluated the relationship between HCC stage and the four components of the IGF-CTP classification (serum levels of IGF-1, albumin, and total bilirubin and prothrombin time [PT]) using nonparametric trend analysis.

RESULTS

We included a total of 393 patients in this study. In all, 55 patients died during the median follow-up of 59.1 months. There was a difference between IGF-CTP class and CTP class in 14% of patients. Overall, the IGF-CTP classification system had a higher prognostic value (C-index = 0.604, 95% confidence interval [CI] = 0.539-0.668) than the CTP system (C-index = 0.558, 95% CI = 0.501-0.614), but the difference was not statistically significant (P = .07 by U-statistics). A lower serum level of IGF-1 was related to a more advanced cancer stage (P < .01). The remaining components of the IGF-CTP classification were not significantly related to tumor stage (P = .11 for total bilirubin; P = .33 for albumin; and P = .39 for PT).

CONCLUSIONS

The IGF-CTP classification was slightly better than the original CTP classification for predicting survival of patients with HCC in a chronic hepatitis B endemic area. This is most likely due to the fact that serum IGF-1 levels reflect underlying HCC status.

Integrated analysis of noncoding RNAs and mRNAs reveals their potential roles in the biological activities of the growth hormone receptor

Accumulating evidence has indicated that noncoding RNAs (ncRNAs) have important regulatory potential in various biological processes. The molecular mechanisms by which growth hormone receptor (GHR) deficiency protects against age-related pathologies, reduces the incidence and delays the occurrence of fatal neoplasms are unclear. The aim of this study was to investigate miRNA, lncRNA and mRNA expression profiles and the potential functional roles of these RNA molecules in GHR knockout (GHR-KO) mice. Microarray expression profiles of miRNAs, lncRNAs and mRNAs were determined in wild type control mice and in GHR-KO mice. Differential expression, pathway and gene network analyses were developed to identify the possible biological roles of functional RNA molecules. Compared to wild type control mice, 1695 lncRNAs, 914 mRNAs and 9 miRNAs were upregulated and 1747 lncRNAs, 786 mRNAs and 21 miRNAs were downregulated in female GHR-KO mice. Moreover, 1265 lncRNAs, 724 mRNAs and 41 miRNAs were upregulated and 1377 lncRNAs, 765 mRNAs and 16 miRNAs were downregulated in male GHR-KO mice compared to wild type mice. Co-expression analysis of mRNAs, lncRNAs, and miRNAs showed that mRNAs including Hemxi2, Ero1Ib, 4933434i20RIK, Pde7a and Lgals1, lncRNAs including ASMM9PARTA014848, EL605414-P1, ASMM9PARTA051724, ASMM9PARTA045378 and ASMM9PARTA049185, and miRNAs including miR-188-3p, miR-690, miR-709 and miR-710 are situated at the core position of a three-dimensional lncRNA-mRNA-miRNA regulatory network. KEGG analysis showed that the most significantly regulated pathway was steroid hormone biosynthesis. We identified a set of lncRNAs, miRNAs and mRNAs that were aberrantly expressed in GHR-KO mice. Our results provide a foundation and an expansive view of the biological activities of the GHR.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1(th) and the 5(th) day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Review article: sarcopenia in cirrhosis--aetiology, implications and potential therapeutic interventions

BACKGROUND

Sarcopenia (loss of muscle mass) is common in cirrhosis and is associated with poor outcomes. Current teaching recommends the use of protein supplementation and exercise, however, this fails to address many other factors which contribute to muscle loss in this setting.

AIMS

To summarise existing knowledge regarding the aetiology of sarcopenia in cirrhosis, diagnostic modalities and the clinical significance of this condition. In addition to discuss recent research findings that may allow the development of more effective treatments.

METHODS

We conducted a Medline and PubMed search using the search terms 'sarcopenia', 'muscle', 'body composition', 'cirrhosis', 'liver' and 'malnutrition' from inception to October 2015.

RESULTS

Cirrhotic patients with sarcopenia have reduced survival, experience increased rates of infection and have worse outcomes following liver transplantation. The aetiology of this condition is more complex than simple protein and calorie malnutrition. Cirrhosis also results in depleted glycogen stores and metabolic alterations that cause excessive protein catabolism, increased activation of the ubiquitin-proteasome pathway and inappropriate muscle autophagy. Satellite cell differentiation and proliferation is also reduced due to a combination of elevated myostatin levels, reduced IGF-1 and hypogonadism. Although there is some evidence supporting the use of late evening snacks, branched chain amino acid supplementation and high protein/high calorie diets, well designed clinical trials addressing the effects of treatment on body composition in cirrhosis are lacking.

