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Mestvirishvili, T.

Publications and source records attributed to Mestvirishvili, T..

3 recordsLinked to original sources

Non-segmented unsupervised learning of multispectral whole slide images for robust analysis of tissue repair and regeneration

Analyzing whole tissue architecture remains challenging due to the inherent complexity of multicellular organization, variable morphology, and the limitations of conventional segmentation-based image analysis. Traditional approaches often rely on partial sampling or nuclear/cytoplasmic boundaries, which risk introducing bias and fail to capture the contextual interplay of diverse tissue compartments. To overcome these barriers, we developed a segmentation free framework for analyzing multispectral whole slide images (WSIs). By tiling WSIs into fixed sized regions and extracting quantitative tile features, we applied unsupervised machine learning to systematically reveal patterns of tissue organization at scale. This approach preserved spatial context without the need for cell-level delineation, recapitulating expected compartments such as epidermis, adipose, and scab, while also revealing subtle but coherent substructures within stromal and granulation regions. Applied to murine wound healing, the method distinguished wild type from diabetic repair dynamics without prior labels, uncovering both gross and nuanced differences in tissue composition. Together, this work establishes a robust, unbiased strategy for whole-tissue analysis that circumvents the limitations of segmentation, leverages unsupervised learning for discovery, and advances the study of tissue repair and regenerative pathology.

cell biology↗

Functional high capacity exosome-encapsulating bioinspired hydrogel promotes microvascularbed expansion in diabetic mice

Chronic wounds present a significant clinical challenge due to impaired skin microvasculature, particularly in diabetes. The tissue engineering study introduces therapeutic Exo-Q, a unique thermoresponsive polymer hydrogel created with Q protein nanofibers and cultured human bone marrow multipotent stromal cell exosomes with consistent gene signature. Limited, local and topical application of Exo-Q hydrogel is feasible for maximum neovascularization during murine diabetic wound closure in a xenotransplantation model, as well as compatibility and vascular delivery in human skin in a xenograft model. Exo-Q hydrogel treatment significantly reduces diabetic wound closure time within ranges of non-diabetic wounds. This innovative, non-invasive tissue engineered therapeutic option offers a promising approach to addressing the complex pathologies of non-healing wounds.

bioengineering↗

The Sin3B chromatin modifier restricts cell cycle progression to dictate hematopoietic stem cell differentiation

Abstract/SummaryTo maintain blood homeostasis, millions of terminally differentiated effector cells are produced every day. At the apex of this massive and constant blood production lie hematopoietic stem cells (HSCs), a rare cell type harboring unique self-renewal and multipotent properties. A key feature of HSCs is their ability to temporarily exit the cell cycle in a state termed quiescence. Defective control of cell cycle progression can eventually lead to bone marrow failure or malignant transformation. It is thought that HSCs must re-enter the cell cycle in order to commit to terminal differentiation. However, the molecular mechanisms tying cell cycle re-entry to cell fate commitment in HSCs remain elusive. Here, we identify the chromatin-associated Sin3B protein as a molecular link between cell cycle progression and differentiation in HSCs. We demonstrate that Sin3B is necessary for HSCs commitment to differentiation, but dispensable for their self-renewal or survival. Single cell transcriptional profiling of hematopoietic stem and progenitor cells (HSPCs) inactivated for Sin3B reveals aberrant cell cycle gene expression, consistent with the observed aberrant progression through the G1 phase of the cell cycle. The defective cell cycle control elicited upon Sin3B inactivation correlates with the engagement of discrete signaling programs, including aberrant expression of cell adhesion molecules and essential components of the interferon signaling cascade in LT-HSCs. Additionally, chromatin accessibility profiling in LT-HSCs reveals the Sin3B-dependent accessibility of genomic elements controlling HSC differentiation, suggesting a functional link between cell cycle progression, and priming of hematopoietic stem cells for differentiation. Together, these results point to controlled progression through the G1 phase of the cell cycle as a likely regulator of HSC lineage commitment through the modulation of chromatin features.

cell biology↗