Biology subjects

De Ieso, M. L.

Publications and source records attributed to De Ieso, M. L..

4 recordsLinked to original sources

bioRxiv2025

Resident Tissue Macrophages Govern Intraocular Pressure Homeostasis

Intraocular pressure is tightly regulated by the conventional outflow tissues, preventing ocular hypertension that leads to neurodegeneration of the optic nerve, or glaucoma. Although macrophages reside throughout the conventional outflow tract, their role in regulating intraocular pressure remains unknown. Using macrophage lineage tracing approaches, we uncovered a dual macrophage ontogeny with distinct spatial organizations across the mouse lifespan. Long-lived, resident tissue macrophages concentrated in the trabecular meshwork and Schlemms canal, whereas short-lived monocyte-derived macrophages, instead, were abundant around distal vessels. Specific depletion of resident tissue macrophages triggered elevated intraocular pressure and outflow resistance, linked to aberrant extracellular matrix turnover in the resistance-generating tissues of the trabecular meshwork. This dysregulated physiology and tissue remodeling were not observed when we depleted monocyte-derived macrophages. Results show ontogeny and tissue-specific macrophage function within the outflow tract, uncovering the integral homeostatic role of resident tissue macrophages in resistance-generating tissues whose dysfunction is responsible for glaucoma.

immunology↗

bioRxiv2023

Targeting YAP mechanosignaling to ameliorate stiffness-induced Schlemm's canal cell pathobiology

Pathologic alterations in the biomechanical properties of the Schlemms canal (SC) inner wall endothelium and its immediate vicinity are strongly associated with ocular hypertension in glaucoma due to decreased outflow facility. Specifically, the underlying trabecular meshwork is substantially stiffer in glaucomatous eyes compared to that from normal eyes. This raises the possibility of a critical involvement of mechanotransduction processes in driving SC cell dysfunction. Yes-associated protein (YAP) has emerged as a key contributor to glaucoma pathogenesis. However, the molecular underpinnings of SC cell YAP mechanosignaling in response to glaucomatous extracellular matrix (ECM) stiffening are not well understood. Using a novel biopolymer hydrogel that facilitates dynamic and reversible stiffness tuning, we investigated how ECM stiffening modulates YAP activity in primary human SC cells, and whether disruption of YAP mechanosignaling attenuates SC cell pathobiology and increases ex vivo outflow facility. We demonstrated that ECM stiffening drives pathologic YAP activation and cytoskeletal reorganization in SC cells, which was fully reversible by matrix softening in a distinct time-dependent manner. Furthermore, we showed that pharmacologic or genetic disruption of YAP mechanosignaling abrogates stiffness-induced SC cell dysfunction involving altered cytoskeletal and ECM remodeling. Lastly, we found that perfusion of the clinically-used, small molecule YAP inhibitor verteporfin (without light activation) increases ex vivo outflow facility in normal mouse eyes. Collectively, our data provide new evidence for a pathologic role of aberrant YAP mechanosignaling in SC cell dysfunction and suggest that YAP inhibition has therapeutic value for treating ocular hypertension in glaucoma.

cell biology↗

bioRxiv2020

Mechanotransduction and dynamic outflow regulation in trabecular meshwork requires Piezo1 channels

Mechanosensitivity of the trabecular meshwork (TM) is a key determinant of intraocular pressure (IOP) yet our understanding of the molecular mechanisms that subserve it remains in its infancy. Here, we show that mechanosensitive Piezo1 channels modulate the TM pressure response via calcium signaling and dynamics of the conventional outflow pathway. Pressure steps evoked fast, inactivating cation currents and calcium signals that were inhibited by Ruthenium Red, GsMTx4 and Piezo1 shRNA. Piezo1 expression was confirmed by transcript and protein analysis, and by visualizing Yoda1-mediated currents and [Ca2+]i elevations in primary human TM cells. Piezo1 activation was obligatory for transduction of physiological shear stress and was coupled to reorganization of F-actin cytoskeleton and focal adhesions. The importance of Piezo1 channels as pressure sensors was shown by the GsMTx4 -dependence of the pressure-evoked current and conventional outflow function. We also demonstrate that Piezo1 collaborates with the stretch-activated TRPV4 channel, which mediated slow, delayed currents to pressure steps. Collectively, these results suggest that TM mechanosensitivity utilizes kinetically, regulatory and functionally distinct pressure transducers to inform the cells about force-sensing contexts. Piezo1-dependent control of shear flow sensing, calcium homeostasis, cytoskeletal dynamics and pressure-dependent outflow suggests a novel potential therapeutic target for treating glaucoma. Significance StatementTrabecular meshwork (TM) is a highly mechanosensitive tissue in the eye that regulates intraocular pressure through the control of aqueous humor drainage. Its dysfunction underlies the progression of glaucoma but neither the mechanisms through which TM cells sense pressure nor their role in aqueous humor outflow are understood at the molecular level. We identified the Piezo1 channel as a key TM transducer of tensile stretch, shear flow and pressure. Its activation resulted in intracellular signals that altered organization of the cytoskeleton and cell-extracellular matrix contacts, and modulated the trabecular component of aqueous outflow whereas another channel, TRPV4, mediated a delayed mechanoresponse. These findings provide a new mechanistic framework for trabecular mechanotransduction and its role in the regulation of fast fluctuations in ocular pressure, as well as chronic remodeling of TM architecture that epitomizes glaucoma.

physiology↗

bioRxiv2018

Effect of Compound Kushen Injection, a natural compound mixture, and its identified chemical components on migration and invasion of colon, brain and breast cancer cell lines

Cancer metastasis is a major cause of death. Traditional Chinese medicines (TCM) are promising sources of new anti-metastatic agents. Compound Kushen Injection (CKI), extracted from medicinal plants, Kushen (Sophora flavescens) and Baituling (Heterosmilax chinensis), contains a mixture of alkaloids and flavonoids known to disrupt cell cycle and induce apoptosis in breast cancer (MCF7). However, effects on cancer cell migration and invasion have remained unknown. CKI, fractionated mixtures, and single identified components were tested in migration assays with colon (HT-29, SW-480, DLD-1), brain (U-87 MG, U-251 MG), and breast (MDA-MB-231) cancer cell lines. Human embryonic kidney (HEK-293) and human foreskin fibroblast (HFF) served as non-cancerous controls. Wound closure, transwell invasion, and live cell imaging assays showed that CKI reduced motility in all eight cell lines. The greatest inhibition of migration occurred in HT-29 and MDA-MB-231, and the least in HEK-293. Fractionation and reconstitution of CKI showed that combinations of compounds were required for activity. Live cell imaging confirmed CKI strongly reduced migration of HT-29 and MDA-MB-231 cells, moderately slowed brain cancer cells, and had no effect on HEK-293. CKI uniformly blocked invasiveness through extracellular matrix. Apoptosis was increased by CKI in MDA-MB-231 cells but not in non-cancerous cells. Cell viability in CKI was unaffected in all cell lines. Transcriptomic analyses of MDA-MB-231 with and without CKI indicated down-regulated expression of actin cytoskeletal and focal adhesion genes, consistent with the observed impairment of cell migration. The pharmacological complexity of CKI is important for its effective block of cancer cell migration and invasion.

cancer biology↗