Thymosin β4 protects against aortic aneurysm via endocytic regulation of growth factor signaling
The Journal of clinical investigation
Munshaw, S;Bruche, S;Redpath, AN;Jones, A;Patel, J;Dubé, KN;Lee, R;Hester, SS;Davies, R;Neal, G;Handa, A;Sattler, M;Fischer, R;Channon, KM;Smart, N;
PMID: 33784254 | DOI: 10.1172/JCI127884
Vascular stability and tone are maintained by contractile smooth muscle cells (VSMCs). However, injury-induced growth factors stimulate a contractile-synthetic phenotypic modulation which increases susceptibility to abdominal aortic aneurysm (AAA). As a regulator of embryonic VSMC differentiation, we hypothesised that Thymosin β4 (Tβ4) may function to maintain healthy vasculature throughout postnatal life. This was supported by the identification of an interaction with Low density lipoprotein receptor related protein 1 (LRP1), an endocytic regulator of PDGF-BB signalling and VSMC proliferation. LRP1 variants have been implicated by genome-wide association studies with risk of AAA and other arterial diseases. Tβ4-null mice displayed aortic VSMC and elastin defects, phenocopying LRP1 mutants, and their compromised vascular integrity predisposed to Angiotensin II-induced aneurysm formation. Aneurysmal vessels were characterised by enhanced VSMC phenotypic modulation and augmented platelet-derived growth factor (PDGF) receptor (PDGFR)β signalling. In vitro, enhanced sensitivity to PDGF-BB, upon loss of Tβ4, associated with dysregulated endocytosis, with increased recycling and reduced lysosomal targeting of LRP1-PDGFRβ. Accordingly, the exacerbated aneurysmal phenotype in Tβ4-null mice was rescued upon treatment with the PDGFRβ antagonist, Imatinib. Our study identifies Tβ4 as a key regulator of LRP1 for maintaining vascular health and provides insights into the mechanisms of growth factor-controlled VSMC phenotypic modulation underlying aortic disease progression.
Zhao, L;Song, J;Sun, Y;Ju, Q;Mu, H;Dong, X;Ding, J;Liu, Y;Wang, X;Sun, L;Wu, J;Jiao, Y;Lu, S;Zhao, X;
PMID: 37337648 | DOI: 10.1002/cam4.5946
Circulating tumor cells (CTCs), an indispensable liquid biopsy classifier, can provide extra information for the diagnosis and prognosis of hepatocellular carcinoma (HCC).We systematically analyzed the peripheral blood of preoperative HCC patients (n = 270) for CTC number, Ki67 index reflecting the proliferative CTC percentage (PCP), and CTC clusters correlated with the characteristics of malignant HCC tumors.Driver gene mutations were found with high levels of consistency between CTCs and primary tumors (n = 73). CTC number and PCP were associated with tumor size, microvascular invasion (MVI), presence or absence of multiple tumors, and thrombosis significantly. CTC number and PCP robustly separated patients with and without relapse, with a sensitivity of 88.89%/81.48% and a specificity of 72.73%/94.81% in the training set (n = 104) and corresponding values of 80.00%/86.67% and 78.38%/89.19% in the validation set (n = 52), showing a better performance than that associated with the alpha-fetoprotein (AFP) level. CTC number, PCP, CTC clusters, and MVI were independent significant risk factors for HCC recurrence (P = 0.0375, P < 0.0001, P = 0.0017, and P = 0.0157). A nomogram model based on these risk factors showed a considerable prediction ability for HCC recurrence (area under the curve = 0.947). PCP (training: log-rank P < 0.0001; hazard ratio [HR] 30.13, 95% confidence interval [CI] = 11.12-81.62; validation: log-rank P < 0.0001; HR 25.73, 95% CI = 5.28-106.60) and CTC clusters (training: log-rank P < 0.0001; HR 17.34, 95% CI = 7.46-40.30; validation: log-rank P < 0.0001; HR 9.92, 95% CI = 2.55-38.58) were more significantly correlated with worse recurrence-free survival than CTC number (training: log-rank P < 0.0001; HR 14.93, 95% CI = 4.48-49.78; validation: log-rank P = 0.0007; HR 9.03, 95% CI = 2.53-32.24).PCP and CTC clusters may predict HCC recurrence and improve the performance of the serum biomarker AFP.
