CRISPR technology: A decade of genome editing is only the beginning

Barcodes based on nucleic acid sequences: Applications and challenges (Review)

Cells are the fundamental structural and functional units of living organisms and the study of these entities has remained a central focus throughout the history of biological sciences. Traditional cell research techniques, including fluorescent protein tagging and microscopy, have provided preliminary insights into the lineage history and clonal relationships between progenitor and descendant cells. However, these techniques exhibit inherent limitations in tracking the full developmental trajectory of cells and elucidating their heterogeneity, including sensitivity, stability and barcode drift. In developmental biology, nucleic acid barcode technology has introduced an innovative approach to cell lineage tracing. By assigning unique barcodes to individual cells, researchers can accurately identify and trace the origin and differentiation pathways of cells at various developmental stages, thereby illuminating the dynamic processes underlying tissue development and organogenesis. In cancer research, nucleic acid barcoding has played a pivotal role in analyzing the clonal architecture of tumor cells, exploring their heterogeneity and resistance mechanisms and enhancing our understanding of cancer evolution and inter‑clonal interactions. Furthermore, nucleic acid barcodes play a crucial role in stem cell research, enabling the tracking of stem cells from diverse origins and their derived progeny. This has offered novel perspectives on the mechanisms of stem cell self‑renewal and differentiation. The present review presented a comprehensive examination of the principles, applications and challenges associated with nucleic acid barcode technology.

Single nanoparticle analysis-based CRISPR/Cas12 bioassay for amplification-free HIV detection

To reduce the "window period" in HIV detection, most analytical methods require additional enzymes for signal amplification. Exempting challenges like primer interference and false positives in amplification strategies, we developed an amplification-free bioassay that uses CRISPR's potent cleavage activity and the competent sensitivity of single-nanoparticle analysis. An attomolar detection limit was achieved with adequate selectivity. Serum and cell tests confirm the bioassay's accurate and sensitive HIV detection.

CRISPR Digital Sensing: From Micronano-Collaborative Chip to Biomolecular Detection

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) sensing technology proved to be valuable during the COVID-19 pandemic through its sensitivity, specificity, robustness, and versatility. However, issues such as overreliance on amplification, susceptibility to false positives, lack of quantification strategies, and complex operation procedures have hindered its broader application in bioanalysis and clinical diagnostics. The collision between micronano-collaborative chips and CRISPR technology has effectively addressed these bottlenecks, offering innovative solutions for diagnosis and treatment. Unlike conventional micronano chips, micronano digital chips enhance CRISPR's response to trace amounts of target molecules by leveraging highly controllable local environments and compartmentalized microreactors. This advancement improves detection efficiency and revolutionizes traditional in vitro bioanalytical processes. First, the working principles, fabrication techniques, and performance metrics of CRISPR-based digital droplet microfluidics and microarray chips are examined. Then, the applications of CRISPR digital sensing chips in bioassays are reviewed, emphasizing their importance in advancing in vitro detection systems for gene editing. Finally, the prospects of CRISPR digital sensing technology are explored, particularly its potential for body surface biomonitoring and its broader development opportunities in the biomedical field.

Functional Delivery Systems for Targeting Tumor Heterogeneity: Reversing Immunosuppression and Modulating Cancer-Immune Interplay

Understanding and modulating the interplay between cancer cells and immune cells is critical for deciphering cancer progression and developing effective therapies. However, studying this interplay using patient-derived cells in animal models remains challenging, and the inherent heterogeneity of human tumors adds complexity to traditional approaches. Here, we demonstrate that functional delivery systems targeting heterogeneous malignant cells enable precise immune modulation and real-time assessment of cancer-immune interactions. By developing a delivery vector that specifically targets circulating malignant cells (CMCs) in patient blood samples, we established an ex vivo platform to study the dynamic interplay between patient-derived cancer cells and immune cells. Using a biomacromolecule-based delivery vector functionalized with the ME07 aptamer with high affinity for multiple subtypes of epidermal growth factor receptor (EGFR), we achieved efficient delivery of the genome editing plasmid and molecular beacons (MBs), enabling EGFR knockout to reverse tumor immunosuppression and in situ mRNA probing in heterogeneous malignant cells. EGFR knockout downregulates both wild-type and mutant EGFR, leading to a reduction in PD-L1 expression. Visualization of the interplay between CMCs and peripheral blood mononuclear cells (PBMCs) shows that edited CMCs with low EGFR and PD-L1 expression become susceptible to immune-mediated clearance, while unedited CMCs with higher EGFR and PD-L1 expression can resist immune attack. After coincubation with edited CMCs, the proportions of CD8+CD69+ and CD8+CD44+ T cells significantly increase, while the proportion of CD4+Foxp3+ Tregs notably decreases, indicating the restoration of immune responses. Our study outlines a methodology for precise evaluation of therapeutic interventions at single-cell resolution, advancing personalized cancer therapy.

