Transmission of LDLR mutation from donor through liver transplantation resulting in hypercholesterolemia in the recipient

Transplantation of heterozygous familial hypercholesterolemia living donor liver resulting in early myocardial infarction: a possible dangerous link

Living donor liver transplantation (LDLT) is a lifesaving procedure that is often curative for several liver diseases. Familial hypercholesterolemia (FH) is a metabolic disease that results from an autosomal dominant mutation in the low-density lipoprotein receptor; yet, young patients with FH can live years without detection. Herein, we report a case of a patient who developed early myocardial infarction (MI) after having a transplant from a donor with undetected heterozygous FH. This was a 67-year-old female with non-alcoholic steatohepatitis-related liver cirrhosis, free from coronary artery disease, who underwent LDLT from her daughter, a 45-year-old female with no past medical history. One year post-transplant, she presented with an acute MI with a large atherosclerotic burden. Genetic analysis confirmed heterozygous FH in the donor but not in the recipient. This case emphasizes the importance of incorporating a thorough clinical history and lipid profile into pre-transplant testing for both the recipient and donor, as well as aggressive lipid-lowering therapy post-transplantation to avoid cardiovascular complications.

A mixed blessing for liver transplantation patients - Rapamycin

BACKGROUND

Liver transplantation (LT) is an effective treatment option for end-stage liver disease. Mammalian target of rapamycin (mTOR) inhibitors, such as rapamycin, are widely used post LT.

DATA SOURCES

In this review, we focused on the anti-cancer activities and metabolic side effects of rapamycin after LT. The literature available on PubMed for the period of January 1999-September 2022 was reviewed. The key words were rapamycin, sirolimus, liver transplantation, hepatocellular carcinoma, diabetes, and lipid metabolism disorder.

RESULTS

Rapamycin has shown excellent effects and is safer than other immunosuppressive regimens. It has exhibited excellent anti-cancer activity and has the potential in preventing hepatocellular carcinoma (HCC) recurrence post LT. Rapamycin is closely related to two long-term complications after LT, diabetes and lipid metabolism disorders.

CONCLUSIONS

Rapamycin prevents HCC recurrence post LT in some patients, but it also induces metabolic disorders. Reasonable use of rapamycin benefits the liver recipients.

MiR-133a-3p/Sirt1 epigenetic programming mediates hypercholesterolemia susceptibility in female offspring induced by prenatal dexamethasone exposure

Mounting evidence indicates that adverse intrauterine conditions increase offspring's hypercholesterolemia susceptibility in adulthood. This study aimed to confirm prenatal dexamethasone exposure (PDE)-induced hypercholesterolemia susceptibility in female adult offspring rats, and elucidate its intrauterine programming mechanism. Pregnant Wistar rats were injected with dexamethasone subcutaneously (0, 0.1 and 0.2 mg/kg·d) from gestational day (GD) 9 to 20. Serum and liver of the female offspring were collected at GD21 and postnatal week (PW) 12 and 28. PDE offspring showed elevated serum total cholesterol (TCH) levels and a cholesterol phenotype of high cardiovascular disease risk at PW12 and PW28. The histone acetylation levels of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) and its expression were consistently increased in the PDE offspring both in utero and after birth. Moreover, PDE promoted glucocorticoid receptor (GR) nuclear translocation and miR-133a-3p expression and inhibited sirtuin-1 (Sirt1) expression in the fetal liver. In vitro, dexamethasone increased intracellular and supernatant TCH levels and miR-133a-3p expression, decreased SIRT1 expression, and promoted HMGCR histone acetylation and expression in bone marrow mesenchymal stem cells (BMSCs) hepatoid differentiated cells and HepG2 cell line. GR siRNA, miR-133a-3p inhibitor or SIRT1 overexpression reversed dexamethasone-induced downstream molecular and phenotypic changes. Furthermore, elevated TCH levels in umbilical cord blood and increased HMGCR expression in peripheral blood mononuclear cells (PBMCs) were observed in human female neonates who had received dexamethasone treatment during pregnancy. In conclusion, PDE can cause persistent enhancement of hepatic cholesterol synthesis function before and after birth through GR/miR-133a-3p/Sirt1 pathway, eventually leading to increased hypercholesterolemia susceptibility in female offspring rats.

Is Liver Transplant Curative in Homozygous Familial Hypercholesterolemia? A Review of Nine Global Cases

INTRODUCTION

Homozygous familial hypercholesterolemia (HoFH) is a rare, life-threatening, inherited condition characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C). Patients are at high risk of atherosclerotic cardiovascular disease, adverse cardiovascular events, and associated early mortality. Liver transplant is sometimes used with curative intent. The objective of the current case series was to evaluate the follow-up of a range of patients who have undergone liver transplant for the treatment of HoFH.

