Biology subjects

Lerario, A. M.

Publications and source records attributed to Lerario, A. M..

7 recordsLinked to original sources

bioRxiv2024

Non-canonical Wnt signaling triggered by WNT2B drives adrenal aldosterone production

The steroid hormone aldosterone, produced by the zona glomerulosa (zG) of the adrenal gland, is a master regulator of plasma electrolytes and blood pressure. While aldosterone control by the renin-angiotensin system is well understood, other key regulatory factors have remained elusive. Here, we replicated a prior association between a non-coding variant in WNT2B and an increased risk of primary aldosteronism, a prevalent and debilitating disease caused by excessive aldosterone production. We further show that in both mice and humans, WNT2B is expressed in the mesenchymal capsule surrounding the adrenal cortex, in close proximity to the zG. Global loss of Wnt2b in the mouse results in a dysmorphic and hypocellular zG, with impaired aldosterone production. Similarly, humans harboring WNT2B loss-of-function mutations develop a novel form of Familial Hyperreninemic Hypoaldosteronism, designated here as Type 4. Additionally, we demonstrate that WNT2B signals by activating the non-canonical Wnt/planar cell polarity pathway. Our findings identify WNT2B as a key regulator of zG function and aldosterone production with important clinical implications. HighlightsO_LIWNT2B variant is associated with increased risk for primary aldosteronism C_LIO_LIWnt2b knock-out mice show defects in adrenal morphology C_LIO_LIWnt2b knock-out mice have hyperreninemic hypoaldosteronism C_LIO_LIWNT2B activates non-canonical Wnt/planar cell polarity signaling C_LIO_LIWNT2B deficiency causes a new form of familial hyperreninemic hypoaldosteronism C_LI

genetics↗

bioRxiv2023

ATE1 activates ER-stress and UPR pathways in glioblastoma

Post-translational modifications (PTM) have been recognized as a relevant regulation of key processes in cancer pathophysiology, such as cell migration, adhesion, and proliferation. N-terminal protein arginylation is an emerging PTM involved in tumor progression; however, the mechanisms by which this modification influences these events are poorly understood and vary according to cancer type. Glioblastoma (GBM) is an aggressive intra-axial brain tumor associated with poor prognosis, low survival, and high recurrence rate. We performed a study combining in silico, in vitro, and patients samples analysis to understand the impact of N-terminal protein arginylation in GBM, including overexpression and silencing of ATE1 in GBM-U87MG cell line with RNASeq analysis, immunofluorescence, and validation of the identified targets at the protein level by immunoblotting. The arginylation pattern differed in GBM compared with non-neoplastic brain tissues, and upregulation of ATE1 was associated with increased tumor cell proliferation. We identified a strong activation of the unfolded protein response (UPR) pathway associated with increased ATE1 level, inducing autophagy and not apoptosis. Protein arginylation in GBM proved to be an important mechanism for tumor growth, with the recycling of cell substrates by autophagy, providing fitness for tumor cells. The expressions of the main markers of UPR and autophagy pathways were validated in human GBM samples, reinforcing the role of ATE1 in the most aggressive brain tumor.

cancer biology↗

bioRxiv2022

Targeting oncogenic Wnt/β-catenin signaling in adrenocortical carcinoma disrupts ECM expression and impairs tumor growth.

