Differential label free quantiation of Sec24D interactome, Boyce Lab
Ontology highlight
ABSTRACT: Relative quantitative analysis of Sec24D interactions using nanoscale liquid chromotography coupled with MS1 based LFQ on an Orbitrap Astral.
Project description:In this study, we performed a comparative proteomics analysis of the iridocorneal region in DBA/2J and Gpnmb+ mice to gain deeper insight into the molecular mechanisms underlying IOP elevation following iris pigment dispersion/
Project description:Rapid and comprehensive analysis of complex proteomes across large sample sets is essential to fulfill the potential of systems biology. We present a novel mass spectrometry (MS) method that integrates narrow-window data-independent acquisition (nDIA) with short-gradient micro-flow chromatography, enabling profiling of >240 samples per day. The optimized MS method identifies 6,201 and 7,466 human proteins with 1- and 2-min gradients, respectively.
Project description:This study investigated sex-dependent proteomic alterations in peripheral blood mononuclear cells (PBMCs) from Alzheimer’s disease (AD) patients. Quantitative DIA-based proteomics revealed both shared and sex-specific pathways, including complement activation, coagulation, and metabolic processes. These findings highlight systemic immune and metabolic remodeling in AD that differ between males and females.
Project description:The adaptive responses to oxygen depletion orchestrated by hypoxia-inducible factors (HIFs) produce profound effects on multiple pathways. A canonical metabolic response is enhanced fermentation, but this can generate an unfavorably acidic environment under poor capillary perfusion. It is unclear how cells balance the metabolic benefits of hypoxic responses against knock-on consequences on acid-base homeostasis. We studied the interplay between hypoxia and acidosis on HIF signaling in colorectal cancer cell lines that can survive acidic conditions. Hypoxia stabilized HIF-1α, but this effect was transient in combination with acidosis. By 48 h, HIF-1α induction decreased in proportion to acidification. Proteomic analyses identified responses that followed HIF-1α, including canonical HIF targets (CA9, PDK1), but these did not reflect a proteome-wide downregulation. Responses to acidosis and hypoxia were enriched in lysosomal proteins, but not proteasomal components, implicating the former degradation pathway in transient HIF-1α activation under acidosis. Moreover, HIF-1α decay was not due to decreased HIF1A transcription but was blocked by lysosomal inactivation (bafilomycin-A1). Acidotic hypoxia increased the abundance of lysosomes and activated autophagy by disabling the inhibitory influence of mammalian target of rapamycin complex 1, resulting in HIF-1α degradation. By blocking HIF-driven fermentative upregulation, this mechanism protects the cellular environment from deleterious acid-overloading, an outcome that outweighs the biosynthetic benefits of raised glycolytic flux under suppressed respiration. Thus, alkaline conditions are permissive for at least some aspects of HIF-1α signaling, but may not reflect tumor microenvironment chemistry. Consequently, acidic hypoxic tumor regions may not necessarily overlay with sites of HIF induction
Project description:Acute pancreatitis (AP), a severe inflammatory disorder of the pancreas, lacks effective pharmacological treatment. The disease is primarily driven by necrosis of pancreatic acinar cells (PACs), which intensifies inflammation and organ injury. This study explores the potential of BCL2 inhibitors, specifically Navitoclax and Venetoclax, to shift cell death pathways from necrosis to apoptosis and thereby mitigate disease severity. Ex vivo models using cerulein or ethanol/palmitoleic acid (EtOH/POA) showed that both inhibitors significantly reduced necrosis, increased apoptosis, and improved PAC viability and ATP levels. In mouse models of AP, both drugs promoted apoptosis and decreased tissue necrosis, with Venetoclax showing superior efficacy and safety. Venetoclax markedly reduced disease severity in two AP models without affecting healthy tissue or inducing thrombocytopenia. In contrast, Navitoclax caused apoptosis even in healthy tissue and triggered thrombocytopenia. Importantly, both drugs attenuated pathological Ca2+ responses in PACs and upregulated the expression of Ca²⁺-binding proteins S100A8/A9 and the chemokine CCL8. The latter may mediate enhanced apoptotic clearance and limit secondary necrosis, supporting the therapeutic shift from necrosis to apoptosis. Proteomic analyses revealed extensive drug-induced remodeling. In the short-term AP model, both inhibitors altered expression of proteins linked to intracellular compartments and extracellular signaling, reflecting cellular adaptation. In CP, Navitoclax strongly upregulated ECM and lysosomal proteins while downregulating ribosomal components – indicating intensified fibrosis and suppressed protein synthesis. Venetoclax had milder effects and did not worsen fibrosis. Despite Navitoclax’s efficacy toward activated pancreatic stellate cells in vitro, it exacerbated fibrosis and tissue atrophy in CP in vivo, likely due to ongoing parenchymal damage and stellate cell activation. Together, these findings demonstrate that selective BCL2 inhibition with Venetoclax promotes apoptosis, reduces necrosis, and improves outcomes in AP, supporting its repurposing as a therapeutic strategy. However, BCL2 inhibition does not benefit CP and may aggravate fibrosis, underscoring the need for context-specific approaches.
Project description:DNA interstrand crosslinks (ICLs) are highly cytotoxic lesions that block essential cellular processes like replication and transcription. Endogenous ICLs can be induced by reactive aldehydes produced during normal cellular metabolism. Defective repair of these aldehyde-induced ICLs is associated with Fanconi anemia (FA), a cancer predisposition syndrome. We previously showed that acetaldehyde-induced ICLs are repaired by the FA-pathway and a novel excision-independent pathway. Here, we demonstrate that ICLs induced by acrolein, another cellular aldehyde, are also repaired by both pathways, establishing the generality of aldehyde ICL repair. Focusing on the FA pathway, we identify DNA polymerase kappa (Polκ) as the primary translesion synthesis (TLS) polymerase responsible for the insertion step during lesion bypass of unhooked aldehyde ICLs. This function requires Polκ's catalytic activity and PCNA interaction domains but is independent of Rev1 interaction. In contrast, Polκ has a minor non-catalytic role in the extension step of cisplatin ICL repair that is dependent on Rev1 interaction. Our work reveals a key role for Polκ in aldehyde ICL repair and provides mechanistic insights into how different ICL structures determine the choice of TLS polymerases during repair.
Project description:Mass spectrometry (MS)-based proteomics aims to characterize comprehensive proteomes in a fast and reproducible manner. Here, we present an ultra-fast scanning data-independent acquisition (DIA) strategy consisting on 2-Th precursor isolation windows, dissolving the differences between data-dependent and independent methods. This is achieved by pairing a Quadrupole Orbitrap mass spectrometer with the asymmetric track lossless (Astral) analyzer that provides >200 Hz MS/MS scanning speed, high resolving power and sensitivity, as well as low ppm-mass accuracy. Narrow window DIA enables profiling of up to 100 full yeast proteomes per day, or ~10,000 human proteins in half-an-hour. Moreover, multi-shot acquisition of fractionated samples allows comprehensive coverage of human proteomes in ~3h, showing comparable depth to next-generation RNA sequencing and with 10x higher throughput compared to current state-of-the-art MS. High quantitative precision and accuracy is demonstrated with high peptide coverage in a 3-species proteome mixture, quantifying 14,000+ proteins in a single run in half-an-hour.