Hepatocyte Transplantation Research Articles

Cell-based clinical and experimental methods for assisting the function of impaired livers – Present and future of liver support systems

Currently, one of the most serious public health issues is the increasing number of cases of chronic liver disease and cirrhosis both of which can lead to liver failure. The only effective method of treatment for this life-threatening condition remains liver transplantation. Unfortunately, the chronic shortage of transplantable organs seriously limits its accessibility to patients. Thus, tremendous research has been done to develop methods capable of replacing liver transplantation by artificial means or to create techniques to partially or fully replace liver function in patients with impaired livers, until liver regeneration or transplantation. This review article is focused on research results that utilize living cells in order to establish bridging therapies in cases of liver failure. This includes both experimental and clinically tested techniques, such as hepatocyte transplantation and usage of the hybrid bioartificial liver devices. The article also discusses research which presents the long-term culture of hepatocytes in conditions that preserve their differentiated state, which is important for such applications as drug development and toxicity testing. Last but not least, the article describes the groundbreaking efforts toward building sophisticated scaffolds for hepatocyte culture that mimic their natural environment, which are based on decellularized tissues and on three-dimensional bioprinting.

Supportive Hepatocyte Transplantation after Partial Hepatectomy Enhances Liver Regeneration in a Preclinical Pig Model

Background: Hepatocyte transplantation (HTx) is regarded as a potential treatment modality for various liver diseases including acute liver failure. We developed a preclinical pig model to evaluate if HTx could safely support recovery from liver function impairment after partial hepatectomy. Methods: Pigs underwent partial hepatectomy with reduction of the liver volume by 50% to induce a transient but significant impairment of liver function. Thereafter, 2 protocols for HTx were evaluated and compared to a control group receiving liver resection only (group 1, n = 5). Portal pressure-controlled HTx was performed either immediately after surgery (group 2, n = 6) or 3 days postoperatively (group 3, n = 5). In all cases, liver regeneration was monitored by conventional laboratory tests and the novel noninvasive maximum liver function capacity (LiMAx) test with a follow-up of 4 weeks. Results: Partial hepatectomy significantly impaired liver function according to conventional liver function tests as well as LiMAx in all groups. A mean of 4.10 ± 1.1 × 10⁸ and 3.82 ± 0.7 × 10⁸ hepatocytes were transplanted in groups 2 and 3, respectively. All animals remained stable with respect to vital parameters during and after HTx. The animals in group 2 showed enhanced liver regeneration as observed by mean postoperative LiMAx values (621.5 vs. 331.3 μg/kg/h on postoperative day 7; p < 0.001) whereas HTx in group 3 led to a significant increase in mean liver-specific coagulation factor VII (112.2 vs. 54.0% on postoperative day 7; p = 0.003) compared to controls (group 1), respectively. In both experimental groups, thrombotic material was observed in the portal veins and pulmonary arteries on histology, despite the absence of clinical symptoms. Conclusion: HTx can be performed safely and effectively immediately after a partial (50%) hepatectomy as well as 3 days postoperatively, with comparable results regarding the enhancement of liver function and regeneration.

Invariant NKT cells promote expansion of novel CXCR3+CCR4+CD8+ T cells in the liver following allogeneic hepatocyte transplant

