En masse organoid phenotyping informs metabolic-associated genetic susceptibility to NASH.

Genotype-phenotype associations for common diseases are often compounded by pleiotropy and metabolic state. Here, we devised a pooled human organoid-panel of steatohepatitis to investigate the impact of metabolic status on genotype-phenotype association. En masse population-based phenotypic analysis under insulin insensitive conditions predicted key non-alcoholic steatohepatitis (NASH)-genetic factors including the glucokinase regulatory protein (GCKR)-rs1260326:C>T. Analysis of NASH clinical cohorts revealed that GCKR-rs1260326-T allele elevates disease severity only under diabetic state but protects from fibrosis under non-diabetic states. Transcriptomic, metabolomic, and pharmacological analyses indicate significant mitochondrial dysfunction incurred by GCKR-rs1260326, which was not reversed with metformin. Uncoupling oxidative mechanisms mitigated mitochondrial dysfunction and permitted adaptation to increased fatty acid supply while protecting against oxidant stress, forming a basis for future therapeutic approaches for diabetic NASH. Thus, "in-a-dish" genotype-phenotype association strategies disentangle the opposing roles of metabolic-associated gene variant functions and offer a rich mechanistic, diagnostic, and therapeutic inference toolbox toward precision hepatology. VIDEO ABSTRACT.

Genetic causes of growth hormone insensitivity beyond GHR.

Growth hormone insensitivity (GHI) syndrome, first described in 1966, is classically associated with monogenic defects in the GH receptor (GHR) gene which result in severe post-natal growth failure as consequences of insulin-like growth factor I (IGF-I) deficiency. Over the years, recognition of other monogenic defects downstream of GHR has greatly expanded understanding of primary causes of GHI and growth retardation, with either IGF-I deficiency or IGF-I insensitivity as clinical outcomes. Mutations in IGF1 and signaling component STAT5B disrupt IGF-I production, while defects in IGFALS and PAPPA2, disrupt transport and release of circulating IGF-I, respectively, affecting bioavailability of the growth-promoting IGF-I. Defects in IGF1R, cognate cell-surface receptor for IGF-I, disrupt not only IGF-I actions, but actions of the related IGF-II peptides. The importance of IGF-II for normal developmental growth is emphasized with recent identification of defects in the maternally imprinted IGF2 gene. Current application of next-generation genomic sequencing has expedited the pace of identifying new molecular defects in known genes or in new genes, thereby expanding the spectrum of GH and IGF insensitivity. This review discusses insights gained and future directions from patient-based molecular and functional studies.

Waist-to-height ratio remains an accurate and practical way of identifying cardiometabolic risks in children and adolescents.

AIM: We evaluated how effectively the waist-to-height ratio (WHtR) identified cardiometabolic risk (CMR) in children and adolescents, compared with the tri-ponderal mass index, percentage of body fat and other obesity indexes. METHODS: Eligible subjects were recruited from three metropolitan regions of China from May 2013 to June 2014. Subjects with at least three of the following abnormalities - hypertension, dyslipidemia, elevated fasting blood glucose and central obesity - were defined as CMR1 and children with at least two were defined as CMR2. The area under the curve (AUC) of the receiver operating characteristic curve was used to compare how effectively obesity indexes predicted CMR. RESULTS: We recruited 3556 subjects aged 7-18 years. All five obesity indexes showed good, comparable performances in identifying CMR and the AUCs ranged from 0.89 to 0.90 for CMR1 and 0.83 to 0.85 for CMR2. The cut-off of 0.467 for WHtR achieved a sensitivity of 0.91 and specificity of 0.80 for predicting CMR1, with the best cut-offs being 0.463 for boys and 0.469 for girls. CONCLUSION: The WHtR was a superior and practical screening tool for detecting CMR in this paediatric population, as it provided comparable accuracy to other methods and just required a simple calculation.

[Novel PHEX gene mutations in patients with X-linked hypophosphatemic rickets: an analysis of 2 cases].

