The Journal of clinical investigation
Yadav, VK;Berger, JM;Singh, P;Nagarajan, P;Karsenty, G;
PMID: 34905510 | DOI: 10.1172/JCI153752
Through their ability to regulate gene expression in most organs, glucocorticoid hormones influence numerous physiological processes and therefore are key regulators of organismal homeostasis. In bone, glucocorticoid hormones inhibit the expression of the hormone Osteocalcin for poorly understood reasons. Here we show that in a classical endocrine feedback loop, osteocalcin in return enhances the biosynthesis of glucocorticoid but also mineralocorticoid hormones (adrenal steroidogenesis) in rodents and primates. Conversely, inactivating osteocalcin signalling in adrenal glands significantly impairs adrenal growth and steroidogenesis in mice. Embryo-made osteocalcin is necessary for normal Sf1 expression in foetal adrenal cells and adrenal cell steroidogenic differentiation, it therefore determines the number of steroidogenic cells present in adrenal glands of adult animals. Embryonic not postnatal osteocalcin also governs adrenal growth, adrenal steroidogenesis, blood pressure, electrolyte equilibrium and the rise of circulating corticosterone during the acute stress response in adult offspring. This osteocalcin-dependent regulation of adrenal development and steroidogenesis occurs even in the absence of a functional of hypothalamus-pituitary-adrenal axis; this explains why osteocalcin administration during pregnancy promotes adrenal growth and steroidogenesis and improves survival of adrenocorticotropic hormone signalling-deficient animals. This study reveals that a bone-derived, embryonic hormone influences lifelong adrenal functions and organismal homeostasis in the mouse.
Bando, H;Brinkmeier, ML;Castinetti, F;Fang, Q;Lee, MS;Saveanu, A;Albarel, F;Dupuis, C;Brue, T;Camper, SA;
PMID: 35951005 | DOI: 10.1093/hmg/ddac192
Congenital hypopituitarism is a genetically heterogeneous condition that is part of a spectrum disorder that can include holoprosencephaly. Heterozygous mutations in SIX3 cause variable holoprosencephaly in humans and mice. We identified two children with neonatal hypopituitarism and thin pituitary stalk who were doubly heterozygous for rare, likely deleterious variants in the transcription factors SIX3 and POU1F1. We used genetically engineered mice to understand the disease pathophysiology. Pou1f1 loss of function heterozygotes are unaffected; Six3 heterozygotes have pituitary gland dysmorphology and incompletely ossified palate; and the Six3+/-; Pou1f1+/dw double; heterozygote mice have a pronounced phenotype, including pituitary growth through the palate. The interaction of Pou1f1 and Six3 in mice supports the possibility of digenic pituitary disease in children. Disruption of Six3 expression in the oral ectoderm completely ablated anterior pituitary development, and deletion of Six3 in the neural ectoderm blocked development of the pituitary stalk and both anterior and posterior pituitary lobes. Six3 is required in both oral and neural ectodermal tissues for activation of signaling pathways and transcription factors necessary for pituitary cell fate. These studies clarify the mechanism of SIX3 action in pituitary development and provide support for a digenic basis for hypopituitarism.
Jarmas, AE;Brunskill, EW;Chaturvedi, P;Salomonis, N;Kopan, R;
PMID: 34732708 | DOI: 10.1038/s41467-021-26626-9
Mammalian nephron endowment is determined by the coordinated cessation of nephrogenesis in independent niches. Here we report that translatome analysis in Tsc1+/- nephron progenitor cells from mice with elevated nephron numbers reveals how differential translation of Wnt antagonists over agonists tips the balance between self-renewal and differentiation. Wnt agonists are poorly translated in young niches, resulting in an environment with low R-spondin and high Fgf20 promoting self-renewal. In older niches we find increased translation of Wnt agonists, including R-spondin and the signalosome-promoting Tmem59, and low Fgf20, promoting differentiation. This suggests that the tipping point for nephron progenitor exit from the niche is controlled by the gradual increase in stability and possibly clustering of Wnt/Fzd complexes in individual cells, enhancing the response to ureteric bud-derived Wnt9b inputs and driving synchronized differentiation. As predicted by these findings, removing one Rspo3 allele in nephron progenitors delays cessation and increases nephron numbers in vivo.