Abstract Hepatocyte transplant (HcTx) is a treatment for metabolic diseases and a bridge to liver transplant but is limited by immunogenicity. Our prior work identified the critical role of CD4-dependent and CD4-independent CD8+ T cells in HcTx rejection. Herein, we evaluated the influence of invariant natural killer T cells (iNKTs), abundant in the liver, upon CD8+ T cell responses in the presence and absence of CD4+ T cells. To investigate this, C57BL/6 (wild-type; WT) or iNKT deficient Jα18 KO (H-2b) received FVB/N (H-2q) HcTx. Cohorts were depleted of CD4+ T cells and/or reconstituted with iNKTs. Recipients were evaluated for cytotoxicity, CD8+ T cell phenotype, and HcTx rejection. By comparing CD4-sufficient WT and Jα18 KO recipients, we found that the presence of iNKTs significantly enhanced in vivo CD8-mediated cytotoxicity (83±3% vs 23±3%; p&amp;lt;0.001) but did not affect survival (10 days vs 14 days; p=ns). However, in CD4-deficient recipients, iNKTs were critical, since without CD4+ T cells and iNKTs, CD8-mediated in vivo cytotoxicity was completely abrogated (31±3% vs 2±1%; p&amp;lt;0.001) and HcTx survival was significantly prolonged (14 days vs 56 days; p&amp;lt;0.001). iNKTs enhanced the quantity of a novel CD8+ T cell subset, CD44+IFN-γ+CXCR3+CCR4+CD8+ T cells, in the liver (2-fold) in all HcTx recipients (p&amp;lt;0.03 for all comparisons). CXCR3+CCR4+CD8+ T cells, when compared to CXCR3+CCR4−CD8+ T cells, express higher IFN-γ (32±3% vs 9±1%; p&amp;lt;0.001) and TNF-α (37±3% vs 6±1%; p&amp;lt;0.001). They also exhibit greater in vivo cytotoxicity (13±1% vs 5±1%; p&amp;lt;0.001) and mediate rapid HcTx rejection in RAG1 KO recipients (5 days vs 16 days; p=0.02). We show that iNKTs enhance the expansion of highly cytotoxic CXCR3+CCR4+CD8+ T cells that mediate rapid rejection of HcTx.

Messenger RNA for Cell Editing -Disease Treatment and Cell Transplantation Using Pro-survival mRNA

Vigorous efforts are being made to manipulate cellular functions in a desirable manner for biomedical purposes. Recent advances in platform technologies have made cell editing achievable; this includes generation of induced pluripotent stem cells and chimeric antigen receptor T cells, as well as direct cell reprogramming. mRNA, as compared to DNA, is an excellent tool for potentiating cell editing technologies, owing to its distinct properties in gene introduction. Herein, hepatocytes were edited ex vivo and in vivo, by introducing pro-survival mRNA, to be resistant to cell death. DNA-based introduction of pro-survival gene poses safety concerns due to its genomic integration, as prolonged and uncontrolled expression of pro-survival proteins after the integration may promote cancer. In contrast, mRNA lacks such a risk. Moreover, mRNA-based introduction of Bcl-2, a pro-survival factor, was more effective in preventing the death of cultured hepatocytes than Bcl-2 plasmid DNA (pDNA) introduction. Mechanistically, mRNA induced protein expression in a larger percentage of the hepatocytes compared to pDNA, presumably because the process of pDNA nuclear entry in transfection is challenging. In hepatocyte transplantation to mouse liver, ex vivo introduction of Bcl-2 mRNA significantly improved the engraftment efficiency of the hepatocytes, leading to successful functional support of the liver in a mouse model of chronic hepatitis. Furthermore, in vivo administration of Bcl-2 mRNA exhibited an anti-apoptotic effect on the hepatocytes of a mouse model of fulminant hepatitis. These results demonstrate the potential advantages of mRNA introduction over DNA introduction in cell editing.

Primary human hepatocyte gene editing: Prometheus’ chains are loosening

Primary human hepatocytes (PHHs) isolated from livers retain proliferative properties when xeno-transplanted into chimeric mouse models1 or other species. Serial transplantation experiments in mice showed that PHH populations multiply by at least 100-fold per round,2 illustrating their greater than million-fold expansion potential. This has sparked widespread research into therapeutic hepatocyte transplantation for patients with liver conditions. Two major roadblocks that have limited clinical progress with hepatocyte transplantation are the lack of renewable high-quality human hepatocyte sources and the inability to efficiently correct inborn errors in PHHs.

Preclinical Application of Reduced Manipulated Processing Strategy to Collect Transplantable Hepatocytes: A Pilot and Feasibility Study.

