Reduced Ceramides Are Associated with Acute Rejection in Liver Transplant Patients and Skin Graft and Hepatocyte Transplant Mice, Reducing Tolerogenic Dendritic Cells.

We set up this study to understand the underlying mechanisms of reduced ceramides on immune cells in acute rejection (AR). The concentrations of ceramides and sphingomyelins were measured in the sera from hepatic transplant patients, skin graft mice and hepatocyte transplant mice by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Serum concentrations of C24 ceramide, C24:1 ceramide, C16:0 sphingomyelin, and C18:1 sphingomyelin were lower in liver transplantation (LT) recipients with than without AR. Comparisons with the results of LT patients with infection and cardiac transplant patients with cardiac allograft vasculopathy in humans and in mouse skin graft and hepatocyte transplant models suggested that the reduced C24 and C24:1 ceramides were specifically involved in AR. A ceramide synthase inhibitor, fumonisin B1 exacerbated allogeneic immune responses in vitro and in vivo, and reduced tolerogenic dendritic cells (tDCs), while increased P3-like plasmacytoid DCs (pDCs) in the draining lymph nodes from allogeneic skin graft mice. The results of mixed lymphocyte reactions with ceranib-2, an inhibitor of ceramidase, and C24 ceramide also support that increasing ceramide concentrations could benefit transplant recipients with AR. The results suggest increasing ceramides as novel therapeutic target for AR, where reduced ceramides were associated with the changes in DC subsets, in particular tDCs.

Different antibody responses between liver and kidney transplant recipients elicited by third doses of COVID-19 mRNA vaccines.

Background: Solid organ transplant recipients exhibit decreased antibody responses, mainly due to their weakened immune systems. However, data are limited on antibody responses after the primary series of coronavirus disease 2019 (COVID-19) vaccines among recipients of various solid organ transplant types. Thus, we compared the antibody responses after three COVID-19 vaccine doses between liver transplant (LT) and kidney transplant (KT) recipients. Methods: We prospectively enrolled solid organ transplant recipients who received three COVID-19 vaccine doses from June 2021 to February 2022 and measured S1-specific immunoglobulin G antibodies using an enzyme-linked immunosorbent assay. Results: Seventy-six LT and 17 KT recipients were included in the final analysis. KT recipients showed consistently lower antibody responses even after the third vaccine dose (86.2% vs. 52.9%, P=0.008) and lower antibody titers (median, 423.0 IU/mL [interquartile range, 99.6-2,057 IU/mL] vs. 19.7 IU/mL [interquartile range, 6.9-339.4 IU/mL]; P=0.006) than were observed in LT recipients. Mycophenolic acid was a significant risk factor for a seropositive antibody response after the third vaccine dose in the multivariable analysis (odds ratio, 0.06; 95% confidence interval, 0.00-0.39; P=0.02). Conclusions: We found a weaker antibody response despite the completion of the primary series of COVID-19 vaccines in KT recipients than in LT recipients. Mycophenolic acid use in KT recipients might be the main contributor to this observation.

Time taken to resume activities of daily living after transsphenoidal surgery for pituitary tumors.

Postoperative management after transsphenoidal surgery (TSS) is important; however, the guidelines for resuming daily activities after TSS are insufficient. This study aimed to examine the time to return to activities of daily living (ADL) after TSS for pituitary tumors. A 4-month prospective data collection was completed for 114 of 117 patients who underwent TSS for pituitary tumors from April to July 2021. The time when the patient returned to ADL after surgery was measured using the self-recording sheet. More than 97% and 92% of the patients returned within 1 month (median: within 7 days) for the elements of basic ADL and within 2 months (median: within 15 days) for the elements of instrumental ADL, excluding a few. Notably, 73.3% of patients returned to work within 4 months. The median time for the activities included 64 days for washing hair head down, 44 days for blowing nose, 59 days for lifting heavy objects, and 102 days for sexual activity. For patients who received extended-TSS or had postoperative problems, the time to return was delayed. Based on these results, it will be possible to provide practical information and guidelines on the time to return to ADL after TSS in pituitary tumor patients.

A single-center prospective study regarding time to return to activities of daily living after craniotomy for brain tumors.

