Project description:The RNA binding protein IGF2BP2/IMP2 alters the cargo of cancer cell-derived extracellular vesicles supporting tumor-associated macrophages
Project description:The N-methyl-D-aspartate (NMDA) receptor is a glutamate-activated cation channel critical to many processes in the brain. Genome-wide association studies (GWAS) suggest that glutamatergic neurotransmission and NMDA receptor-mediated synaptic plasticity is important for body weight homeostasis1. Here, we report the engineering and preclinical development of a first-in-class bimodal molecule that integrates NMDA receptor antagonism with glucagon-like peptide-1 (GLP-1) receptor agonism to effectively reverse obesity, hyperglycemia, and dyslipidemia in rodent models of metabolic disease. We demonstrate that GLP-1-directed delivery of the NMDA receptor antagonist MK-801 affects NMDA receptor-mediated synaptic plasticity in the hypothalamus. Importantly, peptide-targeting of MK-801 specifically to GLP-1 receptor-expressing brain regions circumvent adverse physiological and behavioral effects associated with MK-801 monotherapy. In sum, our approach demonstrates the feasibility of cell specific ionotropic receptor-modulation via peptide targeting and highlights the therapeutic potential of unimolecular mixed GLP-1 receptor agonism and NMDA receptor antagonism for obesity treatment.
Project description:LD3 knock out cells were generated in HEK293T and HMC3 cells. Proteomics was done to test if they have any significant changes in the abundance of proteins that metabolize sugar lipids like gangliosides.
Project description:Calpains are a class of non-lysosomal cysteine proteases that exert their regulatory functions via limited proteolysis of their substrates. Similar to the lysosomal and proteasomal systems, calpain dysregulation is implicated in the pathogenesis of neurodegenerative disease and cancer. Despite intensive efforts placed on the identification of mechanisms that regulate calpains, however, global regulators of calpains activity have remained elusive. Here we show that calpains are regulated by KCTD7, a cytosolic protein of previously uncharacterized function whose pathogenic mutations result in epilepsy, progressive ataxia, and severe neurocognitive deterioration. We show that KCTD7 works in complex with Cullin-3 and Rbx1 to execute atypical, non-degradative ubiquitination of calpains at specific sites (K398 of calpain 1, and K280 and K674 of calpain 2). Experiments based on single-lysine mutants of ubiquitin determined that KCTD7 mediates ubiquitination of calpain 1 via K6-, K27-, K29-, and K63-linked chains, whereas it uses K6- mediated ubiquitination to modify calpain 2. Loss of KCTD7-mediated ubiquitination of calpains led to calpain hyperactivation, aberrant cleavage of downstream targets, and caspase-3 activation. CRISPR/Cas9-mediated knockout of Kctd7 in mice phenotypically recapitulated human KCTD7 deficiency and resulted in calpain hyperactivation, behavioral impairments, and neurodegeneration. These phenotypes were largely prevented by pharmacological inhibition of calpains, thus demonstrating a major role of calpain dysregulation in KCTD7-associated disease. Finally, we determined that Cullin-3–KCTD7 mediates ubiquitination of all ubiquitous calpains. These results unveil a global mechanism and potential target to restrain calpain activity in human disease and shed light on the molecular pathogenesis of KCTD7-associated disease.
Project description:LKB1 is among the most frequently altered tumor suppressors in lung adenocarcinoma. Inactivation of Lkb1 accelerates the growth and progression of oncogenic KRAS-driven lung tumors in mouse models. However, the molecular mechanisms by which LKB1 constrains lung tumorigenesis and whether the aggressive cancer state that stems from Lkb1 deficiency can be reverted remains unknown. To identify the processes governed by LKB1 in vivo, we generated an allele which enables Lkb1 inactivation during tumor development and subsequent Lkb1 restoration in established tumors. Restoration of Lkb1 in oncogenic KRAS-driven lung tumors suppressed proliferation and promoted tumor stasis. Lkb1 restoration activated targets of C/EBP transcription factors and drove the transition of neoplastic cells from a progenitor-like state to a less proliferative alveolar type II cell-like state. We show that C/EBP transcription factors govern a subset of genes that are induced by LKB1 and depend upon NKX2-1. We also demonstrate that a defining factor of the alveolar type II lineage, C/EBPα, constrains oncogenic KRAS-driven lung tumor growth. Thus, we uncover a role for a critical tumor suppressor in the regulation of key lineage-specific transcription factors, thereby constraining lung tumor development through the enforcement of differentiation.
