Long-Term Fate of Human Fetal Liver Progenitor Cells Transplanted in Injured Mouse Livers.

Liver progenitor cells have the potential to repair and regenerate a diseased liver. The success of any translational efforts, however, hinges on thorough understanding of the fate of these cells after transplant, especially in terms of long-term safety and efficacy. Here, we report transplantation of a liver progenitor population isolated from human fetal livers into immune-permissive mice with follow-up up to 36 weeks after transplant. We found that human progenitor cells engraft and differentiate into functional human hepatocytes in the mouse, producing albumin, alpha-1-antitrypsin, and glycogen. They create tight junctions with mouse hepatocytes, with no evidence of cell fusion. Interestingly, they also differentiate into functional endothelial cell and bile duct cells. Transplantation of progenitor cells abrogated carbon tetrachloride-induced fibrosis in recipient mice, with downregulation of procollagen and anti-smooth muscle actin. Paradoxically, the degree of engraftment of human hepatocytes correlated negatively with the anti-fibrotic effect. Progenitor cell expansion was most prominent in cirrhotic animals, and correlated with transcript levels of pro-fibrotic genes. Animals that had resolution of fibrosis had quiescent native progenitor cells in their livers. No evidence of neoplasia was observed, even up to 9 months after transplantation. Human fetal liver progenitor cells successfully attenuate liver fibrosis in mice. They are activated in the setting of liver injury, but become quiescent when injury resolves, mimicking the behavior of de novo progenitor cells. Our data suggest that liver progenitor cells transplanted into injured livers maintain a functional role in the repair and regeneration of the liver. Stem Cells 2018;36:103-113.

Hepatic differentiation of human amniotic epithelial cells and in vivo therapeutic effect on animal model of cirrhosis.

BACKGROUND AND AIM: Human amniotic epithelial cells (hAECs) have been touted as an ideal stem cell candidate, being ethically neutral, immunologically naïve, plentiful in origin, and retaining plasticity in its fetal stage. We hypothesized that by applying natural physiological signals of the developing liver, hAECs can be coaxed into becoming functional immunopermissive hepatocyte-like cells. These cells would have tremendous potential for allogenic cellular transplantation in the treatment of chronic liver insufficiency. METHODS: hAECs were obtained from term placentas and subjected to hepatic trans-differentiation. Hepatic differentiated cells were analyzed with immunophenotyping, electron microscopy, reverse transcription-polymerase chain reaction as well as characterized for hepatic metabolic function. In vivo efficacy was tested using intrasplenic transplantation into non-obese diabetic (NOD) Scid Gamma mice with thioacetamide-induced chronic liver failure and analyzed for engraftment and improvement in liver indices. RESULTS: With hepatic differentiation, hAECs assumed a hepatocytic polygonal morphology with upregulation of transcription factors responsible for liver specification. These hepatic differentiated-hAECs (HD-AECs) demonstrated bile canaliculi formation, secreted albumin, eliminated indo-cyanine green, uptook low-density lipoprotein, and inducible CYP3A4 and CYP2C9 enzymatic activities. Transplantation of HD-AECs and de novo hAECs in mice model of cirrhosis showed successful in vivo engraftment and differentiation into functional hepatocytes positive for human-specific albumin. HD-AEC cells that had undergone hepatic differentiation showed the greatest improvement in albumin function while preserving human leukocyte antigen-G expression postdifferentiation. CONCLUSION: hAECs were able to differentiate into functional hepatocyte-like cells both in vivo and in vitro. They showed therapeutic efficacy after transplantation in mice model of cirrhosis, offering an exciting source of cells for generation of functionally useful hepatocytes.

Single-tube nonaplex microsatellite PCR panel for preimplantation genetic diagnosis of Hb Bart's hydrops fetalis syndrome.

OBJECTIVE: To develop a single-tube multi-marker assay for improved preimplantation genetic diagnosis (PGD) of deletional and/or non-deletional Hb Bart's hydrops fetalis syndrome, providing haplotype confirmation of deletional status, and maximization of linkage informativity. METHODS: We performed in silico mining to identify novel microsatellites within 1 Mb flanking the alpha-globin gene cluster, and optimized a single-tube assay combining detection of α(0) -thalassemia deletions with multi-marker linkage analysis. We performed validation on 100 single cells prior to clinical PGD application. RESULTS: Of 42 markers encompassing the α-globin gene cluster that were identified in silico, 9 were highly polymorphic (0.68 ≤ polymorphism information content ≤ 0.92; 0.66 ≤ Ho ≤ 0.90; 10 ≤ alleles ≤ 35) and optimized to co-amplify directly from a single cell. A validation analysis of 100 single lymphoblasts yielded 100% amplification success for all markers, and individual marker allele drop-out (ADO) rates of 0-5%. Clinical application of the assay in PGD for Hb Bart's (2 cases/cycles) resulted in a twin pregnancy and healthy live birth of two baby girls. CONCLUSIONS: This single-tube nonaplex microsatellite PCR panel can be applied directly to PGD of most deletional Hb Bart's without the need for deletion-specific customization, and to linkage-based PGD of non-deletional Hb Bart's.