BACKGROUND: There are few studies on the time to return to activities of daily living (ADL) after craniotomy in patients with brain tumors. This study aimed to investigate the duration before returning to ADLs after craniotomy for brain tumors and present data that can provide information and guidelines on the appropriate time needed. METHODS: Patients (n = 183 of 234) who underwent craniotomy for brain tumors between April 2021 and July 2021 capable of self-care upon discharge were enrolled, and data of 158 were collected. The start time of 85 ADL items was prospectively investigated for 4 months postoperatively, using the self-recording sheet. RESULTS: Over 89% and 87% of the patients performed basic ADL items within a month and instrumental ADL items within 2 months (medians: within 18 days), except for a few. Regarding work, 50% of the patients returned within 4 months. Washing hair with a wound was performed at 18 days of median value, after 4 months of dyeing/perming hair, 6 days of drinking coffee/tea, after 4 months of air travel, and 40 days of complementary and alternative medicine. In patients with infratentorial tumors or surgical problems, return times were much later for various items. CONCLUSIONS: It is possible to provide practical information and guidelines on the duration to return to ADL after craniotomy in brain tumor patients. These study findings also reduce uncertainty about recovery and daily life and help patients return to their daily life at the appropriate time, thereby maintaining function and daily well-being after surgery.

Cytotoxicity of Human Hepatic Intrasinusoidal Gamma/Delta T Cells Depends on Phospho-antigen and NK Receptor Signaling.

BACKGROUND/AIM: We previously showed that human hepatic intrasinusoidal (HI) natural killer (NK) T cells selectively eliminate hepatocellular carcinoma (HCC) cell lines. In this study, we investigated the underlying mechanisms on how HI γδ T cells, expanded with zoledronate, exhibit a superior cytotoxic effect on HI NK-resistant Huh7 HCC cells. MATERIALS AND METHODS: γδ T cells were obtained from living liver transplant donors or from peripheral blood mononuclear cells (PBMC) of healthy volunteers and were expanded in the presence of IL-2, IL-15, and zoledronate for 2 weeks. Cytotoxicity was measured using the lactate dehydrogenase (LDH) assay in vitro and by flow cytometry using carboxyfluorescein succinimidyl ester (CFSE) in vivo. RESULTS: The cytotoxicity of expanded HI γδ T cells against Huh7 cells was associated with a higher pyrophosphate expression in Huh7 cells compared to SNU398 cells. In contrast, the cytotoxicity of HI γδ T cells against SNU398 cells depended on NKG2D. HI γδ T cells expressed less PD-1 than PB γδ T cells. The cytotoxicity of HI γδ T cells against Du145 and PC3 prostate cancer cells was also associated with pyrophosphate expression in these cells, as well as NKG2D and DNAM-1. CONCLUSION: The expression levels of phospho-antigen in tumor cells determined the cytotoxicity of HI γδ T cells, although the NK activating receptors, death ligands, and immune checkpoint molecules also contribute to their cytotoxicity. γδ T cells are attractive candidates for cancer immune cell therapy.

Incidence of superficial left hepatic vein and its usability for graft hepatic vein venoplasty in pediatric liver transplantation.

BACKGROUNDS: The anatomy of the left hepatic vein (LHV) is variable; thus, it should be considered for graft hepatic vein (GHV) venoplasty for left lateral section (LLS) and left liver grafts. This study assessed the incidence of superficial LHV (sLHV) branches according to LHV anatomy and its usability for GHV venoplasty in pediatric liver transplantation (LT). METHODS: This study consisted of three parts: (1) anatomical classification of LHV variations and the incidence of sLHV branches; (2) morphometric simulative analysis of GHV reconstruction and (3) clinical application based on LHV anatomy. RESULTS: The LHV anatomy of 248 potential LLS graft donors was classified into four types according to the number and location of GHV openings: one single opening (type 1; n = 186 [75.0%]), two large openings (type 2; n = 35 [14.1%]), one large and one small adjacent opening (type 3; n = 14 [5.6%]), and two large widely-separated openings (type 4; n = 13 [5.2%]). An sLHV branch was identified in 87 of 248 (35.1%) donor livers. Morphometric analysis of simulative GHV venoplasty with an sLHV branch increased GHV diameters by 30% in type 1 LLS grafts and 20% in type 2/3 LLS grafts. An analysis of 50 consecutive patients who underwent pediatric LT showed that the 2-year rates of GHV obstruction were 2.0% with LLS grafts and 0% with left liver grafts. CONCLUSIONS: The GHV orifice can be enlarged through LHV anatomy-based unification venoplasty. Unification venoplasty with an sLHV branch provided sufficient enlargement of the GHV orifice.

