Everolimus therapy is associated with reduced lipoprotein-associated phospholipase A2 (Lp-Pla2) activity and oxidative stress in heart transplant recipients

Tuning macrophages for atherosclerosis treatment

Atherosclerosis is a chronic inflammatory vascular disease and a leading cause of death worldwide. Macrophages play an important role in inflammatory responses, cell-cell communications, plaque growth and plaque rupture in atherosclerotic lesions. Here, we review the sources, functions and complex phenotypes of macrophages in the progression of atherosclerosis, and discuss the recent approaches in modulating macrophage phenotype and autophagy for atherosclerosis treatment. We then focus on the drug delivery strategies that target macrophages or use macrophage membrane-coated particles to deliver therapeutics to the lesion sites. These biomaterial-based approaches that target, modulate or engineer macrophages have broad applications for disease therapies and tissue regeneration.

Management of cardiac diseases in liver transplant recipients: Comprehensive review and multidisciplinary practice-based recommendations

Cardiac diseases are one of the most common causes of morbidity and mortality following liver transplantation (LT). Prior studies have shown that cardiac diseases affect close to one-third of liver transplant recipients (LTRs) long term and that their incidence has been on the rise. This rise is expected to continue as more patients with advanced age and/or non-alcoholic steatohepatitis undergo LT. In view of the increasing disease burden, a multidisciplinary initiative was developed to critically review the existing literature (between January 1, 1990 and March 17, 2021) surrounding epidemiology, risk assessment, and risk mitigation of coronary heart disease, arrhythmia, heart failure, and valvular heart disease and formulate practice-based recommendations accordingly. In this review, the expert panel emphasizes the importance of optimizing management of metabolic syndrome and its components in LTRs and highlights the cardioprotective potential for the newer diabetes medications (e.g., sodium glucose transporter-2 inhibitors) in this high-risk population. Tailoring the multidisciplinary management of cardiac diseases in LTRs to the cardiometabolic risk profile of the individual patient is critical. The review also outlines numerous knowledge gaps to pave the road for future research in this sphere with the ultimate goal of improving clinical outcomes.

Cardiovascular effects of immunosuppression agents

Immunosuppressive medications are widely used to treat patients with neoplasms, autoimmune conditions and solid organ transplants. Key drug classes, namely calcineurin inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and purine synthesis inhibitors, have direct effects on the structure and function of the heart and vascular system. In the heart, immunosuppressive agents modulate cardiac hypertrophy, mitochondrial function, and arrhythmia risk, while in vasculature, they influence vessel remodeling, circulating lipids, and blood pressure. The aim of this review is to present the preclinical and clinical literature examining the cardiovascular effects of immunosuppressive agents, with a specific focus on cyclosporine, tacrolimus, sirolimus, everolimus, mycophenolate, and azathioprine.

Lipid metabolism, inflammation, and foam cell formation in health and metabolic disorders: targeting mTORC1

Metabolic homeostasis is important for maintaining a healthy lifespan. Lipid metabolism is particularly necessary for the maintenance of metabolic energy sources and their storage, and the structure and function of cell membranes, as well as for the regulation of nutrition through lipogenesis, lipolysis, and lipophagy. Dysfunctional lipid metabolism leads to the development of metabolic disorders, such as atherosclerosis, diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD). Furthermore, dyslipidaemia causes inflammatory responses and foam cell formation. Mechanistic target of rapamycin (mTOR) signalling is a key regulator of diverse cellular processes, including cell metabolism and cell fate. mTOR complex 1 (mTORC1) is involved in lipid metabolism and immune responses in the body. Therefore, the mTORC1 signalling pathway has been suggested as a potential therapeutic target for the treatment of metabolic disorders. In this review, we focus on the roles of mTORC1 in lipid metabolism and inflammation, and present current evidence on its involvement in the development and progression of metabolic disorders.