METHODS

Patients with clinical and/or genetic diagnoses of HoFH were treated according to local practices in four units in Europe and the Middle East. All patients underwent liver transplantation. Baseline and long-term follow-up data were collected, including LDL-C levels, DNA mutations, lipid-lowering medications, and complications due to surgery and immunosuppressive therapy.

RESULTS

Nine patients were included with up to 22 years' follow-up (mean ± SD 11.7 ± 11.7 years; range 0.5-28 years). Three of the patients died as a result of complications of transplant surgery (mortality rate 33%). Among the surviving six patients, four required continued lipid-lowering therapy (LLT) to maintain LDL-C levels and two patients show signs of increasing LDL-C levels that require management. One case (11%) required two consecutive transplants to achieve a viable graft and is awaiting a third transplant because of graft failure.

CONCLUSIONS

Liver transplant did not enable attainment of recommended LDL-C targets in most patients with HoFH, and the majority of patients still required post-transplant LLT. Liver transplant was not curative in most of the patients with HoFH followed. Guidelines suggest that transplant is a treatment of last resort if contemporary treatments are not available or possible.

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

An observational study on the effect of hypercholesterolemia developed after living donor liver transplantation on cardiac event and graft failure

This study sought to evaluate the association between newly-developed significant hypercholesterolemia within one year following living donor liver transplantation (LDLT) and long term outcomes in light of cardiovascular events and graft failure. From October 2003 to July 2017, 877 LDLT recipients were stratified according to development of significant hypercholesterolemia within one year following LDLT. The primary outcome was occurrence of a major adverse cardiac event (MACE), defined as a composite of cardiac death, myocardial infarction, and coronary revascularization after LDLT. The incidence of graft failure, defined as all-cause death or retransplantation, was also compared. A total of 113 (12.9%) recipients developed significant hypercholesterolemia within one year. The differences in incidences of cardiac related events and graft related events began emerging significantly higher in the hypercholesterolemia group after 24 months and 60 months since the LDLT, respectively. After adjustment using the inverse probability of weighting, the hazard ratio (HR) for MACE was 2.77 (95% confidence interval (CI) 1.16–6.61; p = 0.02), while that for graft failure was 3.76 (95% CI 1.97–7.17, p < 0.001). A significant hypercholesterolemia after LDLT may be associated with cardiac and graft-related outcome; therefore, a further study and close monitoring of cholesterol level after LDLT is needed.

miR-148a/LDLR mediates hypercholesterolemia induced by prenatal dexamethasone exposure in male offspring rats

Epidemiology suggests that adverse environmental exposure during pregnancy may predispose children to hypercholesterolemia in adulthood. This study aimed to demonstrate hypercholesterolemia induced by prenatal dexamethasone exposure (PDE) in adult male offspring rats and explore the intrauterine programming mechanisms. Pregnant Wistar rats were injected subcutaneously with dexamethasone (0, 0.1, 0.2, and 0.4 mg/kg∙d) from gestational days (GD) 9 to 21, and the serum and liver of the male offsprings were collected at GD21, postnatal week (PW) 12 and 28. Furthermore, the effects of dexamethasone on the expression of low-density lipoprotein receptor (LDLR) and its epigenetic mechanism was confirmed in the bone marrow mesenchymal stem cells (BMSCs) hepatoid differentiated cells and continuous hepatocyte line. PDE could reduce the birth weight of male offsprings, increase the serum total cholesterol (TCH) level in adult rats, and decrease the liver low-density lipoprotein receptor (LDLR) expression. Serum TCH level and liver LDLR expression were decreased in PDE male fetuses in utero (GD21). Moreover, PDE increased the translocation of the glucocorticoid receptor (GR) in the fetal liver, the expression of DiGeorge syndrome critical region 8 gene (DGCR8), the pre- and post-natal expression of miR-148a. The results of PDE offspring in vivo and in vitro exhibited similar changes. These changes could be reversed by overexpressing LDLR, inhibiting miR-148a or GR. PDE caused hypercholesterolemia in male adult offspring rats, which was mediated via dexamethasone activated intrauterine hepatic GR, enhanced the expression of DGCR8 and miR-148a, thereby reducing the expression of LDLR, leading to impaired liver cholesterol reverse transport function, and finally causing hypercholesterolemia in adult rats.

