Human induced pluripotent stem cell based hepatic-modeling of lipid metabolism associated TM6SF2 E167K variant.

BACKGROUND AND AIMS: TM6SF2 rs58542926 (E167K) is related to increased prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD). Conflicting mouse study results highlight the need for a human model to understand this mutation's impact. This study aims to create and characterize a reliable human in vitro model to mimic the effects of the TM6SF2-E167K mutation for future studies. APPROACH AND RESULTS: We used gene editing on human human-induced pluripotent stem cells (iPSC) from a healthy individual to create cells with the TM6SF2-E167K mutation. After hepatocyte directed differentiation, we observed decreased TM6SF2 protein expression, increased intracellular lipid droplets and total cholesterol in addition to reduced VLDL secretion. Transcriptomics revealed upregulation of genes involved in lipid, fatty acid, and cholesterol transport, flux, and oxidation. Global lipidomics showed increased lipid classes associated with ER stress, mitochondrial dysfunction, apoptosis, and lipid metabolism. Additionally, the TM6SF2-E167K mutation conferred a pro-inflammatory phenotype with signs of mitochondria and ER stress. Importantly, by facilitating protein folding within the ER of hepatocytes carrying TM6SF2-E167K mutation, VLDL secretion and ER stress markers improved. CONCLUSIONS: Our findings indicate that induced hepatocytes generated from iPSCs carrying the TM6SF2-E167K recapitulate the effects observed in human hepatocytes from individuals with the TM6SF2 mutation. This study characterizes an in vitro model that can be used as a platform to identify potential clinical targets and highlights the therapeutic potential of targeting protein misfolding to alleviate ER stress and mitigate the detrimental effects of the TM6SF2-E167K mutation on hepatic lipid metabolism.

Prediction of portal venous pressure in living donor liver transplantation: A retrospective study.

Liver transplantation is the definitive treatment for advanced liver cirrhosis with portal hypertension. In Japan, the scarcity of deceased donors leads to reliance on living donors, often resulting in smaller grafts. Managing portal venous pressure (PVP) is critical to prevent fatal posttransplant complications. This study explored the possibility of predicting intraoperative PVP. We analyzed 475 living donor liver transplant cases from 2006 to 2023, excluding those with acute liver failure or prior splenectomy or splenic artery embolization. Patients were divided into a training group (n = 425) and a test group (n = 50). We evaluated the correlation between preoperative factors and PVP at laparotomy to predict PVP at laparotomy and closure. The predictive model was validated with the test group data. PVP at laparotomy could be predicted using correlated preoperative factors: prothrombin time ( p < 0.001), predicted splenic volume ( p < 0.001), and presence of a portosystemic shunt ( p = 0.002), as follows: predicted PVP at laparotomy (mm Hg)=25.818 - 0.077 × (prothrombin time [%]) + 0.004 × (predicted splenic volume [mL]) - 2.067 × (1: with a portosystemic shunt) ( p < 0.001; R = 0.346). In addition, PVP at closure could be predicted using correlated operative factors, including measured PVP at laparotomy, as follows: predicted PVP at closure (mm Hg)=14.268 + 0.149 × (measured PVP at laparotomy [mm Hg]) - 0.040 × (GV/SLV [%]) - 0.862 × (1: splenectomy [if yes]) - 3.511 × (1: splenic artery ligation without splenectomy [if yes]) ( p < 0.001; R = 0.339). This study demonstrated the feasibility of predicting intraoperative PVP using preoperative factors in patients with decompensated cirrhosis undergoing liver transplant. This predictive approach could refine surgical planning, potentially improving patient outcomes.