Cas9-Rep fusion tethers donor DNA in vivo and boosts the efficiency of HDR-mediated genome editing

Genome editing based on the homology-directed repair (HDR) pathway enables scar-free and precise genetic manipulations. However, the low frequency of HDR hinders its application in plant genome editing. In this study, we engineered the fusion of Cas9 and a viral replication protein (Rep) as a molecular bridge to tether donor DNA in vivo, which enhances the efficiency of targeted gene insertion via the HDR pathway. This Rep-bridged knock-in (RBKI) method combines the advantages of rolling cycle replication of viral replicons and in vivo enrichment of donor DNA at the target site for HDR. Chromatin immunoprecipitation indicated that the Cas9-Rep fusion protein bound up to 66-fold more donor DNA than Cas9 did. We exemplified the RBKI method by inserting small- to middle-sized tags (33-519 bp) into 3 rice genes. Compared to Cas9, Cas9-Rep fusion increased the KI frequencies by 4-7.6-fold, and up to 72.2% of stable rice transformants carried in-frame knock-in events in the T0 generation. Whole-genome sequencing of 6 plants segregated from heterozygous KI lines indicated that the knock-in events were faithfully inherited by the progenies with neither off-target editing nor random insertions of the donor DNA fragment. Further analysis suggested that the RBKI method reduced the number of byproducts from nonhomologous end joining; however, HDR-mediated knock-in tended to accompany microhomology-mediated end joining events. Together, these findings show that the in vivo tethering of donor DNAs with Cas9-Rep is an effective strategy to increase the frequency of HDR-mediated genome editing.

Rapid detection of Klebsiella pneumoniae based on one-tube RPA-CRISPR/Cas12a system

Klebsiella pneumoniae (KP) is a prevalent pathogen implicated in both community-acquired and nosocomial infections, often leading to severe clinical outcomes. The conventional methods for KP identification are characterized by intricacy and suboptimal efficiency. In this research, we have engineered a novel One-Tube RPA- CRISPR/Cas12a system, integrating recombinase polymerase amplification (RPA) method with the CRISPR/Cas12a diagnostic platform, to facilitate the detection of K. pneumoniae. To minimize the likelihood of aerosol-based contamination, the RPA components are positioned at the base of the tube, while the CRISPR/Cas12a components are placed at the tube's cap. The systems are combined post-RPA amplification through a brief centrifugation step, ensuring that RPA reactions are conducted independently to produce an adequate amount of target DNA before interaction with the CRISPR/Cas12a system. This method was validated using both fluorescent and lateral flow strip assays, achieving a limit of detection (LOD) of 100 copies/μL and 101 copies/μL respectively. The specificity for KP detection was found to be 100 %. Furthermore, the system demonstrated a positivity rate of 78 % (18/23) when directly extracting DNA from sputum samples, corroborated by culture and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). The simplicity and rapidity of the assay are augmented by a straightforward sample processing without extraction. The complete assay duration from specimen receipt to result is approximately 40 min, significantly reducing the turnaround time (TAT). Collectively, this system presents a streamlined, expeditious, and highly specific diagnostic approach for the detection of Klebsiella pneumoniae strains.