Resveratrol Treatment Is Associated with Lipid Regulation and Inhibition of Lipoprotein-Associated Phospholipase A2 (Lp-PLA2) in Rabbits Fed a High-Fat Diet

The effects of resveratrol on various conditions have been widely studied previously. This paper aimed to investigate the influence of resveratrol on atherosclerosis (AS). Twenty-four New Zealand male rabbits were randomly and equally assigned to the normal diet group (NDG), fat diet group (FDG), and fat diet with resveratrol group (80 mg/kg/d, RFG). Biochemical indicators from blood samples were analyzed at baseline and 3 months to investigate the effects of resveratrol on blood lipid, lipoprotein-associated phospholipase A2 (Lp-PLA2), liver, and renal function. The indicators including alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and Lp-PLA2. At 3 months, arteries were stained with hematoxylin and eosin to study the influence of resveratrol on the aortic intima, smooth muscle layer, and the intima/media ratio. Comparisons of weight, ALT, AST, CREA, TG, TC, HDL-C, LDL-C, and Lp-PLA2 among the three groups showed no significant difference at baseline. However, at the end of 3 months, significant differences were observed in AST, CREA, TC, HDL-C, LDL-C, and Lp-PLA2 between the three groups (P < 0.05). In pairwise comparison, CREA, TC, LDL-C, and Lp-PLA2 had significant differences between any two groups (P < 0.05). In addition, there were significant differences in the AST and HDL-C levels between RFG and NDG groups (P < 0.05). Meanwhile, the HDL-C levels were also significantly different between the FDG and NDG groups (P < 0.01). The histologic analysis also showed that the thickness of the aortic intima and the ratio of the intima and aortic tunica media (P < 0.05) significantly decreased in RFG compared to FDG. Resveratrol may have an antiatherosclerosis effect on a rabbit model of AS.

Association Between Renal Dysfunction and Major Adverse Cardiac Events After Liver Transplantation: Evidence from an International Randomized Trial of Everolimus-Based Immunosuppression

Background

Prospective evidence is lacking regarding the association between renal dysfunction and cardiovascular events after liver transplantation.

Material/Methods

Data were analyzed post hoc regarding renal function and major adverse cardiac events in a two-year prospective trial of de novo liver transplant recipients randomized at 30 days post-transplant to (i) everolimus [EVR]/reduced tacrolimus [EVR/rTAC] (ii) EVR with tacrolimus discontinued [TAC Elimination] or (iii) standard tacrolimus [TAC Control].

Results

By month 24 post-transplant, 32/716 patients had experienced a first major cardiac event (4.5%): 4.1% (10/245), 2.2% (5/229) and 7.0% (17/242) of patients in the EVR/rTAC, TAC Elimination and TAC Control groups, respectively (p=0.043). The cumulative eGFR area under the curve (AUC) from randomization to month 24 was 119 706, 123 082, and 105 946 mL in the EVR/rTAC, TAC Elimination, and TAC Control groups, respectively, corresponding to a mean eGFR AUC of 82.4, 83.0, and 71.9 mL/min/1.73 m². Cox regression modeling showed that mean eGFR AUC was inversely associated with time to first major cardiac event: the hazard ratio per mL/min/1.73 m² was −0.0000015 [95% CI −0.00000078; −0.0000024] (p<0.001).

Conclusions

These findings confirm retrospective evidence that the risk of major cardiac events increases with deteriorating renal function after liver transplantation and demonstrate the need for careful cardiovascular risk management in patients with renal impairment. Immunosuppression based on everolimus with tacrolimus withdrawal, or to a lesser extent tacrolimus reduction, improves both renal function and the risk of major cardiac events compared to standard tacrolimus therapy in liver transplant recipients.

Targeted and global pharmacometabolomics in everolimus-based immunosuppression: association of co-medication and lysophosphatidylcholines with dose requirement

INTRODUCTION

The immunosuppressive therapy with everolimus (ERL) after heart transplantation is characterized by a narrow therapeutic window and a substantial variability in dose requirement. Factors explaining this variability are largely unknown.

