scholarly journals Tailored tetravalent antibodies potently and specifically activate Wnt/Frizzled pathways in cells, organoids and mice

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yuyong Tao ◽  
Monika Mis ◽  
Levi Blazer ◽  
Mart Ustav ◽  
Zachary Steinhart ◽  
...  

Secreted Wnt proteins regulate development and adult tissue homeostasis by binding and activating cell-surface Frizzled receptors and co-receptors including LRP5/6. The hydrophobicity of Wnt proteins has complicated their purification and limited their use in basic research and as therapeutics. We describe modular tetravalent antibodies that can recruit Frizzled and LRP5/6 in a manner that phenocopies the activities of Wnts both in vitro and in vivo. The modular nature of these synthetic Frizzled and LRP5/6 Agonists, called FLAgs, enables tailored engineering of specificity for one, two or multiple members of the Frizzled family. We show that FLAgs underlie differentiation of pluripotent stem cells, sustain organoid growth, and activate stem cells in vivo. Activation of Wnt signaling circuits with tailored FLAgs will enable precise delineation of functional outcomes directed by distinct receptor combinations and could provide a new class of therapeutics to unlock the promise of regenerative medicine.

2020 ◽  
Author(s):  
Engi Ahmed ◽  
Mathieu Fieldes ◽  
Chloé Bourguignon ◽  
Joffrey Mianné ◽  
Aurélie Petit ◽  
...  

AbstractRationaleHighly reproducible in vitro generation of human bronchial epithelium from pluripotent stem cells is an unmet key goal for drug screening to treat lung diseases. The possibility of using induced pluripotent stem cells (hiPSC) to model normal and diseased tissue in vitro from a simple blood sample will reshape drug discovery for chronic lung, monogenic and infectious diseases.MethodsWe devised a simple and reliable method that drives a blood sample reprogrammed into hiPSC subsequently differentiated within 45 days into air-liquid interface bronchial epithelium (iALI), through key developmental stages, definitive-endoderm (DE) and Ventralized-Anterior-Foregut-Endoderm (vAFE) cells.ResultsReprogramming blood cells from one healthy and 3 COPD patients, and from skin-derived fibroblasts obtained in one PCD patient, succeeded in 100% of samples using Sendai viruses. Mean cell purity at DE and vAFE stages was greater than 80%, assessed by expression of CXCR4 and NKX2.1, avoiding the need of cell sorting. When transferred to ALI conditions, vAFE cells reliably differentiated within 4 weeks into bronchial epithelium with large zones covered by beating ciliated, basal, goblets, club cells and neuroendocrine cells as found in vivo. Benchmarking all culture conditions including hiPSCs adaptation to single-cell passaging, cell density and differentiation induction timing allowed for consistently producing iALI bronchial epithelium from the five hiPSC lines.ConclusionsReliable reprogramming and differentiation of blood-derived hiPSCs into mature and functional iALI bronchial epithelium is ready for wider use and this will allow better understanding lung disease pathogenesis and accelerating the development of novel gene therapies and drug discovery.


2019 ◽  
Author(s):  
Rongqun Guo ◽  
Fangxiao Hu ◽  
Qitong Weng ◽  
Cui Lv ◽  
Hongling Wu ◽  
...  

ABSTRACTAchievement of immunocompetent and therapeutic T lymphopoiesis from pluripotent stem cells is a central aim in T cell regenerative medicine. To date, preferentially regenerating T lymphopoiesis in vivo from pluripotent stem cells (PSC) remains a practical challenge. Here we documented that synergistic and transient expression of Runx1 and Hoxa9 restricted in the time window of endothelial to hematopoietic transition and hematopoietic maturation stages induced in vitro from PSC (iR9-PSC) preferentially generated engraftable hematopoietic progenitors capable of homing to thymus and developing into mature T (iT) cells in primary and secondary immunodeficient recipients. Single-cell transcriptome and functional analyses illustrated the cellular trajectory of T lineage induction from PSC, unveiling the T-lineage specification determined at as early as hemogenic endothelial cell stage and identifying the bona fide pre-thymic progenitors. The iT cells distributed normally in central and peripheral lymphoid organs and exhibited abundant TCRαβ repertoire. The regenerative T lymphopoiesis rescued the immune-surveillance ability in immunodeficient mice. Furthermore, gene-edited iR9-PSC produced tumor-specific-T cells in vivo that effectively eradicated tumor cells. This study provides insight into universal generation of functional and therapeutic T lymphopoiesis from the unlimited and editable PSC source.