Enhanced the Trans-Cleavage Activity of CRISPR-Cas12a Using Metal-Organic Frameworks as Stimulants for Efficient Electrochemical Sensing of Circulating Tumor DNA

Continued development of clustered regularly interspaced short palindromic repeats (CRISPR)-powered biosensing system on the electrochemical interface is vital for accurate and timely diagnosis in clinical practice. Herein, an electrochemical biosensor based on manganese metal-organic frameworks (MOFs)-enhanced CRISPR (MME-CRISPR) is proposed that enables the efficient detection of circulating tumor DNA (ctDNA). In this design, customized enzyme stimulants (Mn2+) are co-assembled with Cas12a/crRNA to form enzyme-MOF composites, which can be released quickly under mild conditions. The MOFs-induced proximity effect can continuously provide adequate Mn2+ to sufficiently interact with Cas12a/crRNA during the release process, enhancing the trans-cleavage activity of complex available for biosensor construction. The MOFs-based enzyme biocomposites also afford efficient protection against various external stimulus. It is demonstrated that the developed biosensor can achieve ultrasensitive detection of epidermal growth factor receptor L858R mutation in ctDNA with a low detection limit of 0.28 fm without pre-amplification. Furthermore, the engineered mismatch crRNA enables the biosensor based on MME-CRISPR to detect single nucleotide variant with a high signal-to-noise ratio. More importantly, it has been successfully used to detect the targets in clinical practice, requiring low-dose samples and a short time. This strategy is believed to shed new light on the applications of cancer diagnosis, treatment, and surveillance.

CRISPR-Cas applications in agriculture and plant research

Growing world population and deteriorating climate conditions necessitate the development of new crops with high yields and resilience. CRISPR-Cas-mediated genome engineering presents unparalleled opportunities to engineer crop varieties cheaper, easier and faster than ever. In this Review, we discuss how the CRISPR-Cas toolbox has rapidly expanded from Cas9 and Cas12 to include different Cas orthologues and engineered variants. We present various CRISPR-Cas-based methods, including base editing and prime editing, which are used for precise genome, epigenome and transcriptome engineering, and methods used to deliver the genome editors into plants, such as bacterial-mediated and viral-mediated transformation. We then discuss how promoter editing and chromosome engineering are used in crop breeding for trait engineering and fixation, and important applications of CRISPR-Cas in crop improvement, such as de novo domestication and enhancing tolerance to abiotic stresses. We conclude with discussing future prospects of plant genome engineering.

Purification of CRISPR Cas12a from E. coli cell lysates using peptide affinity ligands

CRISPR Cas nucleases are revolutionizing gene therapy by providing a precise and efficient tool for editing the human genome, and are increasingly applied for engineering microorganisms for bioremediation, drought-resistant crops, and livestock with higher productivity. While Cas9 is currently the most widely utilized member of the CRISPR family, Cas12a stands is gaining prominence for its ability to produce staggered cuts in the target DNA while requiring a shorter guide RNA (crRNA). Current methods of Cas purification such as affinity tag, immunoaffinity, and ion exchange chromatography do not provide either the productivity or the purity needed to meet the demand of clinics and biotechnology industries. Responding to this need, this study presents the first affinity ligands for Cas12a purification via affinity chromatography. The ligands were initially designed in silico as peptide mimetics of anti-CRISPR protein inhibitors AcrVA1 and AcrVA4, and ranked experimentally by Cas12a dynamic binding. Selected ligands P5 and P9 were utilized for purifying Cas12a derived from Acidaminococcus sp. (AsCas12a) and Lachnospiraceae sp. (LbCas12a) from clarified Escherichia coli cell lysates. P5-functionalized resin afforded high yield (up to 80 %), purity (> 93 %), and DNA editing activity (∼72 %) of Cas12a from E. coli lysates featuring different Cas12a and host cell protein titers. The characterization of ligand P5 by surface plasmon resonance (SPR) indicated adsorption kinetics (ka ∼ 1.21·105 M-1s-1) and dissociation constant (KD ∼ 1.76·10-6 M) that confirmed the ligand design criteria and are characteristic of peptide affinity ligands.

