Treatment of newborn G6pc(-/-) mice with bone marrow-derived myelomonocytes induces liver repair

Human Umbilical Cord Blood Mononuclear Cells Ameliorate CCl4-Induced Acute Liver Injury in Mice via Inhibiting Inflammatory Responses and Upregulating Peripheral Interleukin-22

Background: Human umbilical cord blood mononuclear cells (hUCBMNCs) show therapeutic effects on many inflammatory diseases. The deterioration of acute liver injury is attributed to excessive inflammatory responses triggered by damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs). Whether hUCBMNCs treatment is a promising strategy for acute liver injury/failure needs to be investigated.

Methods: Liver injury mice induced by PAMPs, DAMPs, or DAMPs plus PAMPs were developed. DAMPs included CCl4 (carbon tetrachloride), APAP (acetaminophen), and ConA (Concanavalin A). PAMPs included Klebsiella pneumoniae (K.P.) and Salmonella typhimurium (S. Typhimurium). DAMP plus PAMP-induced liver injury was developed by sequential CCl4 and K.P. administration. hUCBMNCs were injected intravenously.

Results: hUCBMNCs significantly prolonged mice survival time in DAMP plus PAMP-induced liver failure but had no benefit in bacteria-infected mice. hUCBMNCs significantly alleviated hepatic necrosis post CCl4/ConA insult. In CCl4-induced acute liver injury, peripheral levels of interleukin (IL)-22 were upregulated and liver regeneration was enhanced after treating with hUCBMNCs at 48h. The levels of p62 and LC3B-II, autophagy markers, were also upregulated in the hUCBMNC-treated group.

Conclusion: hUCBMNCs as a kind of cell therapeutic strategy could attenuate acute liver injury in mice, which is executed by enhancing autophagy and regeneration in the liver via inhibiting inflammatory responses and upregulating peripheral IL-22.

Veratrilla baillonii Franch Ameliorates Diabetic Liver Injury by Alleviating Insulin Resistance in Rats

Type 2 diabetes mellitus (T2DM) is a complex and polygenic disorder with diverse complications. Veratrilla baillonii Franch (V. baillonii) has been applied in the intervention and treatment a diverse range of diseases, including diabetes. In this study, we revealed that water extracts of V. baillonii (WVBF) can ameliorate liver injury and insulin resistance in T2DM rat model. To elucidate the anti-diabetic mechanisms of WVBF, we performed liver transcriptome analysis that displayed WVBF treatment significantly suppressed many gene expressions involved in insulin resistance. Furthermore, functional experiments showed that WVBF treatment reduced the pathological damages of liver and pancreas, which may be regulated by Foxo1, Sirt1, G6pc, c-Met, Irs1, Akt1, Pik3r1. These results indicated that WVBF improves diabetic liver injury and insulin resistance in diabetic rats. Therefore, this study demonstrated WVBF could be used as a promising therapeutic agent for intervention and treatment of diabetes.

Donor-derived hepatocytes in human hematopoietic cell transplant recipients: evidence of fusion

Reconstitution of hepatocytes by hematopoietic stem cells-a phenomenon which occurs in rodents under highly selective conditions-results from infrequent fusion between incoming myelomonocytes and host hepatocytes, with subsequent proliferation. Human hematopoietic stem cell transplant recipients have been little studied, with some support for transdifferentiation (direct differentiation). We studied routinely obtained autopsy liver tissue of four female hematopoietic cell transplant recipients with male donors, using a highly specific conjoint immunohistochemistry in situ hybridization light microscopic technique. Hepatocyte nuclei were identified by cytokeratin (Cam5.2) staining and evaluated for X and Y chromosome content. Over 1.6 million hepatocytes were assessed for rare instances of donor origin, revealing a Y chromosome in 67. Mixed tetraploids (XXXY) and their nuclear truncation products (XXY, XY, Y) were directly demonstrated, with no detection of the male tetraploids (XXYY) that may result from transdifferentiation with subsequent tetraploidization, nor their unique truncation products (XYY, YY), implicating fusion as the mechanism. To determine whether it is the sole mechanism, we modeled the chromosome distribution based on the same probability of detection of each X chromosome, deriving parameters of sensitivity and female tetraploidy by best fit. We then hypothesized that the distribution of Y chromosome-containing cells could be predicted by a similar model. After modification to account for "clumpy" Y chromosomes, the observed results were in accord with the predicted results (p = 0.6). These results suggest that all the Y-containing cells, including apparent XY cells, derive from mixed tetraploids, consistent with fusion as the sole mechanism.

