-
Tracking-seq reveals the heterogeneity of off-target effects in CRISPR-Cas9-mediated genome editing.Nature Biotechnology Jul 2024The continued development of novel genome editors calls for a universal method to analyze their off-target effects. Here we describe a versatile method, called...
The continued development of novel genome editors calls for a universal method to analyze their off-target effects. Here we describe a versatile method, called Tracking-seq, for in situ identification of off-target effects that is broadly applicable to common genome-editing tools, including Cas9, base editors and prime editors. Through tracking replication protein A (RPA)-bound single-stranded DNA followed by strand-specific library construction, Tracking-seq requires a low cell input and is suitable for in vitro, ex vivo and in vivo genome editing, providing a sensitive and practical genome-wide approach for off-target detection in various scenarios. We show, using the same guide RNA, that Tracking-seq detects heterogeneity in off-target effects between different editor modalities and between different cell types, underscoring the necessity of direct measurement in the original system.
PubMed: 38956324
DOI: 10.1038/s41587-024-02307-y -
Nature Metabolism Jul 2024
PubMed: 38956323
DOI: 10.1038/s42255-024-01091-y -
Scientific Reports Jul 2024Influenza A virus subtype H1N1 can cause severe acute respiratory distress syndrome and death in young children and elderly individuals. H1N1 initiates inflammatory...
Influenza A virus subtype H1N1 can cause severe acute respiratory distress syndrome and death in young children and elderly individuals. H1N1 initiates inflammatory responses that aim to contain and eliminate microbial invaders. Various lipid mediators (LMs) are biosynthesized and play a critical role in fighting viruses during inflammation; thus, by profiling the LMs in patients, researchers can obtain mechanistic insights into diseases, such as the pathways disrupted. To date, the relationship between molecular alterations in LMs and the pathogenesis of H1N1 influenza in children is poorly understood. Here, we employed a targeted liquid chromatography coupled with tandem mass spectrometry (LC‒MS/MS) to profile LMs in serum from children with H1N1 influenza (H1N1 children) and recovered children. We found that 22 LM species were altered in H1N1 children with mild symptoms. Analysis of the LM profiles of recovered children revealed a decrease in the levels of thromboxane B2 (TxB) and thromboxane B3 (TxB) and an increase in the levels of other 8 altered LM species associated with H1N1 influenza, including cytochrome P450 (CYP) enzyme-derived dihydroxyeicosatrienoic acids (DiHETrEs) and hydroxyeicosatetraenoic acids (HETEs) from arachidonic acid (AA), and epoxyoctadecamonoenoic acids (EpOMEs) from linoleic acid (LA). Taken together, the results of this study revealed that serum LMs change dynamically in H1N1 children with mild symptoms. The dramatically altered LMs in H1N1 children could serve as a basis for potential therapeutics or adjuvants against H1N1 influenza.
Topics: Humans; Influenza A Virus, H1N1 Subtype; Influenza, Human; Child; Male; Female; Child, Preschool; Tandem Mass Spectrometry; Lipids; Chromatography, Liquid; Infant; Lipidomics
PubMed: 38956313
DOI: 10.1038/s41598-024-66190-y -
Communications Biology Jul 2024G protein-coupled receptors (GPCRs) are mainly regulated by GPCR kinase (GRK) phosphorylation and subsequent β-arrestin recruitment. The ubiquitously expressed GRKs are...
G protein-coupled receptors (GPCRs) are mainly regulated by GPCR kinase (GRK) phosphorylation and subsequent β-arrestin recruitment. The ubiquitously expressed GRKs are classified into cytosolic GRK2/3 and membrane-tethered GRK5/6 subfamilies. GRK2/3 interact with activated G protein βγ-subunits to translocate to the membrane. Yet, this need was not linked as a factor for bias, influencing the effectiveness of β-arrestin-biased agonist creation. Using multiple approaches such as GRK2/3 mutants unable to interact with Gβγ, membrane-tethered GRKs and G protein inhibitors in GRK2/3/5/6 knockout cells, we show that G protein activation will precede GRK2/3-mediated β-arrestin2 recruitment to activated receptors. This was independent of the source of free Gβγ and observable for Gs-, Gi- and Gq-coupled GPCRs. Thus, β-arrestin interaction for GRK2/3-regulated receptors is inseparably connected with G protein activation. We outline a theoretical framework of how GRK dependence on free Gβγ can determine a GPCR's potential for biased agonism. Due to this inherent cellular mechanism for GRK2/3 recruitment and receptor phosphorylation, we anticipate generation of β-arrestin-biased ligands to be mechanistically challenging for the subgroup of GPCRs exclusively regulated by GRK2/3, but achievable for GRK5/6-regulated receptors, that do not demand liberated Gβγ. Accordingly, GRK specificity of any GPCR is foundational for developing arrestin-biased ligands.
