Zilong WEN
@ust.hk
Professor
Hong Kong University of Science and Technology
Professor Wen received his Ph.D. in Molecular Cell Biology from the Rockefeller University in 1997 and postdoctoral training with Professor Irving Weissman at Stanford University. He was a Principle Investigator at the Institute of Molecular Agrobiolgy and the Institute of Molecular and Cell Biology, Singapore, until 2007. He subsequently moved to Hong Kong and joined the Department of Biochemistry at the Hong Kong University Science and Technology as an Associate Professor. He is currently a Professor of Division of Life Science at the Hong Kong University Science and Technology.
EDUCATION
PhD The Rockefeller University
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ao Zhang, Jingao Lu, Shachuan Feng, Huapeng Yu, Tao Yu, Shizheng Zhao, Kemin Chen, Zhibin Huang, Jin Xu, Jianan Y. Qu,et al.
Elsevier BV
Linh Thi My Nguyen, Shaoli Hassan, Hongru Pan, Shuting Wu, and Zilong Wen
The Company of Biologists
ABSTRACT In vertebrates, the central nervous system (CNS) harbours various immune cells, including parenchymal microglia, perivascular macrophages and dendritic cells, which act in coordination to establish an immune network to regulate neurogenesis and neural function, and to maintain the homeostasis of the CNS. Recent single cell transcriptomic profiling has revealed that the adult zebrafish CNS contains microglia, plasmacytoid dendritic cells (pDCs) and two conventional dendritic cells (cDCs), ccl35+ cDCs and cnn3a+cDCs. However, how these distinct myeloid cells are established in the adult zebrafish CNS remains incompletely defined. Here, we show that the Inhibitor of DNA binding 2a (Id2a) is essential for the development of pDCs and cDCs but is dispensable for the formation of microglia, whereas the Basic leucine zipper transcription factor ATF-like 3 (Batf3) acts downstream of id2a and is required exclusively for the formation of the cnn3a+ cDC subset. In contrast, the Zinc finger E-box-binding homeobox 2a (Zeb2a) promotes the expansion of microglia and inhibits the DC specification, possibly through repressing id2a expression. Our study unravels the genetic networks that govern the development of microglia and brain-associated DCs in the zebrafish CNS.
Wenwei Sun, Meimei Wang, Jun Zhao, Shuang Zhao, Wenchao Zhu, Xiaoting Wu, Feifei Li, Wei Liu, Zhuo Wang, Meng Gao,et al.
Springer Science and Business Media LLC
AbstractNonsteroidal anti-inflammatory drugs compose one of the most widely used classes of medications, but the risks for early development remain controversial, especially in the nervous system. Here, we utilized zebrafish larvae to assess the potentially toxic effects of nonsteroidal anti-inflammatory drugs and found that sulindac can selectively induce apoptosis of GABAergic neurons in the brains of zebrafish larvae brains. Zebrafish larvae exhibit hyperactive behaviour after sulindac exposure. We also found that akt1 is selectively expressed in GABAergic neurons and that SC97 (an Akt1 activator) and exogenous akt1 mRNA can reverse the apoptosis caused by sulindac. Further studies showed that sulindac binds to retinoid X receptor alpha (RXRα) and induces autophagy in GABAergic neurons, leading to activation of the mitochondrial apoptotic pathway. Finally, we verified that sulindac can lead to hyperactivity and selectively induce GABAergic neuron apoptosis in mice. These findings suggest that excessive use of sulindac may lead to early neurodevelopmental toxicity and increase the risk of hyperactivity, which could be associated with damage to GABAergic neurons.