Glucocorticoid programming mechanism for hypercholesterolemia in prenatal ethanol-exposed adult offspring rats

Our previous studies showed that prenatal ethanol exposure (PEE) elevated blood total cholesterol (TCH) level in adult offspring rats. This study was aimed at elucidating the intrauterine programming mechanism of hypercholesterolemia in adult rats induced by PEE. Pregnant Wistar rats were intragastrically administered ethanol (4 mg/kg∙d) from gestational day (GD) 9 to 20. The offspring rats were euthanized at GD20 and postnatal week 24. Results showed that PEE decreased serum TCH and HDL-C levels (female and male) as well as LDL-C level (female only) in fetal rats but increased serum TCH level and the TCH/HDL-C and LDL-C/HDL-C ratios in adult rats. Furthermore, PEE elevated serum corticosterone levels but inhibited hepatic insulin-like growth factor 1 (IGF1) signaling pathway, cholesterol synthesis and output in fetal rats. The conversed changes were observed in adult rats. Moreover, histone acetylation (H3K9ac and H3K14ac) and expression of hepatic reverse cholesterol transport (RCT) related genes, scavenger receptor BI and low-density lipoprotein receptor were decreased before and after birth by PEE. In HepG2 cells, cortisol negatively regulated the IGF1 signaling pathway and cholesterol metabolic genes, but this inhibition of the cholesterol metabolic genes could be reversed by glucocorticoid receptor antagonist RU486, whereas exogenous IGF1 treatment only reversed the downregulation of RCT genes by cortisol. We confirmed a "two programming" mechanism for PEE-induced hypercholesterolemia in adult rats. The "first programming" was a glucocorticoid (GC)-induced persistent reduction of RCT genes by epigenetic modifications, and the "second programming" was the negative regulation of cholesterol synthesis and output by the GC-IGF1 axis.

Two intrauterine programming mechanisms of adult hypercholesterolemia induced by prenatal nicotine exposure in male offspring rats

Epidemiologic studies showed that low birth weight is associated with high cholesterol and an increased risk of cardiovascular diseases in adulthood. This study aimed to elucidate the intrauterine programming mechanisms of adult hypercholesterolemia. The results showed that prenatal nicotine exposure (PNE) caused intrauterine growth retardation and hypercholesterolemia in male adult offspring rats. Hepatic cholesterol synthesis and output were deceased in utero but increased in adults; hepatic reverse cholesterol transport (RCT) persistently deceased before and after birth. Meanwhile, PNE elevated serum corticosterone level and decreased hepatic IGF1 pathway activity in male fetuses, whereas converse changes were observed in male adults. The chronic stress model and cortisol-treated HepG2 cells verified that excessive glucocorticoid (GC)-induced GC-IGF1 axis programming enhanced hepatic cholesterol synthesis and output. In addition, PNE decreased the expression of specific protein 1 and P300 enrichment and H3K27 acetylation at the promoter region of genes responsible for RCT both in fetal and adult, male livers and reduced expression of those genes, similar alterations were also confirmed in cortisol-treated HepG2 cells, suggesting that excessive GC-related programming induced continuous RCT reduction by epigenetic modification. Taken together, the "2-programming" approach discussed above may ultimately contribute to the development of hypercholesterolemia in male adult offspring.-Zhou, J., Zhu, C., Luo, H., Shen, L., Gong, J., Wu, Y., Magdalou, J., Chen, L., Guo, Y., Wang, H. Two intrauterine programming mechanisms of adult hypercholesterolemia induced by prenatal nicotine exposure in male offspring rats.

Immune complexome analysis of antigens in circulating immune complexes from patients with acute cellular rejection after living donor liver transplantation

Liver transplantation is a life-saving procedure for many end-stage liver diseases; however, rejection after transplantation is still occurs in some recipients. The most common form of rejection is T cell-related acute cellular rejection (ACR). To understand the mechanism of rejection, it is necessary to identify immune targets. Since the development of B cell immunity depends upon concordant T cell immunity, we hypothesized that rejection-specific antigens in circulating immune complexes (CICs) may be present in the sera of recipients experiencing rejection, and as such, may be useful as diagnostic biomarkers for ACR. The purpose of this study was to investigate rejection-specific antigens in CICs (CIC-antigens) in serum of ACR patients. We applied immune complexome analysis, in which CICs are separated from whole serum and then subjected to direct tryptic digestion and identification of CIC-antigens by nano-liquid chromatography-tandem mass spectrometry, to sera of 32 living donor liver transplant recipients (10 recipients experienced ACR and the others did not experience). CIC-antigens were compared between rejection and non-rejection groups to elucidate those that were only detected in the rejection group. We identified 11 CIC-antigens that were only detected in patients who experienced rejection, 4 of which (thrombospondin-1, apolipoprotein E, apolipoprotein C-III, and complement factor H) were only detected during ACR.