Determination of gestational age in twin pregnancy: Which fetal crown-rump length should be used?

AIM: For twin pregnancy, discrepancies in the crown-rump length (CRL) between two fetuses often exist. Evidence is lacking regarding which fetal CRL should be used for estimation of gestational age (GA). Our aim was to determine whether the larger, smaller or the mean CRL is more accurate in determining the GA in the first trimester of pregnancy. METHODS: This is a retrospective study of twin pregnancies conceived by assisted reproduction. The oocyte retrieval date was used for determination of the true gestational age. CRL dating charts by Robinson, Hadlock and Chitty were used for reference. The values of the larger, smaller and mean CRL were compared with the reference CRL for the corresponding GA, which was obtained from each of the three reference charts. The differences between the reference CRL and measured CRL were calculated. The percentages of which CRL, the larger, smaller or the mean, was closest to the expected reference values were calculated. RESULTS: A total of 52 pairs of twins were included in the study. According to Robinson's chart, the proportion of larger, smaller and mean CRL values that were closest to the reference value was found in 11.5%, 75.0% and 5.8% of cases respectively. The larger, smaller and the mean CRLs were closest to the reference CRL in the Hadlock chart for 28.9%, 44.2% and 19.2% of cases, respectively, and closest to the reference CRL in the Chitty chart for 17.3%, 59.6% and 15.4% of cases, respectively. CONCLUSION: The smaller CRL is more accurate in the estimation of the GA for twin pregnancy compared to the larger or mean CRL values.

Preimplantation genetic diagnosis of chromosome translocations by analysis of polymorphic short tandem repeats.

INTRODUCTION: We aimed to develop and implement a short tandem repeat (STR) polymerase chain reaction alternative to fluorescence in situ hybridisation (FISH) for the preimplantation genetic diagnosis (PGD) of chromosomal translocations. METHODS: Selected informative STRs located on translocated arms of relevant chromosomes were used to discriminate between normal and unbalanced chromosome states in each embryo. RESULTS: PGD cycles were performed on five couples where one spouse carried a balanced translocation. 27 embryos were analysed, of which 12 were normal/balanced, 12 were abnormal/unbalanced and three were indeterminate. Four PGD cycles proceeded to embryo transfer, of which two led to pregnancy. The first pregnancy showed a normal male karyotype, and a healthy baby was delivered at term. A second pregnancy unexpectedly miscarried in the second trimester from unknown causes. CONCLUSION: STR analysis is a simple and suitable alternative to FISH for detecting unbalanced chromosomal states in preimplantation embryos.

CD166(pos) subpopulation from differentiated human ES and iPS cells support repair of acute lung injury.

Previous efforts to derive lung progenitor cells from human embryonic stem (hES) cells using embryoid body formation or stromal feeder cocultures had been limited by low efficiencies. Here, we report a step-wise differentiation method to drive both hES and induced pluripotent stem (iPS) cells toward the lung lineage. Our data demonstrated a 30% efficiency in generating lung epithelial cells (LECs) that expresses various distal lung markers. Further enrichment of lung progenitor cells using a stem cell marker, CD166 before transplantation into bleomycin-injured NOD/SCID mice resulted in enhanced survivability of mice and improved lung pulmonary functions. Immunohistochemistry of lung sections from surviving mice further confirmed the specific engraftment of transplanted cells in the damaged lung. These cells were shown to express surfactant protein C, a specific marker for distal lung progenitor in the alveoli. Our study has therefore demonstrated the proof-of-concept of using iPS cells for the repair of acute lung injury, demonstrating the potential usefulness of using patient's own iPS cells to prevent immune rejection which arise from allogenic transplantation.

Current opinion on use of luteinizing hormone supplementation in assisted reproduction therapy: an Asian perspective.

