Biology subjects

Cada, S.

Publications and source records attributed to Cada, S..

4 recordsLinked to original sources

bioRxiv2026

RASAL3 regulates RAC/CDC42 GTPases, SAPK/JNK signaling, IL-2 gene activity, and directed motility in human T cells

RASAL3 acts as a negative regulator of small cellular GTPases in hematopoietic cells. In immune cells, it primarily modulates the RAS/MAPK signaling pathway and affects cellular events including proliferation, differentiation, survival, and migration. Due to its inhibitory role in T cells, RASAL3 may represent a potential modulatory target for improving therapeutic strategies such as cell-based immunotherapy. However, most existing knowledge about RASAL3 function is derived from murine models, and its role in human T-cell signaling remains insufficiently characterized. To address this gap, we systematically investigated the function of RASAL3 in human primary T cells and T-cell line. For this purpose, we employed RASAL3 overexpression, CRISPR/Cas9-mediated deletion, and siRNA-mediated knockdown to thoroughly analyze the effects of RASAL3 on T-cell signaling, proliferation, and migration. Our data demonstrate that RASAL3 modulates primarily CDC42 and RAC1/RAC2 GTPases activity, SAPK/JNK phosphorylation, c-Fos and c-Jun expression, and IL-2 gene promoter activation. In addition, RASAL3 regulates actin polymerization and T-cell migration. Notably, loss of RASAL3 increases Jurkat T cells motility in vivo and potentiates their homing to the spleen. Collectively, these findings identify RASAL3 as an important regulator of human T-cell activation and motility and highlight its application potential for improving CAR-T cell therapy.

cell biology↗

bioRxiv2025

Effects of Sodium Glucose Co-Transporter Inhibitors on Work in Human Hypertrophic Cardiomyopathy Living Myocardial Slices

BackgroundDisease modifying therapies for hypertrophic cardiomyopathy (HCM) remain a prevailing unmet need. Human-based experimental platforms capable of controlled manipulation of preload and afterload can distinguish direct myocardial and systemic effects and facilitate development of targeted cardiac therapeutics. Sodium glucose cotransporter inhibitors (SGLTi) may directly affect cardiac contractility, potentially related to increased ketone availability. These effects have not been adequately studied in human HCM myocardium under defined loading conditions. AimsWe sought to establish human living myocardial slices (LMS) as a platform to interrogate load-dependent myocardial mechanics in HCM and to quantify the acute effects of metabolic and pharmacologic interventions--including SGLTi--on myocardial work under physiologic loading conditions. MethodsHuman myocardial tissue was procured from non-failing donor hearts or individuals with HCM undergoing septal myectomy. Freshly prepared human LMS were mechanically tested to generate biomimetic work loops across a range of physiologic preloads and afterloads in either glucose-only fuel or glucose supplemented with ketone. Following baseline measurements, slices were loaded with drug (isoproterenol, mavacamten, sotagliflozin, or empagliflozin) or vehicle (DMSO) and work loop analysis was repeated, allowing each slice to serve as its own control. Mixed effects linear regression models incorporating random effects for heart and slice and fixed effects for clinical characteristics evaluated determinants of myocardial work and drug response across loading conditions. ResultsA total of 120 LMS from 32 individuals (16 non-failing and 16 HCM) were analyzed. At baseline, myocardial work was positively associated with younger age, hypertension, and ejection fraction. Ketone supplementation augmented work and work-strain slope particularly in HCM LMS at high afterloads. We validated our drug testing methodology by demonstrating increased work with known positive inotrope isoproterenol, decreased work with negative inotrope mavacamtem most pronounced in HCM LMS, and a null effect of DMSO. Acute exposure to SGLTi sotagliflozin and empagliflozin directly reduced myocardial work, with increased potency of sotagliflozin at high afterloads. ConclusionsOur LMS platform enables assessment of myocardial mechanics across controlled loading conditions and is an ideal platform to rigorously phenotype human myocardial tissue and interrogate direct effects of pharmacologic intervention. We demonstrate that SGLTi and ketones have distinct and discordant effects on human myocardial contractility.

physiology↗

bioRxiv2025

Proximity interactomics identifies RAI14, EPHA2 and PHACTR4 as essential components of Wnt/planar cell polarity pathway in vertebrates

Wnt/planar cell polarity (Wnt/PCP) pathway is an evolutionarily conserved signaling cascade playing an inevitable role in cell biology. Deregulation of Wnt/PCP leads to severe developmental defects or cancer progression. Here, we applied proximity-dependent biotinylation (BioID) to capture the intracellular interactome of key Wnt/PCP components: transmembrane ROR1, ROR2 and VANGL2, and cytoplasmic DVL3 and PRICKLE1. Mapping of individual preys across the baits and subcellular compartments identified a group of 30 proteins that we tested by loss-of-function in zebrafish. Among those rai14, epha2 and phactr4 were essential for several Wnt/PCP-dependent processes such as zebrafish convergent extension, orientation of lateral organ cells, or migration of melanoma cells. Mechanistically, RAI14, EPHA2 and PHACTR4 connect the receptor complex to effector actomyosin. In summary, this study identified novel essential components of vertebrate WNT/PCP pathway and provides a detailed characterization of PCP complex composition that can serve as comprehensive resource for further analysis of Wnt/PCP function.

cell biology↗

bioRxiv2020

Lyn controls chemotaxis and motility of CLL cells via phosphorylation of ROR1.

Chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) are malignancies characterized by the dependence on B-cell receptor (BCR) signaling and by the high expression of the cell surface receptor ROR1. Both, BCR and ROR1 are therapeutic targets in these diseases and the understanding of their mutual cross talk is thus of direct therapeutic relevance. In this study we analyzed the role of Lyn, a kinase from the Src family, as a mediator of the BCR-ROR1 crosstalk. We confirm the functional interaction between Lyn and ROR1 and demonstrate that Lyn kinase efficiently phosphorylates ROR1 in its kinase domain and aids the recruitment of an E3 ligase c-CBL. The absence of Lyn in Lyn KO Maver-1 cells produced by CRISPR-Cas9 resulted in the increased ROR1 cell surface levels and deregulated migratory properties. Similar correlations between ROR1 surface dynamics, levels of active Lyn and chemotactic properties were confirmed in primary CLL samples. Our data establish Lyn-mediated phosphorylation of ROR1 as a point of crosstalk between BCR and ROR1 signaling pathways.

cancer biology↗