Qiuxia Zhou, Changlong Zhao, Zhiyong Yang, Rui Qu, Yunbo Li, Yining Fan, Jinlin Tang, Ting Xie, and Zilong Wen
Elsevier BV
Tao Yu, Haoyue Kuang, Xiaohai Wu, Ying Huang, Jianzhong Wang, and Zilong Wen
American Association for the Advancement of Science (AAAS)
Microglia are brain-resident macrophages capable of long-term maintenance through self-renewal. Yet the mechanism governing the turnover and lifespan of microglia remains unknown. In zebrafish, microglia arise from two sources, rostral blood island (RBI) and aorta-gonad-mesonephros (AGM). The RBI-derived microglia are born early but have a short lifespan and diminish in adulthood, while the AGM-derived microglia emerge later and are capable of long-term maintenance in adulthood. Here, we show that the attenuation of RBI microglia is due to their less competitiveness for neuron-derived interleukin-34 (Il34) caused by age-dependent decline of colony-stimulating factor-1 receptor a ( csf1ra ). Alterations of Il34/Csf1ra levels and removal of AGM microglia revamp the proportion and lifespan of RBI microglia. The csf1ra/CSF1R expression in zebrafish AGM-derived microglia and murine adult microglia also undergo age-dependent decline, leading to the elimination of aged microglia. Our study reveals cell competition as a general mechanism controlling the turnover and lifespan of microglia.
Changlong Zhao, Yunbo Li, Jinlin Tang, Qiuxia Zhou, Xi Lin, and Zilong Wen
Elsevier BV
Mei Wu, Jin Xu, Yiyue Zhang, and Zilong Wen
Springer Nature Singapore
Shizheng Zhao, Ao Zhang, Hao Zhu, and Zilong Wen
The Company of Biologists
ABSTRACT The E26 transformation-specific or E-twenty-six (ETS) genes encode a superfamily of transcription factors involved in diverse biological processes. Here, we report the identification and characterization of a previously unidentified member of the ETS transcription factors, Spi2, that is found exclusively in the ray-finned fish kingdom. We show that the expression of spi2 is restricted to hemogenic endothelial cells (HECs) and to hematopoietic stem and progenitor cells (HSPCs) in zebrafish. Using bacteria artificial chromosome transgenesis, we generate a spi2 reporter line, TgBAC(spi2:P2a-GFP), which manifests the GFP pattern recapitulating the endogenous spi2 expression. Genetic ablation of spi2 has little effect on HEC formation and the endothelial-to-hematopoietic transition, but results in compromised proliferation of HSPCs in the caudal hematopoietic tissue (CHT) during early development and in severe myeloid lineage defect in adulthood. Epistatic analysis shows that spi2 acts downstream of runx1 in regulating HSPC development in the CHT. Our study identifies Spi2 as an essential regulator for definitive hematopoietic cell development and creates a TgBAC(spi2:P2a-GFP) reporter line for tracking HECs, HSPCs, myeloid cells and thrombocytes from early development to adulthood.
Liang Lou, Tao Yu, Yimei Dai, Shizheng Zhao, Shachuan Feng, Jin Xu, and Zilong Wen
Proceedings of the National Academy of Sciences
Microglia are the central nervous system (CNS)–resident macrophages involved in neural inflammation, neurogenesis, and neural activity regulation. Previous studies have shown that naturally occurring neuronal apoptosis plays a critical role in regulating microglial colonization of the brain in zebrafish. However, the molecular signaling cascades underlying neuronal apoptosis-mediated microglial colonization and the regulation of these cascades remain undefined. Here, we show that basic leucine zipper (b-Zip) transcription factors, Mafba and Mafbb, two zebrafish orthologs of mammalian MAFB, are key regulators in neuronal apoptosis-mediated microglial colonization of the brain in zebrafish. We document that the loss of Mafba and Mafbb function perturbs microglial colonization of the brain. We further demonstrate that Mafba and Mafbb act cell-autonomously and cooperatively to orchestrate microglial colonization, at least in part, by regulating the expression of G protein–coupled receptor 34a (Gpr34a), which directs peripheral macrophage recruitment into the brain through sensing the lysophosphatidylserine (lysoPS) released by the apoptotic neurons. Our study reveals that Mafba and Mafbb regulate neuronal apoptosis-mediated microglial colonization of the brain in zebrafish via the lysoPS-Gpr34a pathway.
