Publications by authors named "Gilles Lajoie"

The Pro/N-degron recognizing C-terminal to LisH (CTLH) complex is an E3 ligase of emerging interest in the developmental biology field and for targeted protein degradation (TPD) modalities. The human CTLH complex forms distinct supramolecular ring-shaped structures dependent on the multimerization of WDR26 or muskelin β-propeller proteins. Here, we find that, in HeLa cells, CTLH complex E3 ligase activity is dictated by an interplay between WDR26 and muskelin in tandem with muskelin autoregulation.

View Article and Find Full Text PDF

Background: The five-year prognosis for patients with late-stage high-grade serous carcinoma (HGSC) remains dismal, underscoring the critical need for identifying early-stage biomarkers. This study explores the potential of extracellular vesicles (EVs) circulating in blood, which are believed to harbor proteomic cargo reflective of the HGSC microenvironment, as a source for biomarker discovery.

Results: We conducted a comprehensive proteomic profiling of EVs isolated from blood plasma, ascites, and cell lines of patients, employing both data-dependent (DDA) and data-independent acquisition (DIA) methods to construct a spectral library tailored for targeted proteomics.

View Article and Find Full Text PDF
Article Synopsis
  • The CTLH complex, involved in recognizing specific protein substrates via GID4, has unclear functions and targets in humans.
  • Researchers introduced PFI-7, a chemical probe that inhibits GID4's ability to bind Pro/N-degrons, which helps identify proteins GID4 interacts with and regulates.
  • Their findings reveal GID4's role in regulating levels of nucleolar proteins and metabolic enzymes, suggesting both degradative and nondegradative actions, and highlighting PFI-7's potential for future research on protein degradation strategies.
View Article and Find Full Text PDF
Article Synopsis
  • Extracellular vesicles (EVs) are important carriers of biomolecules, facilitating communication between cells and potentially serving as disease biomarkers, but their analysis can be complicated by methodology.
  • The study outlines a comprehensive method for isolating and analyzing EVs from blood plasma using advanced techniques like surface-enhanced Raman spectroscopy (SERS) and mass spectrometry (MS), focusing on samples from healthy donors and women with early-stage ovarian cancer.
  • By applying machine learning to SERS data, the researchers developed a reliable workflow that could help distinguish between healthy and cancerous EVs, presenting a potential diagnostic tool for early-stage high-grade serous carcinoma.
View Article and Find Full Text PDF

Biological aging can be described as accumulative, prolonged metabolic stress and is the major risk factor for cognitive decline and Alzheimer's disease (AD). Recently, we identified and described a quinone reductase 2 (QR2) pathway in the brain, in which QR2 acts as a removable memory constraint and metabolic buffer within neurons. QR2 becomes overexpressed with age, and it is possibly a novel contributing factor to age-related metabolic stress and cognitive deficit.

View Article and Find Full Text PDF

The Ku70/80 heterodimer is a key player in non-homologous end-joining DNA repair but is involved in other cellular functions like telomere regulation and maintenance, in which Ku's role is not fully characterized. It was previously reported that knockout of Ku80 in a human cell line results in lethality, but the underlying cause of Ku essentiality in human cells has yet to be fully explored. Here, we established conditional Ku70 knockout cells using CRISPR/Cas9 editing to study the essentiality of Ku70 function.

View Article and Find Full Text PDF

Glomerular filtration rate (GFR) is the most widely used tool for the measurement of kidney function, but endogenous biomarkers such as cystatin C and creatinine have limitations. A previous metabolomic study revealed ,,-trimethyl-L-alanyl-L-proline betaine (TMAP) to be reflective of kidney function. In this study, we developed a quantitative LCMS assay for the measurement of TMAP and evaluated TMAP as a biomarker of GFR.

View Article and Find Full Text PDF

Glioblastoma (GBM) is the most common and aggressive malignant primary brain tumor in adults. The standard treatment achieves a median overall survival for GBM patients of only 15 months. Hence, novel therapies based on an increased understanding of the mechanistic underpinnings of GBM are desperately needed.