Adrenocortical carcinoma (ACC) is a rare, but highly aggressive cancer with limited treatment options and poor survival for patients with advanced disease. Improved understanding of transcriptional programs engaged in ACC will help direct rational, targeted therapies. While activating mutations in Wnt/{beta}-catenin signaling are frequently observed, the {beta}-catenin-dependent transcriptional targets that promote tumor progression are poorly understood. To address this question, we used independent component analysis and identified a novel Wnt/{beta}-catenin-associated signature in ACC predictive of poor survival. This signature was enriched for the extracellular matrix (ECM), suggesting a potential role for Wnt/{beta}-catenin in regulating the ACC microenvironment. We further investigated the minor fibrillar collagen, collagen XI alpha 1 (COL11A1), and found that COL11A1 expression strongly correlated with both Wnt/{beta}-catenin activation and poor patient survival. Inhibition of constitutively active Wnt/{beta}-catenin signaling in the human ACC cell line, NCI-H295R, significantly reduced expression of COL11A1 and other ECM components, and decreased viability of cancer cells in vitro. To investigate the preclinical potential of Wnt/{beta}-catenin inhibition in vivo, we developed and characterized a novel orthotopic xenograft model utilizing minimally invasive techniques. Treatment with the newly developed Wnt/{beta}-catenin:TBL1 inhibitor Tegavivint significantly reduced tumor growth in this preclinical model. Together, our data supports that inhibition of aberrantly active Wnt/{beta}-catenin disrupts transcriptional reprogramming of the microenvironment and reduces ACC growth and survival. Furthermore, this {beta}-catenin-dependent oncogenic program can be therapeutically targeted with a newly developed Wnt/{beta}-catenin inhibitor. These results show promise for further clinical development of Wnt/{beta}-catenin inhibitors in ACC and unveil a novel Wnt/{beta}-catenin-regulated transcriptome. Simple SummaryAdrenocortical carcinoma (ACC) is a rare, often deadly cancer arising from the adrenal gland. Mortality associated with ACC remains unchanged over the last several decades. The rarity of ACC, an incomplete understanding of its molecular basis, and limited availability of pre-clinical models have hampered the development of new effective therapies. The present work aims to address these gaps with a focus on the Wnt/{beta}-catenin cell signaling pathway, which is aberrantly activated in ~40% of ACC tumors. We discover a novel ECM program activated in ACC that is associated with Wnt/{beta}-catenin and poor survival. Wnt/{beta}-catenin inhibition disrupts expression of ECM genes and induces loss of cancer cell viability. To extend these findings, we develop a rapid orthotopic mouse model of ACC and demonstrate that disruption of the Wnt/{beta}-catenin axis with novel small molecule inhibitor Tegavivint is a potential effective therapeutic strategy to reduce ACC tumor burden in vivo.

cancer biology↗

bioRxiv2022

Zinc transporter somatic gene mutations cause primary aldosteronism

Primary aldosteronism (PA) is the most common form of endocrine hypertension and effects one in 50 adults. PA is characterized by inappropriately elevated aldosterone production via renin-independent mechanisms. Driver somatic mutations for aldosterone excess have been found in approximately 90% of aldosterone-producing adenomas (APAs). Using next-generation sequencing, we identified recurrent in-frame deletions in SLC30A1 in five APAs (p.L51_A57del, n=3; p.L49_L55del, n=2). SLC30A1 encodes the ubiquitous zinc efflux transporter ZnT1 (zinc transporter 1). The identified SLC30A1 variants are situated in close proximity of the zincbinding site (H43 and D47) in transmembrane domain II and likely cause abnormal ion transport. PA cases with the unique SLC30A1 mutations showed male dominance and demonstrated increased aldosterone and 18-oxo-cortisol concentrations. Functional studies of the mutant SLC30A151_57del variant in a doxycycline-inducible adrenal cell system revealed abnormal Na+ conductivity caused by the mutant, which in turn led to the depolarization of the resting membrane potential, and thus to the opening of voltage-gated calcium channels. This resulted in an increase in cytosolic Ca2+ activity, which stimulated CYP11B2 mRNA expression and aldosterone production. Collectively, these data implicate the first-in-field zinc transporter mutations as a dominant driver of aldosterone excess in PA.