LH and FSH have complementary functions in ensuring optimal oocyte maturation and ovulation. In women undergoing assisted reproduction technology protocols with gonadotrophin-releasing hormone analogues, LH and FSH concentrations are reduced. While FSH use in assisted reproduction technology is well established, there is no published consensus on the need for exogenous LH in Asian patients. Having reviewed the concept of the LH therapeutic window and differences between recombinant human LH (r-HLH) and human menopausal gonadotrophin, a consensus was reached on which patient subgroups may benefit from LH supplementation. Adjuvant r-HLH gives clinicians precise control over the dose of LH bioactivity administered to target the therapeutic window. The use of r-HLH is recommended in women with poor response in a previous cycle or suboptimal follicular progression in a current cycle by day 6-8 of stimulation. r-HLH should also be considered in women at risk of suboptimal response, specifically age > 35 years. Other risk markers that suggest the need for LH supplementation, which include baseline/day-6 serum LH and anti-Müllerian hormone concentrations, antral follicle count and LH polymorphisms require further research and verification. For measurement of LH response adequacy, the monitoring of follicular progression, oestradiol concentrations and endometrial thickness is recommended.

Simplified PGD of common determinants of haemoglobin Bart's hydrops fetalis syndrome using multiplex-microsatellite PCR.

The high incidence of double-gene deletions in α-thalassaemia increases the risk of having pregnancies with homozygous α(0)-thalassaemia, the cause of the lethal haemoglobin (Hb) Bart's hydrops fetalis syndrome. Preimplantation genetic diagnosis (PGD) has played an important role in preventing such cases. However, the current gap-PCR based PGD protocol for deletional α-thalassaemia requires specific primer design for each specific deletion. A universal PGD assay applicable to all common deletional determinants of Hb Bart's hydrops fetalis syndrome has been developed. Microsatellite markers 16PTEL05 and 16PTEL06 within the α-globin gene cluster were co-amplified with a third microsatellite marker outside the affected region in a multiplex-PCR reaction and analysed by capillary electrophoresis. Eight informed couples at risk of having Hb Bart's hydrops fetalis were recruited in this study and all patients underwent standard procedures associated with IVF. A total of 47 embryos were analysed. Three pregnancies were achieved from three couples, with the births of two healthy babies and one ongoing pregnancy. This work has successfully adapted an earlier protocol and developed a simple and reliable single-cell assay applicable to PGD of Hb Bart's hydrops fetalis syndrome regardless of type of deletion. Alpha-thalassaemia is one of the most common inheritable disorders worldwide. It is a blood disorder that, in its lethal form caused by deletion of all four copies of the α-globin gene, results in the demise of the affected fetus, a condition referred to as haemoglobin (Hb) Bart's hydrops fetalis syndrome. Preimplantation genetic diagnosis (PGD) has played an important role in preventing such cases. Current PGD protocols for deletional α-thalassaemia utilize a strategy called gap-PCR, which requires the different assays for different deletion types. We have developed a universal PGD assay applicable to all common deletional determinants of Hb Bart's hydrops fetalis syndrome based on microsatellite marker analysis. Eight informed couples at risk of having Hb Bart's hydrops fetalis were recruited in this study and all patients underwent standard procedures associated with IVF. Forty-five embryos were analysed in total. Three pregnancies were achieved from three couples, with the births of two healthy babies and one pregnancy still ongoing. We have successfully adapted our earlier protocol and developed a simple and reliable single cell assay applicable to PGD of Hb Bart's hydrops fetalis syndrome regardless of the type of deletion.

Human feeders support prolonged undifferentiated growth of human inner cell masses and embryonic stem cells.

Previous reports have demonstrated the growth of undifferentiated human embryonic stem (HES) cells on mouse embryonic fibroblast (MEF) feeders and on laminin- or Matrigel-coated plastic surfaces supplemented with MEF-conditioned medium. These xenosupport systems run the risk of cross-transfer of animal pathogens from the animal feeder, matrix, or conditioned medium to the HES cells, thus compromising later clinical application. Here we show that human fetal and adult fibroblast feeders support prolonged undifferentiated HES cell growth of existing cell lines and are superior to cell-free matrices (collagen I, human extracellular matrix, Matrigel, and laminin) supplemented with human or MEF feeder-conditioned medium. Additionally, we report the derivation and establishment of a new HES cell line in completely animal-free conditions. Like HES cells cultured on MEF feeders, the HES cells grown on human feeders had normal karyotypes, tested positive for alkaline phosphatase activity, expressed Oct-4 and cell surface markers including SSEA-3, SSEA-4, Tra 1-60, and GCTM-2, formed teratomas in severely combined immunodeficient (SCID) mice, and retained all key morphological characteristics. Human feeder#150;supported HES cells should provide a safer alternative to existing HES cell lines in therapeutic applications.