Biology subjects

Suman, S.

Publications and source records attributed to Suman, S..

4 recordsLinked to original sources

bioRxiv2026

A proteomic atlas of organelle remodeling identifies lysosomal SNX3 as a regulator of Notch signaling in epidermal differentiation

Differentiation of epidermal keratinocytes is accompanied by profound reorganization of intracellular architecture, but how organelle remodeling interfaces with cell fate control is not well understood. Here, we generate a compartment-resolved proteomic map of keratinocyte differentiation and identify extensive remodeling of lysosomes, mitochondria, autophagic vesicles, plasma membrane, and nucleus. Differentiating keratinocytes display coordinated enrichment of lysosomal degradative machinery, vesicular trafficking factors, and mitochondrial metabolic proteins, revealing organelle remodeling as a prominent feature of epidermal differentiation. From the lysosomal proteome, we identify Sorting Nexin 3 (SNX3) as a critical regulator of epidermal homeostasis. SNX3 increasingly localizes to LAMP1-positive vesicles during differentiation, and its loss impairs epidermal differentiation, suppresses Notch signaling, and promotes proliferative gene expression. In vivo, SNX3-deficient skin grafts fail to maintain normal epidermal architecture and instead develop into squamous cell carcinoma. Mechanistically, SNX3 mediates efficient Notch receptor activation, as SNX3 loss reduces nuclear Notch1 and NICD production, whereas NICD re-expression can rescue the differentiation defect. Our study defines a proteomic framework for organelle remodeling during epidermal differentiation and identifies lysosome-associated SNX3 as a key link between endolysosomal trafficking, Notch signaling, and epidermal tissue homeostasis.

cell biology↗

bioRxiv2025

Proteomic analysis of exosomes from lymphatic affluents reveals their implications in developing premetastatic niche in melanoma.

Melanoma is an aggressive form of skin cancer that often spreads via lymphatic pathways to regional and distant sites. Melanoma-derived lymphatic exosomes play a crucial role in forming a tumor-supportive environment for metastasis, or premetastatic niche, within the first tumor draining lymph node, also known as the sentinel lymph node (SLN). Therefore, analyzing the proteomic content of tumor-draining lymphatic exosomes that deliver oncogenic molecules to the SLN is important in understanding the premetastatic niche. To reveal the proteomic landscape of lymphatic exosomes, we performed multidimension liquid chromatography-tandem mass spectrometry with multiplexing (18-samples) using tandem mass tag (TMT) labeling to profile the lymphatic exosomal proteomes obtained from afferent lymphatic channels leading to the SLN of patients with melanoma (n=6), control afferent lymphatic channels from prophylactic mastectomy (n=3) and non-cancer post-operative lymphatic fluid (n=9). Lymphatic fluid from postoperative lymphadenectomy drains served as another control to filter out non-melanoma alteration in lymph that may be related to the procedure of surgical resection and wound healing process. Our proteomic analysis identified 3929 proteins in the lymphatic exosomes, of which 968 were unique proteins absent from the current exosomal database. Interestingly, melanoma lymphatic exosomes possess distinctive proteomic cargo, which is significantly associated with cancer-associated and cellular structural remodeling pathways (FDR <0.05). Moreover, proinflammatory wound healing pathways are predominantly present in melanoma and postoperative lymph fluid compared to normal control afferent lymphatic channels. We identified a total of 17 uniquely modulated proteins in melanoma compared to control and postoperative lymph, which are critically involved in the process of melanoma tumorigenesis. At least ten upregulated proteins strongly correlate with each other at the gene expression levels in melanoma tumors compared to controls and may serve as a signature panel for melanoma (p = 2.13 x 10-58). In summary, this study represents the first comparative analysis of the lymphatic exosomal proteome and highlights distinct exosomal proteins that may support premetastatic niche formation in the SLN.

cancer biology↗

bioRxiv2024

Structure-Based Design of Small-Molecule Inhibitors of Human Interleukin-6

Human Interleukin-6 (hIL-6) is a pro inflammatory cytokine that binds to its receptor, IL-6R followed by binding to gp130 and subsequent dimerization to form a hexamer signaling complex. A critical inflammation mediator, hIL-6 is associated with a diverse range of diseases and monoclonal antibodies are in clinical use that either target IL-6R or hIL-6 to inhibit signaling. Here, we perform high throughput structure-based computational screening using ensemble docking for small molecule antagonists for which the target conformations were taken from 600 ns long molecular dynamics simulations of the apo protein. Prior knowledge of the contact sites from binary complex studies and experimental work was incorporated into the docking studies. The top 20 scored ligands from the in silico studies after post analysis were subjected to in vitro functional assays. Among these compounds, the ligand with second-highest calculated binding affinity showed experimentally [~]84% inhibitory effect on IL6-induced STAT3 reporter activity at 10-5 molar concentration. This finding may pave the way for designing small molecule inhibitors of hIL-6 of therapeutic significance.

bioinformatics↗

bioRxiv2024

White adipose tissue remodeling in Little Brown Myotis (Myotis lucifugus) with white-nose syndrome

White-nose syndrome (WNS) is a fungal wildlife disease of bats that has caused precipitous declines in certain Nearctic bat species. A key driver of mortality is premature exhaustion of fat reserves, primarily white adipose tissue (WAT), that bats rely on to meet their metabolic needs during winter. However, the pathophysiological and metabolic effects of WNS have remained ill-defined. To elucidate metabolic mechanisms associated with WNS mortality, we infected a WNS susceptible species, the Little Brown Myotis (Myotis lucifugus), with Pseudogymnoascus destructans (Pd) and collected WAT biopsies for histology and targeted lipidomics. These results were compared to the WNS-resistant Big Brown Bat (Eptesicus fuscus). A similar distribution in broad lipid class was observed in both species, with [~]60% of total WAT consisting of triacylglycerides (TAGs). We found several baseline differences in WAT chemical composition between species. M. lucifugus WAT had significantly higher levels of measured TAGs ([~]30%). Higher lipid levels in E. fuscus WAT were primarily sphingomyelins and glycerophosphoethanolamines (PEs), along with glycerophospholipids (GPs) dominated by unsaturated or monounsaturated moieties and n-6 (18:2, 20:2, 20:3, 20:4) fatty acids. These differences between M. lucifugus and E. fuscus may indicate dietary differences that lead to differential "fuel" reserves that are available during torpor. Following Pd-infection, we found that perturbation to WAT reserves occurs in M. lucifugus, but not in the resistant E. fuscus. A total of 36 GPs (primarily PEs) were higher in Pd-infected M. lucifugus, indicating perturbation to the WAT structural component. In addition to changes in lipid chemistry, smaller adipocyte sizes and increased extracellular matrix deposition was observed in Pd-infected M. lucifugus. This is the first study to describe WAT lipidomic composition of bats with different susceptibilities to WNS and highlights that recovery from WNS may require repair from adipose remodeling in addition to replenishing depot fat during spring emergence.

biochemistry↗