CONCLUSION

Sarcopenia in cirrhosis has a complex pathogenesis and simple dietary interventions are insufficient. Improved understanding of the multiple mechanisms involved should allow the development of more effective therapies, which target the specific underlying metabolic derangements.

Type I insulin-like growth factor as a liver reserve assessment tool in hepatocellular carcinoma

Chronic liver diseases (CLDs) encompass a wide range of illnesses, including nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, and viral hepatitis. Deterioration of liver capacity, with subsequent progression into cirrhosis and hepatocellular carcinoma (HCC), ultimately leads to a further decrease in the hepatic reserve. The Child-Turcotte-Pugh scoring system is the standard tool for assessing underlying liver reserve capacity in routine practice and in clinical trials of CLD and HCC. In this review, we highlight the clinical significance of insulin-like growth factor-I (IGF-I) and the growth hormone (GH) signaling pathway in HCC. IGF-I could be a marker for liver reserve capacity in CLDs and HCC in clinical practice. This approach could improve the risk assessment and stratifications of patients on the basis of their underlying liver reserve, either before active treatment in routine practice or before they are enrolled in clinical trials.

Postoperative Insulin-Like Growth Factor 1 Levels Reflect the Graft's Function and Predict Survival after Liver Transplantation

BACKGROUND

The reduction of insulin-like growth factor 1 (IGF-1) plasma levels is associated with the degree of liver dysfunction and mortality in cirrhotic patients. However, little research is available on the recovery of the IGF-1 level and its prognostic role after liver transplantation (LT).

METHODS

From April 2010 to May 2011, 31 patients were prospectively enrolled (25/6 M/F; mean age±SEM: 55.2±1.4 years), and IGF-1 serum levels were assessed preoperatively and at 15, 30, 90, 180 and 365 days after transplantation. The influence of the donor and recipient characteristics (age, use of extended criteria donor grafts, D-MELD and incidence of early allograft dysfunction) on hormonal concentration was analyzed. The prognostic role of IGF-1 level on patient survival and its correlation with routine liver function tests were also investigated.

RESULTS

All patients showed low preoperative IGF-1 levels (mean±SEM: 29.5±2.1), and on postoperative day 15, a significant increase in the IGF-1 plasma level was observed (102.7±11.7 ng/ml; p<0.0001). During the first year after LT, the IGF-1 concentration remained significantly lower in recipients transplanted with older donors (>65 years) or extended criteria donor grafts. An inverse correlation between IGF-1 and bilirubin serum levels at day 15 (r = -0.3924, p = 0.0320) and 30 (r = -0.3894, p = 0.0368) was found. After multivariate analysis, early (within 15 days) IGF-1 normalization [Exp(b) = 3.913; p = 0.0484] was the only prognostic factor associated with an increased 3-year survival rate.

CONCLUSION

IGF-1 postoperative levels are correlated with the graft's quality and reflect liver function. Early IGF-1 recovery is associated with a higher 3-year survival rate after LT.

IGF-1 decreases portal vein endotoxin via regulating intestinal tight junctions and plays a role in attenuating portal hypertension of cirrhotic rats

Background

Intestinal barrier dysfunction is not only the consequence of liver cirrhosis, but also an active participant in the development of liver cirrhosis. Previous studies showed that external administration of insulin-like growth factor 1 (IGF-1) improved intestinal barrier function in liver cirrhosis. However, the mechanism of IGF-1 on intestinal barrier in liver cirrhosis is not fully elucidated. The present study aims to investigate the mechanisms of IGF-1 improving intestinal barrier function via regulating tight junctions in intestines.

Methods

We used carbon tetrachloride induced liver cirrhotic rats to investigate the effect of IGF-1 on intestinal claudin-1 and occludin expressions, serum alanine transaminase (ALT) and aspartate transaminase (AST) levels, severity of liver fibrosis, portal pressures, enterocytic apoptosis and lipopolysaccharides (LPS) levels in portal vein. The changes of IGF-1 in serum during the development of rat liver cirrhosis were also evaluated. Additionally, we assessed the effect of IGF-1 on claudin-1 and occludin expressions, changes of transepithelial electrical resistance (TEER) and apoptosis in Caco-2 cells to confirm in vivo findings.

Results

Serum IGF-1 levels were decreased in the development of rat liver cirrhosis, and external administration of IGF-1 restored serum IGF-1 levels. External administration of IGF-1 reduced serum ALT and AST levels, severity of liver fibrosis, LPS levels in portal vein, enterocytic apoptosis and portal pressure in cirrhotic rats. External administration of IGF-1 increased the expressions of claudin-1 and occludin in enterocytes, and attenuated tight junction dysfunction in intestines of cirrhotic rats. LPS decreased TEER in Caco-2 cell monolayer. LPS also decreased claudin-1 and occludin expressions and increased apoptosis in Caco-2 cells. Furthermore, IGF-1 attenuated the effect of LPS on TEER, claudin-1 expression, occludin expression and apoptosis in Caco-2 cells.

