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Nature Biotechnology Mar 2024A number of mitochondrial diseases in humans are caused by point mutations that could be corrected by base editors, but delivery of CRISPR guide RNAs into the...
A number of mitochondrial diseases in humans are caused by point mutations that could be corrected by base editors, but delivery of CRISPR guide RNAs into the mitochondria is difficult. In this study, we present mitochondrial DNA base editors (mitoBEs), which combine a transcription activator-like effector (TALE)-fused nickase and a deaminase for precise base editing in mitochondrial DNA. Combining mitochondria-localized, programmable TALE binding proteins with the nickase MutH or Nt.BspD6I(C) and either the single-stranded DNA-specific adenine deaminase TadA8e or the cytosine deaminase ABOBEC1 and UGI, we achieve A-to-G or C-to-T base editing with up to 77% efficiency and high specificity. We find that mitoBEs are DNA strand-selective mitochondrial base editors, with editing results more likely to be retained on the nonnicked DNA strand. Furthermore, we correct pathogenic mitochondrial DNA mutations in patient-derived cells by delivering mitoBEs encoded in circular RNAs. mitoBEs offer a precise, efficient DNA editing tool with broad applicability for therapy in mitochondrial genetic diseases.
Topics: Humans; Gene Editing; DNA, Mitochondrial; CRISPR-Cas Systems; RNA, Guide, CRISPR-Cas Systems; Mitochondria; Mitochondrial Diseases; Deoxyribonuclease I; Cytosine
PubMed: 37217751
DOI: 10.1038/s41587-023-01791-y -
Nature Communications Aug 2023Optimization of CRISPR/Cas9-mediated genome engineering has resulted in base editors that hold promise for mutation repair and disease modeling. Here, we demonstrate the...
Optimization of CRISPR/Cas9-mediated genome engineering has resulted in base editors that hold promise for mutation repair and disease modeling. Here, we demonstrate the application of base editors for the generation of complex tumor models in human ASC-derived organoids. First we show efficacy of cytosine and adenine base editors in modeling CTNNB1 hot-spot mutations in hepatocyte organoids. Next, we use C > T base editors to insert nonsense mutations in PTEN in endometrial organoids and demonstrate tumorigenicity even in the heterozygous state. Moreover, drug sensitivity assays on organoids harboring either PTEN or PTEN and PIK3CA mutations reveal the mechanism underlying the initial stages of endometrial tumorigenesis. To further increase the scope of base editing we combine SpCas9 and SaCas9 for simultaneous C > T and A > G editing at individual target sites. Finally, we show that base editor multiplexing allow modeling of colorectal tumorigenesis in a single step by simultaneously transfecting sgRNAs targeting five cancer genes.
Topics: Adult; Humans; RNA, Guide, CRISPR-Cas Systems; Oncogenes; Carcinogenesis; Cell Transformation, Neoplastic; Adult Stem Cells; Organoids
PubMed: 37591832
DOI: 10.1038/s41467-023-40701-3 -
Tomography (Ann Arbor, Mich.) Jun 2023The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating... (Review)
Review
The skull base provides a platform for supporting the brain while serving as a conduit for major neurovascular structures. In addition to malignant lesions originating in the skull base, there are many benign entities and developmental variants that may simulate disease. Therefore, a basic understanding of the relevant embryology is essential. Lesions centered in the skull base can extend to the adjacent intracranial and extracranial compartments; conversely, the skull base can be secondarily involved by primary extracranial and intracranial disease. CT and MRI are the mainstay imaging methods and are complementary in the evaluation of skull base lesions. Advances in cross-sectional imaging have been crucial in the management of patients with skull base pathology, as this represents a complex anatomical area that is hidden from direct clinical exam. Furthermore, the clinician must rely on imaging studies for therapy planning and to monitor treatment response. It is crucial to have a thorough understanding of skull base anatomy and its various pathologies, as well as to recognize the appearance of treatment-related changes. In this review, we aim to describe skull base tumors and tumor-like lesions in an anatomical compartmental approach and present imaging methods that aid in diagnosis, management, and follow-up.