Unrecognized role of photosynthetic bacteria in aquaculture water purification: Producing singlet oxygen to degrade residual pharmaceuticals

Photosynthetic bacteria (PSB) are widely used in the purification of aquaculture waters due to their ability to utilize ammonia, nitrite, hydrogen sulfide, etc. However, PSB are usually considered to be ineffective in removing biologically inert pharmaceutical residues in aquaculture waters. Herein, we found that PSB were capable of degrading pharmaceuticals in aquaculture waters, such as cimetidine and sulfamethazine, by generating extracellular singlet oxygen (1O2) under light irradiation. PSB were highly efficient to produce 1O2, and the quantum yield of 1O2 was four orders of magnitude higher than that of hydroxyl radicals. The efficient production of 1O2 by PSB arose from the photosensitization of extracellular metabolites, which produced 1O2 with an order of magnitude higher quantum yield (0.41) compared to the commonly reported dissolved organic matter (< 0.04) and could efficiently produce 1O2 even under visible light irradiation. The photosensitized extracellular metabolites were mainly hydrophobic metabolites with the molecular weight < 1 kDa, and a porphyrin (i.e., COPRO III) was identified as the dominant photosensitizer for 1O2 production. This work provides new insights into the role of PSB inoculants in aquaculture water purification, and offers new ideas for the removal of pharmaceutical residues from aquaculture waters.

Recombinant Adeno-Associated Virus Vector Mediated Gene Editing in Proliferating and Polarized Cultures of Human Airway Epithelial Cells

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. While CRISPR-based CFTR editing approaches have shown proof-of-concept for functional rescue in primary airway basal cells, induced pluripotent stem cells, and organoid cultures derived from patients with CF, their efficacy remains suboptimal. Here, we developed the CuFiCas9(Y66S)eGFP reporter system by integrating spCas9 and a non-fluorescent Y66S eGFP mutant into CuFi-8 cells, an immortalized human airway epithelial cell line derived from a patient with CF with homozygous F508del mutations. These cells retain the basal cell phenotype in proliferating cultures and can differentiate into polarized airway epithelium at an air-liquid interface (ALI), enabling both visualized detection of gene editing and electrophysiological assessment of CFTR functional restoration. Using this system, recombinant adeno-associated virus (rAAV)-mediated homology-directed repair (HDR) was evaluated in proliferating cultures. A correction rate of 13.5 ± 0.8% was achieved in a population where 82.3 ± 5.6% of cells were productively transduced by AAV.eGFP630g2-CMVmCh, an rAAV editing vector with an mCherry reporter. Dual-editing of F508del CFTR and Y66S eGFP was explored using AAV.HR-eGFP630-F508(g03) to deliver two templates and single guide RNAs. eGFP+ (Y66S-corrected) cells and eGFP- (non-corrected) cells were sorted via fluorescence-activated cell sorting and differentiated at an ALI to assess the recovery of CFTR function. Despite a low F508 correction rate of 2.8%, ALI cultures derived from the eGFP- population exhibited 25.2% of the CFTR-specific transepithelial Cl- transport observed in CuFi-ALI cultures treated with CFTR modulators. Next-generation sequencing revealed frequent co-editing at both genomic loci, with sixfold higher F508 correction rate in the eGFP+ cells than eGFP- cells. In both populations, non-homology end joining predominated over HDR. This reporter system provides a valuable platform for optimizing editing efficiencies in proliferating airway basal cells, particularly for development of strategies to enhance HDR through modulation of DNA repair pathways.

An NGS-based approach for precise and footprint-free CRISPR-based gene editing in human stem cells

