The potential interplay of adipokines with toll-like receptors in the development of hepatocellular carcinoma

Investigation of Anti-Liver Cancer Activity of the Herbal Drug FDY003 Using Network Pharmacology

Globally, liver cancer (LC) is the sixth-most frequently occurring and the second-most fatal malignancy, responsible for 0.83 million deaths annually. Although the application of herbal drugs in cancer therapies has increased, their anti-LC activity and relevant mechanisms have not been fully studied from a systems perspective. To address these issues, we conducted a system-perspective network pharmacological investigation into the activity and mechanisms underlying the action of the herbal drug. FDY003 reduced the viability of human LC treatment. FDY003 reduced the viability of human LC cells and elevated their chemosensitivity. There were a total of 16 potential bioactive chemical components in FDY003 and they had 91 corresponding targets responsible for the pathological processes in LC. These FDY003 targets were functionally involved in regulating the survival, proliferation, apoptosis, and cell cycle of LC cells. Additionally, we found that FDY003 may target key signaling cascades connected to diverse LC pathological mechanisms, namely, PI3K-Akt, focal adhesion, IL-17, FoxO, MAPK, and TNF pathways. Overall, this study contributed to integrative mechanistic insights into the anti-LC potential of FDY003.

Linking Nonalcoholic Fatty Liver Disease to Hepatocellular Carcinoma: From Bedside to Bench and Back

Aims and background

Nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) are two major causes of liver disease worldwide. Epidemiological and clinical data have clearly demonstrated that NAFLD and its associated metabolic abnormalities are a risk factor for HCC. Traditionally, the mechanisms whereby NAFLD acts as a risk for HCC are believed to include replicative senescence of steatotic hepatocytes and compensatory hyperplasia of progenitor cells as a reaction to chronic hepatic injury. Recent years have witnessed significant advances in our understanding of the mechanisms underlying the link between NAFLD and HCC.

Methods

In the present review, we provide an update on the pathophysiological pathways linking NAFLD and its associated metabolic derangements to malignant hepatic transformation, with a special focus on insulin resistance, adipokines, inflammation, and angiogenesis. We will also discuss the potential therapeutic implications that such molecular links carry.

Results

Although treating NAFLD could reduce the risk of malignant hepatic transformation, no long-term studies focusing on this issue have been conducted thus far. Insulin resistance, inflammation as well as derangements in adipokines and angiogenic factors associated with NAFLD are closely intertwined with the risk of developing HCC.

Conclusions

Traditional therapeutic approaches in NAFLD including metformin and statins may theoretically reduce the risk of HCC by acting on common pathophysiological pathways shared by NAFLD and HCC.

INVITED REVIEW: Evolution of meat animal growth research during the past 50 years: Adipose and muscle stem cells

If one were to compare today's animal growth research to research from a mere 50 yr ago, one would see programs with few similarities. The evolution of this research from whole-animal through cell-based and finally molecular and genomic studies has been enhanced by the identification, isolation, and in vitro evaluation of adipose- and muscle-derived stem cells. This paper will highlight the struggles and the milestones that make this evolving area of research what it is today. The contribution of adipose and muscle stem cell research to development and growth, tissue regeneration, and final carcass composition are reviewed.

Cytokine and Adipokine Levels in Patients with Premalignant Oral Lesions or in Patients with Oral Cancer Who Did or Did Not Receive 1α,25-Dihydroxyvitamin D3 Treatment upon Cancer Diagnosis

Differences in levels of inflammation-modulating cytokines and adipokines in patients with premalignant oral lesions versus in patients that develop squamous cell carcinoma of the head and neck (HNSCC) were assessed. Also assessed was the impact of treating HNSCC patients with the immune regulatory mediator, 1α,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], on modulators of inflammation. Compared to healthy controls, patients with premalignant oral lesions had increases in their systemic levels of the inflammatory cytokines IL-6 and IL-17, and increases in the adipokine, leptin. However, levels of these pro-inflammatory cytokines and adipokine were reduced in patients with HNSCC. Treatment of HNSCC patients with 1,25(OH)₂D₃ increased levels of each of the measured immune mediators. Levels of the anti-inflammatory adipokine, adiponectin, were shifted inversely with the levels of the pro-inflammatory cytokines and with leptin. These studies demonstrate heightened immune reactivity in patients with premalignant lesions, which wanes in patients with HNSCC, but which is restored by treatment with 1,25(OH)₂D₃.

Dietary Supplementation of Genistein Alleviates Liver Inflammation and Fibrosis Mediated by a Methionine-Choline-Deficient Diet in db/db Mice

Nonalcoholic fatty liver disease is a complex disorder which includes simple steatosis, steatohepatitis, fibrosis and ultimately cirrhosis. Previous studies have reported that genistein, a soy phytoestrogen, attenuates steatohepatitis induced in obese and type 2 diabetic models. Here we investigated the effect of dietary genistein supplementation (0.05%) on nonalcoholic steatohepatitis (NASH) development induced by a methionine-choline-deficient (MCD) diet in db/db mice. MCD-diet-fed mice exhibited a significantly lower body weight and a higher degree of steatohepatitis with increased oxidative stress, steatosis, inflammation, stellate cell activation, and mild fibrosis. Although genistein did not inhibit hepatic steatosis, we observed that oxidative stress, endoplasmic reticulum stress, and AMP-dependent kinase inactivation were alleviated by genistein. Genistein also down-regulated the augmented gene expressions associated with hepatic inflammation and fibrosis. Therefore, these results suggest that genistein may protect MCD-diet-mediated NASH development by suppressing lipid peroxidation, inflammation, and even liver fibrosis in db/db mice.