OBJECTIVE: To investigate PHEX gene mutations in 2 patients with X-linked hypophosphatemic rickets (XLH) and their families and to clarify the genetic etiology. METHODS: A retrospective analysis was performed for the clinical data of two patients with XLH. High-throughput sequencing was used to detect the PHEX gene, a pathogenic gene of XLH. PCR-Sanger sequencing was used to verify the distribution of mutations in families. RESULTS: Both patients had novel mutations in the PHEX gene; one patient had a frameshift mutation, c.931dupC, which caused early termination of translation and produced the truncated protein p.Gln311Profs*13; the other patient had a splice site mutation, IVS14+1G>A, which caused the skipping of exon 15 and produced an incomplete amino acid chain. Their parents had normal gene phenotypes. CONCLUSIONS: c.931dupC and IVS14+1G>A are two novel mutations of the PHEX gene and might be the new pathogenic mutations of XLH.

Functional characteristics of reversibly immortalized hepatic progenitor cells derived from mouse embryonic liver.

BACKGROUND/AIMS: Liver is a vital organ and retains its regeneration capability throughout adulthood, which requires contributions from different cell populations, including liver precursors and intrahepatic stem cells. To overcome the mortality of hepatic progenitors (iHPs) in vitro, we aim to establish reversibly immortalized hepatic progenitor cells from mouse embryonic liver. METHODS AND RESULTS: Using retroviral system to stably express SV40 T antigen flanked with Cre/LoxP sites, we establish a repertoire of iHP clones with varied differentiation potential. The iHP cells maintain long-term proliferative activity and express varied levels of progenitor markers (Pou5f1/Oct4 and Dlk) and hepatocyte markers (AFP, Alb and ApoB). Five representative iHP clones express hepatic/pancreatic transcription factors HNF3α/Foxa1, HNF3ß/Foxa2, and HNF4α/MODY1. Dexamethasone is shown to promote the expression of hepatocyte markers AFP and TAT, along with ICG-uptake and glycogen storage functions in the iHP clones. Cre-mediated removal of SV40 T antigen reverses the proliferative activity of iHP cells. When iHP cells are subcutaneously implanted in athymic nude mice, no tumor formation is observed for up to 8 weeks. CONCLUSIONS: We demonstrate that the established iHP cells are stable, reversible, and non-tumorigenic hepatic progenitor-like cells, which should be valuable for studying liver organogenesis, metabolic regulations, and hepatic lineage-specific differentiation.

Skeletal overgrowth in a pre-pubescent child treated with pan-FGFR inhibitor.

Fibroblast growth factors and their receptors (FGFR) have major roles in both human growth and oncogenesis. In adults, therapeutic FGFR inhibitors have been successful against tumors that carry somatic FGFR mutations. In pediatric patients, trials testing these anti-tumor FGFR inhibitor therapeutics are underway, with several recent reports suggesting modest positive responses. Herein, we report an unforeseen outcome in a pre-pubescent child with an FGFR1-mutated glioma who was successfully treated with FDA-approved erdafitinib, a pan-FGFR inhibitor approved for treatment of Bladder tumors. While on treatment with erdafitinib, the patient experienced rapid skeletal and long bone overgrowth resulting in kyphoscoliosis, reminiscent of patients with congenital loss-of-function FGFR3 mutations. We utilized normal dermal fibroblast cells established from the patient as a surrogate model to demonstrate that insulin-like growth factor 1 (IGF-1), a factor important for developmental growth of bones and tissues, can activate the PI3K/AKT pathway in erdafitinib-treated cells but not the MAPK/ERK pathway. The IGF-I-activated PI3K/AKT signaling rescued normal fibroblasts from the cytotoxic effects of erdafitinib by promoting cell survival. We, therefore, postulate that IGF-I-activated P13K/AKT signaling likely continues to promote bone elongation in the growing child, but not in adults, treated with therapeutic pan-FGFR inhibitors. Importantly, since activated MAPK signaling counters bone elongation, we further postulate that prolonged blockage of the MAPK pathway with pan-FGFR inhibitors, together with actions of growth-promoting factors including IGF-1, could explain the abnormal skeletal and axial growth suffered by our pre-pubertal patient during systemic therapeutic use of pan-FGFR inhibitors. Further studies to find more targeted, and/or appropriate dosing, of pan-FGFR inhibitor therapeutics for children are essential to avoid unexpected off-target effects as was observed in our young patient.

Effects of Aquatic Exercise and Floor Curling on Balance Ability and Lower Limb Muscle Strength in Children with Intellectual Disabilities: A Pilot Study in China.