A rat model of cirrhosis with well-differentiated hepatocellular carcinoma induced by thioacetamide.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths, and commonly associated with hepatic fibrosis or cirrhosis. This study aims to establish a rat model mimicking the progression from liver fibrosis to cirrhosis and subsequently to HCC using thioacetamide (TAA). We utilized male Lewis rats, treating them with intra-peritoneal injections of TAA. These rats received bi-weekly injections of either 200 mg/kg TAA or saline (as a control) over a period of 34 weeks. The development of cirrhosis and hepatocarcinogenesis was monitored through histopathological examinations, biochemical markers, and immunohistochemical analyses. Our results demonstrated that chronic TAA administration induced cirrhosis and well-differentiated HCC, characterized by increased fibrosis, altered liver architecture, and enhanced hepatocyte proliferation. Biochemical analyses revealed significant alterations in liver function markers, including elevated alpha-fetoprotein (AFP) levels, without affecting kidney function or causing significant weight loss or mortality in rats. This TAA-induced cirrhosis and HCC rat model successfully replicates the clinical progression of human HCC, including liver function impairment and early-stage liver cancer characteristics. It presents a valuable tool for future research on the mechanisms of antitumor drugs in tumor initiation and development.

What Are Risk Factors for Graft Loss in Patients Who Underwent Simultaneous Splenectomy During Living-donor Liver Transplantation?

BACKGROUND: The consensus that portal venous pressure modulation, including splenectomy (Spx), prevents portal hypertension-related complications after living-donor liver transplantation (LDLT) has been established. However, little evidence about the risk factors for graft loss after simultaneous Spx during LDLT is available. This study aimed to identify the independent predictors of graft loss after simultaneous Spx during LDLT. METHODS: Data of 655 recipients who underwent LDLT between 1997 and 2021 were collected and separated into the simultaneous Spx group (n = 461) and no-Spx group (n = 194). RESULTS: The simultaneous Spx group had significantly lower serum total bilirubin levels, drained ascites volumes, and prothrombin time-international normalized ratios on postoperative day 14 than the no-Spx group ( P < 0.001 for each). Incidences of small-for-size graft syndrome ( P < 0.001), acute cellular rejection ( P = 0.002), and sepsis ( P = 0.007) were significantly lower in the Spx group. Graft survival of the Spx group was significantly better than that of the no-Spx group ( P < 0.001; hazard ratio [HR], 1.788; 95% confidence interval, 1.214-2.431). A multivariate analysis revealed that 3 variables, platelet count ≤4.0 × 10 4 /mm 3 ( P = 0.029; HR, 2.873), donor age ≥60 y old ( P = 0.013; HR, 6.693), and portal venous pressure at closure ≥20 mm Hg ( P = 0.010; HR, 3.891), were independent predictors of graft loss within 6 mo after simultaneous Spx during LDLT. CONCLUSIONS: Spx is a safe inflow modulation procedure with a positive impact on both postoperative complications and prognosis for most patients. However, patients with the 3 aforementioned independent factors could experience graft loss after LDLT.

Feasibility of venous cuff using an open round ligament or inferior mesenteric vein around the hepatic vein for a left lobe graft in living-donor liver transplantation.

Living-donor liver transplantation (LDLT) is an established treatment for patients with end-stage liver disease or acute liver failure, and outflow reconstruction is considered one of the most vital techniques in LDLT. To date, many strategies have been reported to prevent outflow obstruction, which can be refractory to liver dysfunction and can cause life-threatening graft loss or mortality. In addition, in this era of laparoscopic hepatectomy in donor surgery, especially LDLT using a left liver graft, it has been predicted that cutting the hepatic vein with automatic linear staplers will lead to more outflow-related problems than with conventional open hepatectomy because of the short neck of the anastomosis orifice. We herein review 10 cases of venoplasty performed with a novel venous cuff system using a donor's round ligament around the hepatic vein in LDLT with a left lobe graft, which makes anastomosis of the hepatic vein sterically easy for postoperative venous patency.

Polymorphisms Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease Influence the Progression of End-Stage Liver Disease.

