Pancreatic Cancer Progression Involves Increased Lysyl Oxidase-Mediated Collagen Cross-Links as Part of the Desmoplastic Reaction.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and lethal disease characterized by extensive extracellular matrix (ECM) remodeling and fibrosis. In general, the formation of a desmoplastic stroma is associated with dynamic ECM remodeling and resistance to most standard-of-care treatments, such as conventional chemotherapy. Here, we report on alterations to core ECM and ECM remodeling enzymes, which include significant changes in levels of lysyl hydroxylase and oxidase enzymes that modulate collagen cross-linking reactions.

Proteomic characterization of type I collagen N-terminal crosslinked peptides.

Collagen cross-links mediated by the lysyl oxidase and lysyl hydroxylase families of enzymes significantly contribute to the biomechanical strength and rigidity of tissues, influencing cell signaling and the downstream cell phenotype. In the clinic, the proteolytically liberated N-terminal cross-linked peptide of collagen I (NTX) is used as a biomarker of bone and connective tissue turnover, which is altered in several disease processes. Despite the clinical utility of these collagen breakdown products, the majority of the cross-linked peptide species have not been identified in proteomic datasets.

Proteomics of arterial thrombi in acute limb ischemia.

Acute limb ischemia (ALI) is characterized by a sudden decrease in limb perfusion due to arterial occlusion. Without urgent revascularization, patients are at risk of ischemic damage and amputation. This study uses novel proteomic techniques to investigate the molecular architecture of ALI thrombi, identifying key proteins that may influence coagulation dynamics and fibrinolysis resistance.

Integrated cross-linking by TG2 and FXIII generates hepatoprotective fibrin(ogen) deposits in injured liver.

The transglutaminase coagulation factor XIII (FXIII) is critical for the stability and function of intravascular fibrin clots. Prorepair extravascular fibrin(ogen) deposits are potentially subject to cross-linking by FXIII and other transglutaminases not typically resident in plasma. However, the impact of these alternative modifiers on fibrin(ogen) structure and function is not known.

A bovine model of hypoxia-induced pulmonary hypertension reveals a gradient of immune and matrisome response with a complement signature found in circulation.

Pulmonary hypertension (PH) is a progressive vascular disease characterized by vascular remodeling, stiffening, and luminal obstruction, driven by dysregulated cell proliferation, inflammation, and extracellular matrix (ECM) alterations. Despite the recognized contribution of ECM dysregulation to PH pathogenesis, the precise molecular alterations in the matrisome remain poorly understood. In this study, we employed a matrisome-focused proteomics approach to map the protein composition in a young bovine calf model of acute hypoxia-induced PH.

Assessing Heterogeneity in the N-Telopeptides of Type I Collagen by Mass Spectrometry.

Collagen cross-links created by the lysyl oxidase and lysyl hydroxylase families of enzymes are a significant contributing factor to the biomechanical strength and rigidity of tissues, which in turn influence cell signaling and ultimately cell phenotype. In the clinic, the proteolytically liberated N-terminal cross-linked peptide of collagen I (NTX) is used as a biomarker of bone and connective tissue turnover, which is altered in several disease processes. Despite the clinical utility of these collagen breakdown products, the majority of the cross-linked peptide species have not been identified in proteomic datasets.

Altered fibrinogen γ-chain cross-linking in mutant fibrinogen-γ mice drives acute liver injury.

Background: Hepatic deposition of cross-linked fibrin(ogen) occurs alongside platelet accumulation as a hallmark of acetaminophen (APAP)-induced liver injury.

Objectives: We sought to define the precise role of the fibrinogen γ-chain C-terminal integrin αβ binding domain in APAP-induced liver injury.

Methods: Mice expressing mutant fibrinogen incapable of engaging integrin αβ due to a C-terminal fibrinogen γ-chain truncation (mutant fibrinogen-γ [Fibγ] mice) and wild-type mice were challenged with APAP (300 mg/kg, intraperitoneally).

