Nature Cardiovascular Research
Cheng, P;Wirka, R;Kim, J;Kim, H;Nguyen, T;Kundu, R;Zhao, Q;Sharma, D;Pedroza, A;Nagao, M;Iyer, D;Fischbein, M;Quertermous, T;
| DOI: 10.1038/s44161-022-00042-8
Atherosclerotic plaques consist mostly of smooth muscle cells (SMCs), and genes that influence SMC phenotype can modulate coronary artery disease (CAD) risk. Allelic variation at 15q22.33 has been identified by genome-wide association studies to modify the risk of CAD and is associated with the expression of _SMAD3_ in SMCs. However, the mechanism by which this gene modifies CAD risk remains poorly understood. Here we show that SMC-specific deletion of _Smad3_ in a murine atherosclerosis model resulted in greater plaque burden, more outward remodeling and increased vascular calcification. Single-cell transcriptomic analyses revealed that loss of _Smad3_ altered SMC transition cell state toward two fates: an SMC phenotype that governs both vascular remodeling and recruitment of inflammatory cells as well as a chondromyocyte fate. Together, the findings reveal that _Smad3_ expression in SMCs inhibits the emergence of specific SMC phenotypic transition cells that mediate adverse plaque features, including outward remodeling, monocyte recruitment and vascular calcification.
Genetics in medicine : official journal of the American College of Medical Genetics
Al-Jawahiri, R;Foroutan, A;Kerkhof, J;McConkey, H;Levy, M;Haghshenas, S;Rooney, K;Turner, J;Shears, D;Holder, M;Lefroy, H;Castle, B;Reis, LM;Semina, EV;Lachlan, K;Chandler, K;Wright, T;Clayton-Smith, J;Hug, FP;Pitteloud, N;Bartoloni, L;Hoffjan, S;Park, SM;Thankamony, A;Lees, M;Wakeling, E;Naik, S;Hanker, B;Girisha, KM;Agolini, E;Giuseppe, Z;Alban, Z;Tessarech, M;Keren, B;Afenjar, A;Zweier, C;Reis, A;Smol, T;Tsurusaki, Y;Nobuhiko, O;Sekiguchi, F;Tsuchida, N;Matsumoto, N;Kou, I;Yonezawa, Y;Ikegawa, S;Callewaert, B;Freeth, M;Kleinendorst, L;Donaldson, A;Alders, M;De Paepe, A;Sadikovic, B;McNeill, A;University of Washington Center for Mendelian Genomics (UW-CMG), ;Genomics England Research Consortium, ;
PMID: 35341651 | DOI: 10.1016/j.gim.2022.02.013
This study aimed to undertake a multidisciplinary characterization of the phenotype associated with SOX11 variants.Individuals with protein altering variants in SOX11 were identified through exome and genome sequencing and international data sharing. Deep clinical phenotyping was undertaken by referring clinicians. Blood DNA methylation was assessed using Infinium MethylationEPIC array. The expression pattern of SOX11 in developing human brain was defined using RNAscope.We reported 38 new patients with SOX11 variants. Idiopathic hypogonadotropic hypogonadism was confirmed as a feature of SOX11 syndrome. A distinctive pattern of blood DNA methylation was identified in SOX11 syndrome, separating SOX11 syndrome from other BAFopathies.SOX11 syndrome is a distinct clinical entity with characteristic clinical features and episignature differentiating it from BAFopathies.
Han, Y;Villarreal-Ponce, A;Gutierrez, G;Nguyen, Q;Sun, P;Wu, T;Sui, B;Berx, G;Brabletz, T;Kessenbrock, K;Zeng, YA;Watanabe, K;Dai, X;
PMID: 35021086 | DOI: 10.1016/j.celrep.2021.110240
Maintenance of undifferentiated, long-lived, and often quiescent stem cells in the basal compartment is important for homeostasis and regeneration of multiple epithelial tissues, but the molecular mechanisms that coordinately control basal cell fate and stem cell quiescence are elusive. Here, we report an epithelium-intrinsic requirement for Zeb1, a core transcriptional inducer of epithelial-to-mesenchymal transition, for mammary epithelial ductal side branching and for basal cell regenerative capacity. Our findings uncover an evolutionarily conserved role of Zeb1 in promoting basal cell fate over luminal differentiation. We show that Zeb1 loss results in increased basal cell proliferation at the expense of quiescence and self-renewal. Moreover, Zeb1 cooperates with YAP to activate Axin2 expression, and inhibition of Wnt signaling partially restores stem cell function to Zeb1-deficient basal cells. Thus, Zeb1 is a transcriptional regulator that maintains both basal cell fate and stem cell quiescence, and it functions in part through suppressing Wnt signaling.
