技术资料

Many adult tissues contain resident stem cells,such as the Pax7+ satellite cells within skeletal muscle,that regenerate parenchymal elements following damage. Tissue-resident mesenchymal progenitors (MPs) also participate in regeneration,although their function and fate in this process are unclear. Here,we identify Hypermethylated in cancer 1 (Hic1) as a marker of MPs in skeletal muscle and further show that Hic1 deletion leads to MP hyperplasia. Single-cell RNA-seq and ATAC-seq analysis of Hic1+ MPs in skeletal muscle shows multiple subpopulations,which we further show have distinct functions and lineage potential. Hic1+ MPs orchestrate multiple aspects of skeletal muscle regeneration by providing stage-specific immunomodulation and trophic and mechanical support. During muscle regeneration,Hic1+ derivatives directly contribute to several mesenchymal compartments including Col22a1-expressing cells within the myotendinous junction. Collectively,these findings demonstrate that HIC1 regulates MP quiescence and identifies MP subpopulations with transient and enduring roles in muscle regeneration. View Publication

CRISPR/Cas is a transformative gene editing tool,that offers a simple and effective way to target a catalytic Cas9,the most widely used is derived from Streptococcus pyogenes (SpCas9),with a complementary small guide RNA (sgRNA) to inactivate endogenous genes resulting from insertions and deletions (indels). CRISPR/Cas9 has been rapidly applied to basic research as well as expanded for potential clinical applications. Utilization of spCas9 as an ribonuclearprotein complex (RNP) is considered the most safe and effective method to apply Cas9 technology,and the efficacy of this system is critically dependent on the ability of Cas9 to generate high levels of indels. We find here that novel sequence changes to the tracrRNA significantly improves Cas9 activity when delivered as an RNP. We demonstrate that a dual-guide RNA (dgRNA) with a modified tracrRNA can improve reporter knockdown and indel formation at several targets within the long terminal repeat (LTR) of HIV. Furthermore,the sequence-modified tracrRNAs improved Cas9-mediated reduction of CCR5 surface receptor expression in cell lines,which correlated with higher levels of indel formation. It was demonstrated that a Cas9 RNP with a sequence modified tracrRNA enhanced indel formation at the CCR5 target site in primary CD4+ T-cells. Finally,we show improved activity at two additional targets within the HBB locus and the BCL11A GATA site. Overall,the data presented here suggests that novel facile tracrRNA sequence changes could potentially be integrated with current dgRNA technology,and open up the possibility for the development of sequence modified tracrRNAs to improve Cas9 RNP activity. View Publication

Exosomes are nanosized membranous vesicles secreted by a variety of cells. Due to their unique and pharmacologically important properties,cell-derived exosome nanoparticles have drawn significant interest for drug development. By genetically modifying exosomes with two distinct types of surface-displayed monoclonal antibodies,we have developed an exosome platform termed synthetic multivalent antibodies retargeted exosome (SMART-Exo) for controlling cellular immunity. Here,we apply this approach to human epidermal growth factor receptor 2 (HER2)-expressing breast cancer by engineering exosomes through genetic display of both anti-human CD3 and anti-human HER2 antibodies,resulting in SMART-Exos dually targeting T cell CD3 and breast cancer-associated HER2 receptors. By redirecting and activating cytotoxic T cells toward attacking HER2-expressing breast cancer cells,the designed SMART-Exos exhibited highly potent and specific anti-tumor activity both in vitro and in vivo. This work demonstrates preclinical feasibility of utilizing endogenous exosomes for targeted breast cancer immunotherapy and the SMART-Exos as a broadly applicable platform technology for the development of next-generation immuno-nanomedicines. View Publication

Mask family proteins were discovered in Drosophila to promote the activity of the transcriptional coactivator Yorkie (Yki),the sole fly homolog of mammalian YAP (YAP1) and TAZ (WWTR1). The molecular function of Mask,or its mammalian homologs Mask1 (ANKHD1) and Mask2 (ANKRD17),remains unclear. Mask family proteins contain two ankyrin repeat domains that bind Yki/YAP as well as a conserved nuclear localisation sequence (NLS) and nuclear export sequence (NES),suggesting a role in nucleo-cytoplasmic transport. Here we show that Mask acts to promote nuclear import of Yki,and that addition of an ectopic NLS to Yki is sufficient to bypass the requirement for Mask in Yki-driven tissue growth. Mammalian Mask1/2 proteins also promote nuclear import of YAP,as well as stabilising YAP and driving formation of liquid droplets. Mask1/2 and YAP normally colocalise in a granular fashion in both nucleus and cytoplasm,and are co-regulated during mechanotransduction. View Publication