BACKGROUND AND AIMS: Chronic liver injury that results in cirrhosis and end-stage liver disease (ESLD) causes more than 1 million deaths annually worldwide. Although the impact of genetic factors on the severity of metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-related liver disease (ALD) has been previously studied, their contribution to the development of ESLD remains largely unexplored. METHODS: We genotyped 6 MASLD-associated polymorphisms in healthy (n = 123), metabolic dysfunction-associated steatohepatitis (MASH) (n = 145), MASLD-associated ESLD (n = 72), and ALD-associated ESLD (n = 57) cohorts and performed multinomial logistic regression to determine the combined contribution of genetic, demographic, and clinical factors to the progression of ESLD. RESULTS: Distinct sets of factors are associated with the progression to ESLD. The PNPLA3 rs738409:G and TM6SF2 rs58542926:T alleles, body mass index (BMI), age, and female sex were positively associated with progression from a healthy state to MASH. The PNPLA3 rs738409:G allele, age, male sex, and having type 2 diabetes mellitus were positively associated, while BMI was negatively associated with progression from MASH to MASLD-associated ESLD. The PNPLA3 rs738409:G and GCKR rs780094:T alleles, age, and male sex were positively associated, while BMI was negatively associated with progression from a healthy state to ALD-associated ESLD. The findings indicate that the PNPLA3 rs738409:G allele increases susceptibility to ESLD regardless of etiology, the TM6SF2 rs58542926:T allele increases susceptibility to MASH, and the GCKR rs780094:T allele increases susceptibility to ALD-associated ESLD. CONCLUSION: The PNPLA3, TM6SF2, and GCKR minor alleles influence the progression of MASLD-associated or ALD-associated ESLD. Genotyping for these variants in MASLD and ALD patients can enhance risk assessment, prompting early interventions to prevent ESLD.

Effect of Early Enteral Nutrition on Graft Loss After Living Donor Liver Transplantation: A Propensity Score Matching Analysis.

BACKGROUND: This study aimed to elucidate the effect of early enteral nutrition on graft loss within 12 h after living-donor liver transplantation (LDLT) using propensity score-matching analysis and subsequently examine the risk factors for graft loss after LDLT. METHODS: We retrospectively reviewed the data of 467 LDLT patients who were assigned to the early and non-early groups based on the optimal cutoff value of 12 h for the starting time of early enteral nutrition after LDLT to predict graft loss. RESULTS: The 1-year graft survival rate of the early group before propensity score-matching was 92.1%, whereas the 1-year graft survival rate of the non-early group was 86.2%. There was no significant difference between the 2 groups (P = .067). The incidences of early allograft dysfunction (EAD), small-for-size graft (SFSG) syndrome, acute cellular rejection (ACR), and sepsis were not statistically different between the 2 groups (P = .12, .91, .46, and .056, respectively). After propensity score-matching, the 1-year graft survival rate of the early group was 94.4%, whereas the 1-year graft survival rate of the non-early group was 85.4% (P = .034). The incidences of EAD, SFSG syndrome, and ACR were not statistically different between the 2 groups (P = .43, .81, and .24, respectively). However, the incidence of sepsis was statistically different between the 2 groups (non-early: 10.7% vs early: 3.6%, P = .038). CONCLUSION: Early enteral nutrition within 12 h after LDLT may contribute to better graft survival in LDLT patients by preventing sepsis.

Evaluation of Human Hepatocyte Drug Metabolism Carrying High-Risk or Protection-Associated Liver Disease Genetic Variants.

Metabolic-dysfunction-associated steatotic liver disease (MASLD), which affects 30 million people in the US and is anticipated to reach over 100 million by 2030, places a significant financial strain on the healthcare system. There is presently no FDA-approved treatment for MASLD despite its public health significance and financial burden. Understanding the connection between point mutations, liver enzymes, and MASLD is important for comprehending drug toxicity in healthy or diseased individuals. Multiple genetic variations have been linked to MASLD susceptibility through genome-wide association studies (GWAS), either increasing MASLD risk or protecting against it, such as PNPLA3 rs738409, MBOAT7 rs641738, GCKR rs780094, HSD17B13 rs72613567, and MTARC1 rs2642438. As the impact of genetic variants on the levels of drug-metabolizing cytochrome P450 (CYP) enzymes in human hepatocytes has not been thoroughly investigated, this study aims to describe the analysis of metabolic functions for selected phase I and phase II liver enzymes in human hepatocytes. For this purpose, fresh isolated primary hepatocytes were obtained from healthy liver donors (n = 126), and liquid chromatography-mass spectrometry (LC-MS) was performed. For the cohorts, participants were classified into minor homozygotes and nonminor homozygotes (major homozygotes + heterozygotes) for five gene polymorphisms. For phase I liver enzymes, we found a significant difference in the activity of CYP1A2 in human hepatocytes carrying MBOAT7 (p = 0.011) and of CYP2C8 in human hepatocytes carrying PNPLA3 (p = 0.004). It was also observed that the activity of CYP2C9 was significantly lower in human hepatocytes carrying HSD17B13 (p = 0.001) minor homozygous compared to nonminor homozygous. No significant difference in activity of CYP2E1, CYP2C8, CYP2D6, CYP2E1, CYP3A4, ECOD, FMO, MAO, AO, and CES2 and in any of the phase II liver enzymes between human hepatocytes carrying genetic variants for PNPLA3 rs738409, MBOAT7 rs641738, GCKR rs780094, HSD17B13 rs72613567, and MTARC1 rs2642438 were observed. These findings offer a preliminary assessment of the influence of genetic variations on drug-metabolizing cytochrome P450 (CYP) enzymes in healthy human hepatocytes, which may be useful for future drug discovery investigations.

