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Chauhan, J.

Publications and source records attributed to Chauhan, J..

6 recordsLinked to original sources

Inverse Protocol Prediction from Spheroid Microscopy Imaging via Morphology-Aware Structured Learning

We introduce Inverse Protocol Prediction (IPP), which is a task of inferring experimental culture conditions directly from a single bright-field spheroid image. We formulate IPP as a structured multi-label prediction problem and propose a protocol-aware learning framework that integrates morphology extraction, multimodal representation learning, and dependency-aware inference. Morphometric descriptors derived from automated spheroid segmentation are fused with deep visual embeddings via a morphometry vision fusion module. To capture biological and procedural dependencies, we develop a Hierarchical Multi-Task Transformer that conditions predictions across protocol attributes. The framework is trained with domainadversarial supervision and morphology-preserving augmentation to improve robustness to acquisition variability. Hybrid convolution attention encoders achieve the best performance, reaching 95.7% multi-attribute accuracy. We further evaluate cross dataset transfer and temporal morphology forecasting. Results demonstrate that structured, dependency-aware modeling enables reliable reconstruction of experimental protocols from imaging alone, supporting reproducibility auditing and protocol validation in 3D cell culture systems.

bioinformatics↗

Geometric Characterization of Pediatric Multiple Sclerosis Lesion Morphology: A Cross-Sectional and Temporal Analysis using Differential Geometry

Pediatric-onset multiple sclerosis (POMS) involves aggressive inflammation and large lesions; however, its detailed shapes and structures remain poorly understood. Traditional volumetric metrics often overlook the complex geometry of these lesions. The main objective of this study is to develop a differential geometry-based framework to quantify the shape and structure of lesions in pediatric multiple sclerosis(MS) patients using longitudinal 3D FLAIR MRI. The goal was to identify reproducible lesion morphotypes and to track their evolution over time. Our approach sensitively tracked shape changes over time and revealed consistent progression patterns. Our findings suggest that geometric biomarkers offer a powerful new lens for decoding MS heterogeneity and tracking disease activity in the pediatric population.

neuroscience↗

Tuning antibody stability and function by rational designs of framework mutations

Artificial intelligence and machine learning models have been developed to engineer antibodies for specific recognition of antigens, however these approaches often focus on the antibody complementarity determining region (CDR) whilst ignoring the immunoglobulin framework (FW) which provides structural rigidity and support for the flexible CDR loops. Here we present an integrated computational-experimental workflow, combining static structure analyses, molecular dynamics simulations and in vitro physicochemical and functional assays to generate rational designs of FW mutations for modulating antibody stability and activity. We first showed that recent antibody-specific language models lacked insights in FW mutagenesis, in comparison to approaches which utilised antibody structure information. Using the widely-used breast cancer therapeutic trastuzumab as a use case, we designed stabilising mutants which were distal to the CDR and preserved the antibodys functionality to engage its cognate antigen (HER2) and induce antibody-dependent cellular cytotoxicity (ADCC). Interestingly, guided by local backbone motions predicted using molecular dynamics simulations, we designed a FW mutation on the trastuzumab light chain which retained antigen-binding effects but lost Fab-mediated and Fc-mediated effector functions. This highlighted effects of FW on immunological functions engendered in distal areas of the antibody, and the importance to consider attributes other than binding affinity when assessing antibody function. Our approach incorporates interdomain dynamics and distal effects between FW and the Fc domains, expands the scope of antibody engineering beyond the CDR, and underscores the importance of a holistic perspective that considers the entire antibody structure as a whole in optimising antibody stability, developability and function.

immunology↗

Functional specialization of MITF, TFEB and TFE3 drives radically distinct adaptive gene expression programs in melanoma.

Cells can contain multiple related transcription factors targeting the same sequences, leading to potential regulatory cooperativity, redundancy, competition or temporally regulated factor exchange. Yet the differential biological functions of co-targeting transcription factors are poorly understood. In melanoma, three highly related transcription factors are co-expressed: The mTORC1-regulated TFEB and TFE3, key effectors of a wide range of metabolic and microenvironmental cues assumed to perform similar functions; and MITF, that controls melanoma phenotypic identity. Here we reveal the functional specialization of MITF, TFE3 and TFEB and their impact on melanoma progression. Notably, although all bind the same sequences, each regulates different and frequently opposing gene expression programs to coordinate differentiation, metabolism, and protein synthesis, and qualitatively and quantitatively impact tumor immune infiltration. The results uncover a hierarchical cascade whereby microenvironmental stresses, including glucose limitation, lead MITF, TFEB and TFE3 to drive distinct biologically important transcription programs that underpin phenotypic transitions in cancer.

cancer biology↗

Phenotype-specific melanoma uptake of fatty acid from human adipocytes activates AXL and CAV1-dependent beta-catenin nuclear accumulation

Phenotypic diversity of cancer cells within tumors generated through bi-directional interactions with the tumor microenvironment has emerged as a major driver of disease progression and therapy resistance. Nutrient availability plays a critical role in determining phenotype, but whether specific nutrients elicit different responses on distinct phenotypes is poorly understood. Here we show, using melanoma as a model, that only MITFLow undifferentiated cells, but not MITFHigh cells, are competent to drive lipolysis in human adipocytes. In contrast to MITFHigh melanomas, adipocyte-derived free fatty acids are taken up by undifferentiated MITFLow cells via a fatty acid transporter (FATP)-independent mechanism. Importantly, oleic acid (OA), a monounsaturated long chain fatty acid abundant in adipose tissue and lymph, reprograms MITFLow undifferentiated melanoma cells to a highly invasive state by ligand-independent activation of AXL, a receptor tyrosine kinase associated with therapy resistance in a wide range of cancers. AXL activation by OA then drives SRC-dependent formation and nuclear translocation of a {beta}-catenin-CAV1 complex. The results highlight how a specific nutritional input drives phenotype-specific activation of a pro-metastasis program with implications for FATP-targeted therapies.

cancer biology↗

Studies on the Biosorption Potential of Copper by Rhizopus arrhizus Biomass

Due to rapid industrialization and global urbanization, heavy metal pollution of water reservoirs is a severe environmental threat. Moreover, the removal of these heavy metal ions of copper from the wastewaters using conventional methods are costly, time taking, and less effective. Whereas, biosorption proved as a better alternative technique over the traditional methods for the removal of metal ions from the water bodies. Biological materials or biosorbents have been used for the adsorption of metal ions from the aquatic system. Therefore, Rhizopus arrhizus (living biomass) for the biosorption of copper (Cu) metal was used as biosorbent in the present investigation. The pH and temperature at which biosorption occurs are critical. In case of R. arrhizus the maximum adsorption was recorded at pH 7.0, and a temperature of 35{degrees}C.Whereas, the maximum adsorption capacity (Q value) of 100 mg biomass of Rhizopus arrhizus was observed as 94.46 % at 80 ppm concentration. The maximum adsorption capacity of 200 mg biomass of test fungi was reported as 97.32 % at the metal concentration of 80 ppm. Maximum Q value (biosorption capacity, i.e. mg metal per g biosorbent) was 37.785 mg/g at an 80-ppm concentration in case of 100 mg biomass. In the case of 200 mg biomass, the maximum Q value was 19.464 mg/g observed at 80 ppm concentration. Overall, the present study showed that 100 mg and 200 mg Rhizopus arrhizus biomass acts as an excellent adsorbing material for the adsorption of Cu metal ions.

microbiology↗