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:This part of the data submission of PXD046505. 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: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:A central hallmark of brain aging is the alteration of neuronal functions in the hippocampus, leading to a progressive decline in learning and memory. Multiple reports have shown the importance of blood-borne factors in inter-tissue communication for the maintenance of cognitive fitness and proper regulation of neuronal homeostasis throughout life. Among these blood-borne factors, we identified Osteocalcin (OCN), a bone-derived hormone. OCN induces autophagy machinery in hippocampal neurons which is essential for activity-dependent synaptic plasticity. However, the way in which blood-borne factors like OCN communicate with neurons, including their regulatory mechanisms, remains largely elusive. Here, we show the importance of a core primary cilium (PC)-proteins/autophagy machinery axis in hippocampal neurons that mediate the effects of the pro-youthful blood factor OCN on neuronal homeostasis and cognitive fitness. We found that OCN’s receptor, GPR158, is present at the PC of hippocampal neurons and mediates the regulation of autophagy machinery by OCN. During aging, PC-core proteins are reduced in hippocampal neurons and associated with neuronal PC morphological abnormalities. Restoring their levels is sufficient to improve neuronal autophagy and cognitive impairments in aged mice. Mechanistically, we found that OCN promotes neuronal autophagy in the hippocampus by the induction of PC-dependent cAMP response element-binding protein (CREB) signaling pathway. Altogether, this study proposes a novel paradigm for blood factor-neuron communication dependent on a neuronal PC/autophagy axis by identifying a novel regulatory pathway fostering cognitive fitness and providing the foundation for autophagy-based therapeutic strategies to treat age-related cognitive dysfunction.
Project description:Aerobic glycolysis is a hallmark of virus-infected cells, leading to substantial accumulation and secretion of lactate. However, the regulatory roles of lactate during viral infections are still poorly understood. Here, we report that human cytomegalovirus (HCMV) infection leverages lactate to induce widespread protein lactylation and promote viral spread. Lactyllysine decorates intrinsically disordered regions (IDRs) of proteins, regulating viral protein condensates and immune signaling transduction. Dynamic lactylation of immune response pathways, a feature shared during infection with herpes simplex virus 1 (HSV-1), suppresses immunity through regulation of RBM14 and IFI16. K90 lactylation of the viral DNA sensor IFI16 blocks recruitment of the DNA-damage response master kinase DNA-PK, preventing IFI16-driven gene repression and cytokine responses. Together, we characterize global protein lactylation dynamics during virus infection, finding virus-induced lactate contributes to its immune evasion through direct inhibition of immune signaling pathways.