Biology subjects

Pachane, B. C.

Publications and source records attributed to Pachane, B. C..

3 recordsLinked to original sources

bioRxiv2025

An ex vivo and in vitro investigation of extracellular vesicle interactions with B cells of Macaca nemestrina and humans

AbstractExtracellular vesicles may modify recipient cell behavior through multiple mechanisms, including interacting with the cell surface or internal membrane components and delivering luminal cargo to the cytoplasm. Here, we use a previously established ex vivo approach to investigate the cellular fate of EVs spiked into whole blood samples from nonhuman primate (NHP) and human donors and contrast these findings with results from in vitro assays. We report that EVs are internalized by NHP and human B cells while also associating to some degree with other PBMCs. EVs exhibit greater association with B cells in ex vivo whole blood compared to isolated B cells, suggesting that blood components may promote EV interactions or that cell isolation factors may inhibit this association. Cellular uptake of EVs involves clathrin-dependent endocytosis and may be aided by other pathways, including direct EV-cell membrane fusion. Overall, our data suggest that EV association, including uptake, by B cells occurs in at least two primate species. These findings highlight the potential to develop new strategies to either enhance or inhibit EV tropism toward B cells. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/637883v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@bd28e3org.highwire.dtl.DTLVardef@c76b28org.highwire.dtl.DTLVardef@4c2e44org.highwire.dtl.DTLVardef@1719771_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2024

Tumoral hypoxic extracellular vesicles create a protective microenvironment for triple-negative breast cancer

The highly metastatic triple-negative breast cancer (TNBC) relies on the tumor microenvironment (TME) to maintain phenotypic heterogeneity and progression. Extracellular vesicles from hypoxic TNBC (EVh) have been previously shown to facilitate tumoral invasion; however, their function in the tumor microenvironment remains unclear. We used a novel method to investigate the TME in vitro called multicellular circulating co-culture, to characterize how EVh interferes with tumoral and endothelial cells, fibroblasts, monocytes and macrophages. EVh promoted monocyte differentiation to M2-like macrophages and inhibited macrophage-derived phagocytosis in endothelial and tumoral cells. The protection of endothelial, tumoral and stromal cellular integrity by EVh increased pro-tumoral and pro-angiogenic signaling, collagen matrix synthesis and showed a potential differentiation to cancer-associated fibroblasts. Our findings highlight the critical role of EVh in protecting tumor cells, indicating its cooperation towards a protective TME, which was demonstrated by the multicellular circulating co-culture and conventional co-culture protocols. These findings lead to an adequate system with potential for investigating other tumor-related processes, including circulating tumor cells and metastasis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/621519v3_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@4ff8a0org.highwire.dtl.DTLVardef@4bf15corg.highwire.dtl.DTLVardef@1d2f105org.highwire.dtl.DTLVardef@1cd8346_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Exploring the adhesion properties of extracellular vesicles for functional assays

The "stickiness" of extracellular vesicles (EVs) can pose challenges for EV processing and storage, but adhesive properties may also be exploited to immobilize EVs directly on surfaces for various measurement techniques, including super-resolution microscopy. Direct adhesion to surfaces may allow examination of broader populations of EVs than molecular affinity approaches, which can also involve specialized, expensive affinity reagents. Here, we report on the interaction of EVs with borosilicate glass and quartz coverslips and on the effects of pre-coating coverslips with poly-L-lysine (PLL), a reagent commonly used to facilitate interactions between negatively charged surfaces of cells and amorphous surfaces. Additionally, we compared two mounting media conditions for super-resolution microscopy (SRM) imaging and used immobilized EVs for a B-cell interaction test. Our findings suggest that borosilicate glass coverslips immobilize EVs better than quartz glass coverslips. We also found that PLL is not strictly required for EV retention but contributes to the uniform distribution of EVs on borosilicate glass coverslips. Overall, these findings suggest that standard lab materials like borosilicate glass coverslips, with or without PLL, can be effectively used for the immobilization of EVs in specific imaging techniques.

cell biology↗