Human Hepatocellular response in Cholestatic Liver Diseases.

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), the most common types of cholestatic liver disease (CLD), result in enterohepatic obstruction, bile acid accumulation, and hepatotoxicity. The mechanisms by which hepatocytes respond to and cope with CLD remain largely unexplored. This study includes the characterization of hepatocytes isolated from explanted livers of patients with PBC and PSC. We examined the expression of hepatocyte-specific genes, intracellular bile acid (BA) levels, and oxidative stress in primary-human-hepatocytes (PHHs) isolated from explanted livers of patients with PBC and PSC and compared them with control normal human hepatocytes. Our findings provide valuable initial insights into the hepatocellular response to cholestasis in CLD and help support the use of PHHs as an experimental tool for these diseases.

Ultrasonic Debridement of Fournier Gangrene.

Ultrasonic debridement devices are minimally invasive and effective for biofilm removal, allowing for debridement of necrotic tissue while minimizing damage to normal tissues, such as the blood vessels and nerves. The use of ultrasonic debridement has been reported for foot ulcers and pressure ulcers but not Fournier gangrene. The perineal area, which is difficult to surgically debride using electrocautery, is a suitable site for the use of an ultrasonic debridement device because of its proximity to vital organs. We report here a case of Fournier gangrene that healed with testicular sparing using an ultrasonic debridement device.

Clinical association between intraoperative indocyanine green fluorescence imaging pattern, preoperative Gd-EOB-DTPA-enhanced magnetic resonance imaging findings, and histological differentiation in hepatocellular carcinoma.

AIM: We aimed to evaluate the association between the intraoperative indocyanine green (ICG) fluorescence imaging (FI) pattern, preoperative magnetic resonance imaging (MRI) findings using gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA), preoperative diffusion-weighted imaging (DWI) of MRI, and histological differentiation of hepatocellular carcinoma (HCC). METHODS: We retrospectively reviewed the data for 80 tumors of 64 patients. Intraoperative ICG FI patterns were classified into cancerous or rim-positive type. We evaluated the signal intensity ratio of the tumor and the surrounding liver tissue in the portal phase (SIRPP) and intensity in the hepatobiliary phase (HBP) of Gd-EOB-DTPA-enhanced MRI, the apparent diffusion coefficient (ADC) in the DWI of MRI, and clinicopathologic factors. RESULTS: In the rim-positive group, the rate of poorly differentiated HCC and hypointensity type in HBP were significantly higher, and SIRPP and ADC were significantly lower than the rim-negative group. In the cancerous group, the rate of well or moderately differentiated HCC and hyperintensity type in HBP, SIRPP, and ADC were significantly higher than the noncancerous group. Multivariate analysis identified low SIRPP, low ADC, and hypointensity type in HBP as the significant predictive factors for rim-positive HCC and high SIRPP, high ADC, and hyperintensity type in HBP as the significant predictive factors for cancerous HCC. The positive rate of programmed cell death 1-ligand 1 and vessels that encapsulate tumor clusters status of the rim-positive HCC and HCC with low SIRPP were significantly higher than the control group. CONCLUSIONS: The intraoperative ICG FI pattern of HCC closely correlated with histological differentiation, preoperative SIRPP and intensity type in the Gd-EOB-DTPA MRI, and preoperative ADC in the DWI of MRI.