Children with intellectual disabilities often face challenges in balance ability and lower limb muscle strength, which negatively impact their daily lives and motor function. Therefore, it is crucial to enhance the balance ability and lower limb muscle strength of children with intellectual disabilities. This study aimed to investigate the effects of a 12-week aquatic exercise and floor curling intervention on the balance ability and lower limb muscle strength of children with intellectual disabilities. Forty-two participants were randomly assigned to the aquatic exercise group, floor curling group, and control group. The aquatic exercise and floor curling groups received a 12-week intervention, while the control group engaged in supervised free activities. The participants' balance ability and lower limb muscle strength were assessed using the Berg Balance Scale and a muscle strength testing device before and after the intervention. The results showed significant improvements in balance ability and lower limb muscle strength for both the aquatic exercise group and the floor curling group after the intervention. The aquatic exercise group demonstrated an average improvement of 10.84% in balance ability and an overall average improvement of 16.28% in lower limb muscle strength. The floor curling group showed an average improvement of 9.04% in balance ability and an overall average improvement of 15.67% in lower limb muscle strength. These improvement results were statistically significant (p < 0.05) and ranged from medium to large effect sizes (d = 0.5~0.8). The findings of this study validate the positive effects of aquatic exercise and floor curling on the balance ability and lower limb muscle strength of children with intellectual disabilities. These interventions can be considered effective approaches for functional rehabilitation in children with intellectual disabilities.

Effects of aquatic exercise intervention on executive function and brain-derived neurotrophic factor of children with autism spectrum disorder.

BACKGROUND: Limited knowledge exists regarding the effectiveness of aquatic exercise intervention for improving executive function (EF) in children with autism spectrum disorder (ASD). Additionally, the impact of aquatic exercise on brain-derived neurotrophic factor (BDNF) in children with ASD requires further investigation. AIMS: This study aimed to explore the effects of a 12-week aquatic exercise intervention on core EF and BDNF levels in children with ASD. METHODS AND PROCEDURES: Thirty children with ASD were assigned to an experimental or control group. The experimental group underwent a 12-week aquatic exercise intervention, while the control group engaged in supervised free activities. Pre- and post-intervention assessments measured EF and BDNF levels. OUTCOMES AND RESULTS: The experimental group showed significant improvements (p < 0.05) in inhibition control, cognitive flexibility, and BDNF levels. However, working memory did not significantly improve. The control group exhibited no significant changes in EF or BDNF levels. CONCLUSIONS AND IMPLICATIONS: Aquatic exercise appears to be a beneficial intervention for cognitive development in children with ASD, as it enhances inhibition control, cognitive flexibility, and BDNF levels in children with ASD. Furthermore, the observed improvements in EF following aquatic exercise intervention in children with ASD may be associated with increased BDNF levels.

Immunopeptidome mining reveals a novel ERS-induced target in T1D.

Autoreactive CD8+ T cells play a key role in type 1 diabetes (T1D), but the antigen spectrum that activates autoreactive CD8+ T cells remains unclear. Endoplasmic reticulum stress (ERS) has been implicated in ß-cell autoantigen generation. Here, we analyzed the major histocompatibility complex class I (MHC-I)-associated immunopeptidome (MIP) of islet ß-cells under steady and ERS conditions and found that ERS reshaped the MIP of ß-cells and promoted the MHC-I presentation of a panel of conventional self-peptides. Among them, OTUB258-66 showed immunodominance, and the corresponding autoreactive CD8+ T cells were diabetogenic in nonobese diabetic (NOD) mice. High glucose intake upregulated pancreatic OTUB2 expression and amplified the OTUB258-66-specific CD8+ T-cell response in NOD mice. Repeated OTUB258-66 administration significantly reduced the incidence of T1D in NOD mice. Interestingly, peripheral blood mononuclear cells (PBMCs) from patients with T1D, but not from healthy controls, showed a positive IFN-γ response to human OTUB2 peptides. This study provides not only a new explanation for the role of ERS in promoting ß-cell-targeted autoimmunity but also a potential target for the prevention and treatment of T1D. The data are available via ProteomeXchange with the identifier PXD041227.

Interaction between the gut microbiota and colonic enteroendocrine cells regulates host metabolism.

