Subcutaneous administration of epidermal growth factor: A true treatment option in case of postoperative liver failure?

Insights into Growth Factors in Liver Carcinogenesis and Regeneration: An Ongoing Debate on Minimizing Cancer Recurrence after Liver Resection

Hepatocellular carcinoma has become a leading cause of cancer-associated mortality throughout the world, and is of great concern. Currently used chemotherapeutic drugs in the treatment of hepatocellular carcinoma lead to severe side effects, thus underscoring the need for further research to develop novel and safer therapies. Liver resection in cancer patients is routinely performed. After partial resection, liver regeneration is a perfectly calibrated response apparently sensed by the body’s required liver function. This process hinges on the effect of several growth factors, among other molecules. However, dysregulation of growth factor signals also leads to growth signaling autonomy and tumor progression, so control of growth factor expression may prevent tumor progression. This review describes the role of some of the main growth factors whose dysregulation promotes liver tumor progression, and are also key in regenerating the remaining liver following resection. We herein summarize and discuss studies focused on partial hepatectomy and liver carcinogenesis, referring to hepatocyte growth factor, insulin-like growth factor, and epidermal growth factor, as well as their suitability as targets in the treatment of hepatocellular carcinoma. Finally, and given that drugs remain one of the mainstay treatment options in liver carcinogenesis, we have reviewed the current pharmacological approaches approved for clinical use or research targeting these factors.

Treatment of AECHB and Severe Hepatitis (Liver Failure)

This chapter describes the general treatment and immune principles and internal management for AECHB and HBV ACLF, including ICU monitoring, general supportive medications/nutrition/nursing, immune therapy, artificial liver supportive systems, hepatocyte/stem cell, and liver transplant, management for special populations, frequently clinical complications and the utilization of Chinese traditional medicines.

Early clinical indicators of severe hepatitis B include acratia, gastrointestinal symptoms, a daily increase in serum bilirubin >1 mg/dL, toxic intestinal paralysis, bleeding tendency and mild mind anomaly or character change, and the presence of other diseases inducing severe hepatitis. Laboratory indicators include T-Bil, PTA, cholinesterase, pre-albumin and albumin. The roles of immune indicators (such as IL-6, TNF-α, and fgl2), gene polymorphisms, HBV genotypes, and gene mutations as early clinical indicators.

Intensive Care Unit monitor patients with severe hepatitis include intracranial pressure, infection, blood dynamics, respiratory function, renal function, blood coagulation function, nutritional status and blood purification process. Nursing care should not only include routine care, but psychological and special care (complications).

Nutrition support and nursing care should be maintained throughout treatment for severe hepatitis. Common methods of evaluating nutritional status include direct human body measurement, creatinine height index (CHI) and subject global assessment of nutrition (SGA). Malnourished patients should receive enteral or parenteral nutrition support.

Immune therapies for severe hepatitis include promoting hepatocyte regeneration (e.g. with glucagon, hepatocyte growth factor and prostaglandin E1), glucocorticoid suppressive therapy, and targeting molecular blocking. Corticosteroid treatment should be early and sufficient, and adverse drug reactions monitored. Treatments currently being investigated are those targeting Toll-like receptors, NK cell/NK cell receptors, macrophage/immune coagulation system, CTLA-4/PD-1 and stem cell transplantation.

In addition to conventional drugs and radioiodine, corticosteroids and artificial liver treatment can also be considered for severe hepatitis patients with hyperthyreosis. Patients with gestational severe hepatitis require preventive therapy for fetal growth restriction, and it is necessary to choose the timing and method of fetal delivery. For patients with both diabetes and severe hepatitis, insulin is preferred to oral antidiabetic agents to control blood glucose concentration. Liver toxicity of corticosteroids and immune suppressors should be monitored during treatment for severe hepatitis in patients with connective tissue diseases including SLE, RA and sicca syndrome. Patient with connective tissue diseases should preferably be started after the antiviral treatment with nucleos(t)ide analogues.

An artificial liver can improve patients’ liver function; remove endotoxins, blood ammonia and other toxins; correct amino acid metabolism and coagulation disorders; and reverse internal environment imbalances. Non-bioartificial livers are suitable for patients with early and middle stage severe hepatitis; for late-stage patients waiting for liver transplantation; and for transplanted patients with rejection reaction or transplant failure. The type of artificial liver should be determined by each patient’s condition and previous treatment purpose, and patients should be closely monitored for adverse reactions and complications. Bio- and hybrid artificial livers are still under development.