2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Yaqi Li ◽  
Peiyuan Tang ◽  
Sanjun Cai ◽  
Junjie Peng ◽  
Guoqiang Hua

AbstractThree-dimensional cultured organoids have become a powerful in vitro research tool that preserves genetic, phenotypic and behavioral trait of in vivo organs, which can be established from both pluripotent stem cells and adult stem cells. Organoids derived from adult stem cells can be established directly from diseased epithelium and matched normal tissues, and organoids can also be genetically manipulated by CRISPR-Cas9 technology. Applications of organoids in basic research involve the modeling of human development and diseases, including genetic, infectious and malignant diseases. Importantly, accumulating evidence suggests that biobanks of patient-derived organoids for many cancers and cystic fibrosis have great value for drug development and personalized medicine. In addition, organoids hold promise for regenerative medicine. In the present review, we discuss the applications of organoids in the basic and translational research.


2016 ◽  
Author(s):  
Ιωάννα Βαρελά

Η ανακάλυψη της μεθόδου του κυτταρικού επαναπρογραμματισμού ανθρώπινων δερματικών ινοβλαστών σε επαγόμενα πολυδύναμα βλαστοκύτταρα (induced pluripotent stem cells, iPSCs) το 2007 άνοιξε το δρόμο για τη μελέτη και την εξατομικευμένη θεραπεία πολλών χρόνιων νόσων. Επιδιώξαμε να δημιουργήσουμε iPS - κυτταρικές σειρές επαναπρογραμματίζοντας μεσεγχυματικά στρωματικά κύτταρα (mesenchymal stromal cells, MSCs) μυελού των οστών, μέσω μιας μεθόδου επαναπρογραμματισμού χωρίς ενσωμάτωση γονιδίων στο γενετικό υλικό των κυττάρων. Δερματικοί ινοβλάστες από φυσιολογικούς δότες και μεσεγχυματικά στρωματικά κύτταρα μυελού των οστών από φυσιολογικό δότη μεταμόσχευσης μυελού των οστών και από ασθενή με β-Μεσογειακή αναιμία (β-ΜΑ) διαμολύνθηκαν, μέσω λιποσωματικών φορέων, με συνθετικά mRNA που κωδικοποιούν τους μεταγραφικούς παράγοντες Oct4, Klf4, Sox2, Lin28, c-Myc. Στη συνέχεια, τα κύτταρα ελέγχθηκαν σε καλλιέργειες για τον σχηματισμό αποικιών πολυδύναμων βλαστοκυττάρων. Οι αποικίες απομονώθηκαν και με συνεχείς ανακαλλιέργειες δημιουργήθηκαν κυτταρικές σειρές, οι οποίες εξετάστηκαν για την πολυδυναμία τους με μεθόδους ανίχνευσης της έκφρασης των μεταγραφικών παραγόντων πολυδυναμίας (κυτταρομετρία ροής, RT-PCR, μελέτη του μεταγραφώματος με RNA μικροσυστοιχίες). Ως θετικός μάρτυρας και μέτρο σύγκρισης χρησιμοποιήθηκε πολύ καλά χαρακτηρισμένη εμβρυονική σειρά πολυδύναμων βλαστοκυττάρων. Οι iPS-κυτταρικές σειρές μελετήθηκαν, επίσης, ως προς τη λειτουργική τους πολυδυναμία με τον έλεγχο της ικανότητας τους να δημιουργούν in vitro εμβρυϊκά σωματίδια και in vivo τερατώματα μετά από υποδόρια εμφύτευση τους σε ανοσοανεπαρκείς ποντικούς, και ως προς τη δυνατότητα διαφοροποίησής τους σε αιμοποιητικά προγονικά κύτταρα. Η γενετική σταθερότητα των κυτταρικών σειρών ελέγχθηκε με DNA μικροσυστοιχίες συγκριτικού γονιδιωματικού υβριδισμού (aCGH). Απομονώθηκαν 3 iPS κυτταρικές σειρές από κάθε δείγμα κυττάρων, οι οποίες εμφανίζουν μεταγράφωμα πανομοιότυπο με εκείνο των πολυδύναμων εμβρυονικών βλαστοκυττάρων και. δημιουργούν εμβρυϊκά σωματίδια in vitro και τερατώματα in vivo, τα οποία αποτελούνται από ιστούς καταγωγής και από τα τρία βλαστικά δέρματα. Τα iPSCs των κυτταρικών σειρών πολλαπλασιάζονται για μεγάλο χρονικό διάστημα χωρίς μορφολογικές ενδείξες διαφοροποίησης. Με τη μέθοδο aCGH, στις iPS κυτταρικές σειρές μετά την 10η ανακαλλιέργεια ανιχνεύθηκαν πολυμορφισμοί στον αριθμό αντιγράφων (CNVs), τα οποία ήταν ελλείμματα μεγέθους περίπου 3 Mb. Η διαφοροποίηση των iPSCs σε αιμοποιητικά προγονικά κύτταρα οδήγησε στην παραγωγή CD34+ κυττάρων σε ποσοστό 8-10% των παραχθέντων κυττάρων με ασθενούς έντασης συνέκφραση του CD45, προσομοιάζοντας στο αιμαγγειακό στελεχιαίο κύτταρο. Στην παρούσα διατριβή παρουσιάζεται, για πρώτη φορά στην Ελλάδα, εξ όσων γνωρίζουμε, η τεχνολογία παραγωγής ανθρώπινων iPSCs με μια ασφαλή και αξιόπιστη μέθοδο. Οι iPSCs-κυτταρικές σειρές μπορεί να χρησιμοποιηθούν στη μελέτη ασθενειών, στον έλεγχο φαρμάκων και στην ανάπτυξη πρωτοκόλλων ιστικής μηχανικής και κυτταρικής θεραπείας.