Nutrient handling is an essential function of the gastrointestinal tract. Hormonal responses of small intestinal enteroendocrine cells (EECs) have been extensively studied but much less is known about the role of colonic EECs in metabolic regulation. To address this core question, we investigated a mouse model deficient in colonic EECs. Here we show that colonic EEC deficiency leads to hyperphagia and obesity. Furthermore, colonic EEC deficiency results in altered microbiota composition and metabolism, which we found through antibiotic treatment, germ-free rederivation and transfer to germ-free recipients, to be both necessary and sufficient for the development of obesity. Moreover, studying stool and blood metabolomes, we show that differential glutamate production by intestinal microbiota corresponds to increased appetite and that colonic glutamate administration can directly increase food intake. These observations shed light on an unanticipated host-microbiota axis in the colon, part of a larger gut-brain axis, that regulates host metabolism and body weight.

Cross-talk between EGF and BMP9 signalling pathways regulates the osteogenic differentiation of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are multipotent progenitors, which give rise to several lineages, including bone, cartilage and fat. Epidermal growth factor (EGF) stimulates cell growth, proliferation and differentiation. EGF acts by binding with high affinity to epidermal growth factor receptor (EGFR) on the cell surface and stimulating the intrinsic protein tyrosine kinase activity of its receptor, which initiates a signal transduction cascade causing a variety of biochemical changes within the cell and regulating cell proliferation and differentiation. We have identified BMP9 as one of the most osteogenic BMPs in MSCs. In this study, we investigate if EGF signalling cross-talks with BMP9 and regulates BMP9-induced osteogenic differentiation. We find that EGF potentiates BMP9-induced early and late osteogenic markers of MSCs in vitro, which can be effectively blunted by EGFR inhibitors Gefitinib and Erlotinib or receptor tyrosine kinase inhibitors AG-1478 and AG-494 in a dose- and time-dependent manner. Furthermore, EGF significantly augments BMP9-induced bone formation in the cultured mouse foetal limb explants. In vivo stem cell implantation experiment reveals that exogenous expression of EGF in MSCs can effectively potentiate BMP9-induced ectopic bone formation, yielding larger and more mature bone masses. Interestingly, we find that, while EGF can induce BMP9 expression in MSCs, EGFR expression is directly up-regulated by BMP9 through Smad1/5/8 signalling pathway. Thus, the cross-talk between EGF and BMP9 signalling pathways in MSCs may underline their important roles in regulating osteogenic differentiation. Harnessing the synergy between BMP9 and EGF should be beneficial for enhancing osteogenesis in regenerative medicine.

Establishment and characterization of the reversibly immortalized mouse fetal heart progenitors.

OBJECTIVE: Progenitor cell-based cardiomyocyte regeneration holds great promise of repairing an injured heart. Although cardiomyogenic differentiation has been reported for a variety of progenitor cell types, the biological factors that regulate effective cardiomyogenesis remain largely undefined. Primary cardiomyogenic progenitors (CPs) have a limited life span in culture, hampering the CPs' in vitro and in vivo studies. The objective of this study is to investigate if primary CPs isolated from fetal mouse heart can be reversibly immortalized with SV40 large T and maintain long-term cell proliferation without compromising cardiomyogenic differentiation potential. METHODS: Primary cardiomyocytes were isolated from mouse E15.5 fetal heart, and immortalized retrovirally with the expression of SV40 large T antigen flanked with loxP sites. Expression of cardiomyogenic markers were determined by quantitative RT-PCR and immunofluorescence staining. The immortalization phenotype was reversed by using an adenovirus-mediated expression of the Cre reconbinase. Cardiomyogenic differentiation induced by retinoids or dexamethasone was assessed by an α-myosin heavy chain (MyHC) promoter-driven reporter. RESULTS: We demonstrate that the CPs derived from mouse E15.5 fetal heart can be efficiently immortalized by SV40 T antigen. The conditionally immortalized CPs (iCP15 clones) exhibit an increased proliferative activity and are able to maintain long-term proliferation, which can be reversed by Cre recombinase. The iCP15 cells express cardiomyogenic markers and retain differentiation potential as they can undergo terminal differentiate into cardiomyctes under appropriate differentiation conditions although the iCP15 clones represent a large repertoire of CPs at various differentiation stages. The removal of SV40 large T increases the iCPs' differentiation potential. Thus, the iCPs not only maintain long-term cell proliferative activity but also retain cardiomyogenic differentiation potential. CONCLUSIONS: Our results suggest that the reported reversible SV40 T antigen-mediated immortalization represents an efficient approach for establishing long-term culture of primary cardiomyogenic progenitors for basic and translational research.