OBJECTIVES

Our aim was to evaluate factors affecting ERL metabolism and to identify novel metabolites associated with the individual ERL dose requirement to elucidate mechanisms underlying ERL dose response variability.

METHOD

We used liquid chromatography coupled with mass spectrometry for quantification of ERL metabolites in 41 heart transplant patients and evaluated the effect of clinical and genetic factors on ERL pharmacokinetics. Non-targeted plasma metabolic profiling by ultra-performance liquid chromatography and high resolution quadrupole-time-of-flight mass spectrometry was used to identify novel metabolites associated with ERL dose requirement.

RESULTS

The determination of ERL metabolites revealed differences in metabolite patterns that were independent from clinical or genetic factors. Whereas higher ERL dose requirement was associated with co-administration of sodium-mycophenolic acid and the CYP3A5 expressor genotype, lower dose was required for patients receiving vitamin K antagonists. Global metabolic profiling revealed several novel metabolites associated with ERL dose requirement. One of them was identified as lysophosphatidylcholine (lysoPC) (16:0/0:0). Subsequent targeted analysis revealed that high levels of several lysoPCs were significantly associated with higher ERL dose requirement.

CONCLUSION

For the first time, this study describes distinct ERL metabolite patterns in heart transplant patients and detected potentially new drug-drug interactions. The global metabolic profiling facilitated the discovery of novel metabolites associated with ERL dose requirement that might represent new clinically valuable biomarkers to guide ERL therapy.

Reactive Oxygen Species-Mediated Mechanisms of Action of Targeted Cancer Therapy

Targeted cancer therapies, involving tyrosine kinase inhibitors and monoclonal antibodies, for example, have recently led to substantial prolongation of survival in many metastatic cancers. Compared with traditional chemotherapy and radiotherapy, where reactive oxygen species (ROS) have been directly linked to the mediation of cytotoxic effects and adverse events, the field of oxidative stress regulation is still emerging in targeted cancer therapies. Here, we provide a comprehensive review regarding the current evidence of ROS-mediated effects of antibodies and tyrosine kinase inhibitors, use of which has been indicated in the treatment of solid malignancies and lymphomas. It can be concluded that there is rapidly emerging evidence of ROS-mediated effects of some of these compounds, which is also relevant in the context of drug resistance and how to overcome it.

Reactive Oxygen Species-Mediated Mechanisms of Action of Targeted Cancer Therapy

Targeted cancer therapies, involving tyrosine kinase inhibitors and monoclonal antibodies, for example, have recently led to substantial prolongation of survival in many metastatic cancers. Compared with traditional chemotherapy and radiotherapy, where reactive oxygen species (ROS) have been directly linked to the mediation of cytotoxic effects and adverse events, the field of oxidative stress regulation is still emerging in targeted cancer therapies. Here, we provide a comprehensive review regarding the current evidence of ROS-mediated effects of antibodies and tyrosine kinase inhibitors, use of which has been indicated in the treatment of solid malignancies and lymphomas. It can be concluded that there is rapidly emerging evidence of ROS-mediated effects of some of these compounds, which is also relevant in the context of drug resistance and how to overcome it.

Proteomic analysis of ginsenoside Re attenuates hydrogen peroxide-induced oxidative stress in human umbilical vein endothelial cells

Ginsenoside Re is an active component in ginseng that has attracted much attention because of its evident therapeutic effects on the cardiovascular system. However, little basic information is available on the mechanisms and pharmacological effects of ginsenoside Re. The potential mechanisms and protective effects of Re on H2O2-induced oxidative injury in human umbilical vein endothelial cells (HUVECs) were investigated in this study. An oxidative injury model was established using H2O2. The anti-oxidative effects of Re were determined using a series of experiments, such as MTT and anti-oxidative indicator assays. The potential protective mechanisms of Re were explored at the proteomic level, and differentially expressed proteins were validated by quantitative real-time polymerase chain reaction and western blotting. Results indicated that Re could be a potential anti-oxidant to protect HUVECs against oxidative stress damage. Proteomic analysis showed that the expression of 23 protein spots was upregulated in Re and H2O2 groups to resist oxidative stress, 15 of which were identified by their mass spectrum. These upregulated proteins were involved in stress response, anti-oxidative systems, protein synthesis, regulation of transcription and post-translational modifications, and repair of mitochondrial functions. This study may provide new insights into the mechanisms of ginsenoside Re in protecting the cardiovascular system.

