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Biology subjects

Aldaz, C. M.

Publications and source records attributed to Aldaz, C. M..

6 recordsLinked to original sources

B-cell-Specific Wwox Deletion Promotes Plasmablastic Tumor Development and Pro-Inflammatory Signatures in a Myeloma Mouse Model

Deletions and translocations affecting WWOX accompanied by loss of expression are frequently observed in B cell neoplasms and are linked to poor prognosis. Our previous research showed that Wwox deletion early in B cell development induces genomic instability, neoplastic transformation, and monoclonal gammopathies in mice. In this study, by crossing Cd19 Wwox knockout (KO) with Vk*MYC myeloma model mice, we generated a model with concurrent Wwox deletion and MYC activation, reproducing two common oncogenic alterations in B and plasma cell cancers. We observed that Vk*MYC:Wwox KO mice exhibited significantly reduced survival rates primarily due to the development of plasmablastic plasmacytomas and lymphomas. Transcriptome profiling from bone marrow derived Cd138+ plasma cells and plasmablastic tumors revealed enrichment of biofunctions related to tumorigenic phenotype and inflammation activation upon Wwox deletion in Vk*MYC mice. Wwox KO plasmablastic tumors displayed mutations affecting classical cancer genes, DNA damage response (DDR) genes, as well as overexpression of Aid/Apobec family members associated to hypermutation and DDR mutational signatures. These findings illustrate the significant pathobiological effects of B cell specific Wwox deletion and support a relevant role for WWOX loss of function in B cell neoplastic progression towards more aggressive phenotypes.

cancer biology↗

Therapeutic Potential of PRMT1 as a Critical Survival Dependency Target in Multiple Myeloma

Multiple myeloma (MM) is a neoplasm of antibody-producing plasma cells and is the second most prevalent hematological malignancy worldwide. Development of drug resistance and disease relapse significantly impede the success of MM treatment, highlighting the critical need to discover novel therapeutic targets. In a custom CRISPR/Cas9 screen targeting 197 DNA damage response-related genes, Protein Arginine N-Methyltransferase 1 (PRMT1) emerged as a top hit, revealing it as a potential therapeutic vulnerability and survival dependency in MM cells. PRMT1, a major Type I PRMT enzyme, catalyzes the asymmetric transfer of methyl groups to arginine residues, influencing gene transcription and protein function through post-translational modification. Dysregulation or overexpression of PRMT1 has been observed in various malignancies including MM and is linked to chemoresistance. Treatment with the Type I PRMT inhibitor GSK3368715 resulted in a dose-dependent reduction in cell survival across a panel of MM cell lines. This was accompanied by reduced levels of asymmetric dimethylation of arginine (ADMA) and increased arginine monomethylation (MMA) in MM cells. Cell cycle analysis revealed an accumulation of cells in the G0/G1 phase and a reduction in the S phase upon GSK3368715 treatment. Additionally, PRMT1 inhibition led to a significant downregulation of genes involved in cell proliferation, DNA replication, and DNA damage response (DDR), likely inducing genomic instability and impairing tumor growth. This was supported by Reverse Phase Protein Array (RPPA) analyses, which revealed a significant reduction in levels of proteins associated with cell cycle regulation and DDR pathways. Overall, our findings indicate that MM cells critically depend on PRMT1 for survival, highlighting the therapeutic potential of PRMT1 inhibition in treating MM.

cancer biology↗

Partial Wwox Loss of Function Increases Severity of Murine Sepsis and Neuroinflammation

RationaleWW domain-containing oxidoreductase (WWOX) is a gene associated implicated in both neurologic and inflammatory diseases and is susceptible to environmental stressors. We hypothesize partial loss of Wwox function will result in increased sepsis severity and neuroinflammation. MethodsWwox WT/P47T mice, generated by CRISPR/Cas9, and Wwox WT/WT mice were treated with intraperitoneal PBS vs LPS (10mg/kg) and euthanized 12 hours post-injection. Open Field Testing (OFT) and Murine Sepsis Severity Scores (MSS) were utilized to measure sickness behavior and sepsis severity, respectively. Brain tissue was analyzed using immunohistochemistry and PCR to measure neuroinflammation and apoptosis. ResultsWwox WT/P47T LPS mice demonstrated a more significant response to sepsis with an increase in sickness behavior, sepsis severity, gliosis, and apoptosis compared to Wwow WT/WT LPS littermates. ConclusionsPartial loss of Wwox function increases risk for severe sepsis and neuroinflammation. Given the susceptibility of WWOX to environmental stressors, this may be a target for future therapeutic interventions.

neuroscience↗

Endothelial Knockdown of the Tumor Suppressor, WWOX, Increases Inflammation in Ventilator-Induced Lung Injury