Yimei Dai, Shuting Wu, Canran Cao, Rongtao Xue, Xuefen Luo, Zilong Wen, and Jin Xu
The Company of Biologists
ABSTRACT In vertebrates, hematopoietic stem and progenitor cells (HSPCs) are capable of self-renewal and continuously replenishing all mature blood lineages throughout life. However, the molecular signaling regulating the maintenance and expansion of HSPCs remains incompletely understood. Colony-stimulating factor 1 receptor (CSF1R) is believed to be the primary regulator for the myeloid lineage but not HSPC development. Here, we show a surprising role of Csf1rb, a zebrafish homolog of mammalian CSF1R, in preserving the HSPC pool by maintaining the proliferation of HSPCs. Deficiency of csf1rb leads to a reduction in both HSPCs and their differentiated progenies, including myeloid, lymphoid and erythroid cells at early developmental stages. Likewise, the absence of csf1rb conferred similar defects upon HSPCs and leukocytes in adulthood. Furthermore, adult hematopoietic cells from csf1rb mutants failed to repopulate immunodeficient zebrafish. Interestingly, loss-of-function and gain-of-function assays suggested that the canonical ligands for Csf1r in zebrafish, including Csf1a, Csf1b and Il34, were unlikely to be ligands of Csf1rb. Thus, our data indicate a previously unappreciated role of Csf1r in maintaining HSPCs, independently of known ligands.
Shizheng Zhao, Shachuan Feng, Ye Tian, and Zilong Wen
Proceedings of the National Academy of Sciences
Significance Hematopoietic stem cells (HSCs) are generated from specialized endothelial cells, called hemogenic endothelial cells (HECs). It has been debated whether HECs and non–HSC-forming conventional endothelial cells (cECs) arise from a common precursor or represent distinct lineages. Moreover, the molecular basis underlying their distinct fate determination is poorly understood. We use photoconvertible labeling, time-lapse imaging, and single-cell RNA-sequencing analysis to trace the lineage of HECs. We discovered that HECs and cECs arise from a common hemogenic angioblast precursor, and their distinct fate is determined by high or low dosage of Etv2, respectively. Our results illuminate the lineage origin and a mechanism on the fate determination of HECs, which may enhance the understanding on the ontogeny of HECs in vertebrates.
Jiakui Chen, Gaofei Li, Junwei Lian, Ning Ma, Zhibin Huang, Jianchao Li, Zilong Wen, Wenqing Zhang, and Yiyue Zhang
Springer Science and Business Media LLC
Hematopoietic stem and progenitor cells (HSPCs) are able to self-renew and can give rise to all blood lineages throughout their lifetime, yet the mechanisms regulating HSPC development have yet to be discovered. In this study, we characterized a hematopoiesis defective zebrafish mutant line named smu07, which was obtained from our previous forward genetic screening, and found the HSPC expansion deficiency in the mutant. Positional cloning identified that slc20a1b, which encodes a sodium phosphate cotransporter, contributed to the smu07 blood phenotype. Further analysis demonstrated that mutation of slc20a1b affects HSPC expansion through cell cycle arrest at G2/M phases in a cell-autonomous manner. Our study shows that slc20a1b is a vital regulator for HSPC proliferation in zebrafish early hematopoiesis and provides valuable insights into HSPC development.
Hao Li, Yoonhee Nam, Ran Huo, Weilun Fu, Biaobin Jiang, Qiuxia Zhou, Dong Song, Yingxi Yang, Yuming Jiao, Jiancong Weng,et al.