View Article and Find Full Text PDF
Article Synopsis
  • This study explored how human adipose-derived stromal cells (hASCs) grow on microcarriers made from decellularized adipose tissue (DAT) and decellularized cartilage tissue (DCT) in bioreactor cultures.
  • Results showed that hASCs grew denser on DCT microcarriers compared to DAT, and dynamic culture influenced gene and protein expression related to cell adhesion and ECM remodeling.
  • Although hASCs showed enhanced lipid accumulation with adipogenic differentiation on both microcarriers, only low levels of chondrogenic differentiation were observed, suggesting that future research should consider other cell types for chondrogenic studies.
View Article and Find Full Text PDF

Wnt and Hh are known signalling pathways involved in neural differentiation and recent work has shown the cell cycle regulator, Never in Mitosis Kinase 2 (Nek2) is able to regulate both pathways. Despite its known function in pathway regulation, few studies have explored Nek2 within embryonic development. The P19 embryonal carcinoma cell model was used to investigate Nek2 and neural differentiation through CRISPR knockout and overexpression studies.

View Article and Find Full Text PDF

The C-terminal to LisH (CTLH) complex is a newly discovered multi-subunit E3 ubiquitin ligase and its cellular functions are poorly characterized. Although some CTLH subunits have been found to localize in both the nucleus and cytoplasm of mammalian cells, differences between the compartment-specific complexes have not been explored. Here, we show that the CTLH complex forms different molecular mass complexes in nuclear and cytoplasmic fractions.

View Article and Find Full Text PDF

Casein Kinase 2 (CSNK2) is an extremely pleiotropic, ubiquitously expressed protein kinase involved in the regulation of numerous key biological processes. Mapping the CSNK2-dependent phosphoproteome is necessary for better characterization of its fundamental role in cellular signalling. While ATP-competitive inhibitors have enabled the identification of many putative kinase substrates, compounds targeting the highly conserved ATP-binding pocket often exhibit off-target effects limiting their utility for definitive kinase-substrate assignment.

View Article and Find Full Text PDF

The deposition of thin layers of polymer/ceramic on a lithium surface to produce a strong barrier against dendrites was demonstrated. Different forms (needle, sphere, rod) and types of ceramic (AlO, MgBO) were tested and polymer/ceramic interlayers of a few micrometers (4 μm minimum) between the lithium and the PEO-based solid polymer electrolyte (SPE) were deposited. Interlayers with high amounts of ceramic up to 85 wt% were successfully coated on the surface of lithium foil.

View Article and Find Full Text PDF
Article Synopsis
  • - The CTLH complex, a multi-subunit E3 ligase conserved across species, plays key roles in regulating essential pathways for homeostasis and development.
  • - Recent advancements have highlighted the complex's structural and functional aspects, enhancing our understanding of its mechanism.
  • - This review synthesizes existing literature on the CTLH complex and relates new findings about its subunits to the broader context of its biological significance.
View Article and Find Full Text PDF
Article Synopsis
  • Metabolism is essential for cell survival and function, playing a significant role in embryonic development, particularly in forming pluripotent epiblast stem cells and primitive endoderm cells from the inner cell mass.
  • Recent findings reveal that mouse extraembryonic endoderm (XEN) cells show high sensitivity to glycolytic inhibition and maintain elevated lactate levels due to increased LDHA activity and altered pyruvate processing.
  • Lactate supplementation enhances the differentiation of XEN cells in vitro, suggesting its potential to improve cell reprogramming efficiency for applications in regenerative medicine.
View Article and Find Full Text PDF
Article Synopsis
  • * The study explores using extracellular vesicles (EVs) derived from cancer cells as biomarkers for non-invasive early diagnosis.
  • * Researchers utilized gold nanohole arrays and surface-enhanced Raman spectroscopy (SERS) to analyze EVs from both established and primary ovarian cancer cell lines, achieving around 99% accuracy in distinguishing between them through machine learning.
View Article and Find Full Text PDF
Article Synopsis
  • * The study utilized mass spectrometry to explore the role of the CTLH complex in protein ubiquitination in HeLa cells, focusing on the effects of depleting a member, RanBPM.
  • * Important findings include the identification of glycolysis enzymes (PKM2 and LDHA) affected by RanBPM, showing reduced ubiquitination but increased activity, indicating that the CTLH complex plays a role in inhibiting glycolysis without leading to protein degradation.
View Article and Find Full Text PDF
Article Synopsis
  • Cellular therapies aimed at stimulating blood vessel growth in patients with critical limb ischemia (CLI) are being actively researched, focusing on the effectiveness of the transplanted cells based on their survival and signaling abilities.
  • This study explored the use of human decellularized adipose tissue (DAT) bioscaffolds to guide the differentiation of hematopoietic progenitor cells (HPC) into pro-angiogenic cell types, enhancing their therapeutic potential.
  • Results showed that HPC cultured on DAT scaffolds not only improved their differentiation but also led to better retention in ischemic tissue and enhanced limb recovery in mouse models, indicating that DAT scaffolds could effectively boost the success of cell therapies for CLI.
View Article and Find Full Text PDF