Cellular and molecular gastroenterology and hepatology
Kim, TY;Kim, S;Kim, Y;Lee, YS;Lee, S;Lee, SH;Kweon, MN;
PMID: 34971821 | DOI: 10.1016/j.jcmgh.2021.12.015
Dietary signals are known to modulate stemness and tumorigenicity of intestinal progenitors; however, the impact of a high-fat diet (HFD) on the intestinal stem cell (ISC) niche and its association with colorectal cancer remains unclear. Thus, we aimed to investigate how a HFD affects the ISC niche and its regulatory factors.Mice were fed a purified diet (PD) or HFD for 2 months. The expression levels of ISC-related markers, ISC-supportive signals, and Wnt2b were assessed with real-time quantitative polymerase chain reaction, in situ hybridization, and immunofluorescence staining. RNA sequencing and metabolic function were analyzed in mesenchymal stromal cells (MSCs) from PD- and HFD-fed mice. Fecal microbiota were analyzed by 16s rRNA sequencing. Bile salt hydrolase activity and bile acid (BA) levels were measured.We found that expression of CD44 and Wnt signal-related genes was higher in the colonic crypts of HFD-fed mice than in those fed a PD. Within the ISC niche, MSCs were expanded and secreted predominant levels of Wnt2b in the colon of HFD-fed mice. Of note, increased energy metabolism and cancer-associated fibroblast (CAF)-like properties were found in the colonic MSCs of HFD-fed mice. Moreover, colonic MSCs from HFD-fed mice promoted the growth of tumorigenic properties and accelerated the expression of cancer stem cell (CSC)-related markers in colon organoids. In particular, production of primary and secondary BAs was increased through the expansion of bile salt hydrolase-encoding bacteria in HFD-fed mice. Most importantly, BAs-FXR interaction stimulated Wnt2b production in colonic CAF-like MSCs.HFD-induced colonic CAF-like MSCs play an indispensable role in balancing the properties of CSCs through activation of the BAs-FXR axis.
Trobisch, T;Zulji, A;Stevens, NA;Schwarz, S;Wischnewski, S;Öztürk, M;Perales-Patón, J;Haeussler, M;Saez-Rodriguez, J;Velmeshev, D;Schirmer, L;
PMID: 36112223 | DOI: 10.1007/s00401-022-02497-2
Multiple sclerosis (MS) is a multifocal and progressive inflammatory disease of the central nervous system (CNS). However, the compartmentalized pathology of the disease affecting various anatomical regions including gray and white matter and lack of appropriate disease models impede understanding of the disease. Utilizing single-nucleus RNA-sequencing and multiplex spatial RNA mapping, we generated an integrated transcriptomic map comprising leukocortical, cerebellar and spinal cord areas in normal and MS tissues that captures regional subtype diversity of various cell types with an emphasis on astrocytes and oligodendrocytes. While we found strong cross-regional diversity among glial subtypes in control tissue, regional signatures become more obscure in MS. This suggests that patterns of transcriptomic changes in MS are shared across regions and converge on specific pathways, especially those regulating cellular stress and immune activation. In addition, we found evidence that a subtype of white matter oligodendrocytes appearing across all three CNS regions adopt pro-remyelinating gene signatures in MS. In summary, our data suggest that cross-regional transcriptomic glial signatures overlap in MS, with different reactive glial cell types capable of either exacerbating or ameliorating pathology.
Piskol R, Huw LY, Sergin I, Klijn C, Modrusan Z, Kim D, Kljavin NM, Tam R, Patel R, Burton J, Penuel E, Qu X, Koeppen H, Sumiyoshi T, de Sauvage FJ, Lackner MR, de Sousa E Melo F, Kabbarah O.
PMID: 31004000 | DOI: 10.1158/1078-0432.CCR-18-3032
Abstract
PURPOSE:
Four consensus molecular subtypes (CMS1-4) of colorectal cancer (CRC) were identified in primary tumors and found to be associated with distinctive biological features and clinical outcomes. Given that distant metastasis largely accounts for CRC-related mortality, we examined the molecular and clinical attributes of CMS in metastatic CRC (mCRC).
EXPERIMENTAL DESIGN:
We developed a CRC-focused Nanostring based CMS classifier that is ideally suited to interrogate archival tissues. We successfully employ this panel in the CMS classification of FFPE tissues from mCRC cohorts, one of which is comprised of paired primary tumors and metastases. Finally, we developed novel mouse implantation models to enable modelling of CRC in vivo at relevant sites.
RESULTS:
Using our classifier we find that the biological hallmarks of mCRC, including CMS, are in general highly similar to those observed in non-metastatic early stage disease. Importantly, our data demonstrate that CMS1 has the worst outcome in relapsed disease, compared to other CMS. Assigning CMS to primary tumors and their matched metastases revealed mostly concordant subtypes between primary and metastasis. Molecular analysis of matched discordant pairs revealed differences in stromal composition at each site. The development of two novel in vivo orthotopic implantation models further reinforces the notion that extrinsic factors may impact on CMS identification in matched primary and metastatic CRC.