Ayyaz A, Kumar S, Sangiorgi B, Ghoshal B, Gosio J, Ouladan S, Fink M, Barutcu S, Trcka D, Shen J, Chan K, Wrana JL, Gregorieff A.
PMID: 31019301 | DOI: 10.1038/s41586-019-1154-y
The turnover of the intestinal epithelium is driven by multipotent LGR5+ crypt-base columnar cells (CBCs) located at the bottom of crypt zones1. However, CBCs are lost following injury, such as irradiation2, but the intestinal epithelium is nevertheless able to recover3. Thus, a second population of quiescent '+4' cells, or reserve stem cells (RSCs), has previously been proposed to regenerate the damaged intestine4-7. Although CBCs and RSCs were thought to be mutually exclusive4,8, subsequent studies have found that LGR5+ CBCs express RSC markers9 and that RSCs were dispensable-whereas LGR5+ cells were essential-for repair of the damaged intestine3. In addition, progenitors of absorptive enterocytes10, secretory cells11-15 and slow cycling LGR5+ cells16 have been shown to contribute to regeneration whereas the transcriptional regulator YAP1, which is important for intestinal regeneration, was suggested to induce a pro-survival phenotype in LGR5+cells17. Thus, whether cellular plasticity or distinct cell populations are critical for intestinal regeneration remains unknown. Here we applied single-cell RNA sequencing to profile the regenerating mouse intestine and identified a distinct, damage-induced quiescent cell type that we term the revival stem cell (revSC). revSCs are marked by high clusterin expression and are extremely rare under homoeostatic conditions, yet give rise-in a temporal hierarchy-to all the major cell types of the intestine, including LGR5+ CBCs. After intestinal damage by irradiation, targeted ablation of LGR5+ CBCs, or treatment with dextran sodium sulfate, revSCs undergo a YAP1-dependent transient expansion, reconstitute the LGR5+ CBC compartment and are required to regenerate a functional intestine. These studies thus define a unique stem cell that is mobilized by damage to revive the homoeostatic stem cell compartment and regenerate the intestinal epithelium.
American journal of physiology. Renal physiology
Clayton, DR;Ruiz, WG;Dalghi, MG;Montalbetti, N;Carattino, MD;Apodaca, G;
PMID: 35834272 | DOI: 10.1152/ajprenal.00135.2022
Fibroblasts are crucial to normal and abnormal organ and tissue biology, yet we lack basic insights into the fibroblasts that populate the bladder wall. Candidates may include bladder interstitial cells (also referred to as myofibroblasts, telocytes, interstitial cells of Cajal-like cells), which express the fibroblast-associated marker PDGFRA (along with VIM and CD34) but whose form and function remains enigmatic. By applying the latest insights in fibroblast transcriptomics, coupled with studies of gene expression, ultrastructure, and marker analysis, we observe the following: (1) that mouse bladder PDGFRA-positive cells exhibit all of the ultrastructural hallmarks of fibroblasts including spindle shape, lack of basement membrane, abundant ER and Golgi, and formation of homotypic cell-cell contacts (but not heterotypic ones); (2) that they express multiple canonical fibroblast markers (including Col1a2, CD34, LY6A, and PDGFRA) along with the universal fibroblast genes Col15a1 and Pi16; (3) that PDGFRA-positive fibroblasts include suburothelial ones (which express ACTA2, CAR3, LY6A, MYH10, TNC, VIM, Col1a2, Col15a1),outer lamina propria ones (which express CD34, LY6A, PI16, VIM, Col1a2, Col15a1, Pi16), intermuscular ones (which express CD34, VIM, Col1a2, Col15a1, Pi16), and serosal ones (which express CD34, PI16, VIM, Col1a2, Col15a1,Pi16). Collectively, our studies reveal that the ultrastructure of PDFRA-positiveinterstitial cells combined with their expression of multiple canonical and universal fibroblast-associated gene products indicates they are fibroblasts. We further propose that there are four regionally distinct populations of fibroblasts in the bladder wall, which likely contribute to bladder function and dysfunction.