Four novel mutations identification in 17 beta-hydroxysteroid dehydrogenase-3 deficiency and our clinical experience: possible benefits of early treatment.

Introduction: Individuals with 17-beta-hydroxysteroid dehydrogenase type 3 (17ß-HSD3) deficiency face a multitude of challenges, primarily concerning genital appearance, potential malignancy risks, and fertility issues. This study reports our findings from an investigation involving five individuals affected by 17ß-HSD3 deficiency, ranging in age from pre-adolescence to adolescence. Notably, we identified four previously unreported mutations in these subjects. Methods: Our study included a comprehensive evaluation to determine the potential occurrence of testicular tumors. The methods involved clinical examinations, genetic testing, hormone profiling, and patient history assessments. We closely monitored the progress of the study subjects throughout their treatment. Results: The results of this evaluation conclusively ruled out the presence of testicular tumors among our study subjects. Moreover, four of these individuals successfully underwent gender transition. Furthermore, we observed significant improvements in genital appearance following testosterone treatment, particularly among patients in the younger age groups who received appropriate treatment interventions. Discussion: These findings underscore the critical importance of early intervention in addressing concerns related to genital appearance, based on our extensive clinical experience and assessments. In summary, our study provides insights into the clinical aspects of 17ß-HSD3 deficiency, emphasizing the vital significance of early intervention in addressing genital appearance concerns. This recommendation is supported by our comprehensive clinical assessments and experience.

Defective osteogenic differentiation in the development of osteosarcoma.

Osteosarcoma (OS) is associated with poor prognosis due to its high incidence of metastasis and chemoresistance. It often arises in areas of rapid bone growth in long bones during the adolescent growth spurt. Although certain genetic conditions and alterations increase the risk of developing OS, the molecular pathogenesis is poorly understood. Recently, defects in differentiation have been linked to cancers, as they are associated with high cell proliferation. Treatments overcoming these defects enable terminal differentiation and subsequent tumor inhibition. OS development may be associated with defects in osteogenic differentiation. While early regulators of osteogenesis are unable to bypass these defects, late osteogenic regulators, including Runx2 and Osterix, are able to overcome some of the defects and inhibit tumor propagation through promoting osteogenic differentiation. Further understanding of the relationship between defects in osteogenic differentiation and tumor development holds tremendous potential in treating OS.

Three cases of 3ß-hydroxysteroid dehydrogenase deficiency: Clinical analysis.

BACKGROUND: 3ß-HSD deficiency is a rare type of congenital adrenal hyperplasia (CAH), which is caused by HSD3B2 gene mutations. OBJECTIVES: In order to improve the understanding and diagnosis of the disease, we analyzed and summarized the clinical characteristics, genetic variants and treatment for 3 children with 3ß-HSD deficiency in this study. MATERIAL AND METHODS: A summary of the clinical data, hormone levels (17-hydroxyprogesterone, adrenocorticotropic hormone, cortisol, testosterone, dehydroepiandrosterone, androstenedione, renin, and aldosterone), therapeutic drugs, and gene sequencing results from 3 3ß-HSD deficiency patients was created. RESULTS: The 3 patients developed external genital abnormalities and adrenal insufficiency in infancy. Steroid hormone levels were consistent with 3ß-hydroxysteroid dehydrogenase deficiency. Gene sequencing for the 3 patients detected complex heterozygous mutations in the HSD3B2 gene, which confirmed the diagnosis of 3ß-HSD deficiency type II. Among the mutation types, c.154_162delinsTCCTGTT and c.674T>A have not been reported in the literature. The 3 children were treated with glucocorticoid and mineralocorticoid replacement, which controlled the adrenal insufficiency satisfactorily. In 2 male patients, external genital dysplasia manifested as hypospadias and small penis. After long-acting testosterone intramuscular injection to increase the penis size, the hypospadias were repaired. Mild masculinization in the female patient resulted in skin pigmentation and clitoral hypertrophy; however, no surgical intervention was required. CONCLUSIONS: The main clinical manifestations of 3ß-HSD deficiency were adrenal insufficiency and sex hormone synthesis dysfunction. There was a strong phenotype correlation between the observed clinical manifestations in conjunction with steroid hormone levels and HSD3B2 mutations. The novel mutations c.154_162delinsTCCTGTT and c.674T>A were classified as pathogenic variants. Adrenal cortical function control was satisfactory after hormone replacement therapy, and hypospadias and small penis were attenuated using testosterone replacement therapy during mini-puberty for optimal surgical outcome.

