[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.

Fulminant Hepatitis due to de novo Hepatitis B after Cord Blood Transplantation Rescued by Medical Treatment.

A 53-year-old man presented with fulminant hepatitis due to de novo hepatitis B. He had been diagnosed previously with adult T-cell leukemia (ATL) and previously resolved hepatitis B virus infection. The ATL had been treated with cord blood transplantation (CBT). He developed fulminant hepatitis 18 months after CBT, 15 months after the withdrawal of immunosuppressants, and 10 months after vitreous injections of methotrexate for ATL-related retinal infiltration. The aggressive medical protocol included entecavir, prednisolone, plasma exchange, hemodialysis, and bilirubin adsorption. We herein report successful medical treatment for fulminant de novo hepatitis B in a patient considered unsuitable for liver transplantation.

Decreased hepatic phosphorylated p38 mitogen-activated protein kinase contributes to attenuation of thioacetamide-induced hepatic necrosis in diet-induced obese mice.

We previously reported that thioacetamide (TA)-induced hepatocellular necrosis was attenuated in mice fed a high-fat diet (HFD mice) compared with mice fed a normal rodent diet (ND mice). In this study, we investigated whether p38 mitogen-activated protein kinase (p38 MAPK) was involved in this attenuation. Western blot analysis revealed that hepatic phosphorylated p38 MAPK protein decreased at 8 and 24 hours (hr) after TA dosing in the HFD mice, while it decreased only at 24 hr in the ND mice in comparison to the time- and diet-matched, vehicle-treated mice. p38 MAPK regulates various biological functions including inflammation, therefore, hepatic metabolomics analysis focusing on pro-inflammatory lipid mediators was performed. At 24 hr after TA dosing, only one pro-inflammatory mediator, 12-hydroxyeicosatetraenoic acid (HETE), was higher in the HFD mice. On the other hand, in addition to 12-HETE, 15-HETE and 12-hydroxyeicosapentaenoic acid (HEPE) were higher and omega-3/omega-6 polyunsaturated fatty acids ratios were lower in the ND mice at 24 hr. These results of metabolomics indicated that less pro-inflammatory state was seen in HFD mice than in ND mice at 24 hr. Finally, to confirm whether the observed decrease in phosphorylated p38 MAPK could attenuate TA-induced hepatocellular necrosis, we showed that SB203580 hydrochloride, an inhibitor of p38 MAPK, partially attenuated TA-induced hepatic necrosis in ND mice. Collectively, these results suggest that a prompt decrease in phosphorylation of p38 MAPK after TA administration is one of the factors that attenuate TA-induced hepatic necrosis in HFD mice.

Transplantation of bone marrow cells decreases tumor necrosis factor-α production and blood-brain barrier permeability and improves survival in a mouse model of acetaminophen-induced acute liver disease.

BACKGROUND AIMS: Acute liver failure (ALF), although rare, remains a rapidly progressive and frequently fatal condition. Acetaminophen (APAP) poisoning induces a massive hepatic necrosis and often leads to death as a result of cerebral edema. Cell-based therapies are currently being investigated for liver injuries. We evaluated the therapeutic potential of transplantation of bone marrow mononuclear cells (BMC) in a mouse model of acute liver injury. METHODS: ALF was induced in C57Bl/6 mice submitted to an alcoholic diet followed by fasting and injection of APAP. Mice were transplanted with 10(7) BMC obtained from enhanced green fluorescent protein (GFP) transgenic mice. RESULTS: BMC transplantation caused a significant reduction in APAP-induced mortality. However, no significant differences in serum aminotransferase concentrations, extension of liver necrosis, number of inflammatory cells and levels of cytokines in the liver were found when BMC- and saline-injected groups were compared. Moreover, recruitment of transplanted cells to the liver was very low and no donor-derived hepatocytes were observed. Mice submitted to BMC therapy had some protection against disruption of the blood-brain barrier, despite their hyperammonemia, and serum metalloproteinase (MMP)-9 activity similar to the saline-injected group. Tumor necrosis factor (TNF)-α concentrations were decreased in the serum of BMC-treated mice. This reduction was associated with an early increase in interleukin (IL)-10 mRNA expression in the spleen and bone marrow after BMC treatment. CONCLUSIONS: BMC transplantation protects mice submitted to high doses of APAP and is a potential candidate for ALF treatment, probably via an immunomodulatory effect on TNF-α production.

Hemoperitoneum caused by hepatic necrosis and rupture following a snakebite: a case report with rare CT findings and successful embolization.

We report the computed tomographic and angiographic findings in the case of a recently obtained successful clinical outcome after embolization of the hepatic artery in the case of a snakebite causing hemoperitoneum associated with hepatic necrosis and rupture with active bleeding.