Project description:Despite the increasing prevalence of patients with Long Covid Syndrome (LCS), to date the pathophysiology of the disease is still unclear, and therefore diagnosis and therapy are a complex effort without any standardization. To address these issues, we performed a broad exploratory screening study applying state-of-the-art post-genomic profiling methods to blood plasma derived from three groups: 1) healthy individuals vaccinated against SARS-CoV-2 without exposure to the full virus, 2) asymptomatic fully recovered patients at least three months after SARS-CoV-2 infection, 3) symptomatic patients at least 3 months after a SARS-CoV-2 infection, here designated as Long Covid Syndrome (LCS) patients. Multiplex cytokine profiling indicated slightly elevated cytokine levels in recovered individuals in contrast to LCS patients, who displayed lowest levels of cytokines. Label-free proteome profiling corroborated an anti-inflammatory status in LCS characterized by low acute phase protein levels and a uniform down-regulation of macrophagederived secreted proteins, a pattern also characteristic for chronic fatigue syndrome (CFS). Along those lines, eicosanoid and docosanoid analysis revealed high levels of omega-3 fatty acids and a prevalence of anti-inflammatory oxylipins in LCS patients compared to the other study groups. Targeted metabolic profiling indicated low amino acid and triglyceride levels and deregulated acylcarnithines, characteristic for CFS and indicating mitochondrial stress in LCS patients. The anti-inflammatory osmolytes taurine and hypaphorine were significantly up-regulated in LCS patients. In summary, here we present evidence for a specific anti-inflammatory and highly characteristic metabolic signature in LCS which could serve for future diagnostic purposes and help to establish rational therapeutic interventions in these patients.
Project description:Human betacoronaviruses encode an Internal (I) protein via an alternative reading frame within the nucleocapsid (N) gene, namely ORF8b for Middle-East Respiratory Syndrome Coronavirus (MERS-CoV) and ORF9b for Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and SARS-CoV-2. Previous reports suggested that ORF8b and ORF9b are involved in evading innate immune responses, but their roles in mediating pathogenesis in infected animals has not been determined. In this study, we abrogated the expression of ORF8b in MERS-CoV (rMERS-Δ8b) and ORF9b in SARS-CoV-2 (rSARS2-Δ9b) and found that rMERS-Δ8b was more virulent while rSARS2-Δ9b was attenuated compared to their respective wild-type (WT) viruses in mice. Upon further analysis, we detected high levels of IFN-I expression and enhanced infiltration of immune cells to the lungs of rMERS-Δ8b-infected mice. In addition, mutations identified in previously circulating SARS-CoV-2 variant of concern (VOC) that were proposed to enhance ORF9b expression did not lead to significant changes in virulence. These data suggest the disparate and virus-specific functions of ORF8b and ORF9b which potentially explain the different changes in virulence.
Project description:We employed PeptiCHIP Immunopeptidomics to profile tumor associated antigens (TAA) actively targeted by tumor specific T cells by exploiting the trogocytosis effect, whereby antigen presenting cells (APCs) nibble portions of the cognate T cell containing the TCR. The antigen presenting cells were then processed by Immunoaffinity purification by peptiCHIP to identify the relevant HLA-I peptides by LCMS on the Bruker Tims TOF Pro instrument.
Project description:This study investigated the effect of Vagus Nerve Stimulation (VNS) on innate neuroinflammation and remyelination in lysolecithin (LPC) induced demyelination, a preclinical model for Multiple Sclerosis (MS). In a first experiment (demyelination experiment), LPC was injected in the corpus callosum of 33 Lewis rats, inducing a demyelinated lesion, and rats were treated with either continuously-cycled VNS (cVNS) or one-minute per day VNS (1minVNS) or sham VNS, from two days before the injection until three days post-injection (dpi), when they were killed for immunohistochemistry and proteomics analysis. This timepoint corresponded with a demyelinated lesion and peak inflammation. In a second experiment (remyelination experiment), 13 rats were analogously treated with either cVNS or sham from two days before LPC injection until 11 dpi, when they were killed for tissue prelevation for immunohistochemistry and proteomics. This timepoints corresponded with partial remyelination of the lesion. For proteomics analysis, 20 rats were randomly selected, namely five cVNS and five sham rats of the demyelination experiment, and five cVNS and five sham rats of the remyelination experiment.