Precise gene editing with conventional CRISPR/Cas9 is often constrained by low knock-in (KI) efficiencies (≈ 2-20 %) in human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs). This limitation typically necessitates labour-intensive manual isolation and genotyping of hundreds of colonies to identify correctly edited cells. Fluorescence- or antibiotic-based enrichment methods facilitate the identification process but can compromise cell viability and genomic integrity. Here, we present a footprint-free editing strategy that combines low-density seeding with next-generation sequencing (NGS) to rapidly identify cell populations containing precisely modified clones. By optimising the transfection workflow and adhering to CRISPR/Cas9 KI design principles, we achieved high average editing efficiencies of 64 % in hiPSCs (introducing a Brugada syndrome-associated variant) and 51 % in hESCs (introducing a neurodevelopmental disorder (NDD)-associated variant). Furthermore, under suboptimal CRISPR design conditions, this approach successfully identified hESC clones carrying a second NDD-associated variant, despite average KI efficiencies below 1 %. Importantly, genomic integrity was preserved throughout subcloning rounds, as confirmed by Sanger sequencing and single nucleotide polymorphism (SNP) array analysis. Hence, this NGS-based enrichment strategy reliably identifies desired KI clones under both optimal and challenging conditions, reducing the need for extensive colony screening and offering an effective alternative to fluorescence- and antibiotic-based selection methods.

Data- and knowledge-derived functional landscape of human solute carriers

The human solute carrier (SLC) superfamily of ~460 membrane transporters remains the largest understudied protein family despite its therapeutic potential. To advance SLC research, we developed a comprehensive knowledgebase that integrates systematic multi-omics data sets with selected curated information from public sources. We annotated SLC substrates through literature curation, compiled SLC disease associations using data mining techniques, and determined the subcellular localization of SLCs by combining annotations from public databases with an immunofluorescence imaging approach. This SLC-centric knowledge is made accessible to the scientific community via a web portal featuring interactive dashboards and visualization tools. Utilizing this systematically collected and curated resource, we computationally derived an integrated functional landscape for the entire human SLC superfamily. We identified clusters with distinct properties and established functional distances between transporters. Based on all available data sets and their integration, we assigned biochemical/biological functions to each SLC, making this study one of the largest systematic annotations of human gene function and a potential blueprint for future research endeavors.

CRISPR/Cas9-Mediated Knockout of the White Gene in Agasicles hygrophila

Agasicles hygrophila is the most effective natural enemy for the control of the invasive weed Alternanthera philoxeroides (Mart.) Griseb. However, research on the gene function and potential genetic improvement of A. hygrophila is limited due to a lack of effective genetic tools. In this study, we employed the A. hygrophila white (AhW) gene as a target gene to develop a CRISPR/Cas9-based gene editing method applicable to A. hygrophila. We showed that injection of Cas9/sgRNA ribonucleoprotein complexes (RNPs) of the AhW gene into pre-blastoderm eggs induced genetic insertion and deletion mutations, leading to white eyes. Our results demonstrate that CRISPR/Cas9-mediated gene editing is possible in A. hygrophila, offering a valuable tool for studies of functional genomics and genetic improvement of A. hygrophila, which could potentially lead to more effective control of invasive weeds through the development of improved strains of this biocontrol agent. In addition, the white-eyed mutant strain we developed could potentially be useful for other transgenic research studies on this species.

A New Situation-Specific Theoretical Framework to Guide Ectopic Pregnancy Research in Nursing

Ectopic pregnancy (EP) is a serious and increasing health concern that remains poorly understood despite identified risk factors. This article introduces the N-GEM Theoretical Framework, a novel approach that integrates genomic, epigenomic, environmental, and microbiome factors to address the complex and multifactorial etiology of EP. By offering a comprehensive and dynamic model, the N-GEM framework supports the development of personalized prevention strategies and can enhance early detection methods. This situation-specific theoretical framework not only positions nursing at the forefront of EP research but also fosters interdisciplinary collaboration that can drive significant advancements in clinical practice and ultimately reduce EP-related morbidity and mortality.