Therapeutic strategies for liver diseases based on redox control systems.

In the liver, reactive oxygen species (ROS) are constantly released during cellular metabolic processes, and excess ROS production can cause redox stress. The redox stress is both beneficial for and harmful to the survival of cells since it modulates the cellular redox control system. The redox control system is a series of cellular responses that are responsible for maintaining a balanced oxidation-reduction status. Many cellular processes including growth, proliferation, and senescence are sensitively regulated by the redox control system. Imbalance of redox induces redox stress and damages DNA, proteins, and lipids in cells, and further contributes to the pathogenesis of severe diseases and disorders like cancer. However, the cellular redox control system also utilizes redox stress-responsive pathways and increases antioxidant enzymes to aid cell survival. Therefore, a deeper understanding of the connection between the redox control system and liver disease is likely to pave the way for the future development of new therapeutic strategies. This review will examine the redox control systems in liver with responsive regulating molecules, current knowledge of the redox control system and liver disease, and suggest potential therapeutic targets for liver diseases.

Clusterin Binding Modulates the Aggregation and Neurotoxicity of Amyloid-ß(1-42).

Alzheimer's disease (AD) is the most common neurodegenerative disorder characterized by the accumulation of amyloid-ß (Aß) aggregates in the brain. Clusterin (CLU), also known as apolipoprotein J, is a potent risk factor associated with AD pathogenesis, in which Aß aggregation is essentially involved. We observed close colocalization of CLU and Aß(1-42) (Aß42) in parenchymal amyloid plaques or vascular amyloid deposits in the brains of human amyloid precursor protein (hAPP)-transgenic Tg2576 mice. Therefore, to elucidate the binding interaction between CLU and Aß42 and its impact on amyloid aggregation and toxicity, the two synthetic proteins were incubated together under physiological conditions, and their structural and morphological variations were investigated using biochemical, biophysical, and microscopic analyses. Synthetic CLU spontaneously bound to different possible variants of Aß42 aggregates with very high affinity (Kd = 2.647 nM) in vitro to form solid CLU-Aß42 complexes. This CLU binding prevented further aggregation of Aß42 into larger oligomers or fibrils, enriching the population of smaller Aß42 oligomers and protofibrils and monomers. CLU either alleviated or augmented Aß42-induced cytotoxicity and apoptosis in the neuroblastoma-derived SH-SY5Y and N2a cells, depending on the incubation period and the molar ratio of CLU:Aß42 involved in the reaction before addition to the cells. Thus, the effects of CLU on Aß42-induced cytotoxicity were likely determined by the extent to which it bound and sequestered toxic Aß42 oligomers or protofibrils. These findings suggest that CLU could influence amyloid neurotoxicity and pathogenesis by modulating Aß aggregation.

Enhanced Tumoricidal Immune Responses by Transarterial Chemotherapy Using Novel Nanocomplexes in a Rat Liver Cancer Model.

BACKGROUND/AIM: Locoregional treatments for hepatocellular carcinoma (HCC) induce immunogenic cell death and a tumor-specific immune response, but infiltration and activation of immune cells in the liver have not been clearly described. Transarterial chemoembolization (TACE) or transarterial chemotherapy (TAC) without embolization have been used to treat intermediate or advanced stage HCC patients. The identification of intrahepatic immune cell changes after locoregional therapy provides a theoretical basis for the combination with immune checkpoint inhibitors (ICIs) in HCC. This study aimed to determine the anticancer effect and changes in the liver immune cell population and function after direct injection of polymerized phenylboronic acid-conjugated doxorubicin (pPBA-Dox) nanocomplexes into the liver through TAC. MATERIALS AND METHODS: pPBA-Dox nanocomplexes were delivered directly to the liver cancer in a rat model by transarterial methods. Anticancer effect was confirmed by magnetic resonance imaging (MRI), and the immune cell population and functional changes were confirmed by flow cytometry (FACS). RESULTS: We first established a rat liver cancer model by implanting McA-RH7777 into rats and confirmed the formation of liver cancer through MRI, pathological examinations, and biochemical tests. Transarterial injection of pPBA-Dox nanocomplexes had a stronger anticancer effect than conventional Dox alone. Higher numbers of CD8+ and CD4+ T cells with activated phenotypes were infiltrated into the tumor microenvironment after transarterial pPBA-Dox treatments than after Dox alone treatment, suggesting the induction of stronger local immune responses by pPBA-Dox than Dox alone. CONCLUSION: This study provides a theoretical basis for TAC combined with ICIs and insight into novel targeted therapies using nanocomplexes for the treatment of HCC.