Skewing of immune cell cytokine production by mediators from adipocytes and endothelial cells

Since adipose tissue is composed of adipocytes as well as other cell types including endothelial cells, this study sought to determine how mediators from adipocytes and from endothelial cells impact on immune cell production of cytokines. A minimalistic design was used in which media conditioned by adipocytes or by endothelial cells were added individually or as a mixture to normal spleen cells. Media from adipocytes or endothelial cells each stimulated spleen cell production of Th1 cytokines, Th2 cytokines, most of the measured inflammatory cytokines, and some chemokines. However, a mixture of media conditioned by adipocytes and by endothelial cells inhibited production of Th1 cytokines and skewed reactivity toward a Th2 and inflammatory phenotype. Adiponectin, but not leptin, was shown to contribute to the skewing of immune responsiveness to endothelial cell-derived mediators.

Premalignant lesions skew spleen cell responses to immune modulation by adipocytes

Obesity can promote a chronic inflammatory state and is associated with an increased risk for cancer. Since adipocytes can produce mediators that can regulate conventional immune cells, this study sought to determine if the presence of premalignant oral lesions would skew how immune cells respond to adipocyte-derived mediators to create an environment that may be more favorable for their progression toward cancer. While media conditioned by adipocytes stimulated normal spleen cell production of the T helper (Th) type-1 cytokines interleukin (IL)-2, interferon-γ (IFN-γ), IL-12 and granulocyte-monocyte colony-stimulating factor (GM CSF), media from premalignant lesion cells either blocked or had no added affect on the adipocyte-stimulated Th1 cytokine production. In contrast, media conditioned by premalignant lesion cells exacerbated adipocyte-stimulated spleen cell production of the Th2 cytokines IL-10 and IL-13, although it did not further enhance the adipocyte-stimulated spleen cell production of IL-4 and TGF-β. The premalignant lesion environment also heightened the adipocyte-stimulated spleen cell production of the inflammatory mediators IL 1α, IL-1β, IL-6 and IL-9, although it did not further increase the adipocyte-stimulated production of tumor necrosis factor-α (TNF-α). IL 17 production was unaffected by the adipocyte-derived mediators, but was synergistically triggered by adding media from premalignant lesion cells. These stimulatory effects on spleen cell production of Th2 and inflammatory mediators were not induced in the absence of media conditioned by adipocytes. In contrast, media conditioned by adipocytes did not stimulate production of predominantly monocyte-derived chemokine C-X-C motif ligand (CXCL)9, chemokine C-C motif ligand (CCL)3 or CCL4, although it stimulated production of CCL2 and the predominantly T cell-derived chemokine CCL5, which was the only chemokine whose production was further increased by media from premalignant lesions. These results suggest that the responsiveness of spleen cells to adipocyte-derived mediators is influenced by mediators from premalignant lesion cells to favor conventional immune cell production of a Th2 and inflammatory cytokines.

Adipocytes as immune regulatory cells

Obesity is a chronic inflammatory state and adipocytes are capable of contributing to this inflammation by their production of inflammatory mediators. The present study used fibroblast-derived adipocytes and normal spleen cells as a model to determine if adipocytes can also serve as immune regulatory cells by modulating the functions of conventional immune cells. Media conditioned by the adipocytes stimulated release of the Th1-type cytokines IL-2, IFN-γ and GM-CSF from cultures of normal spleen cells. The adipocytes also stimulated spleen cell release of inhibitory cytokines, although to varying degrees. This included IL-10, IL-13 and, to a lesser extent, IL-4. Spleen cell production of the inflammatory cytokines IL-6, TNF-α and IL-9 was stimulated by adipocytes, although production of the Th17-derived cytokine, IL-17, was not stimulated. The adipocyte-conditioned medium did not stimulate production of predominantly monocytes-derived chemokines CXCL9, CCL2, CCL3, CCL4, but stimulated production of the predominantly T-cell-derived chemokine CCL5. In all cases where cytokine/chemokine production from spleen cells was stimulated by adipocytes, it was to a far greater level than was produced by the adipocytes themselves. Studies initiated to determine the identity of the adipocyte-derived mediators showed that the spleen cell modulation could not be attributed to solely adiponectin or leptin. Studies to determine the source of some of the cytokines whose production was stimulated by adipocytes showed that expression of the inflammatory cytokine IL-6 was not increased in either CD4(+) or CD8(+) T-cell. When the splenic T-cells were examined for IFN-γ, the adipocyte stimulation of IFN-γ was within CD8(+) T-cells, not CD4(+) T-cells. These studies show that adipocytes may be able to serve as immune regulatory cells to stimulate conventional immune cells to release a spectrum of immune mediators.

What is the role of adiponectin in obesity related non-alcoholic fatty liver disease?

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most common type of chronic liver disease in Western countries. Insulin resistance is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of insulin resistance or obesity. Adiponectin is the most abundant adipose-specific adipokine. There is evidence that adiponectin decreases hepatic and systematic insulin resistance, and attenuates liver inflammation and fibrosis. Adiponectin generally predicts steatosis grade and the severity of NAFLD; however, to what extent this is a direct effect or related to the presence of more severe insulin resistance or obesity remains to be addressed. Although there is no proven pharmacotherapy for the treatment of NAFLD, recent therapeutic strategies have focused on the indirect upregulation of adiponectin through the administration of various therapeutic agents and/or lifestyle modifications. In this adiponectin-focused review, the pathogenetic role and the potential therapeutic benefits of adiponectin in NAFLD are analyzed systematically.