CCL21 activation of the MALAT1/SRSF1/mTOR axis underpins the development of gastric carcinoma
Journal of translational medicine
Fu, Q;Tan, X;Tang, H;Liu, J;
PMID: 34001131 | DOI: 10.1186/s12967-021-02806-5
As a significant cause of malignancy mortality, gastric carcinoma (GC) has been well documented to be an often-fatal diagnosis. Despite the limitations of effective therapy, immunotherapy has emerged as a promising therapeutic approach capable of killing cancer cells via the immune system. The current study was conducted to investigate the effect of cytokine C-C motif chemokine ligand 21 (CCL21) on GC progression through the metastasis-associated lung adenocarcinoma transcript 1/serine arginine-rich splicing factor 1/mammalian target of rapamycin (MALAT1/SRSF1/mTOR) axis. Bioinformatics analysis was conducted to identify the key genes associated with GC and to subsequently predict their downstream genes. The effect of CCL21, MALAT1, and SRSF1 on the malignant phenotypes and epithelial-mesenchymal transition (EMT) of SGC-7901 and MGC-803 cells in-vitro and the tumorigenesis of SGC-7901 and MGC-803 cells in-vivo were assessed by expression determination and plasmid transfection. Additionally, RNA pull-down and RNA binding protein immunoprecipitation experiments were performed to determine the MALAT1-microRNA-202-3p (miR-203-3p) interaction and miR-202-3p-SRSF1 interaction followed by the analysis of their effect on the mTOR pathway. CCL21 was identified as a key GC immune gene. Overexpressed CCL21, MALAT1, and SRSF1 along with poorly expressed miR-202-3p were identified in the GC cells. CCL21 induced the MALAT1 expression in a time- and dose-dependent manner. Functionally, MALAT1 targeted miR-202-3p but upregulated SRSF1 and activated mTOR. Crucially, evidence was obtained indicating that CCL21 promoted both the malignant phenotypes and EMT of SGC-7901 and MGC-803 cells in-vitro and the tumorigenesis of SGC-7901 and MGC-803 cells in-vivo by increasing the MALAT1-induced upregulation of SRSF1. Taken together, the key observations of our study provide evidence that CCL21 enhances the progression of GC via the MALAT1/SRSF1/mTOR axis, providing a novel therapeutic target for the treatment of GC.
Single-cell transcriptomic analyses provide insights into the developmental origins of neuroblastoma
Jansky, S;Sharma, AK;Körber, V;Quintero, A;Toprak, UH;Wecht, EM;Gartlgruber, M;Greco, A;Chomsky, E;Grünewald, TGP;Henrich, KO;Tanay, A;Herrmann, C;Höfer, T;Westermann, F;
PMID: 33767450 | DOI: 10.1038/s41588-021-00806-1
Neuroblastoma is a pediatric tumor of the developing sympathetic nervous system. However, the cellular origin of neuroblastoma has yet to be defined. Here we studied the single-cell transcriptomes of neuroblastomas and normal human developing adrenal glands at various stages of embryonic and fetal development. We defined normal differentiation trajectories from Schwann cell precursors over intermediate states to neuroblasts or chromaffin cells and showed that neuroblastomas transcriptionally resemble normal fetal adrenal neuroblasts. Importantly, neuroblastomas with varying clinical phenotypes matched different temporal states along normal neuroblast differentiation trajectories, with the degree of differentiation corresponding to clinical prognosis. Our work highlights the roles of oncogenic MYCN and loss of TFAP2B in blocking differentiation and may provide the basis for designing therapeutic interventions to overcome differentiation blocks.