Clinical Significance of Signal Regulatory Protein Alpha (SIRPα) Expression in Hepatocellular Carcinoma.

BACKGROUND: Signal regulatory protein alpha (SIRPα), expressed in the macrophage membrane, inhibits phagocytosis of tumor cells via CD47/SIRPα interaction, which acts as an immune checkpoint factor in cancers. This study aimed to clarify the clinical significance of SIRPα expression in hepatocellular carcinoma (HCC). METHODS: This study analyzed SIRPα expression using RNA sequencing data of 372 HCC tissues from The Cancer Genome Atlas (TCGA) and immunohistochemical staining of our 189 HCC patient cohort. The correlation between SIRPα expression and clinicopathologic factors, patient survival, and intratumor infiltration of immune cells was investigated. RESULTS: Overall survival (OS) was significantly poorer with high SIRPα expression than with low expression in both TCGA and our cohort. High SIRPα expression correlated with lower recurrence-free survival (RFS) in our cohort. High SIRPα expression was associated with higher rates of microvascular invasion and lower serum albumin levels and correlated with greater intratumor infiltration of CD68-positive macrophages and myeloid-derived suppressor cells (MDSCs). Multivariate analysis showed that SIRPα expression and high infiltration of CD8-positive T cells and MDSCs were predictive factors for both RFS and OS. Patients with high SIRPα expression and infiltration of CD8-positive T cells and MDSCs had significantly lower RFS and OS rates. In spatial transcriptomics sequencing, SIRPα expression was significantly correlated with CD163 expression. CONCLUSIONS: High SIRPα expression in HCC indicates poor prognosis, possibly by inhibiting macrophage phagocytosis of tumor cells, promoting MDSC infiltration and inducing antitumor immunity. Treatment alternatives using SIRPα blockage should be considered in HCC as inhibiting macrophage antitumor immunity and MDSCs.

A rare case of unresectable, microsatellite instability-high hepatocellular carcinoma and an examination of the tumor microenvironment.

Hepatocellular carcinoma (HCC) is a common cause of cancer-related deaths worldwide, and the mortality rate of patients with unresectable HCC is very high. Microsatellite instability (MSI) is an essential biomarker for response to immune checkpoint inhibitors (ICI) in various tumors. However, the frequency of MSI in HCC is low (1.11%). There is only one case report of MSI-high HCC, and it is not well understood how high MSI affects the tumor microenvironment of HCC. Hence, we describe an interesting patient with unresectable MSI-high HCC, including the evaluation of immune status in the tumor microenvironment. A 68-year-old man presented to our department with HCC in liver segment 1. Contrast-enhanced CT revealed a liver tumor of 6.0 cm in maximum size. The patient underwent extended left and caudate lobectomy of the liver for HCC. Four months after surgical resection, contrast-enhanced computed tomography (CECT) detected 13 recurrent nodules. The patient was diagnosed with unresectable hepatocellular carcinoma recurrence, and we decided to administer systematic chemotherapy. Lenvatinib was administered over approximately 2 years as a first-line treatment, which resulted in intrahepatic tumor shrinkage. However, follow-up CECT showed new lesions, hepatogastric mesentery lymph node swelling, and peritoneal dissemination. After MSI-high status was identified, the patient began to receive pembrolizumab (200 mg, every 3 weeks). Eleven cycles of pembrolizumab therapy were administered over approximately 8 months, during which the diameter of the hepatogastric mesentery lymph node swelling and peritoneal dissemination showed shrinkage but later re-increased. As the third- and fourth-line therapy has been administered, the tumors and lymph nodes have shrunk. We report a rare case in which multikinase inhibitors were effectively used to treat MSI-high HCC.

Predictive Factors for the Resectable Type of Hepatocellular Carcinoma Recurrence After Living Donor Liver Transplant.