Topics: Humans; GTP-Binding Protein gamma Subunits; HEK293 Cells; GTP-Binding Protein beta Subunits; G-Protein-Coupled Receptor Kinases; Receptors, G-Protein-Coupled; Phosphorylation; Animals; Signal Transduction
PubMed: 38956302
DOI: 10.1038/s42003-024-06490-1 -
Nature Cell Biology Jul 2024The importance of subcellular mRNA localization is well established, but the underlying mechanisms mostly remain an enigma. Early studies suggested that specific mRNA... (Review)
Review
The importance of subcellular mRNA localization is well established, but the underlying mechanisms mostly remain an enigma. Early studies suggested that specific mRNA sequences recruit RNA-binding proteins (RBPs) to regulate mRNA localization. However, despite the observation of thousands of localized mRNAs, only a handful of these sequences and RBPs have been identified. This suggests the existence of alternative, and possibly predominant, mechanisms for mRNA localization. Here I re-examine currently described mRNA localization mechanisms and explore alternative models that could account for its widespread occurrence.
PubMed: 38956277
DOI: 10.1038/s41556-024-01444-5 -
Scientific Reports Jul 2024Cancer and related disorders are the most common cause of cancer-related mortality with the incidence of 1 in 9 among the pre-menopausal Pakistani females. among the...
Cancer and related disorders are the most common cause of cancer-related mortality with the incidence of 1 in 9 among the pre-menopausal Pakistani females. among the most common ailments worldwide, indicating the importance of developing particular techniques that could help attenuate the effects of breast cancer and related outcomes. The primary aim of the current study was to review the role of inflammatory and stress markers in the development and progression of breast cancer. Four hundred ninety-eight (n = 498) patients with breast cancer and four hundred and ninety-eight (n = 498) age- and sex-matched controls were selected for this case‒control study. Serum samples were obtained, and the levels of stress and inflammatory markers, including Matrix metalloproteases (MMPs), Interleukins (ILs), Heat shock proteins (HSPs), Malondialdehyde (MDA), Nitric Oxide (NO), inducible Nitric Oxide Synthase (iNOS) and Tumour necrosis factor-alpha (TNF-α), were determined. Most (62%) patients had metastatic breast cancer (stage III or IV) with an adverse grade (65% with Grade III and 35% with Grade II). The present study showed that the levels of oxidants such as MDA, ILs, MMPs and HSPs were significantly greater, while the levels of antioxidants such as Superoxide Dismutase (SOD), Glutathione (GSH), Catalase (CAT), vitamin A, C and D were significantly lower in breast cancer patients than in controls, suggesting their diagnostic importance and role in the pathophysiology of breast cancer. Oxidants, including IL-1, HSP27 and MMP9, which are highly specific and sensitive, may be used to develop the pathophysiological pathways of metastatic breast cancer in these patients. These pathways include cell invasion, cell migration and epithelial-mesenchymal transition. Therefore, we concluded that an increase in growth factors, e.g., Vascular Endothelial Growth Factor (VEGF), Tumour Growth Factor-beta (TGF-β) and B-cell lymphoma (Bcl2), under the influence of these variables plays a crucial role in the metastasis of breast cancer.
Topics: Humans; Female; Breast Neoplasms; Middle Aged; Adult; Biomarkers, Tumor; Case-Control Studies; Inflammation; Oxidative Stress; Malondialdehyde; Nitric Oxide
PubMed: 38956273
DOI: 10.1038/s41598-024-65821-8 -
Communications Medicine Jul 2024Human carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) is an inhibitory cell surface protein that functions through homophilic and heterophilic ligand...
BACKGROUND
Human carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) is an inhibitory cell surface protein that functions through homophilic and heterophilic ligand binding. Its expression on immune cells in human tumors is poorly understood.
METHODS
An antibody that distinguishes human CEACAM1 from other highly related CEACAM family members was labeled with Tb and inserted into a panel of antibodies that included specificity for programmed cell death protein 1 (PD1) and PD-L1, which are targets of immunotherapy, to gain a data-driven immune cell atlas using cytometry by time-of-flight (CyTOF). A detailed inventory of CEACAM1, PD1, and PD-L1 expression on immune cells in metastatic lesions to lymph node or soft tissues and peripheral blood samples from patients with treatment-naive and -resistant melanoma as well as peripheral blood samples from healthy controls was performed.
RESULTS
CEACAM1 is absent or at low levels on healthy circulating immune cells but is increased on immune cells in peripheral blood and tumors of melanoma patients. The majority of circulating PD1-positive NK cells, innate T cells, B cells, monocytic cells, dendritic cells, and CD4 T cells in the peripheral circulation of treatment-resistant disease co-express CEACAM1 and are demonstrable as discrete populations. CEACAM1 is present on distinct types of cells that are unique to the tumor microenvironment and exhibit expression levels that are highest in treatment resistance; this includes tumor-infiltrating CD8 T cells.
CONCLUSIONS
To the best of our knowledge, this work represents the first comprehensive atlas of CEACAM1 expression on immune cells in a human tumor and reveals an important correlation with treatment-resistant disease. These studies suggest that agents targeting CEACAM1 may represent appropriate partners for PD1-related pathway therapies.
