In the field of regenerative medicine, one of the ultimate goals is to generate functioning organs from pluripotent cells, such as ES cells or induced pluripotent stem cells (PSCs). We have recently generated functional pancreas and kidney from PSCs in pancreatogenesis-or nephrogenesis-disabled mice, providing proof of principle for organogenesis from PSCs in an embryo unable to form a specific organ. Key when applying the principles of in vivo generation to human organs is compensation for an empty developmental niche in large nonrodent mammals. Here, we show that the blastocyst complementation system can be applied in the pig using somatic cell cloning technology. Transgenic approaches permitted generation of porcine somatic cell cloned embryos with an apancreatic phenotype. Complementation of these embryos with allogenic blastomeres then created functioning pancreata in the vacant niches. These results clearly indicate that a missing organ can be generated from exogenous cells when functionally normal pluripotent cells chimerize a cloned dysorganogenetic embryo. The feasibility of blastocyst complementation using cloned porcine embryos allows experimentation toward the in vivo generation of functional organs from xenogenic PSCs in large animals.apancreatic pig | organ reconstitution | transplantation | somatic cell nuclear transfer | chimera

The biliary system, pancreas and liver all develop from the nearby foregut at almost the same time in mammals. The molecular mechanisms that determine the identity of each organ in this complex area are unknown.

Interindividual differences in hepatic metabolism, which are mainly due to genetic polymorphism in its gene, have a large influence on individual drug efficacy and adverse reaction. Hepatocyte-like cells (HLCs) differentiated from human induced pluripotent stem (iPS) cells have the potential to predict interindividual differences in drug metabolism capacity and drug response. However, it remains uncertain whether human iPSC-derived HLCs can reproduce the interindividual difference in hepatic metabolism and drug response. We found that cytochrome P450 (CYP) metabolism capacity and drug responsiveness of the primary human hepatocytes (PHH)-iPSHLCs were highly correlated with those of PHHs, suggesting that the PHH-iPS-HLCs retained donor-specific CYP metabolism capacity and drug responsiveness. We also demonstrated that the interindividual differences, which are due to the diversity of individual SNPs in the CYP gene, could also be reproduced in PHH-iPS-HLCs. We succeeded in establishing, to our knowledge, the first PHH-iPS-HLC panel that reflects the interindividual differences of hepatic drugmetabolizing capacity and drug responsiveness.human iPS cells | hepatocyte | CYP2D6 | personalized drug therapy | SNP D rug-induced liver injury (DILI) is a leading cause of the withdrawal of drugs from the market. Human induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (HLCs) are expected to be useful for the prediction of DILI in the early phase of drug development. Many groups, including our own, have reported that the human iPS-HLCs have the ability to metabolize drugs, and thus these cells could be used to detect the cytotoxicity of drugs that are known to cause DILI (1, 2). However, to accurately predict DILI, it will be necessary to establish a panel of human iPS-HLCs that better represents the genetic variation of the human population because there are large interindividual differences in the drug metabolism capacity and drug responsiveness of hepatocytes (3). However, it remains unclear whether the drug metabolism capacity and drug responsiveness of human iPS-HLCs could reflect those of donor parental primary human hepatocytes (PHHs). To address this issue, we generated the HLCs differentiated from human iPSCs which had been established from PHHs (PHH-iPS-HLCs). Then, we compared the drug metabolism capacity and drug responsiveness of PHH-iPS-HLCs with those of their parental PHHs, which are genetically identical to the PHH-iPS-HLCs.Interindividual differences of cytochrome P450 (CYP) metabolism capacity are closely related to genetic polymorphisms, especially single nucleotide polymorphisms (SNPs), in CYP genes (4). Among the various CYPs expressed in the liver, CYP2D6 is responsible for the metabolism of approximately a quarter of commercially used drugs and has the largest phenotypic variability, largely due to SNPs (5). It is known that certain alleles result in the poor metabolizer phenotype due to a decrease of CYP2D6 metabolism. Therefore, the appropriate dosage for drugs that are metabolized ...

We studied histological features and long-term outcomes in patients with progressive familial intrahepatic cholestasis type 1 (PFIC1) after liver transplantation (LT). Histological findings were correlated with the post-LT course and treatment in 11 recipients with PFIC1. Ages at LT varied from 1 to 18 years (median, 4 years). Macrovesicular steatosis was observed in 8 patients at a median of 60 days post-LT (range, 21-191 days). Severe steatosis progressed to steatohepatitis in 7 patients at a median of 161 days (range, 116-932 days). The patients were followed up for a median of 7.3 years (range, 2.3-16.1 years). Six showed bridging fibrosis, with 2 progressing to cirrhosis. One patient with cirrhosis died because of the rupture of a splenic artery aneurysm 13.6 years post-LT. Post-LT refractory diarrhea was present in all 8 having steatosis. Three without post-LT diarrhea showed no allograft steatosis. Bile adsorptive resin therapy reduced the diarrhea and steatosis. Patients with posttransplant steatosis typically had more severe mutations of the ATPase class I type 8B member 1 (ATP8B1) gene and were more likely to have systemic complications such as pancreatitis. In conclusion, allograft steatosis was present in patients with PFIC1, progressing to steatohepatitis and cirrhosis. Because expression of the familial intrahepatic cholestasis 1 gene occurs in several organs, including the small intestine, pancreas, and liver, and it is involved in enterohepatic bile acid circulation, post-LT steatosis may be due to a malfunction of the ATP8B1 product. Liver Transpl 15:610-618, 2009.

Summary Background Asthma is a chronic airway inflammatory disease; however, the molecular mechanisms that underlie asthma exacerbation are only partially understood. Objective To identify gene expression signatures that reflect the acute exacerbation of asthma, we examined the differential expression of genes during asthma exacerbation and stable condition by using microarray analysis. Methods The subjects were mite‐sensitive asthmatic children and non‐asthmatic control children. The children were divided into four groups (AE: asthma exacerbation, n=12; SA: stable asthma, n=11; IC: infected control, n=6; and NC: non‐infected control, n=5). Total RNA was extracted from peripheral blood mononuclear cells and subjected to microarray analysis with Illumina Human Ref8 BeadChip arrays. Welch's t‐test was performed to identify genes whose expression was altered during asthma exacerbation. Quantitative real‐time RT‐PCR was performed on samples collected from 43 asthmatic children and 11 control children to verify the microarray results. Results The expression of 137/16 genes was significantly up/down‐regulated during asthma exacerbation assessed by microarray analysis. Of the genes, 62 were also differentially expressed during upper respiratory infection. Many of the asthma exacerbation related genes were involved in defence responses and responses to external stimuli, but these associations disappeared after excluding the infection‐related genes. Quantitative real‐time RT‐PCR confirmed that the genes related (S100A8 and GAS6) and unrelated to infections (CD200 and RBP7) were differentially expressed during asthma exacerbation (P<0.01). Conclusions Previously unidentified immune responses during asthma exacerbation may provide further clarification of the molecular mechanisms underlying asthma.