Recurrence of hepatocellular carcinoma (HCC) after living donor liver transplant (LDLT) is an essential factor defining prognosis, and surgical resection is the only curative treatment. However, the factors that define whether surgical resection is possible remain unclear. Here, we compared resectable and unresectable HCC recurrence cases after LDLT and examined factors that determine whether surgical resection is possible. Resectable (n = 17) and unresectable (n = 14) groups among 264 patients who underwent LDLT for HCC from January 1999 to March 2020 were compared and examined for recurrence type, prognosis, and clinicopathologic factors. Overall survival after LDLT (median, 8.5 vs 1.7 years, P < .01) was significantly longer in the resectable group. In univariate analysis, female recipient rate, lymphocyte to monocyte ratio (LMR) ≥2.75, and tumor size ≤5.0 cm were significantly higher in the resectable group. Younger donors, lower Model for End-Stage Liver Disease scores, lower graft volume, and lower graft volume to standard liver volume ratio were evident in the resectable group. In multivariate analysis, female recipient rate (P = .0034) and LMR ≥2.75 (P = .0203) were independent predictive factors for resectable HCC recurrence after LDLT. Female recipient and LMR ≥2.75 before transplant could predict the surgically resectable type of HCC recurrence after LDLT.

Endovascular therapy and free flap transfer in chronic limb-threatening ischemia.

Although revascularization has evolved, treating foot gangrene with chronic limb-threatening ischemia remains challenging. There have been many reports on bypass surgery and free flap transfer. Meanwhile, few studies have reported on endovascular therapy and free flap transfer, with high flap survival rates and high wound complication rates. Wound complications are a serious problem that can lead to limb amputation, but previous studies have failed to identify risk factors for wound complications. In this study, we evaluated the results of endovascular therapy and free flap transfer for chronic limb-threatening ischemia and analyzed risk factors for wound complications. A total of 31 legs from 28 patients who underwent endovascular therapy and free flap transfer for lower limb salvage between August 2016 and April 2020 were retrospectively reviewed. The primary endpoints were flap survival and limb salvage rates and wound complication rates. In addition, we performed a statistical analysis of risk factors for wound complications. The flap survival rate was 100%, with partial necrosis in 6% of the patients. The limb salvage rate was 100%. The wound complication rate was 45%. The multivariate analysis showed end-stage renal failure on dialysis as a significant risk factor for wound complications (odds ratio = 133, 95% confidence interval = 2.74-6430, p = 0.014). Endovascular therapy and free flap transfer in chronic limb-threatening ischemia achieved high flap survival rate and limb salvage, but had a high incidence of wound complications. We identified end-stage renal failure on dialysis was a significant risk factor for wound complications.

Cancer-associated fibroblasts promote tumor cell growth via miR-493-5p in intrahepatic cholangiocarcinoma.

The association between tumor microenvironment (TME) and cancer-associated fibroblasts (CAFs) in intrahepatic cholangiocarcinoma (ICC) progression is poorly understood. This study aimed to reveal whether specific microRNAs (miRNAs) in extracellular vesicles (EVs) derived from CAFs were involved in ICC progression. Conditioned medium (CM) and EVs in the CM of CAFs and normal fibroblasts (NFs) derived from ICC specimens were used to investigate the effects on tumor cell lines. miRNA microarray assay was used to examine the miRNAs of EVs derived from CAFs and NFs in ICC, and the effects of miR-493-5p on tumor cell lines were examined. Additionally, databases were used to identify miR-493-5p targets, and the relationship between prognosis of ICC patients and cocaine- and amphetamine-regulated transcript propeptide (CARTPT), one of the targets of miR-493-5p, expression in ICC tissues was retrospectively analyzed. Compared with NF-derived CM and EVs, CAF-derived CM and EVs promoted cell lines in proliferation, scratch, migration, and invasion assays. miRNA microarray analysis revealed that miR-493-5p was significantly increased in CAF-derived EVs compared to NF-derived EVs. Tumor cell lines transfected with miR-493-5p were promoted in proliferation and scratch assays. Immunohistochemical staining was performed on 76 ICC specimens; both overall and recurrence-free survival rates were significantly worse in the CARTPT-negative group. Univariate and multivariate analyses showed that low CARTPT expression was an independent poor prognostic factor for overall and recurrence-free survival. Overall, our data suggest that CAFs in the ICC TME suppress CARTPT in tumor cells and promote tumor cells via miR-493-5p in EVs.