Transforming beef quality through healthy breeding: a strategy to reduce carcinogenic compounds and enhance human health: a review

The presence of carcinogenic substances in beef poses a significant risk to public health, with far-reaching implications for consumer safety and the meat production industry. Despite advancements in food safety measures, traditional breeding methods have proven inadequate in addressing these risks, revealing a substantial gap in knowledge. This review aims to fill this gap by evaluating the potential of healthy breeding techniques to significantly reduce the levels of carcinogenic compounds in beef. We focus on elucidating the molecular pathways that contribute to the formation of key carcinogens, such as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), while exploring the transformative capabilities of advanced genomic technologies. These technologies include genomic selection, CRISPR/Cas9, base editing, prime editing, and artificial intelligence-driven predictive models. Additionally, we examine multi-omics approaches to gain new insights into the genetic and environmental factors influencing carcinogen formation. Our findings suggest that healthy breeding strategies could markedly enhance meat quality, thereby offering a unique opportunity to improve public health outcomes. The integration of these innovative technologies into breeding programs not only provides a pathway to safer beef production but also fosters sustainable livestock management practices. The improvement of these strategies, along with careful consideration of ethical and regulatory challenges, will be crucial for their effective implementation and broader impact.

The deLIVERed promises of gene therapy: Past, present, and future of liver-directed gene therapy

Gene therapy has revolutionized modern medicine by offering innovative treatments for genetic and acquired diseases. The liver has been and continues as a prime target for in vivo gene therapy due to its essential biological functions, vascular access to the major target cell (hepatocytes), and relatively immunotolerant environment. Adeno-associated virus (AAV) vectors have become the cornerstone of liver-directed therapies, demonstrating remarkable success in conditions such as hemophilia A and B, with US Food and Drug Administration (FDA)-approved therapies like etranacogene dezaparvovec, Beqvez, and Roctavian marking milestones in the field. Despite these advances, challenges persist, including vector immunogenicity, species-specific barriers, and high manufacturing costs. Innovative strategies, such as capsid engineering, immune modulation, and novel delivery systems, are continuing to address these issues in expanding the scope of therapeutic applications. Some of the challenges with many new therapies result in the discordance between preclinical success and translation into humans. The advent of various genome-editing tools to repair genomic mutations or insert therapeutic DNAs into precise locations in the genome further enhances the potential for a single-dose medicine that will offer durable life-long therapeutic treatments. As advancements accelerate, liver-targeted gene therapy is poised to continue to transform the treatment landscape for both genetic and acquired disorders, for which unmet challenges remain.

Arrest of CRISPR-Cas12a by Nonspecific Single-Stranded DNA for Biosensing

CRISPR-Cas technologies have emerged as powerful biosensing tools for the sensitive and specific detection of non-nucleic acid targets. However, existing biosensing strategies suffer from poor compatibility across diverse targets due to the complicated engineering of crRNA and DNA activator required for the CRISPR-Cas activity regulation. Herein, we report a novel and straightforward strategy for designing CRISPR-Cas12a-based biosensors that function by switching structures from single-stranded (ss)DNA/CRISPR-Cas12a assembly to DNA activator/CRISPR-Cas12a complex in the presence of target bacterium. The strategy begins with a ssDNA assembly made of a trans-acting RNA-cleaving DNAzyme (tRCD) and an RNA/DNA chimeric substrate (RCS). The ssDNA assembly has the ability to bind Cas12a nonspecifically, thus indeed blocking the CRISPR-Cas12a activity. By exploiting the specific recognition and cleavage capacities of tRCD for RCS in the presence of a target, the target-bound tRCD and the cleaved RCS are released from Cas12a, thus restoring the CRISPR-Cas12a activity. This method has been successfully applied for the sensitive (detection limit: 102 CFU/mL) detection of Escherichia coli (E. coli, EC) and Burkholderia gladioli (B. gladioli, BG). For the blind testing of 30 clinical urine samples, it exhibited 100% sensitivity and 100% specificity in identifying E. coli-associated urinary tract infections (UTIs).

The importance of understanding the ethology and ecology of the zebrafish, and of other fish species, in experimental research

This short review appears in a special issue assembled to celebrate the 90th birthday of a Hungarian ethologist, Professor Vilmos Csányi. As such, it includes some autobiographical details specific to that scientist and the author of this review. However, these details also serve an important general message. They exemplify how science, i.e., specifically the use of fish in the analysis of behaviour and brain function progressed from the mid-1970s to the current day. They illuminate how scientists choose their study species, and how this choice influences the research questions one may be able to pose. The review discusses why the zebrafish has become a popular research subject of biology, including behavioural neuroscience. It argues that behavioural analysis should be an integral part of research into the analysis of brain function. It considers the dichotomy between the historical effect of North American behaviourism vs. the legacy of European Nobel laureate ethologists. It demonstrates, through a theoretical example, why merging these two "schools" of thoughts is the appropriate way to conduct behavioural research. It provides a few examples for how combining knowledge of ethology and ecology of the species with systematic laboratory studies may be beneficial. And it presents a brief outlook for the future of fish in biology research.