The roles of macrophage autophagy in atherosclerosis

Although various types of drugs and therapies are available to treat atherosclerosis, it remains a major cause of mortality throughout the world. Macrophages are the major source of foam cells, which are hallmarks of atherosclerotic lesions. Consequently, the roles of macrophages in the pathophysiology of atherosclerosis are increasingly investigated. Autophagy is a self-protecting cellular catabolic pathway. Since its discovery, autophagy has been found to be associated with a variety of diseases, including cardiovascular diseases, malignant tumors, neurodegenerative diseases, and immune system disorders. Accumulating evidence demonstrates that autophagy plays an important role in inhibiting inflammation and apoptosis, and in promoting efferocytosis and cholesterol efflux. These facts suggest the induction of autophagy may be exploited as a potential strategy for the treatment of atherosclerosis. In this review we mainly discuss the relationship between macrophage autophagy and atherosclerosis and the molecular mechanisms, as well as the recent advances in targeting the process of autophagy to treat atherosclerosis.

Neutrophil gelatinase-associated lipocalin (NGAL) in heart transplant recipients after conversion to everolimus therapy

BACKGROUND

Due to the lack of nephrotoxic activity, proliferation signal inhibitors (PSI) such as everolimus are recommended for immunosuppression after heart transplantation, but the assessment of renal function in patients receiving PSI has led to conflicting results. We examined renal integrity and function using neutrophil gelatinase-associated lipocalin (NGAL) and conventional markers [plasma creatinine, cystatin C, urine albumin, α1-microglobulin (α1M)] in heart transplant patients, who underwent conversion to everolimus due to allograft vasculopathy, graft rejection episodes, or renal function deterioration, and in patients maintained on calcineurin inhibitors (CNI).

METHODS

This cross-sectional study included 121 consecutive heart transplant recipients: 44 patients received CNI-free immunosuppressive therapy with everolimus and 77 patients received CNI. Renal parameters were determined in plasma and urine samples using standard enzymatic or immunochemical methods.

RESULTS

Heart transplant recipients receiving everolimus therapy had significantly lower NGAL concentrations in plasma [median (95% CI): 128 (97-176)ng/mL vs. 252 (224-283)ng/mL, p<0.001] and urine [median (95% CI): 6.4 (4.5-7.6)ng/g vs. 15.7 (10.2-25.9)ng/g creatinine, p<0.001]. In contrast, no significant differences were observed between everolimus- and CNI-treated groups with regard to creatinine and cystatin C, as well as urine albumin and α1M levels. Significant correlations were noted between plasma NGAL and creatinine (r=0.42, p<0.001), cystatin C (r=0.44, p<0.001), N-terminal brain natriuretic propeptide (r=0.31, p<0.01) and indicators of chronic inflammation [lipoprotein-associated phospholipase A2 (Lp-PLA2), r=0.31, p<0.01] and soluble CD40 ligand (sCD40L, r=0.22, p<0.05), and between urinary NGAL and α1M (r=0.21, p<0.05). Multiple regression analysis indicated that cystatin C and Lp-PLA2 were the best predictors of plasma NGAL.

CONCLUSION

The present study documents reduced plasma and urinary NGAL levels in the absence of differences in conventional renal parameters in patients on CNI-free immunosuppressive therapy with everolimus. These results support favorable effects of everolimus on renal integrity in heart transplant recipients.