Conclusions

Tight junction dysfunction develops during the development of liver cirrhosis, and endotoxemia will develop subsequently. Correspondingly, increased endotoxin in portal system worsens tight junction dysfunction via decreasing intestinal occludin and claudin-1 expressions and increasing enterocytic apoptosis. Endotoxemia and intestinal barrier dysfunction form a vicious circle. External administration of IGF-1 breaks this vicious circle. Improvement of tight junctions might be one possible mechanism of the restoration of intestinal barrier function mediated by IGF-1.

The GH-IGF-SST system in hepatocellular carcinoma: biological and molecular pathogenetic mechanisms and therapeutic targets

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide. Different signalling pathways have been identified to be implicated in the pathogenesis of HCC; among these, GH, IGF and somatostatin (SST) pathways have emerged as some of the major pathways implicated in the development of HCC. Physiologically, GH-IGF-SST system plays a crucial role in liver growth and development since GH induces IGF1 and IGF2 secretion and the expression of their receptors, involved in hepatocytes cell proliferation, differentiation and metabolism. On the other hand, somatostatin receptors (SSTRs) are exclusively present on the biliary tract. Importantly, the GH-IGF-SST system components have been indicated as regulators of hepatocarcinogenesis. Reduction of GH binding affinity to GH receptor, decreased serum IGF1 and increased serum IGF2 production, overexpression of IGF1 receptor, loss of function of IGF2 receptor and appearance of SSTRs are frequently observed in human HCC. In particular, recently, many studies have evaluated the correlation between increased levels of IGF1 receptors and liver diseases and the oncogenic role of IGF2 and its involvement in angiogenesis, migration and, consequently, in tumour progression. SST directly or indirectly influences tumour growth and development through the inhibition of cell proliferation and secretion and induction of apoptosis, even though SST role in hepatocarcinogenesis is still opened to argument. This review addresses the present evidences suggesting a role of the GH-IGF-SST system in the development and progression of HCC, and describes the therapeutic perspectives, based on the targeting of GH-IGF-SST system, which have been hypothesised and experimented in HCC.

Expression levels of insulin-like growth factors and receptors in hepatocellular carcinoma: a retrospective study

Background

The insulin-like growth factor (IGF) pathway is implicated in the pathogenesis of hepatocellular carcinoma (HCC) and may be important in nonalcoholic fatty liver disease (NAFLD). The aim of this study is to determine expression levels of IGFs and receptors in NAFLD-associated HCC.

Methods

Tissue microarrays were constructed from patients who underwent hepatectomy for HCC. Immunohistochemistry was performed using antibodies for IGF ligands and receptors. Immunostain results were scored by a pathologist blinded to clinical data.

Results

Among 27 patients with HCC, the most common underlying liver diseases included NAFLD, hepatitis C, and alcoholic hepatitis. Expression levels of IGFs and receptors were not associated with patients’ underlying liver disease. In all patients, IGF-2 expression was upregulated in tumor and adjacent non-neoplastic liver. Expression of IGF-1 was low in adjacent liver in 6 of 10 patients with cirrhosis, compared with 2 of 17 patients without cirrhosis (P = 0.025). Higher IGF-1 expression in liver adjacent to tumor was associated with poorer median survival of 22 months, compared with 72 months with equal or lower IGF-1 expression in adjacent liver relative to tumor (P = 0.006).

Conclusions

Our preliminary results demonstrate significant associations between IGF-1 expression and liver cirrhosis and survival after resection in patients with HCC, independent of their underlying liver disease.

Development and validation of insulin-like growth factor-1 score to assess hepatic reserve in hepatocellular carcinoma

Background

Child-Turcotte-Pugh (CTP) score is the standard tool to assess hepatic reserve in hepatocellular carcinoma (HCC), and CTP-A is the classic group for active therapy. However, CTP stratification accuracy has been questioned. We hypothesized that plasma insulin-like growth factor 1 (IGF-1) is a valid surrogate for hepatic reserve to replace the subjective parameters in CTP score to improve its prognostic accuracy.

Methods

We retrospectively tested plasma IGF-1 levels in the training set (n = 310) from MD Anderson Cancer Center. Recursive partitioning identified three optimal IGF-1 ranges that correlated with overall survival (OS): greater than 50ng/mL = 1 point; 26 to 50ng/mL = 2 points; and less than 26ng/mL = 3 points. We modified the CTP score by replacing ascites and encephalopathy grading with plasma IGF-1 value (IGF-CTP) and subjected both scores to log-rank analysis. Harrell’s C-index and U-statistics were used to compare the prognostic performance of both scores in both the training and validation cohorts (n = 155). All statistical tests were two-sided.