Metabolic pathways dynamically regulate tissue development and maintenance. However,the mechanisms that govern the metabolic adaptation of stem or progenitor cells to their local niche are poorly understood. Here,we define the transcription factor PRDM16 as a region-specific regulator of intestinal metabolism and epithelial renewal. PRDM16 is selectively expressed in the upper intestine,with enrichment in crypt-resident progenitor cells. Acute Prdm16 deletion in mice triggered progenitor apoptosis,leading to diminished epithelial differentiation and severe intestinal atrophy. Genomic and metabolic analyses showed that PRDM16 transcriptionally controls fatty acid oxidation (FAO) in crypts. Expression of this PRDM16-driven FAO program was highest in the upper small intestine and declined distally. Accordingly,deletion of Prdm16 or inhibition of FAO selectively impaired the development and maintenance of upper intestinal enteroids,and these effects were rescued by acetate treatment. Collectively,these data reveal that regionally specified metabolic programs regulate intestinal maintenance. View Publication

Molecular- and cellular-based therapies have the potential to reduce obesity-associated disease. In response to cold,beige adipocytes form in subcutaneous white adipose tissue and convert energy stored in metabolic substrates to heat,making them an attractive therapeutic target. We developed a robust method to generate a renewable source of human beige adipocytes from induced pluripotent stem cells (iPSCs). Developmentally,these cells are derived from FOXF1+ mesoderm and progress through an expandable mural-like mesenchymal stem cell (MSC) to form mature beige adipocytes that display a thermogenically active profile. This includes expression of uncoupling protein 1 (UCP1) concomitant with increased uncoupled respiration. With this method,dysfunctional adipogenic precursors can be reprogrammed and differentiated into beige adipocytes with increased thermogenic function and anti-diabetic secretion potential. This resource can be used to (1) elucidate mechanisms that underlie the control of beige adipogenesis and (2) generate material for cellular-based therapies that target metabolic syndrome in humans. View Publication

The main limitations of hematopoietic cord blood (CB) transplantation,viz,low cell dosage and delayed reconstitution,can be overcome by ex vivo expansion. CB expansion under conventional culture causes rapid cell differentiation and depletion of hematopoietic stem and progenitor cells (HSPCs) responsible for engraftment. In this study,we use combinatorial cell culture technology (CombiCult{\textregistered}) to identify medium formulations that promote CD133+ CB HSPC proliferation while maintaining their phenotypic characteristics. We employed second-generation CombiCult screens that use electrospraying technology to encapsulate CB cells in alginate beads. Our results suggest that not only the combination but also the order of addition of individual components has a profound influence on expansion of specific HSPC populations. Top protocols identified by the CombiCult screen were used to culture human CD133+ CB HSPCs on nanofiber scaffolds and validate the expansion of the phenotypically defined CD34+CD38lo/-CD45RA-CD90+CD49f+ population of hematopoietic stem cells and their differentiation into defined progeny. View Publication

CD16a (Fc$\gamma$RIIIa) mediates the antibody dependent cellular cytotoxicity (ADCC) and is important for anti-tumor activities of many therapeutic antibodies. Bispecific antibody targeting natural killer (NK) cells has been studied for cancer therapy. In this work,anti-CD16a single-domain antibodies were identified from hCD16a immunized camel. Bispecific antibodies are then constructed by fusing these single domain antibodies with an anti-CEA single domain antibody. These bispecific antibodies can recruite NK cells to kill CEA-positive tumor cells,and inhibit tumor growth in vivo,suggesting that these anti-CD16a single domain antibodies are powerful tools to engaging NK cells for cancer therapy. View Publication

The angiotensin-converting enzyme 2 (ACE2) is a primary cell surface viral binding receptor for SARS-CoV-2,so finding new regulatory molecules to modulate ACE2 expression levels is a promising strategy against COVID-19. In the current study,we utilized islet organoids derived from human embryonic stem cells (hESCs),animal models and COVID-19 patients to discover that fibroblast growth factor 7 (FGF7) enhances ACE2 expression within the islets,facilitating SARS-CoV-2 infection and resulting in impaired insulin secretion. Using hESC-derived islet organoids,we demonstrated that FGF7 interacts with FGF receptor 2 (FGFR2) and FGFR1 to upregulate ACE2 expression predominantly in ? cells. This upregulation increases both insulin secretion and susceptibility of ? cells to SARS-CoV-2 infection. Inhibiting FGFR counteracts the FGF7-induced ACE2 upregulation,subsequently reducing viral infection and replication in the islets. Furthermore,retrospective clinical data revealed that diabetic patients with severe COVID-19 symptoms exhibited elevated serum FGF7 levels compared to those with mild symptoms. Finally,animal experiments indicated that SARS-CoV-2 infection increased pancreatic FGF7 levels,resulting in a reduction of insulin concentrations in situ. Taken together,our research offers a potential regulatory strategy for ACE2 by controlling FGF7,thereby protecting islets from SARS-CoV-2 infection and preventing the progression of diabetes in the context of COVID-19. View Publication