The tumor microenvironment (TME) is an important mediator of breast cancer progression. Cancer-associated fibroblasts constitute a major component of the TME and may originate from tissue-associated fibroblasts or infiltrating mesenchymal stromal cells (MSCs). The mechanisms by which cancer cells activate fibroblasts and recruit MSCs to the TME are largely unknown, but likely include deposition of a pro-tumorigenic secretome.

View Article and Find Full Text PDF

The secretome of mesenchymal stromal cells (MSCs) is enriched for biotherapeutic effectors contained within and independent of extracellular vesicles (EVs) that may support tissue regeneration as an injectable agent. We have demonstrated that the intrapancreatic injection of concentrated conditioned media (CM) produced by bone marrow MSC supports islet regeneration and restored glycemic control in hyperglycemic mice, ultimately providing a platform to elucidate components of the MSC secretome. Herein, we extend these findings using human pancreas-derived MSC (Panc-MSC) as "biofactories" to enrich for tissue regenerative stimuli housed within distinct compartments of the secretome.

View Article and Find Full Text PDF

Energy storage with high energy density and low cost has been the subject of a decades-long pursuit. Sodium-ion batteries are well expected because they utilize abundant resources. However, the lack of competent cathodes with both large capacities and long cycle lives prevents the commercialization of sodium-ion batteries.

View Article and Find Full Text PDF

Gamma delta T cells (γδTc) have tremendous anti-tumoral activity, thus γδTc immunotherapy is currently under development for various malignancies. We targeted breast cancer stem-like cells (BCSC), a rare cell population responsible for patient mortality. BCSC were mostly susceptible to γδTc immunotherapy, yet some escaped.

View Article and Find Full Text PDF

The comprehensiveness of data collected by "omics" modalities has demonstrated the ability to drastically transform our understanding of the molecular mechanisms of chronic, complex diseases such as musculoskeletal pathologies, how biomarkers are identified, and how therapeutic targets are developed. Standardization of protocols will enable comparisons between findings reported by multiple research groups and move the application of these technologies forward. Herein, we describe a protocol for parallel proteomic and metabolomic analysis of mouse intervertebral disc (IVD) tissues, building from the combined expertise of our collaborative team.

View Article and Find Full Text PDF

Fluorescent-activated cell sorting (FACS) remains a powerful tool to enrich blood-derived progenitor cells for the establishment of highly proliferative endothelial colony-forming cells (ECFC). Further investigation remains necessary to determine whether the retention of progenitor cell phenotypes after expansion can identify ECFC with enhanced proangiogenic and regenerative functions. This study employed FACS purification to segregate umbilical cord blood-derived ECFC using conserved provascular progenitor cell markers CD34 or aldehyde dehydrogenase (ALDH) activity.

View Article and Find Full Text PDF

Multipotent/mesenchymal stromal cells (MSCs) exist within a variety of postnatal tissues; however, global proteomic analyses comparing tissue-specific MSC are limited. Using human bone marrow (BM)-derived MSCs as a gold standard, we used label-free mass spectrometry and functional assays to characterize the proteome, secretome, and corresponding function of human pancreas-derived MSCs (Panc-MSCs) with a classical phenotype (CD90+/CD73+/CD105+/CD45-/CD31-). Both MSC subtypes expressed mesenchymal markers vimentin, α-SMA, and STRO-1; however, expression of nestin was increased in Panc-MSCs.

View Article and Find Full Text PDF