Background: The complex isolation and purification process of hepatocytes for transplantation is labor intensive and with great contamination risk. Here, as a pilot and feasibility study, we examined in vitro and in vivo hepatocyte isolation feasibility and cell function of Cell Saver® Elite®, an intraoperative blood-cell-recovery system. Methods: Rat and pig liver cells were collected using this system and then cultured in vitro, and their hepatocyte-specific enzymes were characterized. We then transplanted the hepatocytes in an established acute liver–injured (retrorsine+D-galactosamine-treated) rat model for engraftment. Recipient rats were sacrificed 1, 2, and 4 weeks after transplantation, followed by donor-cell identification and histological, serologic, and immunohistopathological examination. To demonstrate this Cell Saver® strategy is workable in the first place, traditional (classical) strategy, in our study, behaved as certainty during the cell manufacturing process for monitoring quality assurance throughout the course, from the start of cell isolation to post-transplantation. Results: We noted that in situ collagenase perfusion was followed by filtration, centrifugation, and collection in the Cell Saver® until the process ended. Most (>85%) isolated cells were hepatocytes (>80% viability) freshly demonstrating hepatocyte nuclear factor 4α and carbamoyl-phosphate synthase 1 (a key enzyme in the urea cycle), and proliferating through intercellular contact in culture, with expression of albumin and CYP3A4. After hepatocyte transplantation in dipeptidyl peptidase IV (−/−) rat liver, wild-type donor hepatocytes engrafted and repopulated progressively in 4 weeks with liver functional improvement. Proliferating donor hepatocyte–native biliary ductular cell interaction was identified. Post-transplantation global liver functional recovery after Cell Saver and traditional methods was comparable. Conclusions: Cell Saver® requires reduced manual manipulation for isolating transplantable hepatocytes.

Transplanted hepatocytes rescue mice in acetaminophen-induced acute liver failure through paracrine signals for hepatic ATM and STAT3 pathways.

Acute liver failure constitutes a devastating condition that needs novel cell and molecular therapies. To elicit synergisms in cell types of therapeutic interest, we studied hepatocytes and liver sinusoidal endothelial in mice with acetaminophen-induced acute liver failure. The context of regenerative signals was examined by transplants in peritoneal cavity because it possesses considerable capacity and allows soluble signals to enter the systemic circulation. Whereas transplanted hepatocytes and liver sinusoidal endothelial cells engrafted in peritoneal cavity, only the former could rescue mice in liver failure by improving injury outcomes, activating hepatic DNA damage repair, and inducing liver regeneration. The cytokines secreted by donor hepatocytes or liver sinusoidal endothelial cells differed and in hepatocytes from mice undergoing acetaminophen toxicity major cytokines were even rendered deficient (eg, G-CSF, VEGF, and others). Significantly, recapitulating hepatotoxicity-related DNA damage response in cultured cells identified impairments in ATM and JAK/STAT3 intersections since replacing cytokines produced less from injured hepatocytes restored these pathways to avoid acetaminophen hepatotoxicity. Similarly, hepatocyte transplantation in acute liver failure restored ATM and JAK/STAT3 pathways to advance DNA damage/repair and liver regeneration. The unexpected identification of novel hepatic G-CSF receptor expression following injury allowed paradigmatic studies of G-CSF supplementation to confirm the centrality of this paracrine ATM and STAT3 intersection. Remarkably, DNA damage/repair and hepatic regeneration directed by G-CSF concerned rebalancing of regulatory gene networks overseeing inflammation, metabolism, and cell viability. We conclude that healthy donor hepatocytes offer templates for generating specialized cell types to replace metabolic functions and regenerative factors in liver failure.

Improvement of hepatocyte engraftment by co-transplantation with pancreatic islets in hepatocyte transplantation.

Because of the fragility of isolated hepatocytes, extremely poor engraftment of transplanted hepatocytes remains a severe issue in hepatocyte transplantation. Therefore, improving hepatocyte engraftment is necessary to establish hepatocyte transplantation as a standard therapy. Since the pancreatic islets are known to have favorable autocrine effects, we hypothesized that the transplanted islets might influence not only the islets but also the nearby hepatocytes, subsequently promoting engraftment. We evaluated the effects of islet co‐transplantation using an analbuminemic rat model (in vivo model). Furthermore, we established a mimicking in vitro model to investigate the underlying mechanisms. In an in vivo model, the hepatocyte engraftment was significantly improved only when the islets were co‐transplanted to the nearby hepatocytes (p < 0.001). Moreover, the transplanted hepatocytes appeared to penetrate the renal parenchyma together with the co‐transplanted islets. In an in vitro model, the viability of cultured hepatocytes was also improved by coculture with pancreatic islets. Of particular interest, the coculture supernatant alone could also exert beneficial effects comparable to islet coculture. Although insulin, VEGF, and GLP‐1 were selected as candidate crucial factors using the Bio‐Plex system, beneficial effects were partially counteracted by anti‐insulin receptor antibodies. In conclusion, this study demonstrated that islet co‐transplantation improves hepatocyte engraftment, most likely due to continuously secreted crucial factors, such as insulin, in combination with providing favorable circumstances for hepatocyte engraftment. Further refinements of this approach, especially regarding substitutes for islets, could be a promising strategy for improving the outcomes of hepatocyte transplantation.