Hoeft, K;Schaefer, GJL;Kim, H;Schumacher, D;Bleckwehl, T;Long, Q;Klinkhammer, BM;Peisker, F;Koch, L;Nagai, J;Halder, M;Ziegler, S;Liehn, E;Kuppe, C;Kranz, J;Menzel, S;Costa, I;Wahida, A;Boor, P;Schneider, RK;Hayat, S;Kramann, R;
PMID: 36807143 | DOI: 10.1016/j.celrep.2023.112131
Fibrosis represents the common end stage of chronic organ injury independent of the initial insult, destroying tissue architecture and driving organ failure. Here we discover a population of profibrotic macrophages marked by expression of Spp1, Fn1, and Arg1 (termed Spp1 macrophages), which expands after organ injury. Using an unbiased approach, we identify the chemokine (C-X-C motif) ligand 4 (CXCL4) to be among the top upregulated genes during profibrotic Spp1 macrophage differentiation. In vitro and in vivo studies show that loss of Cxcl4 abrogates profibrotic Spp1 macrophage differentiation and ameliorates fibrosis after both heart and kidney injury. Moreover, we find that platelets, the most abundant source of CXCL4 in vivo, drive profibrotic Spp1 macrophage differentiation. Single nuclear RNA sequencing with ligand-receptor interaction analysis reveals that macrophages orchestrate fibroblast activation via Spp1, Fn1, and Sema3 crosstalk. Finally, we confirm that Spp1 macrophages expand in both human chronic kidney disease and heart failure.
You, Z;Wang, L;He, H;Wu, Z;Zhang, X;Xue, S;Xu, P;Hong, Y;Xiong, M;Wei, W;Chen, Y;
PMID: 36933556 | DOI: 10.1016/j.stem.2023.02.007
The cell lineages across developmental stages remain to be elucidated. Here, we developed single-cell split barcoding (SISBAR) that allows clonal tracking of single-cell transcriptomes across stages in an in vitro model of human ventral midbrain-hindbrain differentiation. We developed "potential-spective" and "origin-spective" analyses to investigate the cross-stage lineage relationships and mapped a multi-level clonal lineage landscape depicting the whole differentiation process. We uncovered many previously uncharacterized converging and diverging trajectories. Furthermore, we demonstrate that a transcriptome-defined cell type can arise from distinct lineages that leave molecular imprints on their progenies, and the multilineage fates of a progenitor cell-type represent the collective results of distinct rather than similar clonal fates of individual progenitors, each with distinct molecular signatures. Specifically, we uncovered a ventral midbrain progenitor cluster as the common clonal origin of midbrain dopaminergic (mDA) neurons, midbrain glutamatergic neurons, and vascular and leptomeningeal cells and identified a surface marker that can improve graft outcomes.
Bi, R;Yin, Q;Li, H;Yang, X;Wang, Y;Li, Q;Fang, H;Li, P;Lyu, P;Fan, Y;Ying, B;Zhu, S;
PMID: 36788226 | DOI: 10.1038/s41467-023-36406-2
The biological characteristics of the temporomandibular joint disc involve complex cellular network in cell identity and extracellular matrix composition to modulate jaw function. The lack of a detailed characterization of the network severely limits the development of targeted therapies for temporomandibular joint-related diseases. Here we profiled single-cell transcriptomes of disc cells from mice at different postnatal stages, finding that the fibroblast population could be divided into chondrogenic and non-chondrogenic clusters. We also find that the resident mural cell population is the source of disc progenitors, characterized by ubiquitously active expression of the NOTCH3 and THY1 pathways. Lineage tracing reveals that Myh11+ mural cells coordinate angiogenesis during disc injury but lost their progenitor characteristics and ultimately become Sfrp2+ non-chondrogenic fibroblasts instead of Chad+ chondrogenic fibroblasts. Overall, we reveal multiple insights into the coordinated development of disc cells and are the first to describe the resident mural cell progenitor during disc injury.