BackgroundChronic cigarette smoke exposure downregulates lung expression of WWOX, an ARDS relevant tumor suppressor. Prior work has revealed a barrier protective function of WWOX during infectious models of ARDS. Proteomic analysis of WWOX-silenced lung endothelial cells suggest involvement of WWOX in protection against mechanical stretch-induced inflammation. MethodsProtein lysates from WWOX-silenced endothelial cells (ECs) were analyzed using tandem mass tag mass spectrometry (TMT-MS) to determine the differential expression status of the proteome compared to wild type ECs. WWOX-silenced ECs as well as those isolated from endothelial Wwox knockout (EC Wwox KO) mice were subjected to cyclic stretch (18% elongation, 0.5 Hz, 4 hours). Cellular lysates and media supernatant were harvested for assays of cellular signaling, protein expression, and cytokine release. Dual silencing of WWOX and zyxin was achieved to determine the role of zyxin upregulation in IL-8 production following mechanical stretch and during WWOX knockdown. Control and EC Wwox KO mice were subjected to high tidal volume ventilation (VILI, 40ml/kg, 65 breath/min, 4hours). Bronchoalveolar lavage fluid and mouse lung tissue were harvested for cellular signaling, cytokine secretion, and histologic assays. ResultsTMT-MS revealed upregulation of zyxin expression during WWOX knockdown which predicted a heightened inflammatory response to mechanical stretch. WWOX-silenced ECs and ECs isolated from EC Wwox mice displayed significantly increased cyclic stretch-mediated secretion of various cytokines (IL-6, KC/IL-8, IL-1{beta}, and MCP-1) relative to controls. This was associated with increased ERK and JNK phosphorylation but decreased p38 MAPK phosphorylation. EC Wwox KO mice subjected to VILI sustained a greater degree of injury than corresponding controls. Silencing of zyxin during WWOX knockdown abrogated stretch-induced increases in IL-8 secretion. ConclusionLoss of WWOX function in ECs is associated with a heightened inflammatory response during mechanical stretch that is associated with increased MAPK phosphorylation and appears to be dependent on upregulation of zyxin.

molecular biology↗

WWOX P47T loss-of-function mutation induces epilepsy, progressive neuroinflammation, and cerebellar degeneration in mice phenocopying human SCAR12

WWOX gene loss-of-function (LoF) has been associated with neuropathologies resulting in developmental, epileptic, and ataxic phenotypes of varying severity based on the level of WWOX dysfunction. WWOX gene biallelic germline variant p.Pro47Thr (P47T) has been causally associated with a new form of autosomal recessive cerebellar ataxia with epilepsy and intellectual disability (SCAR12). This mutation affects the WW1 protein binding domain of WWOX, impairing its ability to interact with canonical proline-proline-X-tyrosine motifs in partner proteins. We generated a mutant knock-in mouse model of Wwox P47T that phenocopies SCAR12. WwoxP47T/P47T mice displayed epilepsy, profound social behavior and cognition deficits, and poor motor coordination, and unlike KO models that survive only for 1 month, live beyond 1 year of age. These deficits progressed with age, and mice became practically immobile, suggesting severe cerebellar dysfunction. WwoxP47T/P47T mice exhibited signs of progressive neuroinflammation with elevated astro-microgliosis that increased with age. The cerebellar cortex displayed significantly reduced molecular and granular layer thickness and a strikingly reduced number of Purkinje cells with degenerated dendrites. Transcriptome profiling from various brain regions from these Wwox LoF mice highlighted widespread changes in neuronal and glial pathways, enrichment of bioprocesses related to neuroinflammation and severe cerebellar dysfunction, activation of pathways compatible with compensatory neurogenesis along with major suppression of gene networks associated with excitability, neuronal cell differentiation and brain development. Our results show significant pathobiological effects and potential mechanisms through which WWOX LoF leads to epilepsy, cerebellar neurodegeneration, neuroinflammation, and ataxia. Additionally, the mouse model described here will be a useful tool for the study of WWOX in common neurodegenerative conditions in which it has been identified as a novel risk factor.

neuroscience↗

Cigarette Smoke and Nicotine-Containing E-cigarette Vapor Downregulate Lung WWOX Expression Which is Associated with Increased Severity of Murine ARDS

RATIONALEA history of chronic cigarette smoking is known to increase risk for ARDS, but the corresponding risks associated with chronic e-cigarette use are largely unknown. The chromosomal fragile site gene, WWOX, is highly susceptible to genotoxic stress from environmental exposures, and thus an interesting candidate gene for the study of exposure-related lung disease. METHODS AND RESULTSLungs harvested from current versus former/never smokers exhibited a 47% decrease in WWOX mRNA levels. Exposure to nicotine-containing e-cigarette vapor resulted in an average 57% decrease in WWOX mRNA levels relative to vehicle treated controls. In separate studies, endothelial (EC)-specific WWOX KO versus wild type mice were examined under ARDS-producing conditions. EC WWOX KO mice exhibited significantly greater levels of vascular leak and histologic lung injury. ECs were isolated from digested lungs of untreated EC WWOX KO mice using sorting by flow cytometry for CD31+CD45- cells. These were grown in culture, confirmed to be WWOX-deficient by RT-PCR and Western blotting, and analyzed by electric cell impedance sensing (ECIS) as well as a FITC dextran transwell assay for their barrier properties during MRSA or LPS exposure. WWOX KO ECs demonstrated significantly greater declines in barrier function relative to wild type cells during either MRSA or LPS treatment as measured by both ECIS and the transwell assay. CONCLUSIONThe increased risk for ARDS observed in chronic smokers may be mechanistically linked, at least in part, to lung WWOX downregulation, and this phenomenon may also manifest in the near future in chronic users of e-cigarettes.

molecular biology↗