The Efficacy of the Hepatocyte Spheroids for Hepatocyte Transplantation

The safety and short-term efficacy of hepatocyte transplantation (HCTx) have been widely proven. However, issues such as reduced viability and/or function of hepatocytes, insufficient engraftment, and lack of a long-term effect have to be overcome for widespread application of HCTx. In this study, we evaluated hepatocyte spheroids (HSs), formed by self-aggregation of hepatocytes, as an alternative to hepatocytes in single-cell suspension. Hepatocytes were isolated from C57BL/6 J mice liver using a three-step collagenase perfusion technique and HSs were formed by the hanging drop method. After the spheroids formation, the HSs showed significantly higher mRNA expression of albumin, ornithine transcarbamylase, glucose-6-phosphate, alpha-1-antitrypsin, low density lipoprotein receptor, coagulation factors, and apolipoprotein E (ApoE) than 2 dimensional (2D)-cultured hepatocytes (p < 0.05). Albumin production by HSs was significantly higher than that by 2D-cultured hepatocytes (9.5 ± 2.5 vs 3.5 ± 1.8 μg/dL, p < 0.05). The HSs, but not single hepatocytes, maintained viability and albumin mRNA expression in suspension (92.0 ± 2.8% and 1.03 ± 0.09 at 6 h). HSs (3.6 × 106 cells) or isolated hepatocytes (fSH, 3.6 × 106 cells) were transplanted into the liver of ApoE knockout (KO-/-) mice via the portal vein. Following transplantation, serum ApoE concentration (ng/mL) of HS-transplanted mice (1w: 63.1 ± 56.7, 4w: 17.0 ± 10.9) was higher than that of fSH-transplanted mice (1 w: 33.4 ± 13.0, 4w: 13.7 ± 9.6). In both groups, the mRNA levels of pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, MCP-1, and MIP-1β) were upregulated in the liver following transplantation; however, no significant differences were observed. Pathologically, transplanted HSs were observed as flat cell clusters in contact with the portal vein wall on day 7. Additionally, ApoE positive cells were observed in the liver parenchyma distant from the portal vein on day 28. Our results indicate that HS is a promising alternative to single hepatocytes and can be applied for HCTx.

Endoderm and Hepatic Progenitor Cells Engraft in the Quiescent Liver Concurrent with Intrinsically Activated Epithelial-to-Mesenchymal Transition

Stem cell transplantation to the liver is a promising therapeutic strategy for a variety of disorders. Hepatocyte transplantation has short-term efficacy but can be problematic due to portal hypertension, inflammation, and sinusoidal thrombosis. We have previously transplanted small mouse endoderm progenitor (EP) cells to successfully reverse a murine model of hemophilia B, and labeling these cells with iron nanoparticles renders them responsive to magnetic fields, which can be used to enhance engraftment. The mechanisms mediating progenitor cell migration from the sinusoidal space to the hepatocyte compartment are unknown. Here we find human EP and hepatic progenitor (HP) cells can be produced from human embryonic stem cells with high efficiency, and they also readily uptake iron nanoparticles. This provides a simple manner through which one can readily identify transplanted cells in vivo using electron microscopy, shortly after delivery. High resolution imaging shows progenitor cell morphologies consistent with epithelial-to-mesenchymal transition (EMT) mediating invasion into the hepatic parenchyma. This occurs in as little as 3 h, which is considerably faster than observed when hepatocytes are transplanted. We confirmed activated EMT in transplanted cells in vitro, as well as in vivo 24 h after transplantation. We conclude that EMT naturally occurs concurrent with EP and HP cell engraftment, which may mediate the rate, safety, and efficacy of early cell engraftment in the undamaged quiescent liver.