Chesnokova, V;Zonis, S;Apostolou, A;Estrada, HQ;Knott, S;Wawrowsky, K;Michelsen, K;Ben-Shlomo, A;Barrett, R;Gorbunova, V;Karalis, K;Melmed, S;
PMID: 34910915 | DOI: 10.1016/j.celrep.2021.110068
Microenvironmental factors modulating age-related DNA damage are unclear. Non-pituitary growth hormone (npGH) is induced in human colon, non-transformed human colon cells, and fibroblasts, and in 3-dimensional intestinal organoids with age-associated DNA damage. Autocrine/paracrine npGH suppresses p53 and attenuates DNA damage response (DDR) by inducing TRIM29 and reducing ATM phosphorylation, leading to reduced DNA repair and DNA damage accumulation. Organoids cultured up to 4 months exhibit aging markers, p16, and SA-β-galactosidase and decreased telomere length, as well as DNA damage accumulation, with increased npGH, suppressed p53, and attenuated DDR. Suppressing GH in aged organoids increases p53 and decreases DNA damage. WT mice exhibit age-dependent colon DNA damage accumulation, while in aged mice devoid of colon GH signaling, DNA damage remains low, with elevated p53. As age-associated npGH induction enables a pro-proliferative microenvironment, abrogating npGH signaling could be targeted as anti-aging therapy by impeding DNA damage and age-related pathologies.
Development (Cambridge, England)
Negretti, NM;Plosa, EJ;Benjamin, JT;Schuler, BA;Habermann, AC;Jetter, CS;Gulleman, P;Bunn, C;Hackett, AN;Ransom, M;Taylor, CJ;Nichols, D;Matlock, BK;Guttentag, SH;Blackwell, TS;Banovich, NE;Kropski, JA;Sucre, JMS;
PMID: 34927678 | DOI: 10.1242/dev.199512
Lung organogenesis requires precise timing and coordination to effect spatial organization and function of the parenchymal cells. To provide a systematic broad-based view of the mechanisms governing the dynamic alterations in parenchymal cells over crucial periods of development, we performed a single-cell RNA-sequencing time-series yielding 102,571 epithelial, endothelial and mesenchymal cells across nine time points from embryonic day 12 to postnatal day 14 in mice. Combining computational fate-likelihood prediction with RNA in situ hybridization and immunofluorescence, we explore lineage relationships during the saccular to alveolar stage transition. The utility of this publicly searchable atlas resource (www.sucrelab.org/lungcells) is exemplified by discoveries of the complexity of type 1 pneumocyte function and characterization of mesenchymal Wnt expression patterns during the saccular and alveolar stages - wherein major expansion of the gas-exchange surface occurs. We provide an integrated view of cellular dynamics in epithelial, endothelial and mesenchymal cell populations during lung organogenesis.
Biochemical and biophysical research communications
Negishi, T;Mihara, N;Chiba, T;D'Armiento, J;Chada, K;Maeda, M;Igarashi, M;Imai, K;
PMID: 34973532 | DOI: 10.1016/j.bbrc.2021.12.093
The mutation and deletion of high mobility group AT-hook 2 (Hmga2) gene exhibit skeletal malformation, but almost nothing is known about the mechanism. This study examined morphological anomaly of facial bone in Hmga2-/- mice and osteoblast differentiation of pre-osteoblast MC3T3-E1 cells with Hmga2 gene knockout (A2KO). Hmga2-/- mice showed the size reduction of anterior frontal part of facial bones. Hmga2 protein and mRNA were expressed in mesenchymal cells at ossification area of nasal bone. A2KO cells differentiation into osteoblasts after reaching the proliferation plateau was strongly suppressed by alizarin red and alkaline phosphatase staining analyses. Expression of osteoblast-related genes, especially Osterix, was down-regulated in A2KO cells. These results demonstrate a close association of Hmga2 with osteoblast differentiation of mesenchymal cells and bone growth. Although future studies are needed, the present study suggests an involvement of Hmga2 in osteoblast-genesis and bone growth.