Antibody Response Induced by Two Doses of ChAdOx1 nCoV-19, mRNA-1273, or BNT162b2 in Liver Transplant Recipients.

Coronavirus disease 2019 (COVID-19) vaccination in immunocompromised, especially transplant recipients, may induce a weaker immune response. But there are limited data on the immune response after COVID-19 vaccination in liver transplant (LT) recipients, especially on the comparison of Ab responses after different vaccine platforms between mRNA and adenoviral vector vaccines. Thus, we conducted a prospective study on LT recipients who received two doses of the ChAdOx1 nCoV-19 (ChAdOx1), mRNA-1273, or BNT162b2 vaccines compared with healthy healthcare workers (HCWs). SARS-CoV-2 S1-specific IgG Ab titers were measured using ELISA. Overall, 89 LT recipients (ChAdOx1, n=16 [18%]) or mRNA vaccines (mRNA-1273 vaccine, n=23 [26%]; BNT162b2 vaccine, n=50 [56%]) received 3 different vaccines. Of them, 16 (18%) had a positive Ab response after one dose of COVID-19 vaccine and 62 (73%) after 2 doses. However, the median Ab titer after two doses of mRNA vaccines was significantly higher (44.6 IU/ml) than after two doses of ChAdOx1 (19.2 IU/ml, p=0.04). The longer time interval from transplantation was significantly associated with high Ab titers after two doses of vaccine (p=0.003). However, mycophenolic acid use was not associated with Ab titers (p=0.53). In conclusion, about 3-quarters of LT recipients had a positive Ab response after 2 doses of vaccine, and the mRNA vaccines induced higher Ab responses than the ChAdOx1 vaccine.

Dynamic increase of M2 macrophages is associated with disease progression of colorectal cancers following cetuximab-based treatment.

We aimed to investigate the dynamic changes of gene expression profiles and immune microenvironment linked to resistance to cetuximab-based treatments in patients with metastatic colorectal cancer (mCRC). A total of 106 patients with RAS-wild type mCRC who were treated with cetuximab-based treatments were included as the study population. RNA-sequencing and multiplexed immunohistochemistry were performed using paired or unpaired pre-treatment and post-treatment tumor tissues. Differentially expressed gene analysis of paired pre-treatment and post-treatment tumor tissues that develop acquired resistance (AR) identified the AR signature. Gene ontology analysis of the AR signature indicated enrichment of immune-related pathway genes. Among the immune subsets whose abundance was estimated by CIBERSORT, M2 macrophages showed the most prominent positive correlation with the expression of the AR signature. Among the post-treatment samples, progressive disease (PD) tumors showed a significantly higher abundance of M2 macrophages compared to non-PD tumors. These findings were validated by multiplexed immunohistochemistry analysis: the density of CD68+CD206+ M2 macrophages significantly increased at the time of PD following cetuximab-based treatment, whereas it did not consistently change in the tumor pairs of non-PD. In conclusion, a dynamic increase of M2 macrophages is associated with disease progression during cetuximab-based treatment of mCRCs. Targeting M2 macrophages is a promising immunotherapeutic strategy in this clinical context.

Expression of neurofibromin 1 in colorectal cancer and cetuximab resistance.