Molecular genetic analysis and phenotypic characteristics of a consanguineous family with glycogen storage disease type Ia

Glycogen storage disease type‑Ia (GSD‑Ia) is a rare autosomal recessive disease caused by a mutation in the gene encoding glucose‑6‑phosphate‑α (G6PC). The present study reported the case of a 3‑month‑old female Chinese patient with GSD‑Ia born to consanguineous parents. The aim of the present study was to identify the precise mutation of the G6PC gene associated with this family and to describe the phenotypic characteristics of the patient. A comprehensive examination was performed on the patient, including physical examination, vein blood gas analysis, abdominal sonography and biochemical analyses. In addition, gene sequencing was performed on the coding region of the G6PC gene to identify the mutation. The patient was diagnosed with GSD‑Ia and a G6PC missense mutation of c.518T>C (p.L173P) located in a highly conserved area was identified. The mutation is in a non‑helical region of the protein, which previous studies have suggested should result in a lesser effect on G6PC enzymatic activity and milder phenotypic characteristics compared with mutations located in helical regions. However, the severity of the disease phenotype in the subject of the present study was inconsistent with that predicted from her genotype. The patient suffered from serious hypoglycemia, lactic acidosis, increased triglycerides, hepatic dysfunction, clear hepatomegaly and nephromegaly. The incidence of the p.L173P mutation may be relatively high in the Chinese population. Knowledge of the various phenotypic presentations of the p.L173P mutation may beneficial for future investigations.

Natural Killer Cells-Produced IFN-γ Improves Bone Marrow-Derived Hepatocytes Regeneration in Murine Liver Failure Model

Bone-marrow transplantation (BMT) can repopulate the liver through BM-derived hepatocyte (BMDH) generation, although the underlying mechanism remains unclear. Using fumarylacetoacetate hydrolase-deficient (Fah(-/-)) mice as a liver-failure model, we confirmed that BMDHs were generated by fusion of BM-derived CD11b(+)F4/80(+)myelomonocytes with resident Fah(-/-) hepatocytes. Hepatic NK cells became activated during BMDH generation and were the major IFN-γ producers. Indeed, both NK cells and IFN-γ were required for BMDH generation since WT, but not NK-, IFN-γ-, or IFN-γR1-deficient BM transplantation successfully generated BMDHs and rescued survival in Fah(-/-) hosts. BM-derived myelomonocytes were determined to be the IFN-γ-responding cells. The IFN-γ-IFN-γR interaction contributed to the myelomonocyte-hepatocyte fusion process, as most of the CD11b(+) BMDHs in mixed BM chimeric Fah(-/-) hosts transplanted with a 1:1 ratio of CD45.1(+) WT and CD45.2(+) Ifngr1(-/-) BM cells were of CD45.1(+) WT origin. Confirming these findings in vitro, IFN-γ dose-dependently promoted the fusion of GFP(+) myelomonocytes with Fah(-/-) hepatocytes due to a direct effect on myelomonocytes; similar results were observed using activated NK cells. In conclusion, BMDH generation requires NK cells to facilitate myelomonocyte-hepatocyte fusion in an IFN-γ-dependent manner, providing new insights for treating severe liver failure.

Development of hepatocellular adenomas and carcinomas in mice with liver-specific G6Pase-α deficiency

Glycogen storage disease type 1a (GSD-1a) is caused by a deficiency in glucose-6-phosphatase-α (G6Pase-α), and is characterized by impaired glucose homeostasis and a high risk of developing hepatocellular adenomas (HCAs). A globally G6Pase-α-deficient (G6pc(-/-)) mouse model that shows pathological features similar to those of humans with GSD-1a has been developed. These mice show a very severe phenotype of disturbed glucose homeostasis and rarely live beyond weaning. We generated liver-specific G6Pase-α-deficient (LS‑G6pc(-/-)) mice as an alternative animal model for studying the long-term pathophysiology of the liver and the potential treatment strategies, such as cell therapy. LS‑G6pc(-/-) mice were viable and exhibited normal glucose profiles in the fed state, but showed significantly lower blood glucose levels than their control littermates after 6 hours of fasting. LS‑G6pc(-/-) mice developed hepatomegaly with glycogen accumulation and hepatic steatosis, and progressive hepatic degeneration. Ninety percent of the mice analyzed developed amyloidosis by 12 months of age. Finally, 25% of the mice sacrificed at age 10-20 months showed the presence of multiple HCAs and in one case late development of hepatocellular carcinoma (HCC). In conclusion, LS‑G6pc(-/-) mice manifest hepatic symptoms similar to those of human GSD-1a and, therefore, represent a valid model to evaluate long-term liver pathogenesis of GSD-1a.

Liver transplantation in glycogen storage disease type I

Glycogen storage disease type I (GSDI), an inborn error of carbohydrate metabolism, is caused by defects in the glucose-6-transporter/glucose-6-phosphatase complex, which is essential in glucose homeostasis. Two types exist, GSDIa and GSDIb, each caused by different defects in the complex. GSDIa is characterized by fasting intolerance and subsequent metabolic derangements. In addition to these clinical manifestations, patients with GSDIb suffer from neutropenia with neutrophil dysfunction and inflammatory bowel disease.

With the feasibility of novel cell-based therapies, including hepatocyte transplantations and liver stem cell transplantations, it is essential to consider long term outcomes of liver replacement therapy. We reviewed all GSDI patients with liver transplantation identified in literature and through personal communication with treating physicians. Our review shows that all 80 GSDI patients showed improved metabolic control and normal fasting tolerance after liver transplantation. Although some complications might be caused by disease progression, most complications seemed related to the liver transplantation procedure and subsequent immune suppression. These results highlight the potential of other therapeutic strategies, like cell-based therapies for liver replacement, which are expected to normalize liver function with a lower risk of complications of the procedure and immune suppression.