YAP regulates alveolar epithelial cell differentiation and AGER via NFIB/KLF5/NKX2-1
Gokey, JJ;Snowball, J;Sridharan, A;Sudha, P;Kitzmiller, JA;Xu, Y;Whitsett, JA;
PMID: 34466790 | DOI: 10.1016/j.isci.2021.102967
Ventilation is dependent upon pulmonary alveoli lined by two major epithelial cell types, alveolar type-1 (AT1) and 2 (AT2) cells. AT1 cells mediate gas exchange while AT2 cells synthesize and secrete pulmonary surfactants and serve as progenitor cells which repair the alveoli. We developed transgenic mice in which YAP was activated or deleted to determine its roles in alveolar epithelial cell differentiation. Postnatal YAP activation increased epithelial cell proliferation, increased AT1 cell numbers, and caused indeterminate differentiation of subsets of alveolar cells expressing atypical genes normally restricted to airway epithelial cells. YAP deletion increased expression of genes associated with mature AT2 cells. YAP activation enhanced DNA accessibility in promoters of transcription factors and motif enrichment analysis predicted target genes associated with alveolar cell differentiation. YAP participated with KLF5, NFIB, and NKX2-1 to regulate AGER. YAP plays a central role in a transcriptional network that regulates alveolar epithelial differentiation.
Perinatal angiogenesis from pre-existing coronary vessels via DLL4-NOTCH1 signalling
Lu, P;Wang, Y;Liu, Y;Wang, Y;Wu, B;Zheng, D;Harvey, RP;Zhou, B;
PMID: 34497373 | DOI: 10.1038/s41556-021-00747-1
New coronary vessels are added to the heart around birth to support postnatal cardiac growth. Here we show that, in late fetal development, the embryonic coronary plexus at the inner myocardium of the ventricles expresses the angiogenic signalling factors VEGFR3 and DLL4 and generates new coronary vessels in neonates. Contrary to a previous model in which the formation of new coronary vessels in neonates from ventricular endocardial cells was proposed, we find that late fetal and neonatal ventricular endocardial cells lack angiogenic potential and do not contribute to new coronary vessels. Instead, we show using lineage-tracing as well as gain- and loss-of-function experiments that the pre-existing embryonic coronary plexus at the inner myocardium undergoes angiogenic expansion through the DLL4-NOTCH1 signalling pathway to vascularize the expanding myocardium. We also show that the pre-existing coronary plexus revascularizes the regenerating neonatal heart through a similar mechanism. These findings provide a different model of neonatal coronary angiogenesis and regeneration, potentially informing cardiovascular medicine.
Microglia-neuron interaction at nodes of Ranvier depends on neuronal activity through potassium release and contributes to remyelination
Ronzano, R;Roux, T;Thetiot, M;Aigrot, MS;Richard, L;Lejeune, FX;Mazuir, E;Vallat, JM;Lubetzki, C;Desmazières, A;
PMID: 34471138 | DOI: 10.1038/s41467-021-25486-7
Microglia, the resident immune cells of the central nervous system, are key players in healthy brain homeostasis and plasticity. In neurological diseases, such as Multiple Sclerosis, activated microglia either promote tissue damage or favor neuroprotection and myelin regeneration. The mechanisms for microglia-neuron communication remain largely unkown. Here, we identify nodes of Ranvier as a direct site of interaction between microglia and axons, in both mouse and human tissues. Using dynamic imaging, we highlight the preferential interaction of microglial processes with nodes of Ranvier along myelinated fibers. We show that microglia-node interaction is modulated by neuronal activity and associated potassium release, with THIK-1 ensuring their microglial read-out. Altered axonal K+ flux following demyelination impairs the switch towards a pro-regenerative microglia phenotype and decreases remyelination rate. Taken together, these findings identify the node of Ranvier as a major site for microglia-neuron interaction, that may participate in microglia-neuron communication mediating pro-remyelinating effect of microglia after myelin injury.