Preferable Transplant Site for Hepatocyte Transplantation in a Rat Model

Intraportal injection is regarded as the current standard procedure of hepatocyte transplantation (HTx). In islet transplantation, which shares many aspects with HTx, recent studies have clarified that instant blood-mediated inflammatory reaction (IBMIR), characterized by strong innate immune responses, can cause poor engraftment, so other transplant sites to avoid such a reaction have been established. Although IBMIR was reported to occur in HTx, few reports have evaluated alternative transplant sites for HTx. In this study, we sought to determine the optimum transplant site for HTx. Rat hepatocytes (1.0 × 107) were transplanted at the 9 transplant sites (intraportal (IPO), intrasplenic (IS), liver parenchyma, subcutaneous, intraperitoneal, renal subcapsular, muscle, inguinal subcutaneous white adipose tissue, and omentum) of analbuminemic rats. The serum albumin levels, immunohistochemical staining (albumin, TUNEL, and BrdU), and in vivo imaging of the grafts were evaluated. The serum albumin levels of the IPO group were significantly higher than those of the other groups (p < .0001). The BrdU-positive hepatocyte ratio of liver in the IS group (0.9% ± 0.2%) was comparable to that of the IPO group (0.9% ± 0.3%) and tended to be higher than that of the spleen in the IS group (0.5% ± 0.1%, p = .16). Considering the in vivo imaging evaluation and the influence of splenectomy, the graft function in the IS group may be almost entirely achieved by hepatocytes that have migrated to the liver. The present study clearly showed that the intraportal injection procedure is more efficient than other procedures for performing HTx

Liver histologic changes in children with type 1 of Crigler-Najjar syndrome

To describe liver histology changes in patients who have undergone liver transplantation. This retrospective cross-sectional study was performed to evaluate the liver pathologies of patients with type 1 of Crigler-Najjar syndrome (CNS1). We analyzed medical records and liver histologic specimens of 53 children who were transplanted in Namazi Hospital Organ Transplant Center affiliated with Shiraz University of Medical Sciences between 2009 and 2019. We studied the tissue of the explanted liver, which was replaced by transplants. Most of the patients were less than 2 years old, with an average age of 1.7 years. The collected data were analyzed using SPSS 22 software. The prevalent pathology found in the liver of these patients was periportal fibrosis (96.2%). Cholestasis was the second common finding (94.3%) followed by pericentral fibrosis (86.7%) and ductal reaction (22.6%). A significant correlation was only present between phototherapy time and ductal reaction grade. Our results indicated a high prevalence of fibrosis of different grades among CNS 1 patients which bolds the necessity of histologic examination before considering treatments such as gene therapy or hepatocyte transplantation.

High Dose Versus Low Dose Syngeneic Hepatocyte Transplantation in Pex1-G844D NMRI Mouse Model is Safe but Does Not Achieve Long Term Engraftment.

Genetic alterations in PEX genes lead to peroxisome biogenesis disorder. In humans, they are associated with Zellweger spectrum disorders (ZSD). No validated treatment has been shown to modify the dismal natural history of ZSD. Liver transplantation (LT) improved clinical and biochemical outcomes in mild ZSD patients. Hepatocyte transplantation (HT), developed to overcome LT limitations, was performed in a mild ZSD 4-year-old child with encouraging short-term results. Here, we evaluated low dose (12.5 million hepatocytes/kg) and high dose (50 million hepatocytes/kg) syngeneic male HT via intrasplenic infusion in the Pex1-G844D NMRI mouse model which recapitulates a mild ZSD phenotype. HT was feasible and safe in growth retarded ZSD mice. Clinical (weight and food intake) and biochemical parameters (very long-chain fatty acids, abnormal bile acids, etc.) were in accordance with ZSD phenotype but they were not robustly modified by HT. As expected, one third of the infused cells were detected in the liver 24 h post-HT. No liver nor spleen microchimerism was detected after 7, 14 and 30 days. Future optimizations are required to improve hepatocyte engraftment in Pex1-G844D NMRI mouse liver. The mouse model exhibited the robustness required for ZSD liver-targeted therapies evaluation.

Regenerative medicine for the hepatobiliary system: A review.