Results

Patients’ stratification was statistically significantly stronger for IGF-CTP than CTP score for the training (P = .003) and the validation cohort (P = .005). Patients reclassified by IGF-CTP relative to their original CTP score were better stratified by their new risk groups. Most important, patients classified as A by CTP but B by IGF-CTP had statistically significantly worse OS than those who remained under class A by IGF-CTP in both cohorts (P = .03 and P < .001, respectively, from Cox regression models). AB patients had a worse OS than AA patients in both the training and validation set (hazard ratio [HR] = 1.45, 95% confidence interval [CI] = 1.03 to 2.04, P = .03; HR = 2.83, 95% CI = 1.65 to 4.85, P < .001, respectively).

Conclusions

The IGF-CTP score is simple, blood-based, and cost-effective, stratified HCC better than CTP score, and validated well on two independent cohorts. International validation studies are warranted.

Serum insulin-like growth factor-1 predicts disease progression and survival in patients with hepatocellular carcinoma who undergo transarterial chemoembolization

Insulin like-growth factor-1 (IGF-1) reflects hepatic synthetic function and plays a major role in the development and progression of various cancers. In the present study, we investigated whether baseline serum IGF-1 levels predict time-to-progression (TTP) and overall survival (OS) in hepatocellular carcinoma (HCC) patients treated with transarterial chemoembolization (TACE). A total of 155 consecutive treatment-naive patients with HCC who had undergone TACE as initial treatment were included from a prospective cohort. Baseline serum IGF-1 levels were analyzed with regard to their associations with disease progression and survival. During a median follow-up period of 41.8 months, patients with low IGF-1 levels showed significantly shorter TTP (median, 6.0 months; 95% confidence interval [CI], 4.5-7.6) than patients with high IGF-1 levels (median, 16.5 months; 95% CI, 4.9-28.1; p = 0.003). In the multivariate analysis, BCLC stage, serum vascular endothelial growth factorlevels, and IGF-1 levels were independent risk factors for disease progression. The hazard ratio (HR) of progression for each 10 ng/mL decrease in IGF-1 level was 1.072 (95% CI, 1.029-1.117; p = 0.001). Furthermore, together with tumor size, stage, and treatment response, IGF-1 levels were an independent predictor of poorer survival (for each 10 ng/mL decrease in IGF-1 level; HR, 1.057; 95% CI, 1.001-1.115; p = 0.045). In conclusion, low baseline IGF-1 levels independently correlated with shorter TTP and poorer OS in patients with HCC who underwent TACE.

Prediagnostic plasma testosterone, sex hormone-binding globulin, IGF-I and hepatocellular carcinoma: etiological factors or risk markers?

Elevated prediagnostic testosterone and insulin-like growth factor I (IGF-I) concentrations have been proposed to increase risk of hepatocellular carcinoma (HCC). However, the metabolism of these hormones is altered as a consequence of liver damage and they may have clinical utility as HCC risk markers. A case-control study was nested within the European Prospective Investigation into Cancer and Nutrition cohort and included 125 incident HCC cases and 247 individually matched controls. Testosterone, sex hormone-binding globulin (SHBG) and IGF-I were analyzed by immunoassays. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by conditional logistic regression. The area under the receiver operating curves (AUC) was calculated to assess HCC predictive ability of the tested models. After adjustments for epidemiological variables (body mass index, smoking, ethanol intake, hepatitis and diabetes) and liver damage (a score based on albumin, bilirubin, aspartate aminotransaminase, alanine aminotransaminase, gamma-glutamyltransferase and alkaline phosphatase concentrations), only SHBG remained significantly associated with risk [OR for top versus bottom tertile of 3.86 (1.32-11.3), p(trend) = 0.009]. As a single factor SHBG had an AUC of 0.81 (0.75-0.86). A small, but significant increase in AUC was observed when SHBG was added to a model including the liver damage score and epidemiological variables (from 0.89 to 0.91, p = 0.02) and a net reclassification of 0.47% (0.45-0.48). The observed associations of HCC with prediagnostic SHBG, free testosterone and IGF-I concentrations are in directions opposite to that expected under the etiological hypotheses. SHBG has a potential to be tested as prediagnostic risk marker for HCC.

Defective thymopoiesis and poor peripheral homeostatic replenishment of T-helper cells cause T-cell lymphopenia in cirrhosis

BACKGROUND & AIMS

Depletion of circulating CD4(+) T-helper (Th) lymphocytes, especially naive Th cells, is common in cirrhosis. Little is known about the pathogenetic mechanisms involved in Th-cell depletion in cirrhosis. We investigated the mechanisms involved in circulating Th-cell lymphopenia in cirrhosis.