Topics: Humans; Skull Base Neoplasms; Diagnostic Imaging; Brain
PubMed: 37489465
DOI: 10.3390/tomography9040097 -
The Surgeon : Journal of the Royal... Jun 2023Reconstruction of the head and neck continues to pose a variety of difficult functional and aesthetic challenges to the plastic surgeon. While the surgical treatment for... (Review)
Review
Reconstruction of the head and neck continues to pose a variety of difficult functional and aesthetic challenges to the plastic surgeon. While the surgical treatment for midfacial and skull base tumours continues to advance, the three-dimensional reconstruction predicaments continue to increase in complexity. Reconstructive strategies of the head and neck require the restoration of intricate skeletal architecture and large volumes of both internal and external soft tissue envelopes that can withstand adjuvant therapies. Vascularized bone grafts in combination with microsurgical techniques is the current trend of most reconstruction and has replaced local and pedicle flaps as the preferred modality for large defects. This article will focus on concise areas of difficulty in craniofacial reconstruction, including mandibular, midfacial, scalp and base of skull reconstruction. As our goals now move from flap survival to refinement, more complex and innovative reconstructions are executed. The problems with each modality are examined, and the frontiers of head and neck reconstruction are explored. With the potential combination of virtual surgery and tissue engineered biotechnology, we may someday be able to expand our reconstructive capabilities beyond free tissue transfer.
Topics: Humans; Plastic Surgery Procedures; Surgical Flaps; Mandible; Head and Neck Neoplasms
PubMed: 35525818
DOI: 10.1016/j.surge.2022.04.004 -
Acta Psychologica Jul 2023People tend to ignore the probabilistic rules cued by the base-rate information and rely on the heuristic intuition cued by the descriptive information to make...
People tend to ignore the probabilistic rules cued by the base-rate information and rely on the heuristic intuition cued by the descriptive information to make "stereotypical" responses in base-rate problems. Conflict detection studies have shown that reasoners can detect conflicts between heuristic intuition and probabilistic considerations despite ultimately stereotypical responses. However, these studies primarily used extreme base-rate tasks. A critical open question is the extent to which successful conflict detection relies on an extreme base rate. The present study explores this issue by manipulating the base-rate extremity of problems in which the descriptive information and the base-rate information conflict or not. As a result, when reasoners made stereotypical responses in the conflict version of the moderate base-rate task, they took longer to respond, had lower confidence in their responses, and were slower to evaluate their confidence than in the no-conflict version of the task. All three measures indicate that stereotypical reasoners can stably detect conflict in moderate base-rate tasks, which expands the scope of successful conflict detection. Moreover, our response confidence data found a larger detection effect size in the extreme base-rate condition than in the moderate base-rate condition. This suggests that conflict detection is more efficient as the base-rate extremity increases. Implications for the boundary conditions of conflict detection are discussed.
Topics: Humans; Problem Solving; Decision Making; Intuition; Heuristics; Extremities
PubMed: 37327658
DOI: 10.1016/j.actpsy.2023.103960 -
Anesthesiology Dec 2023
Topics: Operating Rooms; Acid-Base Equilibrium; Humans
PubMed: 37934110
DOI: 10.1097/ALN.0000000000004712 -
European Journal of Medical Research May 2024The base excess value (BE, mmol/L), not standard base excess (SBE), correctly calculated including pH, pCO (mmHg), sO (%) and cHb (g/dl) is a diagnostic tool for several... (Review)
Review
The base excess value (BE, mmol/L), not standard base excess (SBE), correctly calculated including pH, pCO (mmHg), sO (%) and cHb (g/dl) is a diagnostic tool for several in vivo events, e.g., mortality after multiple trauma or shock, acidosis, bleeding, clotting, artificial ventilation. In everyday clinical practice a few microlitres of blood (arterial, mixed venous or venous) are sufficient for optimal diagnostics of any metabolic acidosis or alkalosis.The same applies to a therapeutic tool-then referred to as potential base excess (BEpot)-for several in vitro assessments, e.g., solutions for infusion, sodium bicarbonate, blood products, packed red blood cells, plasma. Thus, BE or BEpot has been a parameter with exceptional clinical significance since 2007.
Topics: Humans; Acidosis; Acid-Base Imbalance; Acid-Base Equilibrium; Alkalosis
PubMed: 38735983
DOI: 10.1186/s40001-024-01796-6