Ovid Technologies (Wolters Kluwer Health)
Rationale: Brain arteriovenous malformations (bAVMs) are abnormal entanglement of blood vessels in brain, with direct connections from arteries to veins, lacking functional capillary bed. Although several somatic mutations were reported, the molecular mechanism and genetic disposition of bAVM remain poorly understood. Objective: We aim to identify transcriptional anomalies and critical functional pathways in bAVM lesions and explore their association with key de novo germline and somatic variants in bAVM patients. Methods and Results: We established a comprehensive bAVM dataset from 269 patients, by performing single-cell sequencing of 17 bAVM lesions, whole-exome sequencing of germline DNA from 60 case-unaffected-parental trios, and genomic/transcriptomic sequencing of 231 bAVM lesions. We found abnormal expression of endothelial and mesenchymal markers in bAVM at both bulk and single-cell level, which was validated by flow cytometric analysis and immunofluorescence staining, suggesting an involvement of endothelial-to-mesenchymal transition (EndMT) process in AVM (arteriovenous-malformation). Using data from the 60 trios, we identified nonsynonymous de novo germline mutations affecting 46 genes, including EXPH5 (detected in 2 independent cases), and vessel-related genes, such as EPAS1 and ENG . Interestingly, knockdown of epas1 in zebrafish embryo showed AVM-like phenotype exclusively in brain. Subsequent computational and experimental analyses demonstrated that expression of genes affected by de novo germline mutations was enriched in vascular cell types and was involved in EndMT-relevant behaviors including cell migration, angiogenesis, and cell marker transition. Moreover, we detected somatic KRAS mutations in 129 of 179 (72%) cases and showed that KRAS mutations were associated with bleeding as the first symptom ( P =0.0072). Following experimental studies demonstrated that KRAS mutations independently regulated EndMT features, consolidating the involvement of EndMT in this disease. Lastly, we showed that lovastatin reversed EndMT features in vitro and ex vivo. Conclusions: Our results suggest the convergent role of de novo germline mutations and somatic mutations in regulating EndMT in bAVM and provided a potential therapeutic option.
Yan Zhao, Mei Wu, Jing Li, Ping Meng, Jiakui Chen, Zhibin Huang, Jin Xu, Zilong Wen, Wenqing Zhang, and Yiyue Zhang
Springer Science and Business Media LLC
AbstractHematopoietic stem cells (HSCs) possess the potential for self-renew and the capacity, throughout life, to differentiate into all blood cell lineages. Yet, the mechanistic basis for HSC development remains largely unknown. In this study, we characterized a zebrafish smu471 mutant with hematopoietic stem/progenitor cell (HSPC) defects and found that sart3 was the causative gene. RNA expression profiling of the sart3smu471 mutant revealed spliceosome and p53 signaling pathway to be the most significantly enriched pathways in the sart3smu471 mutant. Knock down of p53 rescued HSPC development in the sart3smu471 mutant. Interestingly, the p53 inhibitor, mdm4, had undergone an alternative splicing event in the mutant. Restoration of mdm4 partially rescued HSPC deficiency. Thus, our data suggest that HSPC proliferation and maintenance require sart3 to ensure the correct splicing and expression of mdm4, so that the p53 pathway is properly inhibited to prevent definitive hematopoiesis failure. This study expands our knowledge of the regulatory mechanisms that impact HSPC development and sheds light on the mechanistic basis and potential therapeutic use of sart3 in spliceosome-mdm4-p53 related disorders.
Shuting Wu, Linh T. M. Nguyen, Hongru Pan, Shaoli Hassan, Yimei Dai, Jin Xu, and Zilong Wen
American Association for the Advancement of Science (AAAS)
Microglia are the tissue-resident macrophages in the central nervous system and are critically involved in immune defense, neural development and function, and neuroinflammation. The versatility of microglia has long been attributed to heterogeneity. Recent studies have revealed possible heterogeneity in human but not in murine microglia, yet a firm demonstration linking microglial heterogeneity to functional phenotypes remains scarce. Here, we identified two distinct microglial populations in adult zebrafish that differ in morphology, distribution, development, and function. The predominant population, phagocytotic microglia, which expresses ccl34b.1, is broadly distributed, amoeboid in shape, highly mobile, and phagocytotic. The other white matter–enriched ccl34b.1− population, regulatory microglia, has ramified protrusions but has limited mobility and phagocytosis capability. These functional differences are further supported by distinct transcriptomes and responses to bacterial infection, where ccl34b.1+ microglia function in tissue clearance and ccl34b.1− microglia release immune regulators. Our study sheds light on the heterogeneity and functional diversification of microglia.