METHODS

Circulating naive and memory Th cells were analyzed by flow cytometry in 60 patients with cirrhosis and 40 sex- and age-matched healthy controls. Thymopoiesis, apoptosis, cell activation, and proliferation were assessed through CD31, annexin-V, HLA-DR and Ki-67 expression, respectively. Lipopolysaccharide (LPS)-binding protein (LBP) and spleen size were measured as indicators of bacterial translocation and splenic pooling, respectively.

RESULTS

Compared to controls, patients showed reduced numbers of Th cells involving a greater depletion of the naive than memory Th-cell compartment (2.7- vs. 1.5-fold, respectively). Recent thymic emigrants were diminished (p < 0.01), and each patient had a lower number of CD31(+) naive Th cells than the matched-control. Spontaneous and induced apoptosis (Annexin-V(+)) of Th cells was increased in patients. Activated (HLA-DR(+)) and proliferating (Ki-67(+)) memory Th cells were increased in patients (p < 0.01), and they directly correlated with plasma LBP (p < 0.05) and negatively with naive Th cells (p < 0.01), respectively. Naive Th cells were inversely correlated (p < 0.01) with their frequencies of apoptosis and of activated memory Th cells, LBP, and spleen size. On multivariate analysis, defective thymic generation of naive Th cells, increased memory Th-cell activation, and splenomegaly were independently associated with Th-cell depletion.

CONCLUSIONS

Th-cell immunodeficiency in cirrhosis is explained by a universal defect in thymopoiesis exacerbated by splenic pooling and activation-driven cell-death induced by bacterial translocation.

Serum insulin-like growth factor-I level is an independent predictor of recurrence and survival in early hepatocellular carcinoma: a prospective cohort study

PURPOSE

Insulin-like growth factor-I (IGF-I) reflects hepatic synthetic function and plays an important role in the development and progression of various cancers. In this study, we investigated whether pretreatment serum IGF-I levels predict time-to-recurrence (TTR) and overall survival (OS) in patients with early-stage hepatocellular carcinoma after curative treatment.

EXPERIMENTAL DESIGN

Consecutive patients with hepatocellular carcinoma who had undergone surgical resection, radiofrequency ablation, or percutaneous ethanol injection as curative treatments of early hepatocellular carcinoma were included from two prospective cohorts and the training set (n = 101) and the validation set (n = 91) were established. Serum samples were collected before treatment and the levels of IGF-I and IGF-binding protein-3 (IGFBP-3) were analyzed with regard to their associations with recurrence and survival.

RESULTS

In the training set, patients with low IGF-I levels showed significantly shorter TTR [median, 14.6 months; 95% confidence interval (CI), 1.8-27.5] than patients with high IGF-I levels (median, 50.8 months; 95% CI, 36.9-64.7; P < 0.001) during a median follow-up period of 52.4 months. In the multivariate analysis, low levels of IGF-I were an independent predictor of recurrence (HR, 2.49; 95% CI, 1.52-4.08; P < 0.001). Furthermore, together with high-serum α-fetoprotein and multiple tumors, low levels of IGF-I remained an independent predictor of poorer survival (HR, 8.00; 95% CI, 1.94-33.01; P = 0.004). Applied to the independent validation set, low-serum IGF-I levels maintained their prognostic value for shorter TTR and OS.

CONCLUSIONS

Low-baseline IGF-I levels independently correlated with shorter TTR and poorer survival in patients with early-stage hepatocellular carcinoma after curative treatment.

Insulin-like growth factor 1 enhances bile-duct proliferation and fibrosis in Abcb4(-/-) mice

Adamant progression of chronic cholangiopathies towards cirrhosis and limited therapeutic options leave a liver transplantation the only effective treatment. Insulin-like growth factor 1 (IGF1) effectively blocks fibrosis in acute models of liver damage in mice, and a phase I clinical trial suggested an improved liver function. IGF1 targets the biliary epithelium, but its potential benefit in chronic cholangiopathies has not been studied. To investigate the possible therapeutic effect of increased IGF1 expression, we crossed Abcb4(-/-) mice (a model for chronic cholangiopathy), with transgenic animals that overexpress IGF1. The effect on disease progression was studied in the resulting IGF1-overexpressing Abcb4(-/-) mice, and compared to that of Abcb4(-/-) littermates. The specificity of this effect was further studied in an acute model of fibrosis. The overexpression of IGF1 in transgenic Abcb4(-/-) mice resulted in stimulation of fibrogenic processes - as shown by increased expression of Tgfß, and collagens 1, 3 and 4, and confirmed by Sirius red staining and hydroxyproline measurements. Excessive extracellular matrix deposition was favored by raise in Timp1 and Timp2, while a reduction of tPA expression indicated lower tissue remodeling. These effects were accompanied by an increase in expression of inflammation markers like Tnfα, and higher presence of infiltrating macrophages. Finally, increased number of Ck19-expressing cells indicated proliferation of biliary epithelium. In contrast to liver fibrosis associated with hepatocellular damage, IGF1 overexpression does not inhibit liver fibrogenesis in chronic cholangiopathy.