Liver transplantation, the only proven treatment for end-stage liver disease and acute liver failure, is hampered by the scarcity of donors. Regenerative medicine provides an alternative therapeutic approach. Tremendous efforts dedicated to liver regenerative medicine include the delivery of transplantable cells, microtissues, and bioengineered whole livers via tissue engineering and the maintenance of partial liver function via extracorporeal support. This brief review summarizes the current status of regenerative medicine for the hepatobiliary system. For liver regenerative medicine, the focus is on strategies for expansion of transplantable hepatocytes, generation of hepatocyte-like cells, and therapeutic potential of engineered tissues in liver disease models. For biliary regenerative medicine, the discussion concentrates on the methods for generation of cholangiocyte-like cells and strategies in the treatment of biliary disease. Significant advances have been made in large-scale and long-term expansion of liver cells. The development of tissue engineering and stem cell induction technology holds great promise for the future treatment of hepatobiliary diseases. The application of regenerative medicine in liver still lacks extensive animal experiments. Therefore, a large number of preclinical studies are necessary to provide sufficient evidence for their therapeutic effectiveness. Much remains to be done for the treatment of hepatobiliary diseases with regenerative medicine.

Large-scale Generation of Functional and Transplantable Hepatocytes and Cholangiocytes from Human Endoderm Stem Cells

The ever-increasing therapeutic and pharmaceutical demand for liver cells calls for systems that enable mass production of hepatic cells. Here we describe a large-scale suspension system that uses human endoderm stem cells (hEnSCs) as precursors to generate functional and transplantable hepatocytes (E-heps) or cholangiocytes (E-chos). hEnSC-derived hepatic populations are characterized by single-cell transcriptomic analyses and compared with hESC-derived counterparts, in-vitro-maintained or -expanded primary hepatocytes and adult cells, which reveals that hepatic differentiation of hEnSCs recapitulates invivo development and that the heterogeneities of the resultant populations can be manipulated by regulating the EGF and MAPK signaling pathways. Functional assessments demonstrate that E-heps and E-chos possess properties comparable with adult counterparts and that, when transplanted intraperitoneally, encapsulated E-heps were able to rescue rats with acute liver failure. Our study lays the foundation for cell-based therapeutic agents and invitro applications for liver diseases.

Research progress of hepatocyte transplantation treatment for alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin deficiency is an autosomal codominant genetic disease characterized by low levels of alpha-1 antitrypsin in the blood. Clinically, in young patients, it mainly manifests as emphysema, acute/chronic liver injury and liver cancer. The treatment methods include symptomatic treatment and alpha -1 antitrypsin supplementation. However, the existing treatment cannot prevent the liver fibrosis progression. At present, more than ten cases of the disease have been reported in China, but the understanding of this disease is still indecisive. Moreover, there exists no biotherapy drug for this disorder. This article introduces the research progress of hepatocyte transplantation treatment for this disorder.

In vitro Studies of Transendothelial Migration for Biological and Drug Discovery.

Inflammatory diseases and cancer metastases lack concrete pharmaceuticals for their effective treatment despite great strides in advancing our understanding of disease progression. One feature of these disease pathogeneses that remains to be fully explored, both biologically and pharmaceutically, is the passage of cancer and immune cells from the blood to the underlying tissue in the process of extravasation. Regardless of migratory cell type, all steps in extravasation involve molecular interactions that serve as a rich landscape of targets for pharmaceutical inhibition or promotion. Transendothelial migration (TEM), or the migration of the cell through the vascular endothelium, is a particularly promising area of interest as it constitutes the final and most involved step in the extravasation cascade. While in vivo models of cancer metastasis and inflammatory diseases have contributed to our current understanding of TEM, the knowledge surrounding this phenomenon would be significantly lacking without the use of in vitro platforms. In addition to the ease of use, low cost, and high controllability, in vitro platforms permit the use of human cell lines to represent certain features of disease pathology better, as seen in the clinic. These benefits over traditional pre-clinical models for efficacy and toxicity testing are especially important in the modern pursuit of novel drug candidates. Here, we review the cellular and molecular events involved in leukocyte and cancer cell extravasation, with a keen focus on TEM, as discovered by seminal and progressive in vitro platforms. In vitro studies of TEM, specifically, showcase the great experimental progress at the lab bench and highlight the historical success of in vitro platforms for biological discovery. This success shows the potential for applying these platforms for pharmaceutical compound screening. In addition to immune and cancer cell TEM, we discuss the promise of hepatocyte transplantation, a process in which systemically delivered hepatocytes must transmigrate across the liver sinusoidal endothelium to successfully engraft and restore liver function. Lastly, we concisely summarize the evolving field of porous membranes for the study of TEM.