Inhibition of the cGAS-STING pathway ameliorates the premature senescence hallmarks of Ataxia-Telangiectasia brain organoids
Aguado, J;Chaggar, HK;Gómez-Inclán, C;Shaker, MR;Leeson, HC;Mackay-Sim, A;Wolvetang, EJ;
PMID: 34459078 | DOI: 10.1111/acel.13468
Ataxia-telangiectasia (A-T) is a genetic disorder caused by the lack of functional ATM kinase. A-T is characterized by chronic inflammation, neurodegeneration and premature ageing features that are associated with increased genome instability, nuclear shape alterations, micronuclei accumulation, neuronal defects and premature entry into cellular senescence. The causal relationship between the detrimental inflammatory signature and the neurological deficiencies of A-T remains elusive. Here, we utilize human pluripotent stem cell-derived cortical brain organoids to study A-T neuropathology. Mechanistically, we show that the cGAS-STING pathway is required for the recognition of micronuclei and induction of a senescence-associated secretory phenotype (SASP) in A-T olfactory neurosphere-derived cells and brain organoids. We further demonstrate that cGAS and STING inhibition effectively suppresses self-DNA-triggered SASP expression in A-T brain organoids, inhibits astrocyte senescence and neurodegeneration, and ameliorates A-T brain organoid neuropathology. Our study thus reveals that increased cGAS and STING activity is an important contributor to chronic inflammation and premature senescence in the central nervous system of A-T and constitutes a novel therapeutic target for treating neuropathology in A-T patients.
Yap/Taz inhibit goblet cell fate to maintain lung epithelial homeostasis
Hicks-Berthet, J;Ning, B;Federico, A;Tilston-Lunel, A;Matschulat, A;Ai, X;Lenburg, ME;Beane, J;Monti, S;Varelas, X;
PMID: 34260916 | DOI: 10.1016/j.celrep.2021.109347
Proper lung function relies on the precise balance of specialized epithelial cells that coordinate to maintain homeostasis. Herein, we describe essential roles for the transcriptional regulators YAP/TAZ in maintaining lung epithelial homeostasis, reporting that conditional deletion of Yap and Wwtr1/Taz in the lung epithelium of adult mice results in severe defects, including alveolar disorganization and the development of airway mucin hypersecretion. Through in vivo lineage tracing and in vitro molecular experiments, we reveal that reduced YAP/TAZ activity promotes intrinsic goblet transdifferentiation of secretory airway epithelial cells. Global gene expression and chromatin immunoprecipitation sequencing (ChIP-seq) analyses suggest that YAP/TAZ act cooperatively with TEA domain (TEAD) transcription factors and the NuRD complex to suppress the goblet cell fate program, directly repressing the SPDEF gene. Collectively, our study identifies YAP/TAZ as critical factors in lung epithelial homeostasis and offers molecular insight into the mechanisms promoting goblet cell differentiation, which is a hallmark of many lung diseases.
NOX1-dependent redox signaling potentiates colonic stem cell proliferation to adapt to the intestinal microbiota by linking EGFR and TLR activation
van der Post, S;Birchenough, GMH;Held, JM;
PMID: 33826887 | DOI: 10.1016/j.celrep.2021.108949
The colon epithelium is a primary point of interaction with the microbiome and is regenerated by a few rapidly cycling colonic stem cells (CSCs). CSC self-renewal and proliferation are regulated by growth factors and the presence of bacteria. However, the molecular link connecting the diverse inputs that maintain CSC homeostasis remains largely unknown. We report that CSC proliferation is mediated by redox-dependent activation of epidermal growth factor receptor (EGFR) signaling via NADPH oxidase 1 (NOX1). NOX1 expression is CSC specific and is restricted to proliferative CSCs. In the absence of NOX1, CSCs fail to generate ROS and have a reduced proliferation rate. NOX1 expression is regulated by Toll-like receptor activation in response to the microbiota and serves to link CSC proliferation with the presence of bacterial components in the crypt. The TLR-NOX1-EGFR axis is therefore a critical redox signaling node in CSCs facilitating the quiescent-proliferation transition and responds to the microbiome to maintain colon homeostasis.