Xi Lin, Qiuxia Zhou, Guanzhen Lin, Changlong Zhao, and Zilong Wen
Elsevier BV
Immune cells in the mucosal barriers of vertebrates are highly heterogeneous in their origin and function. This heterogeneity is further exemplified by the recent discovery of ectoderm-derived immune cells-metaphocytes in zebrafish epidermis. Yet, whether non-hematopoiesis-derived immune cells generally exist in barrier tissues remains obscured. Here, we report the identification and characterization of an endoderm-derived immune cell population in the gill and intestine of zebrafish. Transcriptome analysis reveals that the endoderm-derived immune cells are myeloid-like cells with high similarities to the ectoderm-derived metaphocytes in epidermis. Like metaphocytes in epidermis, the endoderm-derived immune cells are non-phagocytic but professional in external soluble antigen uptake. Depletion of the endoderm-derived immune cells in gill hinder the local immune response to external soluble stimulants. This study demonstrates a general existence of non-hematopoiesis-derived immune cells in zebrafish mucosal barriers and challenges the prevalent view that resident immune cells in mucosal barriers arise exclusively from hematopoiesis.
Tao Yu, Haoyue Kuang, Jiahao Chen, Xi Lin, Yi Wu, Keyu Chen, Mingjie Zhang, Wenqing Zhang, and Zilong Wen
Elsevier BV
Microglia are tissue-resident macrophages in the central nervous system (CNS) that play essential roles in the regulation of CNS development and homeostasis. Yet, the genetic networks governing microglia development remain incompletely defined. Here, we report the identification and characterization of a microglia-defective zebrafish mutant wulonghkz12 (wulhkz12) isolated from an ethylnitrosourea (ENU)-based genetic screen. We show that wulhkz12 mutants harbors a missense point mutation in the gene region encoding the PRY/SPRY domain of the tripartite-motif family protein 35-28 (trim35-28) gene. Time-lapse imaging revealed that the loss of Trim35-28 function causes lytic necrosis of microglial precursors/peripheral macrophages, as indicated by cytoplasmic swelling and membrane rupture of these precursors and accompanied by neutrophil infiltration and systemic inflammation. Intriguingly, the lytic necrosis of microglial precursors in trim35-28–deficient mutants appeared to depend neither on the canonical pyroptotic nor necroptotic pathways, as inhibition of the key component in each pathway could not rescue the microglia phenotype in trim35-28–deficient mutants. Finally, results from tissue-specific rescue experiments suggested that Trim35-28 acts cell-autonomously in the survival of microglial precursors. Taken together, the findings of our study reveal Trim35-28 as a regulatory protein essential for microglia development.
Sicong He, Jin Xu, Jianan Y. Qu, and Zilong Wen
Elsevier BV
Hematopoiesis refers to the developmental process generating all blood lineages. In vertebrates, there are multiple waves of hematopoiesis which emerge in distinct anatomic locations at different times and give rise to different blood lineages. In the last decade, numerous lineage-tracing studies have been conducted to investigate the hierarchical structure of the hematopoietic system. Yet, the majority of these lineage-tracing studies are not able to integrate the spatial-temporal information with the developmental potential of hematopoietic cells. With the newly developed infrared laser-evoked gene operator (IR-LEGO) microscope heating system, it is now possible to improve our understanding of hematopoiesis to spatial-temporal controlled single cell resolution. Here, we discuss the recent development of the IR-LEGO system and its applications in hematopoietic lineage-tracing in vivo.