Activation of RXR and RAR signaling promotes myogenic differentiation of myoblastic C2C12 cells.

Differentiation of embryonic and adult myogenic progenitors undergoes a complex series of cell rearrangements and specification events which are controlled by distinct gene regulatory networks. Delineation of the molecular mechanisms that regulate skeletal muscle specification and formation should be important for understanding congenital myopathies and muscular degenerative diseases. Retinoic acid (RA) signaling plays an important role in development. However, the role of RA signaling in adult myogenic progenitors is poorly understood. Here, we investigate the role of RA signaling in regulating myogenic differentiation of myoblastic progenitor cells. Using the mouse myoblast progenitor C2C12 line as a model, we have found that the endogenous expression of most RAR and RXR isotypes is readily detected. While the nuclear receptor co-repressors are highly expressed, two of the three nuclear receptor co-activators and the enzymes involved in RA synthesis are expressed at low level or undetectable, suggesting that the RA signaling pathway may be repressed in myogenic progenitors. Using the alpha-myosin heavy chain promoter-driven reporter (MyHC-GLuc), we have demonstrated that either ATRA or 9CRA is able to effectively induce myogenic differentiation, which can be synergistically enhanced when both ATRA and 9CRA are used. Upon ATRA and 9CRA treatment of C2C12 cells the expression of late myogenic markers significantly increases. We have further shown that adenovirus-mediated exogenous expression of RARalpha and/or RXRalpha is able to effectively induce myogenic differentiation in a ligand-independent fashion. Morphologically, ATRA- and 9CRA-treated C2C12 cells exhibit elongated cell body and become multi-nucleated myoblasts, and even form myoblast fusion. Ultrastructural analysis under transmission electron microscope reveals that RA-treated myogenic progenitor cells exhibit an abundant presence of muscle fibers. Therefore, our results strongly suggest that RA signaling may play an important role in regulating myogenic differentiation.

BMP-9-induced osteogenic differentiation of mesenchymal progenitors requires functional canonical Wnt/beta-catenin signalling.

Bone morphogenetic protein 9 (BMP-9) is a member of the transforming growth factor (TGF)-beta/BMP superfamily, and we have demonstrated that it is one of the most potent BMPs to induce osteoblast differentiation of mesenchymal stem cells (MSCs). Here, we sought to investigate if canonical Wnt/beta-catenin signalling plays an important role in BMP-9-induced osteogenic differentiation of MSCs. Wnt3A and BMP-9 enhanced each other's ability to induce alkaline phosphatase (ALP) in MSCs and mouse embryonic fibroblasts (MEFs). Wnt antagonist FrzB was shown to inhibit BMP-9-induced ALP activity more effectively than Dkk1, whereas a secreted form of LPR-5 or low-density lipoprotein receptor-related protein (LRP)-6 exerted no inhibitory effect on BMP-9-induced ALP activity. beta-Catenin knockdown in MSCs and MEFs diminished BMP-9-induced ALP activity, and led to a decrease in BMP-9-induced osteocalcin reporter activity and BMP-9-induced expression of late osteogenic markers. Furthermore, beta-catenin knockdown or FrzB overexpression inhibited BMP-9-induced mineralization in vitro and ectopic bone formation in vivo, resulting in immature osteogenesis and the formation of chondrogenic matrix. Chromatin immunoprecipitation (ChIP) analysis indicated that BMP-9 induced recruitment of both Runx2 and beta-catenin to the osteocalcin promoter. Thus, we have demonstrated that canonical Wnt signalling, possibly through interactions between beta-catenin and Runx2, plays an important role in BMP-9-induced osteogenic differentiation of MSCs.

Wnt antagonist SFRP3 inhibits the differentiation of mouse hepatic progenitor cells.