IGF-I and IGFBP-3 serum levels in patients hospitalized for complications of liver cirrhosis

BACKGROUND

IGF-I and IGFBP-3 are part of IGF system and, due to their predominantly hepatic synthesis, they seem to correlate with hepatic dysfunction intensity.

AIMS

To investigate the significance of IGF-I and IGFBP-3 in patients with decompensated liver disease.

MATERIAL AND METHODS

Cross-sectional study that included cirrhotic patients admitted to hospital due to complications of the disease, in whom IGF-I and IGFBP-3 serum levels were measured by chemiluminescence.

RESULTS

Seventy-four subjects with a mean age of 53.1 ± 11.6 years were included in the study, 73% were males. IGF-I levels were positively correlated with IGFBP-3 and albumin, and negatively correlated with Child-Pugh, MELD, creatinine, INR and aPTT ratio. IGFBP-3 levels were positively correlated with IGF-I and albumin, and negatively correlated with Child-Pugh, MELD, creatinine, INR, total bilirubin and aPTT ratio. Significantly lower scores of IGF-I and IGFBP-3 were observed in patients with higher MELD values and higher Child-Pugh classes (P < 0.05).

CONCLUSIONS

In cirrhotic patients admitted to hospital due to complications of the disease, IGF-I and IGFBP-3 serum levels were associated with variables related to liver dysfunction and to more advanced liver disease. The levels of these markers seem to undergo little influence from other clinical and laboratory variables, therefore mainly reflecting hepatic functional status.

The insulin like growth factor system in cirrhosis. Relation to changes in body composition following adrenoreceptor blockade

OBJECTIVE

Circulating levels of IGF-I and IGFBP-3 are low in cirrhosis and are related to liver dysfunction. Metabolic disturbances include malnutrition with altered body composition and osteopenia. Since the effects of IGF-I may be associated to changes in body composition and bone mineral content (BMC) in cirrhotic patients, we investigated the relations between changes in the IGF-system and body composition and the effects of long-term alpha- and beta-blockade.

DESIGN

The study was designed as a combined cross-sectional and prospective randomised controlled study of 62 patients with cirrhosis. Twenty-three of these patients were randomised to treatment with beta- or combined alpha/beta-blocker for 3 months. Haemodynamics, body composition, and systemic and hepatic IGF-I and IGFBP-3 levels were determined in all patients. In the subgroup changes in body composition and IGF-I/IGFBP-3 levels after 3 months of beta- or combined alpha/beta-blockade were additionally examined.

RESULTS

Both the hepatic and the systemic IGF systems were suppressed and correlated with liver dysfunction and anthropometrics (p<0.05-0.001). Multivariate analyses revealed that changes in the IGF-system were determined by metabolic liver dysfunction as well as anthropometrics. In the follow-up study, hepatic venous IGF-I (p=0.05) and IGFBP-3 (p=0.02) increased after 3 months only in the group who received beta-blocker. In both groups, fat body mass increased significantly after 3 months (p=0.05-0.001).

CONCLUSIONS

In cirrhosis, the IGF-system is associated with both anthropometrics and synthetic capacity of the liver. Changes in IGF-I relate to changes in anthropometrics and there seems to be a differential effect depending on the type of adrenoreceptor blockade. Future longitudinal studies are needed to unravel these mechanisms in cirrhosis.

Growth-hormone-induced signal transducer and activator of transcription 5 signaling causes gigantism, inflammation, and premature death but protects mice from aggressive liver cancer

Persistently high levels of growth hormone (GH) can cause liver cancer. GH activates multiple signal-transduction pathways, among them janus kinase (JAK) 2-signal transducer and activator of transcription (STAT) 5 (signal transducer and activator of transcription 5). Both hyperactivation and deletion of STAT5 in hepatocytes have been implicated in the development of hepatocellular carcinoma (HCC); nevertheless, the role of STAT5 in the development of HCC as a result of high GH levels remains enigmatic. Thus, we crossed a mouse model of gigantism and inflammatory liver cancer caused by hyperactivated GH signaling (GH(tg) ) to mice with hepatic deletion of STAT5 (STAT5(Δhep) ). Unlike GH(tg) mice, GH(tg) STAT5(Δhep) animals did not display gigantism. Moreover, the premature mortality, which was associated with chronic inflammation, as well as the pathologic alterations of hepatocytes observed in GH(tg) mice, were not observed in GH(tg) animals lacking STAT5. Strikingly, loss of hepatic STAT5 proteins led to enhanced HCC development in GH(tg) mice. Despite reduced chronic inflammation, GH(tg) STAT5(Δhep) mice displayed earlier and more advanced HCC than GH(tg) animals. This may be attributed to the combination of increased peripheral lipolysis, hepatic lipid synthesis, loss of hepatoprotective mediators accompanied by aberrant activation of tumor-promoting c-JUN and STAT3 signaling cascades, and accumulation of DNA damage secondary to loss of cell-cycle control. Thus, HCC was never observed in STAT5(Δhep) mice.