Sicong He, Ye Tian, Shachuan Feng, Yi Wu, Xinwei Shen, Kani Chen, Yingzhu He, Qiqi Sun, Xuesong Li, Jin Xu,et al.
eLife Sciences Publications, Ltd
Heterogeneity broadly exists in various cell types both during development and at homeostasis. Investigating heterogeneity is crucial for comprehensively understanding the complexity of ontogeny, dynamics, and function of specific cell types. Traditional bulk-labeling techniques are incompetent to dissect heterogeneity within cell population, while the new single-cell lineage tracing methodologies invented in the last decade can hardly achieve high-fidelity single-cell labeling and long-term in-vivo observation simultaneously. In this work, we developed a high-precision infrared laser-evoked gene operator heat-shock system, which uses laser-induced CreERT2 combined with loxP-DsRedx-loxP-GFP reporter to achieve precise single-cell labeling and tracing. In vivo study indicated that this system can precisely label single cell in brain, muscle and hematopoietic system in zebrafish embryo. Using this system, we traced the hematopoietic potential of hemogenic endothelium (HE) in the posterior blood island (PBI) of zebrafish embryo and found that HEs in the PBI are heterogeneous, which contains at least myeloid unipotent and myeloid-lymphoid bipotent subtypes.
Tienan Wang, Bo Yan, Liang Lou, Xi Lin, Tao Yu, Shuting Wu, Qing Lu, Wei Liu, Zhibin Huang, Mingjie Zhang,et al.
Elsevier BV
Microglia are tissue-resident macrophages residing in the central nervous system (CNS) and play critical roles in removing cellular debris and infectious agents as well as regulating neurogenesis and neuronal activities. Yet, the molecular basis underlying the establishment of microglia pool and the maintenance of their homeostasis in the CNS remain largely undefined. Here we report the identification and characterization of a mutant zebrafish, which harbors a point mutation in the nucleotide-binding oligomerization domain (NOD) like receptor gene nlrc3-like, resulting in the loss of microglia in a temperature sensitive manner. Temperature shift assay reveals that the late onset of nlrc3-like deficiency leads to excessive microglia cell death. Further analysis shows that the excessive microglia death in nlrc3-like deficient mutants is attributed, at least in part, to aberrant activation of canonical inflammasome pathway. Our study indicates that proper regulation of inflammasome cascade is critical for the maintenance of microglia homeostasis.
Xi Lin, Qiuxia Zhou, Changlong Zhao, Guanzhen Lin, Jin Xu, and Zilong Wen
Elsevier BV
Tissue-resident macrophages (TRMs) are highly heterogeneous and engage in a wide range of diverse functions. Yet, the heterogeneities of their origins and functions remain incompletely defined. Here, we report the identification and characterization of an ectoderm-derived myeloid-like cell, which we refer to as metaphocyte. We show that metaphocytes are highly similar to conventional Langerhans cells (cLCs), the resident macrophages in epidermis, in transcriptome, morphology, and anatomic location. However, unlike cLCs, metaphocytes respond neither to tissue injury nor to bacterial infection but rather sample soluble antigens from external environment through transepithelial protrusions and transfer them to cLCs via apoptosis-phagocytosis axis. This antigen transfer is critical for zebrafish to respond to soluble antigens because the depletion of metaphocytes significantly reduces cLC antigen uptake. Our study documents the existence of ectoderm-derived myeloid-like cells that manifest distinct function from conventional TRMs and opens a new paradigm for investigation of the heterogeneities of resident immune cells.
Wan Jin, Yimei Dai, Funing Li, Lu Zhu, Zhibin Huang, Wei Liu, Jianchao Li, Mingjie Zhang, Jiulin Du, Wenqing Zhang,et al.