Human Induced Pluripotent Stem Cell based Hepatic-Modeling of Lipid metabolism associated TM6SF2 E167K variant.

BACKGROUND AND AIMS: TM6SF2 rs58542926 (E167K) is associated with an increase in the prevalence of Metabolic Disfunction-Associated Steatotic Liver Disease (MASLD). Despite all the investigation related to the role of this variant in lipid metabolism, conflicting results in mouse studies underscore the importance of creating a human model for understanding the TM6SF2 mechanism. Therefore, the aim of this study is to generate a reliable human in vitro model that mimic the effects of the TM6SF2 E167K mutation and can be used for future mechanism studies. APPROACH AND RESULTS: We performed gene editing on human-induced pluripotent stem cells (iPSC) derived from a healthy individual to obtain the cells carrying the TM6SF2 E167K mutation. After hepatic differentiation, a decrease in TM6SF2 protein expression was observed in the mutated-induced hepatocyte. An increase in intracellular lipid droplets and a decrease in the efflux of cholesterol and ApoB100 were also observed. Transcriptomics analysis showed up-regulation of genes related to the transport, flux, and oxidation of lipids, fatty acids, and cholesterol in TM6SF2 E167K cells. Additionally, signs of cellular stress were observed in the ER and mitochondria. CONCLUSIONS: Our findings indicate that induced hepatocytes generated from iPSC carrying the TM6SF2 E167K recapitulate the effects observed in human hepatocytes from individuals with the TM6SF2 mutation. This study characterizes an in vitro model that can be used as a platform to help in the identification of potential clinical targets and therapies and to understand the mechanism by which the TM6SF2 E167K variant leads to vulnerability to MASLD.

Donor Skeletal Muscle Quality Affects Graft Mortality After Living Donor Liver Transplantation- A Single Center, Retrospective Study.

The recipient muscle status is closely associated with postoperative poor survival in recipients of living donor liver transplantation (LDLT). However, it is uncertain whether LDLT donor muscle quality and quantity affect graft quality. Hence, we analyzed the correlation between donor muscle status and graft function. We measured the skeletal muscle mass index (SMI) and intramuscular adipose tissue content (IMAC) of 380 LDLT donors. We examined the correlation between donor SMI or IMAC and graft mortality, the occurrence rates of small-for-size graft (SFSG) syndrome, and 6-month graft survival rates. The donor SMI had no effect on the occurrence of SFSG syndrome and graft survival, while a high IMAC in both male and female donors was significantly correlated with the rate of SFSG syndrome [high vs low: (male donors) 15.8% vs. 2.5%, p = 0.0003; (female donors) 12.8% vs. 3.1%, p = 0.0234] and 6-month graft survival rates [(male donors) 87.7% vs 95.9%, p = 0.02; (female donors) 83.0% vs. 99.0%, p < 0.0001]. Multivariate analysis revealed that a high donor IMAC (HR; 5.42, CI; 2.13-13.8, p = 0.0004) was an independent risk factor for 6-month graft survival, and the donor IMAC is useful for donor selection for high-risk recipients.

Autoimmune Hepatitis in an Immunosuppression-Free Patient Who Underwent Living Donor Liver Transplantation From an Identical Twin: A Case Report.

Although there have been a few liver transplantations (LTs) between identical twins, to our knowledge hepatic damage after LT in an immunosuppressant-free patient has not been reported. Autoimmune liver disease recurrence after LT is also a postoperative problem. In this follow-up to our previous report, we present the case of a 57-year-old man with acute liver failure who underwent living donor liver transplantation (LDLT) from an identical twin. Six months after LDLT, the patient was free from immunosuppressive medication and showed good liver function. However, 1 year after LDLT, he developed liver damage and was diagnosed with autoimmune hepatitis by liver biopsy. His liver function was improved with steroid pulse therapy and the resumption of immunosuppressive medications. Even after LDLT from an identical twin, careful management is required for patients to remain free of immunosuppressive medications, considering the background liver disease.