Mural cells are central to vascular integrity and function. In this study,we demonstrate the innovative use of the transcription factor NKX3.1 to guide the differentiation of human induced pluripotent stem cells into mural progenitor cells (iMPCs). By transiently activating NKX3.1 in mesodermal intermediates,we developed a method that diverges from traditional growth factor-based differentiation techniques. This approach efficiently generates a robust iMPC population capable of maturing into diverse functional mural cell subtypes,including smooth muscle cells and pericytes. These iMPCs exhibit key mural cell functionalities such as contractility,deposition of extracellular matrix,and the ability to support endothelial cell-mediated vascular network formation in vivo. Our study not only underscores the fate-determining significance of NKX3.1 in mural cell differentiation but also highlights the therapeutic potential of these iMPCs. We envision these insights could pave the way for a broader use of iMPCs in vascular biology and regenerative medicine. Mural progenitor cells are crucial for vascular stability. Here,the authors generate these cells from human pluripotent stem cells using NKX3.1 and show that they can mature into various mural cell types and contribute to blood vessel formation. View Publication

SummaryBackgroundMacrophages engineered with chimeric antigen receptors (CAR) are suitable for immunotherapy based on their immunomodulatory activity and ability to infiltrate solid tumours. However,the production and application of genetically edited,highly effective,and mass-produced CAR-modified macrophages (CAR-Ms) are challenging.MethodsHere,we used homology-independent targeted insertion (HITI) for site-directed CAR integration into the safe-harbour region of human pluripotent stem cells (hPSCs). This approach,together with a simple differentiation protocol,produced stable and highly effective CAR-Ms without heterogeneity.FindingsThese engineered cells phagocytosed cancer cells,leading to significant inhibition of cancer-cell proliferation in vitro and in vivo. Furthermore,the engineered CARs,which incorporated a combination of CD3? and Megf10 (referred to as FRP5M?),markedly enhanced the antitumour effect of CAR-Ms by promoting M1,but not M2,polarisation. FRP5M? promoted M1 polarisation via nuclear factor kappa B (NF-?B),ERK,and STAT1 signalling,and concurrently inhibited STAT3 signalling even under M2 conditions. These features of CAR-Ms modulated the tumour microenvironment by activating inflammatory signalling,inducing M1 polarisation of bystander non-CAR macrophages,and enhancing the infiltration of T cells in cancer spheroids.InterpretationOur findings suggest that CAR-Ms have promise as immunotherapeutics. In conclusion,the guided insertion of CAR containing CD3? and Megf10 domains is an effective strategy for the immunotherapy of solid tumours.FundingThis work was supported by KRIBB Research Initiative Program Grant (KGM4562431,KGM5282423) and a Korean Fund for Regenerative Medicine (KFRM) grant funded by the Korean government (Ministry of Science and ICT,10.13039/501100003625Ministry of Health and Welfare) (22A0304L1-01). View Publication

BackgroundMetastasis,the spread,and growth of malignant cells at secondary sites within a patient’s body,accounts for over 90% of cancer-related mortality. Breast cancer is the most common tumor type diagnosed and the leading cause of cancer lethality in women in the United States. It is estimated that 10–16% breast cancer patients will have brain metastasis. Current therapies to treat patients with breast cancer brain metastasis (BCBM) remain palliative. This is largely due to our limited understanding of the fundamental molecular and cellular mechanisms through which BCBM progresses,which represents a critical barrier for the development of efficient therapies for affected breast cancer patients.MethodsPrevious research in BCBM relied on co-culture assays of tumor cells with rodent neural cells or rodent brain slice ex vivo. Given the need to overcome the obstacle for human-relevant host to study cell-cell communication in BCBM,we generated human embryonic stem cell-derived cerebral organoids to co-culture with human breast cancer cell lines. We used MDA-MB-231 and its brain metastatic derivate MDA-MB-231 Br-EGFP,other cell lines of MCF-7,HCC-1806,and SUM159PT. We leveraged this novel 3D co-culture platform to investigate the crosstalk of human breast cancer cells with neural cells in cerebral organoid.ResultsWe found that MDA-MB-231 and SUM159PT breast cancer cells formed tumor colonies in human cerebral organoids. Moreover,MDA-MB-231 Br-EGFP cells showed increased capacity to invade and expand in human cerebral organoids.ConclusionsOur co-culture model has demonstrated a remarkable capacity to discern the brain metastatic ability of human breast cancer cells in cerebral organoids. The generation of BCBM-like structures in organoid will facilitate the study of human tumor microenvironment in culture. View Publication