Wnt/beta-catenin pathway plays an important role in regulating embryonic development. Hepatocytes differentiate from endoderm during development. Hepatic progenitor cells (HPCs) have been isolated from fetal liver and extrahepatic tissues. Most current studies in liver development and hepatic differentiation have been focused on Wnts, beta-catenin, and their receptors. Here, we sought to determine the role of Wnt antagonists in regulating hepatic differentiation of fetal liver-derived HPCs. Using mouse liver tissues derived from embryonic day E12.5 to postnatal day (PD) 28, we found that 13 of the 19 Wnt genes and almost all of Wnt receptors/co-receptors were expressed in most stages. However, Wnt antagonists SFRP2, SFRP3, and Dkk2 were only detected in the early stages. We established and characterized the reversible stable HPCs derived from E14.5 mouse fetal liver (HP14.5). HP14.5 cells were shown to express high levels of early liver progenitor cell markers, but low levels or none of late liver markers. HP14.5 cells were shown to differentiate into mature hepatocytes upon dexamethasone (Dex) stimulation. Dex-induced late marker expression and albumin promoter activity in HP14.5 cells were inhibited by exogenous expression of SFRP3. Furthermore, Dex-induced glycogen synthesis of PAS-positive HP14.5 cells was significantly inhibited by SFRP3. Therefore, our results have demonstrated that the expression of Wnt antagonists decreases as hepatic differentiation progresses, suggesting that a balanced Wnt signaling may be critical during mouse liver development and hepatic differentiation.

Retinoic acid signalling induces the differentiation of mouse fetal liver-derived hepatic progenitor cells.

BACKGROUND: Hepatic progenitor cells (HPCs) can be isolated from fetal liver and extrahepatic tissues. Retinoic acid (RA) signalling plays an important role in development, although the role of RA signalling in liver-specific progenitors is poorly understood. AIMS: We sought to determine the role of RA in regulating hepatic differentiation. METHODS: RNA was isolated from liver tissues of various developmental stages. Liver marker expression was assessed by reverse transcriptase-polymerase chain reaction and immunofluorescence staining. Reversibly immortalized HPCs derived from mouse embryonic day 14.5 (E14.5) liver (aka, HP14.5) were established. Albumin promoter-driven reporter (Alb-GLuc) was used to monitor hepatic differentiation. Glycogen synthesis was assayed as a marker for terminal hepatic differentiation. RESULTS: Retinoic acid receptor (RAR)-alpha, retinoid X receptor (RXR)-alpha and RXR-gamma expressed in E12.5 to postnatal day 28 liver samples. Expression of RAR-beta and RXR-beta was low perinatally, whereas RAR-gamma was undetectable in prenatal tissues and increased postnatally. Retinal dehydrogenase 1 and 2 (Raldh1 and Raldh2) were expressed in all tissues, while Raldh3 was weakly expressed in prenatal samples but was readily detected postnatally. Nuclear receptor corepressors were highly expressed in all tissues, while expression of nuclear co-activators decreased in perinatal tissues and increased after birth. HP14.5 cells expressed high levels of early liver stem cell markers. Expression of RA signalling components and coregulators was readily detected in HP14.5. RA was shown to induce Alb-GLuc activity and late hepatocyte markers. RA was further shown to induce glycogen synthesis in HP14.5 cells, an important function of mature hepatocytes. CONCLUSIONS: Our results strongly suggest that RA signalling may play an important role in regulating hepatic differentiation.

Anti-diabetic compounds from the seeds of Psoralea corylifolia.

A new aurone named (2Z)-2-[(4'-hydroxyphenyl) methylene]-6-hydroxy-7-prenyl-3(2H)-benzofurane (1), two new flavonoids named (2S)-7-methoxy-6-(2-hydroxy-3-methylbut-3-en-1-yl)-2-(4-hydroxyphenyl)chroman-4-one (2), (2S)-4'-hydroxyl-7-hydroxymethylene-6-(2″,3″-epoxy-3″-methylbutyl)flavanone (3), and a new coumestan named bavacoumestan E (4), together with eleven known compounds (5-15), were isolated from the seeds of Psoralea corylifolia. The chemical structures were elucidated by spectroscopic and physico-chemical analyses. All isolates were evaluated for in vitro inhibitory activity against DGAT, PTP1B and α-glucosidase. Compounds 1, 2 and 3 showed potential inhibitory activities on DGAT1 with IC50 values of 35.2 ±â€¯1.3, 51.3 ±â€¯1.1 and 43.4 ±â€¯0.7 µM, respectively. Compounds 6 and 8 displayed the significant inhibitory activities on α-glucosidase with IC50 value of 28.0 and 23.0 µM, respectively.