Elsevier BV
Summary Type IV mucolipidosis (ML-IV) is a neurodegenerative lysosome storage disorder caused by mutations in the MCOLN1 gene. However, the cellular and molecular bases underlying the neuronal phenotypes of ML-IV disease remain elusive. Using a forward genetic screening, we identified a zebrafish mutant, biluo, that harbors a hypomorphic mutation in mcoln1a, one of the two zebrafish homologs of mammalian MCOLN1. The mcoln1a-deficient mutants display phenotypes partially recapitulating the key features of ML-IV disorder, including the accumulation of enlarged late endosomes in microglia and aberrant neuronal activities in both spontaneous and visual-evoking conditions in optic tectal neurons. We further show that the accumulation of enlarged late endosomes in microglia is caused by the impairment of late endosome and lysosome fusion and the aberrant neuronal activities can be partially rescued by the reconstitution of Mcoln1a function in microglia. Our findings suggest that dysregulation of microglial function may contribute to the development and progression of ML-IV disease.
Xi Lin, Zilong Wen, and Jin Xu
Ovid Technologies (Wolters Kluwer Health)
Abstract Tissue-resident macrophages (TRMs), generally found in tissues under normal physiological conditions, play crucial roles not only in immunity but also in tissue development and homeostasis. Because of their diverse functions, dysregulation of their development and function has been implicated in many human disorders. In the past decade, a great deal of extensive studies have been conducted in various model organisms with cutting-edge technologies to explore the origin and function of TRMs. In this review, we summarize the recent findings on TRMs in mouse and zebrafish and compare the similarity/differences between these two species.
Shuting Wu, Rongtao Xue, Shaoli Hassan, Thi My Linh Nguyen, Tienan Wang, Hongru Pan, Jin Xu, Qifa Liu, Wenqing Zhang, and Zilong Wen
Elsevier BV
Microglia are the major immune cells in the central nervous system (CNS). Born in peripheral hematopoietic tissues, microglial precursors colonize the CNS during early embryogenesis and maintain themselves thereafter. However, the mechanism underlying this colonization process remains elusive. We have recently demonstrated that neuronal apoptosis contributes to microglia colonization in zebrafish. Here, we further show that prior to neuronal apoptosis, microglial precursors are attracted to the proximal brain regions by brain-derived interleukin 34 (il34) and its receptor colony-stimulating factor 1 receptor a (csf1ra). In both il34- and csf1ra-deficient zebrafish larva, embryonic macrophages fail to migrate to the anterior head and colonize the CNS, but their initial development and colonization to peripheral tissues remain largely unaffected. Activation of Il34-Csf1ra pathway is sufficient to attract embryonic macrophages to the CNS independent of neuronal apoptosis. Our study shows that cytokine signaling and neuronal apoptosis synergistically orchestrate the colonization of microglia in early zebrafish development.
Sicong He, Jiahao Chen, Yunyun Jiang, Yi Wu, Lu Zhu, Wan Jin, Changlong Zhao, Tao Yu, Tienan Wang, Shuting Wu,et al.
eLife Sciences Publications, Ltd
The origin of Langerhans cells (LCs), which are skin epidermis-resident macrophages, remains unclear. Current lineage tracing of LCs largely relies on the promoter-Cre-LoxP system, which often gives rise to contradictory conclusions with different promoters. Thus, reinvestigation with an improved tracing method is necessary. Here, using a laser-mediated temporal-spatial resolved cell labeling method, we demonstrated that most adult LCs originated from the ventral wall of the dorsal aorta (VDA), an equivalent to the mouse aorta, gonads, and mesonephros (AGM), where both hematopoietic stem cells (HSCs) and non-HSC progenitors are generated. Further fine-fate mapping analysis revealed that the appearance of LCs in adult zebrafish was correlated with the development of HSCs, but not T cell progenitors. Finally, we showed that the appearance of tissue-resident macrophages in the brain, liver, heart, and gut of adult zebrafish was also correlated with HSCs. Thus, the results of our study challenged the EMP-origin theory for LCs.