CONCLUSION:
We describe the utility of a Nanostring panel for CMS classification of FFPE clinical samples. Our work reveals the impact of intrinsic and extrinsic factors on CRC heterogeneity during disease progression.
MEIS-WNT5A axis regulates development of fourth ventricle choroid plexus
Development (Cambridge, England)
Kaiser, K;Jang, A;Kompanikova, P;Lun, MP;Prochazka, J;Machon, O;Dani, N;Prochazkova, M;Laurent, B;Gyllborg, D;van Amerongen, R;Fame, RM;Gupta, S;Wu, F;Barker, RA;Bukova, I;Sedlacek, R;Kozmik, Z;Arenas, E;Lehtinen, MK;Bryja, V;
PMID: 34032267 | DOI: 10.1242/dev.192054
The choroid plexus (ChP) produces cerebrospinal fluid and forms an essential brain barrier. ChP tissues form in each brain ventricle, each one adopting a distinct shape, but remarkably little is known about the mechanisms underlying ChP development. Here, we show that epithelial WNT5A is crucial for determining fourth ventricle (4V) ChP morphogenesis and size in mouse. Systemic Wnt5a knockout, or forced Wnt5a overexpression beginning at embryonic day 10.5, profoundly reduced ChP size and development. However, Wnt5a expression was enriched in Foxj1-positive epithelial cells of 4V ChP plexus, and its conditional deletion in these cells affected the branched, villous morphology of the 4V ChP. We found that WNT5A was enriched in epithelial cells localized to the distal tips of 4V ChP villi, where WNT5A acted locally to activate non-canonical WNT signaling via ROR1 and ROR2 receptors. During 4V ChP development, MEIS1 bound to the proximal Wnt5a promoter, and gain- and loss-of-function approaches demonstrated that MEIS1 regulated Wnt5a expression. Collectively, our findings demonstrate a dual function of WNT5A in ChP development and identify MEIS transcription factors as upstream regulators of Wnt5a in the 4V ChP epithelium.
Overcoming the inhibitory microenvironment surrounding oligodendrocyte progenitor cells following experimental demyelination
Saraswat, D;Shayya, HJ;Polanco, JJ;Tripathi, A;Welliver, RR;Pol, SU;Seidman, RA;Broome, JE;O'Bara, MA;van Kuppervelt, TH;Phillips, JJ;Dutta, R;Sim, FJ;
PMID: 33772011 | DOI: 10.1038/s41467-021-22263-4
Chronic demyelination in the human CNS is characterized by an inhibitory microenvironment that impairs recruitment and differentiation of oligodendrocyte progenitor cells (OPCs) leading to failed remyelination and axonal atrophy. By network-based transcriptomics, we identified sulfatase 2 (Sulf2) mRNA in activated human primary OPCs. Sulf2, an extracellular endosulfatase, modulates the signaling microenvironment by editing the pattern of sulfation on heparan sulfate proteoglycans. We found that Sulf2 was increased in demyelinating lesions in multiple sclerosis and was actively secreted by human OPCs. In experimental demyelination, elevated OPC Sulf1/2 expression directly impaired progenitor recruitment and subsequent generation of oligodendrocytes thereby limiting remyelination. Sulf1/2 potentiates the inhibitory microenvironment by promoting BMP and WNT signaling in OPCs. Importantly, pharmacological sulfatase inhibition using PI-88 accelerated oligodendrocyte recruitment and remyelination by blocking OPC-expressed sulfatases. Our findings define an important inhibitory role of Sulf1/2 and highlight the potential for modulation of the heparanome in the treatment of chronic demyelinating disease.
Acta neuropathologica communications
Chen, S;Chang, Y;Li, L;Acosta, D;Li, Y;Guo, Q;Wang, C;Turkes, E;Morrison, C;Julian, D;Hester, ME;Scharre, DW;Santiskulvong, C;Song, SX;Plummer, JT;Serrano, GE;Beach, TG;Duff, KE;Ma, Q;Fu, H;
PMID: 36544231 | DOI: 10.1186/s40478-022-01494-6
Human middle temporal gyrus (MTG) is a vulnerable brain region in early Alzheimer's disease (AD), but little is known about the molecular mechanisms underlying this regional vulnerability. Here we utilize the 10 × Visium platform to define the spatial transcriptomic profile in both AD and control (CT) MTG. We identify unique marker genes for cortical layers and the white matter, and layer-specific differentially expressed genes (DEGs) in human AD compared to CT. Deconvolution of the Visium spots showcases the significant difference in particular cell types among cortical layers and the white matter. Gene co-expression analyses reveal eight gene modules, four of which have significantly altered co-expression patterns in the presence of AD pathology. The co-expression patterns of hub genes and enriched pathways in the presence of AD pathology indicate an important role of cell-cell-communications among microglia, oligodendrocytes, astrocytes, and neurons, which may contribute to the cellular and regional vulnerability in early AD. Using single-molecule fluorescent in situ hybridization, we validated the cell-type-specific expression of three novel DEGs (e.g., KIF5A, PAQR6, and SLC1A3) and eleven previously reported DEGs associated with AD pathology (i.e., amyloid beta plaques and intraneuronal neurofibrillary tangles or neuropil threads) at the single cell level. Our results may contribute to the understanding of the complex architecture and neuronal and glial response to AD pathology of this vulnerable brain region.