Myoscaffolds reveal laminin scarring is detrimental for stem cell function while sarcospan induces compensatory fibrosis.

We developed an on-slide decellularization approach to generate acellular extracellular matrix (ECM) myoscaffolds that can be repopulated with various cell types to interrogate cell-ECM interactions. Using this platform, we investigated whether fibrotic ECM scarring affected human skeletal muscle progenitor cell (SMPC) functions that are essential for myoregeneration. SMPCs exhibited robust adhesion, motility, and differentiation on healthy muscle-derived myoscaffolds.

Silver Nanoparticle Surface Chemistry Determines Interactions with Human Serum Albumin and Cytotoxic Responses in Human Liver Cells.

Engineered nanomaterials (ENMs) are synthesized with a diversity of surface chemistries that mediate biochemical interactions and physiological response to the particles. In this work, silver engineered nanomaterials (AgENMs) are used to evaluate the role of surface charge in protein interactions and cellular cytotoxicity. The most abundant protein in blood, human serum albumin (HSA), was interacted with 40 nm AgENMs with a range of surface-charged coatings: positively charged branched polyethyleneimine (bPEI), negatively charged citrate (CIT), and circumneutral poly(ethylene glycol) (PEG).

Multi-omics analysis of sarcospan overexpression in mdx skeletal muscle reveals compensatory remodeling of cytoskeleton-matrix interactions that promote mechanotransduction pathways.

Background: The dystrophin-glycoprotein complex (DGC) is a critical adhesion complex of the muscle cell membrane, providing a mechanical link between the extracellular matrix (ECM) and the cortical cytoskeleton that stabilizes the sarcolemma during repeated muscle contractions. One integral component of the DGC is the transmembrane protein, sarcospan (SSPN). Overexpression of SSPN in the skeletal muscle of mdx mice (murine model of DMD) restores muscle fiber attachment to the ECM in part through an associated increase in utrophin and integrin adhesion complexes at the cell membrane, protecting the muscle from contraction-induced injury.

Taf2 mediates DNA binding of Taf14.

The assembly and function of the yeast general transcription factor TFIID complex requires specific contacts between its Taf14 and Taf2 subunits, however, the mechanism underlying these contacts remains unclear. Here, we determined the molecular and structural basis by which the YEATS and ET domains of Taf14 bind to the C-terminal tail of Taf2 and identified a unique DNA-binding activity of the linker region connecting the two domains. We show that in the absence of ligands the linker region of Taf14 is occluded by the surrounding domains, and therefore the DNA binding function of Taf14 is autoinhibited.

Evaluation and Refinement of Sample Preparation Methods for Extracellular Matrix Proteome Coverage.

The extracellular matrix is a key component of tissues, yet it is underrepresented in proteomic datasets. Identification and evaluation of proteins in the extracellular matrix (ECM) has proved challenging due to the insolubility of many ECM proteins in traditional protein extraction buffers. Here we separate the decellularization and ECM extraction steps of several prominent methods for evaluation under real-world conditions.

The Disordered Spindly C-terminus Interacts with RZZ Subunits ROD-1 and ZWL-1 in the Kinetochore through the Same Sites in C. Elegans.

Spindly is a dynein adaptor involved in chromosomal segregation during cell division. While Spindly's N-terminal domain binds to the microtubule motor dynein and its activator dynactin, the C-terminal domain (Spindly-C) binds its cargo, the ROD/ZW10/ZWILCH (RZZ) complex in the outermost layer of the kinetochore. In humans, Spindly-C binds to ROD, while in C.

Mass spectrometry-based molecular mapping of native FXIIIa cross-links in insoluble fibrin clots.

The roles of factor XIIIa-specific cross-links in thrombus formation, regression, or probability for embolization are largely unknown. A molecular understanding of fibrin architecture at the level of these cross-links could inform the development of therapeutic strategies to prevent the sequelae of thromboembolism. Here, we present an MS-based method to map native factor XIIIa cross-links in the insoluble matrix component of whole-blood or plasma-fibrin clots and in thrombi.