genetics↗

bioRxiv2022

β-catenin programs a tissue-specific epigenetic vulnerability in aggressive adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare cancer in which tissue-specific differentiation is paradoxically associated with dismal outcomes. The differentiated ACC subtype CIMP-high is prevalent, incurable, and routinely fatal. CIMP-high ACC possess abnormal DNA methylation and frequent {beta}-catenin activating mutations. Here, we demonstrate that ACC differentiation is maintained by a balance between nuclear, tissue-specific {beta}-catenin-containing complexes and the epigenome. On chromatin, {beta}-catenin binds master adrenal transcription factor SF1 and hijacks the adrenocortical super-enhancer landscape to maintain differentiation. Off chromatin, {beta}-catenin binds histone methyltransferase EZH2, which is redistributed by the CIMP-high DNA methylation signature. SF1/{beta}-catenin and EZH2/{beta}-catenin complexes exist in normal adrenals and are selected for through all phases of ACC evolution. Pharmacologic EZH2 inhibition in CIMP-high ACC favors EZH2/{beta}-catenin assembly and purges SF1/{beta}-catenin from chromatin, erasing differentiation and restraining cancer growth in vitro and in vivo. Our studies illustrate how tissue-specific programs shape oncogene selection, surreptitiously encoding targetable therapeutic vulnerabilities.

cancer biology↗

bioRxiv2021

Epigenetic regulation of innate immune memory in microglia

Microglia are the tissue-resident macrophages of the CNS. They originate in the yolk sac, colonize the CNS during embryonic development and form a self-sustaining population with limited turnover. A consequence of their relative slow turnover is that microglia can serve as a long-term memory for inflammatory or neurodegenerative events. We characterized the epigenomes and transcriptomes of microglia exposed to different stimuli; an endotoxin challenge (LPS) and genotoxic stress (DNA repair deficiency-induced accelerated aging). Whereas the enrichment of permissive epigenetic marks at enhancer regions explains training (hyperresponsiveness) of primed microglia to LPS challenge, the tolerized response of microglia seems to be regulated by loss of permissive epigenetic marks. Here, we identify that inflammatory stimuli and accelerated aging because of genotoxic stress activate distinct gene networks. These gene networks and associated biological processes are partially overlapping, which is likely driven by specific transcription factor networks, resulting in altered epigenetic signatures and distinct functional (desensitized vs. primed) microglia phenotypes.

neuroscience↗

bioRxiv2018

DEAH-box helicase 37 (DHX37) defects are a novel molecular etiology of 46,XY gonadal dysgenesis spectrum

46,XY gonadal dysgenesis is a heterogeneous disorder of sex development (DSD) that features abnormal gonadal development and varying degrees of undervirilization of the external genitalia, ranging from micropenis to female-like genitalia. Embryonic testicular regression syndrome (ETRS; MIM: 273250) is considered part of the clinical spectrum of 46,XY gonadal dysgenesis. Most ETRS patients present micropenis or atypical genitalia associated with a complete absence of gonadal tissue in one or both sides. In most patients with gonadal dysgenesis, the genetic diagnosis is unclear. We performed whole exome sequencing in ETRS patients and identified a rare variant, the p.Arg308Gln, in DEAH (Asp-Glu-Ala-His) box polypeptide 37 (DHX37) in 5 affected individuals from three unrelated families. We expanded the analysis of DHX37 coding region to additional 71 patients with 46,XY gonadal dysgenesis and identified the p.Arg308Gln and three other DHX37 missense variants (p.Arg151Trp, p.Thr304Met and p.Arg674Trp) in 11 affected members from eight distinct families (8 patients with ETRS, two with partial gonadal dysgenesis and one 46,XY DSD female patient previously gonadectomized). The p.Arg308Gln and p.Arg674Trp recurrent variants were identified in six and three families, respectively. Segregation analysis revealed sex-limited autosomal dominant inheritance in 4 families, autosomal dominant with incomplete penetrance in one family and autosomal recessive in another family. Immunohistochemical analysis of normal testes revealed that DHX37 is expressed in germ cells at different stages of maturation.\n\nThis study demonstrates an expressive frequency of rare predicted to be deleterious DHX37 variants in 46,XY gonadal dysgenesis group, particularly those individuals exhibiting the ETRS phenotype (25% and 50%, respectively).\n\nOur findings indicate that DHX37 is a new player in the complex cascade of male gonadal differentiation and maintenance, thus establishing a novel and frequent molecular etiology for 46,XY gonadal dysgenesis spectrum, mainly for embryonic testicular regression syndrome.

developmental biology↗