Bertozzi, A;Wu, CC;Hans, S;Brand, M;Weidinger, G;
PMID: 34748730 | DOI: 10.1016/j.ydbio.2021.11.001
Zebrafish can achieve scar-free healing of heart injuries, and robustly replace all cardiomyocytes lost to injury via dedifferentiation and proliferation of mature cardiomyocytes. Previous studies suggested that Wnt/β-catenin signaling is active in the injured zebrafish heart, where it induces fibrosis and prevents cardiomyocyte cell cycling. Here, via targeting the destruction complex of the Wnt/β-catenin pathway with pharmacological and genetic tools, we demonstrate that Wnt/β-catenin activity is required for cardiomyocyte proliferation and dedifferentiation, as well as for maturation of the scar during regeneration. Using cardiomyocyte-specific conditional inhibition of the pathway, we show that Wnt/β-catenin signaling acts cell-autonomously to promote cardiomyocyte proliferation. Our results stand in contrast to previous reports and rather support a model in which Wnt/β-catenin signaling plays a positive role during heart regeneration in zebrafish.
Wang B, Zhao L, Fish M, Logan CY, Nusse R.
PMID: 26245375 | DOI: 10.1038/nature14863
The source of new hepatocytes in the uninjured liver has remained an open question. By lineage tracing using the Wnt-responsive gene Axin2 in mice, we identify a population of proliferating and self-renewing cells adjacent to the central vein in the liver lobule. These pericentral cells express the early liver progenitor marker Tbx3, are diploid, and thereby differ from mature hepatocytes, which are mostly polyploid. The descendants of pericentral cells differentiate into Tbx3-negative, polyploid hepatocytes, and can replace all hepatocytes along the liver lobule during homeostatic renewal. Adjacent central vein endothelial cells provide Wnt signals that maintain the pericentral cells, thereby constituting the niche. Thus, we identify a cell population in the liver that subserves homeostatic hepatocyte renewal, characterize its anatomical niche, and identify molecular signals that regulate its activity.
El Ayachi I, Fatima I, Wend P, Alva-Ornelas JA, Runke S, Kuenzinger WL, Silva J, Silva W, Gray JK, Lehr S, Barch HC, Krutilina RI, White AC, Cardiff R, Yee LD, Yang L, O'Regan RM, Lowry WE, Seagroves TN, Seewaldt V, Krum SA, Miranda-Carboni GA.
PMID: 30563890 | DOI: 10.1158/0008-5472.CAN-18-1069
Triple-negative breast cancer (TNBC) commonly develops resistance to chemotherapy, yet markers predictive of chemoresistance in this disease are lacking. Here, we define WNT10B-dependent biomarkers for β-CATENIN/HMGA2/EZH2 signaling predictive of reduced relapse-free survival. Concordant expression of HMGA2 and EZH2 proteins is observed in MMTV-Wnt10bLacZ transgenic mice during metastasis, and Hmga2 haploinsufficiency decreased EZH2 protein expression, repressing lung metastasis. A novel autoregulatory loop interdependent on HMGA2 and EZH2 expression is essential for β-CATENIN/TCF-4/LEF-1 transcription. Mechanistically, both HMGA2 and EZH2 displaced Groucho/TLE1 from TCF-4 and served as gatekeepers for K49 acetylation on β-CATENIN, which is essential for transcription. In addition, we discovered that HMGA2-EZH2 interacts with the PRC2 complex. Absence of HMGA2 or EZH2 expression or chemical inhibition of Wnt signaling in a chemoresistant patient-derived xenograft (PDX) model of TNBC abolished visceral metastasis, repressing AXIN2, MYC, EZH2, and HMGA2 expression in vivo. Combinatorial therapy of a WNT inhibitor with doxorubicin synergistically activated apoptosis in vitro, resensitized PDX-derived cells to doxorubicin, and repressed lung metastasis in vivo. We propose that targeting the WNT10B biomarker network will provide improved outcomes for TNBC. SIGNIFICANCE: These findings reveal targeting the WNT signaling pathway as a potential therapeutic strategy in triple-negative breast cancer.
