Biology subjects

Surma, M.

Publications and source records attributed to Surma, M..

4 recordsLinked to original sources

bioRxiv2025

Loss of Cathepsin K impairs collagen biogenesis and enhances actin polymerization in trabecular meshwork

Trabecular meshwork (TM) dysfunction and extracellular matrix (ECM) dysregulation contribute to increased intraocular pressure (IOP) in primary open-angle glaucoma (POAG). Earlier, we provide a proof-of-concept study identifying the regulation and the role of Cathepsin K (CTSK), a potent collagenase, in ECM homeostasis, actin bundling, and IOP regulation. Better understanding of the loss of CTSK function in TM remains unclear. Using siRNA-mediated knockdown of CTSK (siCTSK) in human TM cells, this study investigated the role of CTSK in actin and ECM homeostasis using an unbiased proteomics approach. Loss of CTSK significantly disrupted collagen biogenesis and ECM homeostasis. CTSK depletion also increased intracellular calcium levels, with proteomics data suggesting possible involvement of calcium-regulatory proteins. Additionally, PRKD1 activation enhanced actin polymerization through the LIMK1/SSH1/cofilin pathway, promoting focal adhesion maturation. Despite increased apoptotic markers (CASP3, CASP7, TRADD, PPM1F), caspase 3/7 activation was not induced, suggesting apoptosis-independent cellular remodeling. Notably, RhoQ and myosin motor proteins were significantly downregulated, indicating altered mechanotransduction in TM cells. These findings highlight the role of CTSK in maintaining ECM homeostasis, calcium signaling, and cytoskeletal regulation in TM. Its depletion induces actin polymerization, which may influence aqueous humor outflow. Targeting CTSK-related pathways may provide novel therapeutic strategies for regulating IOP and preventing glaucoma progression.

cell biology↗

bioRxiv2023

Cholesteryl hemiazelate Identified in Cardiovascular Disease Patients Causes in vitro and in vivo Inflammation

Oxidation of polyunsaturated fatty acids (PUFA) in low-density lipoproteins (LDL) trapped in the arterial intima plays a critical role in atherosclerosis. Though there have been many studies on the atherogenicity of oxidized derivatives of unsaturated fatty acid esters of cholesterol, the effects of the oxidation end-products of these esters has been ignored in the literature. Through lipidomics analyses of the plasma of cardiovascular disease patients and human endarterectomy specimens we identified and quantified cholesteryl hemiesters (ChE), end-products of oxidation of polyunsaturated-fatty acid esters of cholesterol. Cholesteryl hemiazelate (ChA) was the most prevalent ChE identified. Importantly human monocytes, monocyte-derived macrophages (MDM) and neutrophils exhibit inflammatory features when exposed to sub-toxic concentrations of ChA in vitro. ChA increases the secretion of proinflammatory cytokines such as IL-1{beta} and IL-6 and modulates the surface markers profile of monocytes and MDM. In vivo, when zebrafish larvae were fed with a ChA-enriched diet they exhibited neutrophil and macrophage accumulation in the vasculature in a caspase 1- and cathepsin B-dependent manner. ChA also triggered lipid accumulation at the bifurcation sites of the vasculature of the zebrafish larvae and negatively impacted their life expectancy. We conclude that ChA has pro-atherogenic properties and can be considered part of a damage-associated molecular pattern (DAMP) in the development of atherosclerosis.

pathology↗

bioRxiv2021

Selection-free non-viral method revealed highly efficient CRISPR-Cas9 genome editing of human pluripotent stem cells guided by cellular autophagy

Cationic liposome-mediated delivery of drugs, DNA, or RNA plays a pivotal role in small molecule therapy, gene editing, and immunization. However, our current knowledge regarding the cellular structures that facilitate this process remains limited. Here, we used human pluripotent stem cells (hPSCs), which form compact colonies consisting of dynamically active cells at the periphery and epithelial-like cells at the core. We discovered that cells at the colony edges selectively got transfected by cationic liposomes through Arp2/3 dependent dynamic lamellipodia, which is augmented by myosin II inhibition. Conversely, cells at the core establish tight junctions at their apical surfaces, impeding liposomal access to the basal lamellipodia and thereby inhibiting transfection. In contrast, liposomes incorporating mannosylated lipids are internalized throughout the entire colony via receptor-mediated endocytosis. These findings contribute a novel mechanistic insight into enhancing therapeutic delivery via liposomes, particularly in cell types characterized by dynamic lamellipodia, such as immune cells, or those comprising the epithelial layer. Significance StatementDrug or gene delivery to human cells is essential for effective treatment. Cationic liposomes provide a safe delivery vehicle compared to viruses. However, the cellular structures required for internalizing liposomes are not yet fully understood. Using human stem cells which grow in compact colonies with more dynamic cells at the periphery and epithelial like cells at the center, here we discovered that Arp2/3 dependent dynamic lamellipodia promotes cationic liposome delivery in dynamic cells while receptor mediated endocytosis is required for epithelial cells. This is significant as it provides mechanisms for enhancing liposome delivery to both migratory and epithelial cells in our body. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/444342v2_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@800db1org.highwire.dtl.DTLVardef@1031a31org.highwire.dtl.DTLVardef@aca227org.highwire.dtl.DTLVardef@1c9df00_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO Mechanisms for liposome transfection to the lamellipodial or epithelial cells. Data shown here suggest cationic liposomes fuse with the negatively charged dynamic lamellipodia membrane in an Arp2/3 dependent manner and the process is enhanced by Myosin II inhibition, such as with the stem cell colony edge cells. However, cells more epithelial in nature such as those inside the stem cell colony center do not possess dynamic lamellipodia at the apical surface, rather they form tight junctions which inhibit cationic liposome transfection. Epithelial cells rely on receptor mediated endocytosis in both Myosin II dependent and independent manners to internalize liposomes with lipids that contain ligands for cell surface receptors such as mannose. C_FIG

cell biology↗

bioRxiv2019

Mapping of Quantitative Trait Loci for Traits linked to Fusarium Head Blight Symptoms Evaluation in Barley RILs

Fusarium head blight (FHB) is a devastating disease in small grain cereals worldwide. The disease results in the reduction of grain yield and affects its quality. In addition, mycotoxins accumulated in grain are harmful to both humans and animals. It has been reported that response to pathogen infection may be associated with the morphological and developmental characteristics of the host plant, e.g. the earliness and plant height. Despite the many studies the effective markers for the selection of barley genotypes with increased resistance to FHB have not thus far been developed. Therefore, exploring the genetic relationship between agronomic traits (e.g. heading date or stem height) and disease resistance is of importance to the understanding of plant resistance via \"diesease escape\" or dwarf stature. The studied plant material consisted of 100 recombinant inbred lines (RIL) of spring barley. Plants were examined in field conditions (three locations) in a completely randomized design with three replications. Barley genotypes were artificially infected with spores of Fusarium before heading. Apart from the main phenotypic traits (plant height, spike characteristic, grain yield) the infected kernels were visually scored and the content of deoxynivalenol (DON) mycotoxin was investigated. A set of 70 Quantitative Trait Loci (QTLs) were detected through phenotyping of the mapping population in field condition and genotyping using a barley Ilumina iSelect platform with 9K markers. Six loci were detected for FHB index on chromosomes 2H, 3H, 5H and 7H. The region on the short arm of the 2H chromosome was detected in the current study, in which many QTLs associated with FHB- and yield-related characters were found. This study confirms that agromorphological traits are tightly related to the FHB and should be taken into consideration when breeding barley plants for FHB resistance.

plant biology↗