Rapid two-step target capture ensures efficient CRISPR-Cas9-guided genome editing

RNA-guided CRISPR-Cas enzymes initiate programmable genome editing by recognizing a ∼20-base-pair DNA sequence next to a short protospacer-adjacent motif (PAM). To uncover the molecular determinants of high-efficiency editing, we conducted biochemical, biophysical, and cell-based assays on Streptococcus pyogenes Cas9 (SpyCas9) variants with wide-ranging genome-editing efficiencies that differ in PAM-binding specificity. Our results show that reduced PAM specificity causes persistent non-selective DNA binding and recurrent failures to engage the target sequence through stable guide RNA hybridization, leading to reduced genome-editing efficiency in cells. These findings reveal a fundamental trade-off between broad PAM recognition and genome-editing effectiveness. We propose that high-efficiency RNA-guided genome editing relies on an optimized two-step target capture process, where selective but low-affinity PAM binding precedes rapid DNA unwinding. This model provides a foundation for engineering more effective CRISPR-Cas and related RNA-guided genome editors.

Development and Characterization of an Inducible Bacterial Artificial Chromosome System for Studying Lytic Replication and Pathogenesis of Kaposi's Sarcoma-Associated Herpesvirus

Bacterial artificial chromosome (BAC) is widely used to manipulate herpesvirus genome and generate recombinant virus. Here, we developed a new KSHV BACmid, namely as iBAC, by replacing the EGFP with TET3G transactivator under EF1α promoter and inserted Tet response elements in the promoter of RTA in the original KSHV BAC16 clone and characterized KSHV lytic replication in SLK-iBAC cells. SLK-iBAC cells developed more efficient lytic replication and generated more progeny virus than iSLK-BAC16 cells upon the same conditions of doxycycline treatment. Since SLK-iBAC cells only occupied hygromycin selection marker, it is convenient to generate cellular gene knockout via lentivirus-mediated CRISPR-Cas9 or stably express viral or cellular gene via lentivirus followed by antibiotic selection, making iBAC system a better tool to identify cellular targets of viral proteins in the context of virus infection or study the role of viral or cellular genes for KSHV lytic replication and pathogenesis. In addition, iBAC is color-free and can be utilized to track subcellular localization of viral proteins or colocalization between different viral proteins by introducing fusing fluorescent proteins into the BAC backbone. Therefore, the new KSHV iBAC is a powerful inducible tool to study KSHV lytic replication and pathogenesis in cell model.

CRISPR/Cas technologies for cancer drug discovery and treatment

Clustered regularly interspaced short palindromic repeats (CRISPR) tools are revolutionizing the establishment of genotype-phenotype relationships and are transforming cell- and gene-based therapies. In the field of oncology, CRISPR/CRISPR-associated protein 9 (Cas9), Cas12, and Cas13 have advanced the generation of cancer models, the study of tumor evolution, the identification of target genes involved in cancer growth, and the discovery of genes involved in chemosensitivity and resistance. Moreover, preclinical therapeutic strategies employing CRISPR/Cas have emerged. These include the generation of chimeric antigen receptor T (CAR-T) cells and engineered immune cells, and the use of precision anticancer gene-editing agents to inactivate driver oncogenes, suppress tumor support genes, and cull cancer cells in response to genetic circuit output. This review summarizes the collective impact that CRISPR technology has had on basic and applied cancer research, and highlights the promises and challenges facing its clinical translation.