PubMed: 38956268
DOI: 10.1038/s43856-024-00525-8 -
Scientific Reports Jul 2024Rapamycin slows cystogenesis in murine models of polycystic kidney disease (PKD) but failed in clinical trials, potentially due to insufficient drug dosing. To improve...
Rapamycin slows cystogenesis in murine models of polycystic kidney disease (PKD) but failed in clinical trials, potentially due to insufficient drug dosing. To improve drug efficiency without increasing dose, kidney-specific drug delivery may be used. Mesoscale nanoparticles (MNP) selectively target the proximal tubules in rodents. We explored whether MNPs can target cystic kidney tubules and whether rapamycin-encapsulated-MNPs (RapaMNPs) can slow cyst growth in Pkd1 knockout (KO) mice. MNP was intravenously administered in adult Pkd1KO mice. Serum and organs were harvested after 8, 24, 48 or 72 h to measure MNP localization, mTOR levels, and rapamycin concentration. Pkd1KO mice were then injected bi-weekly for 6 weeks with RapaMNP, rapamycin, or vehicle to determine drug efficacy on kidney cyst growth. Single MNP injections lead to kidney-preferential accumulation over other organs, specifically in tubules and cysts. Likewise, one RapaMNP injection resulted in higher drug delivery to the kidney compared to the liver, and displayed sustained mTOR inhibition. Bi-weekly injections with RapaMNP, rapamycin or vehicle for 6 weeks resulted in inconsistent mTOR inhibition and little change in cyst index, however. MNPs serve as an effective short-term, kidney-specific delivery system, but long-term RapaMNP failed to slow cyst progression in Pkd1KO mice.
Topics: Animals; Sirolimus; Mice; Polycystic Kidney Diseases; Mice, Knockout; Nanoparticles; Disease Models, Animal; TOR Serine-Threonine Kinases; TRPP Cation Channels; Kidney; Drug Delivery Systems; Male
PubMed: 38956234
DOI: 10.1038/s41598-024-65830-7 -
Scientific Reports Jul 2024Fibulin-2 is a multidomain, disulfide-rich, homodimeric protein which belongs to a broader extracellular matrix family. It plays an important role in the development of...
Fibulin-2 is a multidomain, disulfide-rich, homodimeric protein which belongs to a broader extracellular matrix family. It plays an important role in the development of elastic fiber structures. Malfunction of fibulin due to mutation or poor expression can result in a variety of diseases including synpolydactyly, limb abnormalities, eye disorders leading to blindness, cardiovascular diseases and cancer. Traditionally, fibulins have either been produced in mammalian cell systems or were isolated from the extracellular matrix, a procedure that results in poor availability for structural and functional studies. Here, we produced seven fibulin-2 constructs covering 62% of the mature protein (749 out of 1195 residues) using a prokaryotic expression system. Biophysical studies confirm that the purified constructs are folded and that the presence of disulfide bonds within the constructs makes them extremely thermostable. In addition, we solved the first crystal structure for any fibulin isoform, a structure corresponding to the previously suggested three motifs related to anaphylatoxin. The structure reveals that the three anaphylatoxins moieties form a single-domain structure.
Topics: Humans; Calcium-Binding Proteins; Extracellular Matrix Proteins; Crystallography, X-Ray; Models, Molecular; Protein Conformation; Recombinant Proteins; Protein Stability; Protein Domains
PubMed: 38956220
DOI: 10.1038/s41598-024-64931-7 -
Nature Genetics Jul 2024Mismatch repair (MMR)-deficient cancer evolves through the stepwise erosion of coding homopolymers in target genes. Curiously, the MMR genes MutS homolog 6 (MSH6) and...
Mismatch repair (MMR)-deficient cancer evolves through the stepwise erosion of coding homopolymers in target genes. Curiously, the MMR genes MutS homolog 6 (MSH6) and MutS homolog 3 (MSH3) also contain coding homopolymers, and these are frequent mutational targets in MMR-deficient cancers. The impact of incremental MMR mutations on MMR-deficient cancer evolution is unknown. Here we show that microsatellite instability modulates DNA repair by toggling hypermutable mononucleotide homopolymer runs in MSH6 and MSH3 through stochastic frameshift switching. Spontaneous mutation and reversion modulate subclonal mutation rate, mutation bias and HLA and neoantigen diversity. Patient-derived organoids corroborate these observations and show that MMR homopolymer sequences drift back into reading frame in the absence of immune selection, suggesting a fitness cost of elevated mutation rates. Combined experimental and simulation studies demonstrate that subclonal immune selection favors incremental MMR mutations. Overall, our data demonstrate that MMR-deficient colorectal cancers fuel intratumor heterogeneity by adapting subclonal mutation rate and diversity to immune selection.
PubMed: 38956208
DOI: 10.1038/s41588-024-01777-9