MELD score is the international standard for choosing liver transplantation. Surgical methods mainly include the in situ classic type and the piggyback type; transplantation includes no liver prophase, no liver phase or new liver phase. Preoperative preparation, management of intraoperative and postoperative complications and postoperative long-term treatment are keys to success.

Severe hepatitis belongs to the categories of “acute jaundice”, “scourge jaundice”, and “hot liver” in traditional Chinese medicine. Treatment methods include Chinese traditional medicines, acupuncture and acupoint injection, external application of drugs, umbilical compress therapy, drip, blow nose therapy, earpins, and clysis. Dietary care is also an important part of traditional Chinese medicine treatment.

Effect of LSKL peptide on thrombospondin 1-mediated transforming growth factor β signal activation and liver regeneration after hepatectomy in an experimental model

Background

A strategy for accelerating liver regeneration after hepatectomy would offer great benefits in preventing postoperative liver failure and improving surgical outcomes. Transforming growth factor (TGF) β is a potent inhibitor of hepatocyte proliferation. Recently, thrombospondin (TSP) 1 has been identified as a negative regulator of liver regeneration by activation of local TGF-β signals. This study aimed to clarify whether the LSKL (leucine–serine–lysine–leucine) peptide, which inhibits TSP-1-mediated TGF-β activation, promotes liver regeneration after hepatectomy in mice.

Methods

Mice were operated on with a 70 per cent hepatectomy or sham procedure. Operated mice received either LSKL peptide or normal saline intraperitoneally at abdominal closure and 6 h after hepatectomy. Perioperative plasma TSP-1 levels were measured by enzyme-linked immunosorbent assay in patients undergoing hepatectomy.

Results

Administration of LSKL peptide attenuated Smad2 phosphorylation at 6 h. S-phase entry of hepatocytes was accelerated at 24 and 48 h by LSKL peptide, which resulted in faster recovery of the residual liver and bodyweight. Haematoxylin and eosin tissue staining and blood biochemical examinations revealed no significant adverse effects following the two LSKL peptide administrations. In the clinical setting, plasma TSP-1 levels were lowest on the first day after hepatectomy. However, plasma TSP-1 levels at this stage were significantly higher in patients with subsequent liver dysfunction compared with levels in those without liver dysfunction following hepatectomy.

Conclusion

Only two doses of LSKL peptide during the early period after hepatectomy can promote liver regeneration. The transient inhibition of TSP-1/TGF-β signal activation using LSKL peptide soon after hepatectomy may be a promising strategy to promote subsequent liver regeneration.

Novel developmental biology-based protocol of embryonic stem cell differentiation to morphologically sound and functional yet immature hepatocytes

BACKGROUND/AIMS

Liver diseases are common in the United States and often require liver transplantation; however, donated organs are limited and thus alternative sources for liver cells are in high demand. Embryonic stem cells (ESC) can provide a continuous and readily available source of liver cells. ESC differentiation to liver cells is yet to be fully understood and comprehensive differentiation protocols are yet to be defined. Here, we aimed to achieve human (h)ESC differentiation into mature hepatocytes using defined recombinant differentiation factors and metabolites.

METHODS

Embryonic stem cell H1 line was sub-cultured on feeder layer. We induced hESCs into endodermal differentiation succeeded by early/late hepatic specification and finally into hepatocyte maturation using step combinations of Activin A and fibroblast growth factor (FGF)-2 for 7 days; followed by FGF-4 and bone morphogenic protein 2 (BMP2) for 7 days, succeeded by FGF-10 + hepatocyte growth factor 4 + epidermal growth factor for 14 days. Specific inhibitors/stimulators were added sequentially throughout differentiation. Cells were analysed by PCR, flow cytometry, microscopy or functional assays.

RESULTS

Our hESC differentiation protocol resulted in viable cells with hepatocyte shape and morphology. We observed gradual changes in cell transcriptome, including up-regulation of differentiation-promoting GATA4, GATA6, POU5F1 and HNF4 transcription factors, steady levels of stemness-promoting SOX-2 and low levels of Nanog, as defined by PCR. The hESC-derived hepatocytes expressed alpha-antitrypsin, CD81, cytokeratin 8 and low density lipoprotein (LDL) receptor. The levels of alpha-fetoprotein and proliferation marker Ki-67 in hESC-derived hepatocytes remained elevated. Unlike stem cells, the hESC-derived hepatocytes performed LDL uptake, produced albumin and alanine aminotransferase and had functional alcohol dehydrogenase.

CONCLUSION

We report a novel protocol for hESC differentiation into morphological and functional yet immature hepatocytes as an alternative method for hepatocyte generation.