Neurofibromin 1 (NF1) is a tumor suppressor that has been previously reported to regulate RAS­MAPK signaling. The present study investigated the possible relationship between NF1 expression and anti­EGFR antibody (cetuximab) sensitivity in colorectal cancer cell lines. In addition, primary or metastatic colorectal cancer samples from patients treated with cetuximab were assessed for the association of cetuximab sensitivity. The quantities of the NF1 transcript, NF1­related pathway enrichment and NF1 mutation profile were measured and investigated using RNA sequencing and targeted DNA sequencing. Based on growth inhibition and colony formation assay results, cell lines were designated to be cetuximab­sensitive (NCI­H508 and Caco2) or cetuximab­resistant (KM12C and SM480). Western blotting revealed NF1 was highly expressed in cetuximab­sensitive cell lines whilst there was little expression in their cetuximab­resistant counterparts. Knocking down NF1 expression using small interfering RNA in the cetuximab­sensitive cell lines enhanced the phosphorylation of MEK and ERK according to western blotting. NF1 knockdown also reduced apoptosis, as observed by the decreased number of apoptotic bodies by DAPI nuclear staining and reduced cleavage of caspase and poly­(ADP ribose) polymerase. NF1 overexpression by transfection with GTPase­activating protein­related domain subunit rendered the cetuximab­resistant cell lines, KM12C and SW480, more susceptible to cetuximab­induced apoptosis. RNA sequencing of 111 RAS and BRAFV600 wild­type tumor samples collected from cetuximab­treated patients with metastatic colorectal cancer revealed that the pre­treatment NF1 expression levels were not associated with the cetuximab response. However, tumor samples obtained after cetuximab treatment displayed slightly lower NF1 transcript levels compared with those in the pre­treatment samples, suggesting that exposure to the anti­EGFR antibody may be associated with reduced NF1 expression levels. Next­generation sequencing revealed that the frequency of inactivating mutations in NF1 were rare (1.8%) in patients with colorectal cancer and were not associated with the protein expression levels of NF1 except for in a small number of cases (0.5%), where the biallelic inactivation of NF1 was observed. To conclude, the present study showed that modification of NF1 expression can affect sensitivity to cetuximab in colorectal cancer cell lines, though a limitation exists in terms of its potential application as a biomarker for RAS and BRAFV600 wild­type tumors.

Characterizing Organelles in Live Stem Cells Using Label-Free Optical Diffraction Tomography.

Label-free optical diffraction tomography (ODT), an imaging technology that does not require fluorescent labeling or other pre-processing, can overcome the limitations of conventional cell imaging technologies, such as fluorescence and electron microscopy. In this study, we used ODT to characterize the cellular organelles of three different stem cells-namely, human liver derived stem cell, human umbilical cord matrix derived mesenchymal stem cell, and human induced pluripotent stem cell-based on their refractive index and volume of organelles. The physical property of each stem cell was compared with that of fibroblast. Based on our findings, the characteristic physical properties of specific stem cells can be quantitatively distinguished based on their refractive index and volume of cellular organelles. Altogether, the method employed herein could aid in the distinction of living stem cells from normal cells without the use of fluorescence or specific biomarkers.

Longitudinal change of genetic variations in cetuximab-treated metastatic colorectal cancer.

Recurrent gene mutations and copy number alterations in cancer patients are presumably associated with resistance to targeted therapy. In the present study, we assessed the gene mutations and copy number alterations that recurrently occurred in cetuximab-treated patients with metastatic colorectal cancer (mCRC). Targeted next-generation sequencing was performed in the tumor samples obtained pre- and postcetuximab treatment to assess the variations that occurred during cetuximab treatment. Moreover, we identified the emergent gene mutations (CDK6, EPHA3, ERCC2, MYC, PCMTD1, PIK3CA, PRIM2, RICTOR, and ZNRF3) and copy number alterations (ARAF, BCL2, BRCA2, EGFR, MYC, and SMAD4) that were recurrently observed only in postprogression samples and not in pretreatment or posttreatment samples from patients revealing clinical response. Furthermore, to identify the feasible candidate variations implicated in treatment resistance, we examined the variants with clonal expansion during treatment and discovered PCBP1 as a variant associated with posttreatment progression. Various recurrent mutations were enriched in the TGF-beta signaling pathway. Collectively, we identified recurrent variations in mCRC samples exhibiting post-cetuximab progression. Additionally, future studies are required to evaluate the therapeutic potential of these variations.

Hypoxia-inducible factor-1α-dependent induction of miR122 enhances hepatic ischemia tolerance.