CONCLUSION

As a result of their hepatoprotective functions, STAT5 proteins prevent progressive fatty liver disease and the formation of aggressive HCC in the setting of hyperactivated GH signaling. At the same time, they play a key role in controlling systemic inflammation and regulating organ and body size.

Endocrine and bone metabolic complications in chronic liver disease and after liver transplantation in children

With improved survival of orthotopic liver transplantation (OLT) in children, prevention and treatment of pre- and posttransplant complications have become a major focus of care. End-stage liver failure can cause endocrine complications such as growth failure and hepatic osteodystrophy, and, like other chronic illnesses, also pubertal delay, relative adrenal insufficiency, and the sick euthyroid syndrome. Drug-induced diabetes mellitus post-OLT affects approximately 10% of children. Growth failure is found in 60% of children assessed for OLT. Despite optimisation of nutrition, rarely can further stunting of growth before OLT be prevented. Catch-up growth is usually observed after steroid weaning from 18 months post-OLT. Whether growth hormone treatment would benefit the 20% of children who fail to catch up in height requires testing in randomised controlled trials. Hepatic osteodystrophy in children comprises vitamin D deficiency rickets, low bone mass, and fractures caused by malnutrition and malabsorption. Vitamin D deficiency requires aggressive treatment with ergocalciferol (D2) or cholecalciferol (D3). The active vitamin D metabolites alphacalcidol or calcitriol increase gut calcium absorption but do not replace vitamin D stores. Prevalence of fractures is increased both before OLT (10%-28% of children) and after OLT (12%-38%). Most fractures are vertebral, are associated with low spine bone mineral density, and frequently occur asymptomatically, but they may also cause chronic pain. Fracture prediction in these children is limited. OLT in children is also associated with a greater risk of developing avascular bone necrosis (4%) and scoliosis (13%-38%). This article reviews the literature on endocrine and skeletal complications of liver disease and presents preventive screening recommendations and therapeutic strategies.

EGFR: A Master Piece in G1/S Phase Transition of Liver Regeneration

Unraveling the molecular clues of liver proliferation has become conceivable thanks to the model of two-third hepatectomy. The synchronicity and the well-scheduled aspect of this process allow scientists to slowly decipher this mystery. During this phenomenon, quiescent hepatocytes of the remnant lobes are able to reenter into the cell cycle initiating the G1-S progression synchronously before completing the cell cycle. The major role played by this step of the cell cycle has been emphasized by loss-of-function studies showing a delay or a lack of coordination in the hepatocytes G1-S progression. Two growth factor receptors, c-Met and EGFR, tightly drive this transition. Due to the level of complexity surrounding EGFR signaling, involving numerous ligands, highly controlled regulations and multiple downstream pathways, we chose to focus on the EGFR pathway for this paper. We will first describe the EGFR pathway in its integrity and then address its essential role in the G1/S phase transition for hepatocyte proliferation. Recently, other levels of control have been discovered to monitor this pathway, which will lead us to discuss regulations of the EGFR pathway and highlight the potential effect of misregulations in pathologies.

Insulin-like growth factor-I and the liver

Insulin-like growth factors (IGFs) play an essential role in growth and development, as well as in the overall cellular regulation and metabolism in the human body. In chronic liver disease, IGF levels are decreased, and the circulating levels correlate to the extent of hepatocellular dysfunction. Patients with cirrhosis are characterised by a variety of metabolic disturbances, including nutritional and metabolic complications such as insulin resistance, malnutrition, osteopenia and hypogonadism, all related to IGF-I deficiency. The complex process of hepatic fibrogenesis and the systemic consequences in cirrhosis are only partly understood. Disruption of the growth hormone (GH)-IGF-I axis seems to be closely associated with the development of liver disease, and treatment with recombinant human IGF (rhIGF)-I has been shown to halt, and even reverse, the fibrotic degeneration. IGF-I in itself has a strong antifibrotic effect that acts directly through the GH/IGF system and indirectly by the regulation of hepatoprotective and profibrogenic factors. It is most likely that IGF-I deficiency contributes to the diverse metabolic complications of cirrhosis. At present, liver transplantation remains the only efficient treatment of cirrhosis, and thus new methods of managing the disease are called for. RhIGF-I supplementation and IGF-I gene therapy may represent future perspectives of treatment.