Author(s):  
Hao Xu ◽  
Liying Wu ◽  
Guojia Yuan ◽  
Xiaolu Liang ◽  
Xiaoguang Liu ◽  
...  

: Hepatic disease negatively impacts liver function and metabolism. Primary human hepatocytes are the gold standard for the prediction and successful treatment of liver disease. However, the sources of hepatocytes for drug toxicity testing and disease modeling are limited. To overcome this issue, pluripotent stem cells (PSCs) have emerged as an alternative strategy for liver disease therapy. Human PSCs, including embryonic stem cells (ESC) and induced pluripotent stem cells (iPSC) can self-renew and give rise to all cells of the body. Human PSCs are attractive cell sources for regenerative medicine, tissue engineering, drug discovery, and developmental studies. Several recent studies have shown that mesenchymal stem cells (MSCs) can also differentiate (or trans-differentiate) into hepatocytes. Differentiation of human PSCs and MSCs into functional hepatocyte-like cells (HLCs) opens new strategies to study genetic diseases, hepatotoxicity, infection of hepatotropic viruses, and analyze hepatic biology. Numerous in vitro and in vivo differentiation protocols have been established to obtain human PSCs/MSCs-derived HLCs and mimic their characteristics. It was recently discovered that microRNAs (miRNAs) play a critical role in controlling the ectopic expression of transcription factors and governing the hepatocyte differentiation of human PSCs and MSCs. In this review, we focused on the role of miRNAs in the differentiation of human PSCs and MSCs into hepatocytes.


Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 951 ◽  
Author(s):  
Yong Dong ◽  
Chengxiang Xia ◽  
Qitong Weng ◽  
Tongjie Wang ◽  
Fangxiao Hu ◽  
...  

Natural hematopoietic stem cells (HSC) are susceptible and tend to lose stemness, differentiate, or die on culture condition in vitro, which adds technical challenge for maintaining bona fide HSC-like cells, if ever generated, in protocol screening from pluripotent stem cells. It remains largely unknown whether gene-editing of endogenous genes can genetically empower HSC to endure the culture stress and preserve stemness. In this study, we revealed that both NUP98-HOXA10HD fusion and endogenous Nras mutation modifications (NrasG12D) promoted the engraftment competitiveness of HSC. Furthermore, the synergy of these two genetic modifications endowed HSC with super competitiveness in vivo. Strikingly, single NAV-HSC successfully maintained its stemness and showed robust multi-lineage engraftments after undergoing the in vitro culture. Mechanistically, NUP98-HOXA10HD fusion and NrasG12D mutation distinctly altered multiple pathways involving the cell cycle, cell division, and DNA replication, and distinctly regulated stemness-related genes including Hoxa9, Prdm16, Hoxb4, Trim27, and Smarcc1 in the context of HSC. Thus, we develop a super-sensitive transgenic model reporting the existence of HSC at the single cell level on culture condition, which could be beneficial for protocol screening of bona fide HSC regeneration from pluripotent stem cells in vitro.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Young Sun Hwang ◽  
Shinnosuke Suzuki ◽  
Yasunari Seita ◽  
Jumpei Ito ◽  
Yuka Sakata ◽  
...  

Abstract Establishment of spermatogonia throughout the fetal and postnatal period is essential for production of spermatozoa and male fertility. Here, we establish a protocol for in vitro reconstitution of human prospermatogonial specification whereby human primordial germ cell (PGC)-like cells differentiated from human induced pluripotent stem cells are further induced into M-prospermatogonia-like cells and T1 prospermatogonia-like cells (T1LCs) using long-term cultured xenogeneic reconstituted testes. Single cell RNA-sequencing is used to delineate the lineage trajectory leading to T1LCs, which closely resemble human T1-prospermatogonia in vivo and exhibit gene expression related to spermatogenesis and diminished proliferation, a hallmark of quiescent T1 prospermatogonia. Notably, this system enables us to visualize the dynamic and stage-specific regulation of transposable elements during human prospermatogonial specification. Together, our findings pave the way for understanding and reconstructing human male germline development in vitro.


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