Rodrigo Albors, A;Singer, GA;Llorens-Bobadilla, E;Frisén, J;May, AP;Ponting, CP;Storey, KG;
PMID: 36706756 | DOI: 10.1016/j.devcel.2023.01.003
The adult spinal cord stem cell potential resides within the ependymal cell population and declines with age. Ependymal cells are, however, heterogeneous, and the biological diversity this represents and how it changes with age remain unknown. Here, we present a single-cell transcriptomic census of spinal cord ependymal cells from adult and aged mice, identifying not only all known ependymal cell subtypes but also immature as well as mature cell states. By comparing transcriptomes of spinal cord and brain ependymal cells, which lack stem cell abilities, we identify immature cells as potential spinal cord stem cells. Following spinal cord injury, these cells re-enter the cell cycle, which is accompanied by a short-lived reversal of ependymal cell maturation. We further analyze ependymal cells in the human spinal cord and identify widespread cell maturation and altered cell identities. This in-depth characterization of spinal cord ependymal cells provides insight into their biology and informs strategies for spinal cord repair.
Wu, CT;Lidsky, PV;Xiao, Y;Cheng, R;Lee, IT;Nakayama, T;Jiang, S;He, W;Demeter, J;Knight, MG;Turn, RE;Rojas-Hernandez, LS;Ye, C;Chiem, K;Shon, J;Martinez-Sobrido, L;Bertozzi, CR;Nolan, GP;Nayak, JV;Milla, C;Andino, R;Jackson, PK;
PMID: 36580912 | DOI: 10.1016/j.cell.2022.11.030
How SARS-CoV-2 penetrates the airway barrier of mucus and periciliary mucins to infect nasal epithelium remains unclear. Using primary nasal epithelial organoid cultures, we found that the virus attaches to motile cilia via the ACE2 receptor. SARS-CoV-2 traverses the mucus layer, using motile cilia as tracks to access the cell body. Depleting cilia blocks infection for SARS-CoV-2 and other respiratory viruses. SARS-CoV-2 progeny attach to airway microvilli 24 h post-infection and trigger formation of apically extended and highly branched microvilli that organize viral egress from the microvilli back into the mucus layer, supporting a model of virus dispersion throughout airway tissue via mucociliary transport. Phosphoproteomics and kinase inhibition reveal that microvillar remodeling is regulated by p21-activated kinases (PAK). Importantly, Omicron variants bind with higher affinity to motile cilia and show accelerated viral entry. Our work suggests that motile cilia, microvilli, and mucociliary-dependent mucus flow are critical for efficient virus replication in nasal epithelia.
Kim, JE;Li, B;Fei, L;Horne, R;Lee, D;Loe, AK;Miyake, H;Ayar, E;Kim, DK;Surette, MG;Philpott, DJ;Sherman, P;Guo, G;Pierro, A;Kim, TH;
PMID: 36473468 | DOI: 10.1016/j.immuni.2022.11.003
Intestinal stem cell maturation and development coincide with gut microbiota exposure after birth. Here, we investigated how early life microbial exposure, and disruption of this process, impacts the intestinal stem cell niche and development. Single-cell transcriptional analysis revealed impaired stem cell differentiation into Paneth cells and macrophage specification upon antibiotic treatment in early life. Mouse genetic and organoid co-culture experiments demonstrated that a CD206+ subset of intestinal macrophages secreted Wnt ligands, which maintained the mesenchymal niche cells important for Paneth cell differentiation. Antibiotics and reduced numbers of Paneth cells are associated with the deadly infant disease, necrotizing enterocolitis (NEC). We showed that colonization with Lactobacillus or transfer of CD206+ macrophages promoted Paneth cell differentiation and reduced NEC severity. Together, our work defines the gut microbiota-mediated regulation of stem cell niches during early postnatal development.