Interpreting lipoproteins in nonalcoholic fatty liver disease

PURPOSE OF REVIEW

The pathophysiologies of nonalcoholic fatty liver disease (NAFLD), metabolic syndrome, and cardiovascular disease are closely interlinked and associated with atherogenic dyslipidemia. Liver and cardiovascular disease may silently progress to advanced stages if alarming signs, such as abdominal obesity, elevated fasting and postprandial triglycerides, and low HDL cholesterol are overlooked. We review the metabolic mechanisms in NAFLD at the cellular level in the context of standard clinical lipid measurements.

RECENT FINDINGS

We discuss the pathogenesis of NAFLD, nonalcoholic steatohepatitis (NASH), and metabolic syndrome, atherogenic dyslipidemia, lipotoxicity, and lipophagy.

SUMMARY

Physicians should infer from biomarkers or clinical findings that their abdominally obese patients are at risk of severe cardiovascular, liver fatty disease, or both. Physicians should carry out laboratory tests of plasma cholesterol, triglycerides, LDL and HDL cholesterol, non-HDL cholesterol, apolipoprotein B and platelets, and for diabetes, but importantly, plasma triglycerides also in the nonfasting state. But note, clinical routine plasma lipid and lipoprotein measurements are not necessarily reliable for interpreting severe metabolic changes. Notably, in advanced stages of NAFLD (i.e., late steatohepatitis and cirrhosis), routine lipid profiles do not necessarily show any more abnormalities.

Genetic, hematological, and immunological disorders transmissible with liver transplantation

It is well recognized that solid organ transplantation can transmit bacterial infection and chronic viral hepatitis as well as certain cancers. As indications for liver transplantation (LT) have expanded, it has been used to treat and even cure certain genetic cholestatic disorders, urea cycle defects, and coagulation abnormalities; many of these conditions are potentially transmissible with LT as well. It is important for clinicians and transplant patients to be aware of these potentially transmissible conditions as unexplained post-LT complications can sometimes be related to donor transmission of disease and thus should prompt a thorough exploration of the donor allograft history. Herein, we will review the reported genetic, metabolic, hematologic, and immunological disorders that are transmissible with LT and describe clinical scenarios in which these cases have occurred, such as in inadvertent or recognized transplantation of a diseased organ, domino transplantation, and with living related liver donation. Liver Transplantation 23 663-678 2017 AASLD.

The Hyperlipidemia Caused by Overuse of Glucocorticoid after Liver Transplantation and the Immune Adjustment Strategy

The overuse of glucocorticoid may cause the metabolic disorders affecting the long term outcome of liver transplantation. This study aims to investigate the immune adjustment strategy by decreasing use of glucocorticoid after liver transplantation. The follow-up study was carried out on liver function and lipid metabolism. This study included adult recipients of liver transplantation. There were 3 groups according to their use of glucocorticoid: long term (>3 months, n = 18), short term (<3 months, n = 20), and control group (no use of glucocorticoid, radical hepatic resection, n = 22). The laboratory results of liver function (AST/ALT ratio) and serum lipid were compared 6 months after liver transplantation. AST/ALT ratio, the marker of liver function, showed no significant difference between long and short term group (P > 0.05). The acute rejection had no significant difference between short and long term groups, while TG, HDL, LDL, and glucose showed significant change in the long term group (P < 0.05). At 6 months after liver transplantation, the long term group showed higher metabolic disorders (P < 0.05). The proper immune adjustment strategy should be made to avoid overuse of glucocorticoid. It can decrease hyperlipidemia and other metabolic disorders after liver transplantation without increasing the acute rejection or liver function damage.

Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study

Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk (i.e., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT (i.e., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

Cholesterol metabolism in cholestatic liver disease and liver transplantation: From molecular mechanisms to clinical implications

The aim of this review is to enlighten the critical roles that the liver plays in cholesterol metabolism. Liver transplantation can serve as gene therapy or a source of gene transmission in certain conditions that affect cholesterol metabolism, such as low-density-lipoprotein (LDL) receptor gene mutations that are associated with familial hypercholesterolemia. On the other hand, cholestatic liver disease often alters cholesterol metabolism. Cholestasis can lead to formation of lipoprotein X (Lp-X), which is frequently mistaken for LDL on routine clinical tests. In contrast to LDL, Lp-X is non-atherogenic, and failure to differentiate between the two can interfere with cardiovascular risk assessment, potentially leading to prescription of futile lipid-lowering therapy. Statins do not effectively lower Lp-X levels, and cholestasis may lead to accumulation of toxic levels of statins. Moreover, severe cholestasis results in poor micellar formation, which reduces cholesterol absorption, potentially impairing the cholesterol-lowering effect of ezetimibe. Apolipoprotein B-100 measurement can help distinguish between atherogenic and non-atherogenic hypercholesterolemia. Furthermore, routine serum cholesterol measurements alone cannot reflect cholesterol absorption and synthesis. Measurements of serum non-cholesterol sterol biomarkers - such as cholesterol precursor sterols, plant sterols, and cholestanol - may help with the comprehensive assessment of cholesterol metabolism. An adequate cholesterol supply is essential for liver-regenerative capacity. Low preoperative and perioperative serum cholesterol levels seem to predict mortality in liver cirrhosis and after liver transplantation. Thus, accurate lipid profile evaluation is highly important in liver disease and after liver transplantation.

Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome after Liver Transplant

Liver transplant is the unique curative therapy for patients with acute liver failure or end-stage liver disease, with or without hepatocellular carcinoma. Increase of body weight, onset of insulin resistance and drug-induced alterations of metabolism are reported in liver transplant recipients. In this context, post-transplant diabetes mellitus, hyperlipidemia, and arterial hypertension can be often diagnosed. Multifactorial illnesses occurring in the post-transplant period represent significant causes of morbidity and mortality. This is especially true for metabolic syndrome. Non-alcoholic steatosis and steatohepatitis are hepatic manifestations of metabolic syndrome and after liver transplant both recurrent and de novo steatosis can be found. Usually, post-transplant steatosis shows an indolent outcome with few cases of fibrosis progression. However, in the post-transplant setting, both metabolic syndrome and steatosis might play a key role in the stratification of morbidity and mortality risk, being commonly associated with cardiovascular disease. The single components of metabolic syndrome can be treated with targeted drugs while lifestyle intervention is the only reasonable therapeutic approach for transplant patients with non-alcoholic steatosis or steatohepatitis.

Lipids in liver transplant recipients

Hyperlipidemia is very common after liver transplantation and can be observed in up to 71% of patients. The etiology of lipid disorders in these patients is multifactorial, with different lipid profiles observed depending on the immunosuppressive agents administered and the presence of additional risk factors, such as obesity, diabetes mellitus and nutrition. Due to recent improvements in survival of liver transplant recipients, the prevention of cardiovascular events has become more important, especially as approximately 64% of liver transplant recipients present with an increased risk of cardiovascular events. Management of dyslipidemia and of other modifiable cardiovascular risk factors, such as hypertension, diabetes and smoking, has therefore become essential in these patients. Treatment of hyperlipidemia after liver transplantation consists of life style modification, modifying the dose or type of immunosuppressive agents and use of lipid lowering agents. At the start of administration of lipid lowering medications, it is important to monitor drug-drug interactions, especially between lipid lowering agents and immunosuppressive drugs. Furthermore, as combinations of various lipid lowering drugs can lead to severe side effects, such as myopathies and rhabdomyolysis, these combinations should therefore be avoided. To our knowledge, there are no current guidelines targeting the management of lipid metabolism disorders in liver transplant recipients. This paper therefore recommends an approach of managing lipid abnormalities occurring after liver transplantation.

Risk factors of metabolic syndrome after liver transplantation

BACKGROUND

Liver transplantation is a treatment of choice for both acute and chronic liver failure. Accompanied with the increase of long-term survival rates of recipients, metabolic syndrome and its individual components, including obesity, hyperglycemia, hypertension and hyperlipidemia, have become more frequent post liver transplantation. Here we reviewed the literature concerning the risk factors for the development of metabolic complications in liver recipients.

DATA SOURCES

PubMed was searched for English-language articles published from January 2000 to June 2015. The search criteria focused on risk factors for metabolic syndrome after liver transplantation.

RESULT

The risk factors of metabolic syndrome in liver recipients include older age, obesity, pre-transplantation diabetes mellitus, hepatitis C virus infection, certain genetic polymorphisms and the use of immunosuppressive drugs.

CONCLUSION

Active intervention of the risk factors will reduce the occurrence rate of metabolic syndrome after liver transplantation and improve the recipients' quality of life.