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Kethireddy, S.

Publications and source records attributed to Kethireddy, S..

2 recordsLinked to original sources

Deep-learning-enabled morphodynamic analysis of drug responses in a biomimetic fibrin-based 3D glioblastoma invasion model

Glioblastoma (GBM) lethality arises from aggressive invasion and diffuse infiltration of brain tissue. Conventional GBM preclinical models often fail to predict clinical therapeutic efficacy because they do not recapitulate the pathological extracellular matrix (ECM) cues that drive tumor invasion. Here, we present an ECM mimetic 3D platform using a fibrin scaffold to recapitulate the hemorrhagic, pro-thrombotic tumor microenvironment characteristic of high-grade gliomas. This fibrin scaffold induces a pro-invasive phenotype in GBM spheroids by upregulating proliferation/cell cycle- (MYC, FOXOM1, CCND1) and invasion-associated-(CTSS, FOXM1, CCND1) genes. Traditional cell morphology quantification methods (e.g., circularity) distil complex shapes into singular metrics and cannot capture the nuances of invasion. To address this limitation, we have applied a deep-learning segmentation pipeline (MARS-Net) and high-content morphodynamic descriptors. By using the Preserving Heterogeneity (PHet) algorithm, the 3D platform accurately classifies invasiveness levels and captures the invasion-inhibitory effects of potential repurposable drug candidates. We demonstrate that our model can predict a spheroids long-term invasive fate with high accuracy using only partial image sets from early time-points, rather than the complete time-course images. Our work presents an in vivo-like, scalable 3D platform integrated with a quantitative high-throughput pipeline to elucidate GBM invasion mechanisms and to evaluate anti-invasive compounds.

bioengineering↗

Division of labor among H3K4 Methyltransferases Defines Distinct Facets of Homeostatic Plasticity

Heterozygous mutations in any of the six H3K4 methyltransferases (KMT2s) result in monogenic neurodevelopmental disorders, indicating nonredundant yet poorly understood roles of this enzyme family in neurodevelopment. Recent evidence suggests that histone methyltransferase activity may not be central to KMT2 functions; however, the enzymatic activity is evolutionarily conserved, implicating the presence of selective pressure to maintain the catalytic activity. Here, we show that H3K4 methylation is dynamically regulated during prolonged alteration of neuronal activity. The perturbation of H3K4me by the H3.3K4M mutant blocks synaptic scaling, a form of homeostatic plasticity that buffers the impact of prolonged reductions or increases in network activity. Unexpectedly, we found that the six individual enzymes are all necessary for synaptic scaling and that the roles of KMT2 enzymes segregate into evolutionary-defined subfamilies: KMT2A and KMT2B (fly-Trx homologs) for synaptic downscaling, KMT2C and KMT2D (Trr homologs) for upscaling, and KMT2F and KMT2G (dSet homologs) for both directions. Selective blocking of KMT2A enzymatic activity by a small molecule and targeted disruption of the enzymatic domain both blocked the synaptic downscaling and interfered with the activity-dependent transcriptional program. Furthermore, our study revealed specific phases of synaptic downscaling, i.e., induction and maintenance, in which KMT2A and KMT2B play distinct roles. These results suggest that mammalian brains have co-opted intricate H3K4me installation to achieve stability of the expanding neuronal circuits.

neuroscience↗