Hepatic ischemia and reperfusion (IR) injury contributes to the morbidity and mortality associated with liver transplantation. microRNAs (miRNAs) constitute a family of noncoding RNAs that regulate gene expression at the posttranslational level through the repression of specific target genes. Here, we hypothesized that miRNAs could be targeted to enhance hepatic ischemia tolerance. A miRNA screen in a murine model of hepatic IR injury pointed us toward the liver-specific miRNA miR122. Subsequent studies in mice with hepatocyte-specific deletion of miR122 (miR122loxP/loxP Alb-Cre+ mice) during hepatic ischemia and reperfusion revealed exacerbated liver injury. Transcriptional studies implicated hypoxia-inducible factor-1α (HIF1α) in the induction of miR122 and identified the oxygen-sensing prolyl hydroxylase domain 1 (PHD1) as a miR122 target. Further studies indicated that HIF1α-dependent induction of miR122 participated in a feed-forward pathway for liver protection via the enhancement of hepatic HIF responses through PHD1 repression. Moreover, pharmacologic studies utilizing nanoparticle-mediated miR122 overexpression demonstrated attenuated liver injury. Finally, proof-of-principle studies in patients undergoing orthotopic liver transplantation showed elevated miR122 levels in conjunction with the repression of PHD1 in post-ischemic liver biopsies. Taken together, the present findings provide molecular insight into the functional role of miR122 in enhancing hepatic ischemia tolerance and suggest the potential utility of pharmacologic interventions targeting miR122 to dampen hepatic injury during liver transplantation.

Absence of association between pretransplant serum soluble programmed death protein-1 level and prognosis following living donor liver transplantation in patients with hepatocellular carcinoma.

ABSTRACT: Programmed death protein 1 (PD-1) pathway is one of the most critical mechanisms in tumor biology of hepatocellular carcinoma (HCC). The study aimed to assess the prognostic influence of pretransplant serum soluble PD-1 (sPD-1) in patients undergoing liver transplantation for treatment of HCC.Data from 229 patients with HCC who underwent living donor liver transplantation between January 2010 and December 2015 were retrospectively evaluated. Stored serum samples were used to measure sPD-1 concentrations.Overall survival (OS) and disease-free survival (DFS) rates were 94.3% and 74.5% at 1 year; 78.2% and 59.2% at 3 years; and 75.4% and 55.5% at 5 years, respectively. Prognostic analysis using pretransplant serum sPD-1 with a cut-off of 93.6 µg/mL (median value of the study cohort) did not have significant prognostic influence on OS (P = .69) and DFS (P = .26). Prognostic analysis using sPD-1 with a cut-off of 300 µg/mL showed similar OS (P = .46) and marginally lower DFS (P = .070). Combination of Milan criteria and sPD-1 with a cutoff of 300 µg/mL showed similar outcomes of OS and DFS in patients within and beyond Milan criteria. Multivariate analysis revealed that only Milan criteria was an independent prognostic for OS and DFS, but pretransplant sPD1 with a cut-off of 300 µg/mL did not become a prognostic factor.The results of this study demonstrate that pretransplant serum sPD-1 did not show significant influences on post-transplant outcomes in patients with HCC. Further large-scale, multicenter studies are necessary to clarify the role of serum sPD-1 in liver transplantation recipients.

Phenylboronic acid conjugated to doxorubicin nanocomplexes as an anti-cancer drug delivery system in hepatocellular carcinoma.

Anti-cancer strategies using nanocarrier systems have been explored in a variety of cancers; these systems can easily be incorporated into tumors via the enhanced permeability and retention (EPR) effect leading to enhanced anti-tumor activity while reducing systemic toxicity by specific tumor-targeting. The prognosis of hepatocellular carcinoma (HCC) is extremely poor when the condition is diagnosed at the unresectable stage as treatment options are limited. In order to improve the treatment of cancer and the overall anti-cancer effect, polymerized phenylboronic acid conjugated doxorubicin (pPBA-Dox) nanocomplexes were generated, and conjugated doxorubicin, which is conventionally used in HCC. The nanocomplexes exhibited enhanced anti-tumor activity via tumor-specific targeting in the subcutaneous and orthotopic HCC syngeneic mice tumor model, implying that the nanocomplexes facilitate the targeted Dox delivery to liver cancer in which the sialic acid is over-expressed. Therefore, this study provides insight into the novel targeted therapy using the nanocomplexes for the treatment of HCC.