The Impact of COVID-19 on the State of Clinical and Laboratory Research Globally in Transplantation in May 2020.

The Impact of COVID-19 on the State of Clinical and Laboratory Research Globally in Transplantation in May 2020.

Modern Methods of Devic’s Disease Treatment

BACKGROUND: Neuromyelitis optica (NMO) (also known as opticomyelitis, Devic’s syndrome/disease) is an idiopathic inflammatory disorder of the central nervous system characterized by predominant involvement of the optic nerves, spinal cord, and extensive transverse myelitis. To date, there are no convincing clinical trials that would fully evaluate the efficacy and safety of drugs for the treatment and prevention of NMO exacerbation. Taking into account the malignant course that quickly leads to disability of young, economically active population, the issues of searching for effective methods of NMO treatment remain highly urgent.&#x0D; AIM: The purpose of the study was to examine available modern methods of treatment and prevention of NMO exacerbation, which have potential and require further detailed clinical trials to ensure possible application of these treatment options in clinical practice.&#x0D; MATERIALS AND METHODS: We have reviewed previously applied and modern methods of treatment. We have analyzed systematic reviews, clinical, randomized, and retrospective studies of scientific medical databases: PubMed, Cochrane, The Lancet, UpToDate, and reviews of world medical journals in Russian and English.&#x0D; CONCLUSIONS: The authors concluded that there is a sufficient number of drugs and combinations of methods of Devic’s disease treatment. We were interested in combinations of rituximab (RIT) and autologous stem cell transplantation, RIT and fetal hepatocyte transplantation, and RIT and strengthening the effect by plasmapheresis sessions. However, successful implementation of these methods in clinical practice requires conducting controlled clinical trials with a larger number of patients and longer follow-up periods.

Co-encapsulation of HNF4\u03b1 overexpressing UMSCs and human primary hepatocytes ameliorates mouse acute liver failure

BackgroundAcute liver failure (ALF) is a complicated condition that is characterized by global hepatocyte death and often requires immediate liver transplantation. However, this therapy is limited by shortage of donor organs. Mesenchymal stem cells (MSCs) and hepatocytes are two attractive sources of cell-based therapies to treat ALF. The combined transplantation of hepatocytes and MSCs is considered to be more effective for the treatment of ALF than single-cell transplantation. We have previously demonstrated that HNF4α-overexpressing human umbilical cord MSCs (HNF4α-UMSCs) promoted the expression of hepatic-specific genes. In addition, microencapsulation allows exchange of nutrients, forming a protective barrier to the transplanted cells. Moreover, encapsulation of hepatocytes improves the viability and synthetic ability of hepatocytes and circumvents immune rejection. This study aimed to investigate the therapeutic effect of microencapsulation of hepatocytes and HNF4α-UMSCs in ALF mice.MethodsHuman hepatocytes and UMSCs were obtained separately from liver and umbilical cord, followed by co-encapsulation and transplantation into mice by intraperitoneal injection. LPS/D-gal was used to induce ALF by intraperitoneal injection 24 h after transplantation. In addition, Raw 264.7 cells (a macrophage cell line) were used to elucidate the effect of HNF4α-UMSCs-hepatocyte microcapsules on polarization of macrophages. The protein chip was used to define the important paracrine factors in the conditioned mediums (CMs) of UMSCs and HNF4α-UMSCs and investigate the possible mechanism of HNF4α-UMSCs for the treatment of ALF in mice.ResultsHNF4α-UMSCs can enhance the function of primary hepatocytes in alginate–poly-L-lysine–alginate (APA) microcapsules. The co-encapsulation of both HNF4α-UMSCs and hepatocytes achieved better therapeutic effects in ALF mice by promoting M2 macrophage polarization and reducing inflammatory response mainly mediated by the paracrine factor HB-EGF secreted by HNF4α-UMSCs.ConclusionsThe present study confirms that the co-encapsulation of HNF4α-UMSC and hepatocytes could exert therapeutic effect on ALF mainly by HB-EGF secreted by HNF4α-UMSCs and provides a novel strategy for the treatment of ALF.