Cirrhosis: What are all those factor VIII and protein C for?

Role of HNF6 in liver homeostasis and pathophysiology

BACKGROUND

Hepatocyte nuclear factor 6 (HNF6), a member of the HNF family, contains single cleft and homologous domains, which form a DNA-binding region that targets the promoter regions of genes that bind to liver-specific genes and regulate their expression. Furthermore, HNF6 is highly expressed as an HNF in the liver.

MAIN BODY

HNF6 regulates not only the formation of the liver but also the proliferation and differentiation of hepatocytes. Additionally, HNF6 controls the migration and adhesion of hepatocellular carcinoma cells and plays a significant role in liver metabolism. Its expression is affected by epigenetic modifications such as DNA methylation, post-translational modifications, and microRNAs. Recently, HNF6 was also found to be expressed in tissues, such as the pancreas, intestine, and lungs, where it controls their formation by regulating cell differentiation and influences their pathophysiological processes via various mechanisms.

CONCLUSION

In this review, we highlight advances in HNF6-related research concerning liver diseases and provide a summary of its potential mechanisms of action as a transcription factor in regulating downstream genes and epigenetic modifications. We also highlight gaps in liver disease research and provide future research directions for the application of HNF6 and its downstream molecules as attractive targets in the treatment of liver diseases.

Reappraisal of the conventional hemostasis tests as predictors of perioperative bleeding in the era of rebalanced hemostasis in cirrhosis

New global laboratory procedures mimicking the in vivo hemostasis process led to the changing paradigm of cirrhosis from the prototype of hemorrhagic diseases to a condition in which hemostasis is normal but fragile, thus justifying the hemorrhagic/thrombotic tendencies that affect these patients. The new paradigm was instrumental to change the management of cirrhosis. For example, international guidelines warn against the entrenched practice of testing patients with conventional hemostasis tests and infusing those with abnormalities with fresh-frozen plasma, coagulation factor concentrates, or platelets, prior to surgery/invasive procedures. These recommendations are, however, largely disattended. The practice of testing patients with the prothrombin time or viscoelastometry and using arbitrary cutoffs to make decisions on perioperative prophylaxis is still common and probably driven by medicolegal issues. There is no doubt that prothrombin time and congeners tests are unable to predict bleeding in cirrhosis. However, it cannot be excluded that some tests may be useful in patients who are severely decompensated. Large prospective collaborative studies are warranted. Enrolled patients should be randomized to receive perioperative prophylaxis based on laboratory testing (eg, viscoelastometry, thrombomodulin-modified thrombin generation) or to usual care. However, for these trials to be useful, a third group of patients who do not receive prophylaxis should be included. In conclusion, until results from these studies are available, physicians attending cirrhosis should refrain from using laboratory tests with arbitrary cutoffs to make decision on perioperative prophylaxis. Decision should be made by considering the clinical history of individual patients and the risk of hemorrhage of specific procedures.