Biology subjects

Lenka, N.

Publications and source records attributed to Lenka, N..

3 recordsLinked to original sources

bioRxiv2023

Orchestration of differential mesodermal fate choice from ESCs by Wnt-USP3 link and H2A/H2B contextual deubiquitination.

Wnt, an evolutionarily conserved morphogen, is vital for various cell fates specification during early development. However, a concrete mechanistic understanding of the precise and fine-tuned regulation of Wnt underlying these processes is yet to be uncovered. Using the murine embryonic stem cells (ESCs) model, we have identified USP3, a histone deubiquitinase (DUB), displaying bimodal action, serving both as a downstream Wnt target and a regulator of canonical Wnt signalling. Using both loss- and gain-of-function approaches, we could identify USP3 as essential for mesoderm specification, exerting a differential influence during further differentiation. While cardiogenic mesoderm was negatively regulated and so also cardiomyogenesis, USP3 positively regulated hemangioblasts differentiation. Interestingly, however, these induced hemangioblasts promoted the haematopoietic program at the expense of endothelial differentiation. The mechanistic underpinning revealed USP3 localizing to chromatin and differentially modulating these fate choices by precise and contextual deposition of H2AUb/H2BUb in the promoters of mesoderm genes. Collectively our study underscored the Wnt-USP3 link underlying differential mesodermal fate modulation.

cell biology↗

bioRxiv2023

RORyt+CD4+ T cells promote IL-23R-mediated neuronal cell apoptosis in the central nervous system

Transcription factors T-bet and ROR{psi}t play a crucial role in neuronal autoimmunity, and mice deficient in these two factors do not develop experimental autoimmune encephalomyelitis (EAE). The independent role of T-bet and ROR{psi}t in the pathogenesis of EAE and how they help induce apoptosis of neurons in the central nervous system (CNS) during neuronal autoimmunity is unclear. In the present study, we showed that myelin oligodendrocyte glycoprotein (MOG35-55) peptide-specific Th1 cells deficient in ROR{psi}t could cross BBB but fail to induce apoptosis of neurons and EAE. Pathogenic Th17 cell-derived cytokines GM-CSF, TNF-, IL-17A, and IL-21 significantly increase the surface expression of IL-23R on neuronal cells. Furthermore, we showed that, in EAE, neurons in the brain and spinal cord express IL-23R. IL-23-IL-23R signaling in neuronal cells caused phosphorylation of STAT3 (Ser727 and Tyr705) and induced cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase-1 (PARP-1) molecules in an IL-23R-dependent manner and caused apoptosis. Thus, we provided a mechanism where we showed that T-bet is required to recruit pathogenic Th17 cells and ROR{psi}t expression to drive the apoptosis of IL-23R+ neurons in the CNS and cause EAE. Understanding detailed molecular mechanisms will help to design better strategies to control neuroinflammation and autoimmunity. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=136 SRC="FIGDIR/small/537133v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@2586b0org.highwire.dtl.DTLVardef@1adb3deorg.highwire.dtl.DTLVardef@fbce53org.highwire.dtl.DTLVardef@1a6d4ae_HPS_FORMAT_FIGEXP M_FIG C_FIG One Sentence SummaryIL-23-IL-23R signaling promotes apoptosis of CNS neurons.

immunology↗

bioRxiv2023

Fabrication and Characterization of Ceramic-Polymer composite 3D scaffolds and Demonstration of Osteoinductive propensity with gingival Mesenchymal Stem Cells

Bone tissue engineering involves the usage of metals, polymers, and ceramics as the base constituents in the fabrication of various biomaterial 3D scaffolds. Of late, the composite materials facilitating enhanced osteogenic differentiation/regeneration have been endorsed as the ideally suited bone grafts for addressing critical-sized bone defects. Here, we report the successful fabrication of 3D composite scaffolds with collagen type I (Col-I) in conjunction with three different crystalline phases of calcium-phosphate (CP) nanomaterials [hydroxyapatite (HAp), beta-tricalcium phosphate ({beta}TCP), biphasic hydroxyapatite ({beta}TCP-HAp or BCP)], obtained by altering the pH as the major variable. The fabricated 3D scaffolds consisting of [~]70 wt % CP nanomaterials and [~] 30 Wt % of Col-I did mimic the ECM of bone tissue. The different Ca/P ratio and the orientation of CP nanomaterials in CP/Col-I composite scaffolds altered the microstructure, surface area, porosity, and mechanical strength of the scaffolds and also influenced the bioactivity, biocompatibility, and osteogenic differentiation of gingival-derived mesenchymal stem cells (gMSCs). The microstructure of CP/Col-I 3D scaffolds assessed by Micro-CT analysis revealed randomly oriented interconnected pores with pore sizes ranging from 80-250, 125-380, and 100-450{micro}m respectively for {beta}TCP/Col-I, BCP/Col-I, and HAp/Col-I scaffolds. Among these, the BCP/Col-I achieved the highest surface area ([~] 42.6 m2/g) and porosity ([~]85%), demonstrated improved bioactivity and biocompatibility, and promoted osteogenic differentiation of gMSCs. Interestingly, the Ca2+ ions (3 mM) released from scaffolds could also facilitate the osteocyte differentiation of gMSCs sans osteoinduction. Collectively, our study has demonstrated the ECM mimicking biphasic CP/Col-I 3D scaffold as an ideally suited tissue-engineered bone graft.

bioengineering↗