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Anekal, P. V.

Publications and source records attributed to Anekal, P. V..

4 recordsLinked to original sources

A living organism-level model of subcellular architecture across adult life reveals a midlife architectural state shift

Many features of subcellular organelle architecture change throughout life and influence aging. However, our understanding of this structural dynamism relies on single cell systems or comparisons between data sets focused on a limited number of organelles or timepoints. To overcome this barrier, we developed Multiorganelle Mapper (MoMA), a C. elegans strain enabling simultaneous imaging of six organelles across all somatic cell types in fully intact, living animals via fluorescence microscopy. We use MoMA to generate an organism-level in vivo map of subcellular architecture throughout adult life to understand how and why organelle organization changes with age. Aging drives a widespread and consistent shift in subcellular architecture throughout the body. Strikingly, most of this remodeling does not accumulate progressively, but emerges abruptly within individuals at midlife, an inflection point we term the midlife architectural state shift (MASS). Through a targeted RNAi screen, we show the MASS is not unique to aging, but instead resembles a generalized reactive state which can be triggered by a range of distinct homeostatic challenges. Finally, we show the MASS both coincides with and can be driven by midlife physiological changes, suggesting that this remodeling may largely reflect a coordinated reaction to the aged organismal state. Together, we present MoMA as a practical approach for visualizing subcellular architecture at organismal scale and demonstrate how it can be used to uncover principles underlying the dynamic regulation of subcellular architecture throughout life.

cell biology↗

Lachesin is a mosquito receptor for multiple arthritogenic alphaviruses

Arthritogenic alphaviruses cause acute febrile illnesses associated with rash and arthritis when they are transmitted to humans through the bite of infected mosquitoes. Among these, chikungunya virus (CHIKV), transmitted primarily through the bite of infected Aedes aegypti and Aedes albopictus mosquitoes, causes explosive outbreaks involving hundreds of thousands to millions of cases, with recent re-emergence in several global regions. While several cellular receptors that mediate alphavirus entry into mammalian cells have been identified, their mosquito counterparts remained unknown, largely due to a lack of functional genomics tools for these invertebrate species. Here, we established a CRISPR-based genetic screening platform in Aedes albopictus cells and used it to identify Lachesin, a conserved invertebrate cell adhesion molecule, as a receptor for CHIKV and multiple related alphaviruses including Semliki Forest virus (SFV), onyong-nyong virus (ONNV), Mayaro virus (MAYV), and Ross River virus (RRV). Lachesin depletion using RNA interference, anti-Lachesin antibody treatment, and soluble forms of Lachesin blocked CHIKV and SFV E2-E1 glycoprotein-mediated infection of mosquito cells. We show that alphavirus E2-E1 glycoproteins bind the first immunoglobulin domain of Lachesin, facilitating attachment and internalization of virus-like particles. Orthologs from divergent mosquito genera, but not from arachnids or other arthropods, also serve as alphavirus receptors, suggesting that cellular receptor binding is not the main obstacle to arthritogenic alphavirus vector host expansion. Our findings enhance understanding of the mechanisms of alphavirus emergence and vector competence and could aid in the development of broadly active, entry-targeted therapeutics against multiple alphaviruses that threaten public health.

microbiology↗

Rejuvenation of white adipose tissue in a longitudinal heterochronic transplantation model

Exposure to a younger system can induce organismal rejuvenation, yet whether all tissues can be rejuvenated and by what mechanisms remains understudied. We performed heterochronic and isochronic transplantation of subcutaneous white adipose tissue (WAT) between young and old mice and longitudinally tracked changes in biological age. Transplantation accelerated tissue aging, and the molecular age of grafts shifted toward that of the host. Most importantly, old WAT was rejuvenated in a young body. Epigenetic and transcriptomic clocks revealed a reduction of predicted age, accompanied by coordinated activation of canonical and previously unrecognized thermogenic pathways. Molecular rejuvenation was further supported by architectural changes toward a youthful state, including reduced lipid droplet size and decreased cellular heterogeneity. Mitochondrial abundance and morphology remained unchanged, while collagen deposition increased. These results demonstrate that WAT biological age is partially reversible and identify molecular and cellular features underlying its rejuvenation

systems biology↗

EZH2 synergizes with BRD4-NUT to drive NUT carcinoma growth through silencing of key tumor suppressor genes

NUT carcinoma (NC) is an aggressive carcinoma driven by the BRD4-NUT fusion oncoprotein, which activates chromatin to promote expression of pro-growth genes. BET bromodomain inhibitors (BETi) impede BRD4-NUTs ability to activate genes and are thus a promising treatment but limited as monotherapy. The role of gene repression in NC is unknown. Here, we demonstrate that EZH2, which silences genes through establishment of repressive chromatin, is a dependency in NC. Inhibition of EZH2 with the clinical compound tazemetostat (taz) potently blocked growth of NC cells. Epigenetic and transcriptomic analysis revealed that taz reversed the EZH2-specific H3K27me3 silencing mark, and restored expression of multiple tumor suppressor genes while having no effect on key oncogenic BRD4- NUT-regulated genes. CDKN2A was identified as the only gene amongst all taz-derepressed genes to confer resistance to taz in a CRISPR-Cas9 screen. Combined EZH2 inhibition and BET inhibition synergized to downregulate cell proliferation genes resulting in more pronounced growth arrest and differentiation than either inhibitor alone. In pre-clinical models, combined taz and BETi synergistically blocked growth and prolonged survival of NC-xenografted mice, with all mice cured in one cohort. STATEMENT OF SIGNIFICANCEIdentification of EZH2 as a dependency in NC substantiates the reliance of NC tumor cells on epigenetic dysregulation of functionally opposite, yet highly complementary chromatin regulatory pathways to maintain NC growth. In particular, repression of CDKN2A expression by EZH2 provides a mechanistic rationale for combining EZH2i with BETi for the clinical treatment of NC.

cancer biology↗