Biology subjects

Anantha, P.

Publications and source records attributed to Anantha, P..

4 recordsLinked to original sources

bioRxiv2024

Disordered glass nanowire substrates produce in vivo-like astrocyte morphology revealed by optical diffraction tomography

Astrocytes, integral components of the central nervous system (CNS), fulfill crucial roles such as maintaining ion homeostasis, providing neuroprotection, and contributing to the blood-brain barrier. Their distinctive, star-like morphology is essential to these functions, and abnormalities in astrocyte structure are linked to numerous neurological disorders. However, our understanding of astrocyte morphology, particularly in vivo, remains limited. Traditional imaging methods, such as fluorescence microscopy, introduce challenges like restricting continuous observation and comprehensive morphological analysis. In this study, we present a novel approach utilizing optical diffraction tomography (ODT), an advanced imaging technique that generates 3D refractive index profiles, to image and quantify detailed astrocyte morphology. We demonstrate, for the first time, the application of ODT to image samples through and on disordered glass nanowire (NW) substrates, overcoming the typical challenges posed by nanostructures, which can disrupt phase reconstruction. Crucially, we show that disordered glass nanowire (NW) substrates can induce in vivo-like astrocyte morphology in cultured rat cortical astrocytes. Compared to traditional glass substrates, astrocytes grown on disordered glass NWs substrates exhibited enhanced process branching and greater total arbor length--features typically observed in their natural, in vivo state, a state of advanced maturation. This finding underscores the significant influence of substrate topography on astrocyte structure and highlights the unique potential of nanostructured environments to mimic physiological conditions. By leveraging ODT, we were able to monitor astrocyte behavior on these substrates, providing unprecedented insights into their morphological dynamics. Our study pioneers the use of nanostructured substrates for reconstructing astrocyte morphology and sets the stage for further exploration of how microenvironmental cues shape astrocyte morphology and behavior.

cell biology↗

bioRxiv2024

Sweet science: Exploring the impact of fructose and glucose on brown adipocyte differentiation using optical diffraction tomography

The thermogenic capacity of brown adipose tissue (BAT) has garnered much attention for its potential to regulate systemic energy balance. BAT depot size and function need to be tightly to prevent loss of metabolic homeostasis due to energy dissipation via non-shivering thermogenesis. While adipocyte-intrinsic mechanisms controlling thermogenesis are critical, an increasing appreciation for the role of the BAT microenvironment is emerging. For example, changes in circulating hexoses due to dietary intake have shown to impact BAT function. Here, we show that murine BAT preadipocytes metabolism is impacted when fructose is used as the sole carbon source. Similarly differentiation medium containing only fructose yield mature adipocytes with fewer lipid droplets, with a concomitant decrease in adipogenic genes. These deficiencies are also observed in human BAT preadipocytes, where cutting-edge optical imaging modalities show a decrease in total cell mass and lipid mass in fructose-only medium. Taken together, the metabolic microenvironment significantly impacts BAT growth and function, with implications for the role of diets potentially mitigating the efficacy of BAT-targeted therapies.

biochemistry↗

bioRxiv2024

Uncovering Astrocyte Morphological Dynamics Using Optical Diffraction Tomography and Shape-based Trajectory Inference

Astrocytes, integral components of the central nervous system, are increasingly recognized for their multifaceted roles beyond mere support cells. Despite their acknowledged importance, understanding the intricacies of astrocyte morphology and dynamics remains limited. Our study marks the first exploration of astrocytes using optical diffraction tomography (ODT), aiming to establish a solid foundation for their detailed characterization. It offers valuable insights into the morphological changes in postnatal rat cortical astrocytes over a 7-day in vitro period in a label-free manner. Through comprehensive analysis of 3D refractive index maps and shape characterization techniques, we elucidate the developmental trajectory and dynamic morphological transformations of astrocytes in culture. Specifically, our observations revealed increased area and transition to larger, flattened shapes, and alterations in cell volume and density, indicating shifts in cellular composition. Furthermore, by employing unsupervised clustering and pseudotime trajectory analysis, we tracked the morphological evolution of astrocytes from highly directional to evenly spread shapes. These results emphasize the dynamic nature of astrocytes. In addition, this analysis marks the first use of trajectory inference based solely on morphology for neural cell types. Future studies could employ ODT to examine the morphological dynamics and interactions of various neural cell types on other types of substrates.

cell biology↗

bioRxiv2024

Cell-TIMP: Cellular Trajectory Inference based on Morphological Parameter

Cellular morphology, shaped by various genetic and environmental influences, is pivotal to studying experimental cell biology, necessitating precise measurement and analysis techniques. Traditional approaches, which rely on geometric metrics derived from stained images, encounter obstacles stemming from both the imaging and analytical domains. Staining processes can disrupt the cells natural state and diminish accuracy due to photobleaching, while conventional analysis techniques, which categorize cells based on shape to discern pathophysiological conditions, often fail to capture the continuous and asynchronous nature of biological processes such as cell differentiation, immune responses, and cancer progression. In this work, we propose the use of quantitative phase imaging for morphological assessment due to its label-free nature. For analysis, we repurposed the genomic analysis toolbox to perform trajectory inference analysis purely based on morphology information. We applied the developed framework to study the progression of leukemia and breast cancer metastasis. Our approach revealed a clear pattern of morphological evolution tied to the diseases advancement, highlighting the efficacy of our method in identifying functionally significant shape changes where conventional techniques falter. This advancement offers a fresh perspective on analyzing cellular morphology and holds significant potential for the broader research community, enabling a deeper understanding of complex biological dynamics.

bioinformatics↗