GH receptor plays a major role in liver regeneration through the control of EGFR and ERK1/2 activation

GH is a pleiotropic hormone that plays a major role in proliferation, differentiation, and metabolism via its specific receptor. It has been previously suggested that GH signaling pathways are required for normal liver regeneration but the molecular mechanisms involved have yet to be determined. The aim of this study was to identify the mechanisms by which GH controls liver regeneration. We performed two thirds partial hepatectomies in GH receptor (GHR)-deficient mice and wild-type littermates and showed a blunted progression in the G(1)/S transition phase of the mutant hepatocytes. This impaired liver regeneration was not corrected by reestablishing IGF-1 expression. Although the initial response to partial hepatectomy at the priming phase appeared to be similar between mutant and wild-type mice, cell cycle progression was significantly blunted in mutant mice. The main defect in GHR-deficient mice was the deficiency of the epidermal growth factor receptor activation during the process of liver regeneration. Finally, among the pathways activated downstream of GHR during G(1) phase progression, namely Erk1/2, Akt, and signal transducer and activator of transcription 3, we only found a reduced Erk1/2 phosphorylation in mutant mice. In conclusion, our results demonstrate that GH signaling plays a major role in liver regeneration and strongly suggest that it acts through the activation of both epidermal growth factor receptor and Erk1/2 pathways.

Ascites from patients with alcoholic liver cirrhosis contains higher IGF-I bioactivity than serum

OBJECTIVE

Patients with liver cirrhosis have diminished hepatic IGF-I generation, resulting in low circulating levels, whereas data on IGF-I in ascites are sparse. Therefore, we compared the IGF-system in serum and ascites from cirrhotic patients.

DESIGN AND PATIENTS

The study comprised 43 patients (12 females) with ascites and liver function of 58 +/- 10% of normal. Serum and ascites were collected concomitantly in the fasting state. In 11 patients, second serum and ascitic samples were collected within the first week. Eleven matched controls were also included. All samples were assayed for IGF-related parameters by immunoassays and by cell-based IGF-I bioassay.

RESULTS

As compared with controls, serum total IGF-I, total IGF-II, pro-IGF-II and bioactive IGF-I were reduced in liver patients, whereas IGF-binding protein 1 (IGFBP-1), IGFBP-2 and the soluble IGF-II receptor were elevated (P < 0.005 for all). In ascites, all IGF-related peptides but pro-IGF-II were further reduced as compared with serum (P < 0.001). By contrast, bioactive IGF-I was fourfold elevated in ascites as compared with serum (2.20 +/- 0.33 vs. 0.55 +/- 0.08 microg/l, P < 0.001). In ascites, the IGF-I bioactivity signal was completely blocked by addition of IGFBP-3. Repetitive measurements (n = 11) in ascites showed that all peptides but IGFBP-1 remained unchanged within 1 week.

CONCLUSIONS

It is a novel observation that the in vitro bioactivity of IGF-I can be higher in fluids from an extravascular compartment than in serum, in contrast to immunoreactive levels. This supports different roles for endocrine and paracrine/autocrine IGF-I, but the pathophysiological significance of our observation remains to be clarified.

Disruption of the growth hormone--signal transducer and activator of transcription 5--insulinlike growth factor 1 axis severely aggravates liver fibrosis in a mouse model of cholestasis

Growth hormone (GH) resistance and low serum levels of insulinlike growth factor 1 (IGF-1) are common features in human liver fibrosis and cirrhosis. Signal transducer and activator of transcription 5 (STAT5) controls several vital functions in the liver, including GH-mediated transcription of IGF-1. To investigate the role of STAT5 in liver fibrogenesis, we specifically deleted the Stat5a/b locus both in hepatocytes and cholangiocytes in the multidrug resistance gene 2 knockout (Mdr2(-/-)) mouse model of cholestasis. Double knockout mice develop an early and severe liver fibrosis phenotype, accompanied by perturbed expression of key regulators of bile acid homeostasis. Deletion of Stat5 resulted in GH resistance, and IGF-1 levels in serum were undetectable. We could observe reduced expression of important hepatoprotective genes, such as epidermal growth factor receptor (Egfr), hepatocyte nuclear factor 6 (Hnf6), prolactin receptor (Prlr), and leukemia inhibitory factor receptor (Lifr) as well as increased numbers of apoptotic hepatocytes.

CONCLUSION

Our data suggest that loss of STAT5 sensitizes hepatocytes to bile acid-induced damage and apoptosis caused by disruption of GH-induced transcription of Igf-1 and down-regulation of hepatoprotective genes. These findings could contribute to the understanding of liver fibrosis and future treatment strategies for liver fibrosis.