Sotrastaurin in liver transplantation: has it had a fair trial?

Novel biomarkers of acute kidney injury following living donor liver transplantation

Urinary biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) and renalase were recently studied for their potential role in the early detection of acute kidney injury (AKI) in patients with cirrhosis. Our study was conducted on 50 patients with end-stage liver disease undergoing living donor liver transplantation. The patients were divided into two groups: Group I contained 23 patients with AKI who had undergone liver transplantation and Group II included 27 non-AKI patients who had undergone liver transplantation. Serum renalase and NGAL levels were measured by ELISA; renalase was measured on day 1, day 7, and three months after liver transplantation. NGAL was measured on day 1 postliver transplantation. There was an improvement in liver function, kidney functions, hemoglobin level, platelet count, and C- reactive protein levels in patients at three months posttransplantation when compared to day 1, day 3, and day 7 (P < 0.01). Comparison of the renalase level at day 1, day 7, and three months showed that there was a highly significant decline at three months in the AKI group compared to the non-AKI group (P < 0.01). Regarding the NGAL level at day 1, there was no significant difference between the AKI and non-AKI groups (P > 0.05). The receiver operating characteristic curve for the renalase biomarker showed a borderline significant change between the AKI and non-AKI groups at day 1 [area under the curve (AUC): 0.54, P = 0.08], day 7 (AUC: 0.605, P = 0.08), and three months (AUC: 0.605, P = 0.08). However, the NGAL biomarker level was not significantly different between the AKI and non-AKI groups. Our study suggests that renalase showed a better predictive value and a higher accuracy in identifying postliver transplantation patients with AKI than NGAL.

PKC and PKN in heart disease

The protein kinase C (PKC) and closely related protein kinase N (PKN) families of serine/threonine protein kinases play crucial cellular roles. Both kinases belong to the AGC subfamily of protein kinases that also include the cAMP dependent protein kinase (PKA), protein kinase B (PKB/AKT), protein kinase G (PKG) and the ribosomal protein S6 kinase (S6K). Involvement of PKC family members in heart disease has been well documented over the years, as their activity and levels are mis-regulated in several pathological heart conditions, such as ischemia, diabetic cardiomyopathy, as well as hypertrophic or dilated cardiomyopathy. This review focuses on the regulation of PKCs and PKNs in different pathological heart conditions and on the influences that PKC/PKN activation has on several physiological processes. In addition, we discuss mechanisms by which PKCs and the closely related PKNs are activated and turned-off in hearts, how they regulate cardiac specific downstream targets and pathways, and how their inhibition by small molecules is explored as new therapeutic target to treat cardiomyopathies and heart failure.

The immunological synapse as a pharmacological target

The development of T cell mediated immunity relies on the assembly of a highly specialized interface between T cell and antigen presenting cell (APC), known as the immunological synapse (IS). IS assembly is triggered when the T cell receptor (TCR) binds to specific peptide antigen presented in association to the major histocompatibility complex (MHC) by the APC, and is followed by the spatiotemporal dynamic redistribution of TCR, integrins, co-stimulatory receptors and signaling molecules, allowing for the fine-tuning and integration of the signals that lead to T cell activation. The knowledge acquired to date about the mechanisms of IS assembly underscores this structure as a robust pharmacological target. The activity of molecules involved in IS assembly and function can be targeted by specific compounds to modulate the immune response in a number of disorders, including cancers and autoimmune diseases, or in transplanted patients. Here, we will review the state-of-the art of the current therapies which exploit the IS to modulate the immune response.

The use of kinase inhibitors in solid organ transplantation

INTRODUCTION

Despite the efficacy of current immunosuppression regimes used in solid organ transplantation, graft dysfunction, graft lost and antibody-mediated rejection continue to be problematic. As a result, clear attraction in exploiting key potential targets controlled by kinase phosphorylation has led to a number of studies exploring the use of these drugs in transplantation. Aim In this review, we consider the role of tyrosine kinase as a target in transplantation and summarize the relevant studies on kinase inhibitors that have been reported to date.

METHODS

Narrative review of literature from inception to December 2016, using OVID interface searching EMBASE and MEDLINE databases. All studies related to kinase based immunosuppression were examined for clinical relevance with no exclusion criteria. Key ideas were extracted and referenced.

CONCLUSION

The higher incidence of infections when using kinase inhibitors is an important consideration, however the number and range inhibitors and their clinical indications are likely to expand, but their exact role in transplantation is yet to be determined.