Safe use of right lobe living donor livers with moderate steatosis in adult-to-adult living donor liver transplantation: a retrospective study.

Hepatic steatosis (HS) beyond a certain degree can jeopardize living donor (LD) safety, particularly in right lobe (RL) donors, making it a major obstacle for donor pool expansion in adult-to-adult living donor liver transplantation (ALDLT). From July 2004 to June 2016, 58 LDs donated their RLs despite having moderate HS (30%-50% steatosis) determined by intraoperative biopsy at a single center. We performed greedy matching to compare the outcomes of the donors and recipients of this group with those of LDs with no HS. The mean left lobe (LL) HS value in the 58 cases was 20.9 ± 12.4%, which was significantly lower than the mean RL HS value (38.8 ± 6.7%, P < 0.001). The mean ratio of the remnant LL to the total liver volume was 37.8 ± 2.2. No differences were observed in the postoperative liver function and donor and recipient morbidity and mortality rates. The liver regeneration rates in recipients and donors at 1 month, 6 months, and 1 year postoperatively did not differ significantly. The patient and graft survival rates of the recipients showed no differences. The use of well-selected RL grafts with moderate steatosis does not impair graft function, recipient outcomes, or donor safety.

Hepatogenic Potential and Liver Regeneration Effect of Human Liver-derived Mesenchymal-Like Stem Cells.

Human liver-derived stem cells (hLD-SCs) have been proposed as a possible resource for stem cell therapy in patients with irreversible liver diseases. However, it is not known whether liver resident hLD-SCs can differentiate toward a hepatic fate better than mesenchymal stem cells (MSCs) obtained from other origins. In this study, we compared the differentiation ability and regeneration potency of hLD-SCs with those of human umbilical cord matrix-derived stem cells (hUC-MSCs) by inducing hepatic differentiation. Undifferentiated hLD-SCs expressed relatively high levels of endoderm-related markers (GATA4 and FOXA1). During directed hepatic differentiation supported by two small molecules (Fasudil and 5-azacytidine), hLD-SCs presented more advanced mitochondrial respiration compared to hUC-MSCs. Moreover, hLD-SCs featured higher numbers of hepatic progenitor cell markers on day 14 of differentiation (CPM and CD133) and matured into hepatocyte-like cells by day 7 through 21 with increased hepatocyte markers (ALB, HNF4A, and AFP). During in vivo cell transplantation, hLD-SCs migrated into the liver of ischemia-reperfusion injury-induced mice within 2 h and relieved liver injury. In the thioacetamide (TAA)-induced liver injury mouse model, transplanted hLD-SCs trafficked into the liver and spontaneously matured into hepatocyte-like cells within 14 days. These results collectively suggest that hLD-SCs hold greater hepatogenic potential, and hepatic differentiation-induced hLD-SCs may be a promising source of stem cells for liver regeneration.

Association between Metformin Use and Clinical Outcomes Following Pancreaticoduodenectomy in Patients with Type 2 Diabetes and Pancreatic Ductal Adenocarcinoma.

Retrospective studies on the association between metformin and clinical outcomes have mainly been performed on patients with non-resectable pancreatic ductal adenocarcinoma and may have been affected by time-related bias. To avoid this bias, recent studies have used time-varying analysis; however, they have only considered the start date of metformin use and not the stop date. We studied 283 patients with type 2 diabetes and pancreatic ductal adenocarcinoma following pancreaticoduodenectomy, and performed analysis using a Cox model with time-varying covariates, while considering both start and stop dates of metformin use. When start and stop dates were not considered, the metformin group showed significantly better survival. Compared with previous studies, adjusted analysis based on Cox models with time-varying covariates only considering the start date of postoperative metformin use showed no significant differences in survival. However, although adjusted analysis considering both start and stop dates showed no significant difference in recurrence-free survival, the overall survival was significantly better in the metformin group (Hazard ratio (HR), 0.747; 95% confidence interval (CI), 0.562-0.993; p = 0.045). Time-varying analysis incorporating both start and stop dates thus revealed that metformin use is associated with a higher overall survival following pancreaticoduodenectomy in patients with type 2 diabetes and pancreatic ductal adenocarcinoma.