Weaponizing CRISPR/Cas9 for selective elimination of cells with an aberrant genome

The CRISPR/Cas9 technology is a powerful and versatile tool to disrupt genes' functions by introducing sequence-specific DNA double-strand breaks (DSBs). Here, we repurpose this technology to eradicate aberrant cells by specifically targeting silent and non-functional genomic sequences present only in target cells to be eliminated. Indeed, an intrinsic challenge of most current therapies against cancer and viral infections is the non-specific toxicity that they can induce in normal tissues because of their impact on important cellular mechanisms shared, to different extents, between unhealthy and healthy cells. The CRISPR/Cas9 technology has potential to overcome this limitation; however, so far effectiveness of these approaches was made dependent on the targeting and inactivation of a functional gene product. Here, we generate proof-of-principle evidence by engineering HeLa and RKO cells with a promoterless Green Fluorescent Protein (GFP) construct. The integration of this construct simulates either a genomic alteration, as in cancer cells, or a silent proviral genome. Cas9-mediated DSBs in the GFP sequence activate the DNA damage response (DDR), reduce cell viability and increase mortality. This is associated with increased cell size, multinucleation, cGAS-positive micronuclei accumulation and the activation of an inflammatory response. Pharmacological inhibition of the DNA repair factor DNA-PK enhances cell death. These results demonstrate the therapeutic potential of the CRISPR/Cas9 system in eliminating cells with an aberrant genome, regardless of the expression or the function of the target DNA sequence.

Inhibitors of Cyclic Dinucleotide Phosphodiesterases and Cyclic Oligonucleotide Ring Nucleases as Potential Drugs for Various Diseases

The phosphodiester linkage is found in DNA, RNA and many signaling molecules, such as cyclic mononucleotide, cyclic dinucleotides (CDNs) and cyclic oligonucleotides (cONs). Enzymes that cleave the phosphodiester linkage (nucleases and phosphodiesterases) play important roles in cell persistence and fitness and have therefore become targets for various diseased states. While various inhibitors have been developed for nucleases and cyclic mononucleotide phosphodiesterases, and some have become clinical successes, there is a paucity of inhibitors of the recently discovered phosphodiesterases or ring nucleases that cleave CDNs and cONs. Inhibitors of bacterial c-di-GMP or c-di-AMP phosphodiesterases have the potential to be used as anti-virulence compounds, while compounds that inhibit the degradation of 3',3'-cGAMP, cA3, cA4, cA6 could serve as antibiotic adjuvants as the accumulation of these second messengers leads to bacterial abortive infection. In humans, 2'3'-cGAMP plays critical roles in antiviral and antitumor responses. ENPP1 (the 2'3'-cGAMP phosphodiesterase) or virally encoded cyclic dinucleotide phosphodiesterases, such as poxin, however, blunt this response. Inhibitors of ENPP1 or poxin-like enzymes have the potential to be used as anticancer and antiviral agents, respectively. This review summarizes efforts made towards the discovery and development of compounds that inhibit CDN phosphodiesterases and cON ring nucleases.

Trojan Horse-Like Vehicles for CRISPR-Cas Delivery: Engineering Extracellular Vesicles and Virus-Like Particles for Precision Gene Editing in Cystic Fibrosis

The advent of genome editing has kindled the hope to cure previously uncurable, life-threatening genetic diseases. However, whether this promise can be ultimately fulfilled depends on how efficiently gene editing agents can be delivered to therapeutically relevant cells. Over time, viruses have evolved into sophisticated, versatile, and biocompatible nanomachines that can be engineered to shuttle payloads to specific cell types. Despite the advances in safety and selectivity, the long-term expression of gene editing agents sustained by viral vectors remains a cause for concern. Cell-derived vesicles (CDVs) are gaining traction as elegant alternatives. CDVs encompass extracellular vesicles (EVs), a diverse set of intrinsically biocompatible and low-immunogenic membranous nanoparticles, and virus-like particles (VLPs), bioparticles with virus-like scaffold and envelope structures, but devoid of genetic material. Both EVs and VLPs can efficiently deliver ribonucleoprotein cargo to the target cell cytoplasm, ensuring that the editing machinery is only transiently active in the cell and thereby increasing its safety. In this review, we explore the natural diversity of CDVs and their potential as delivery vectors for the clustered regularly interspaced short palindromic repeats (CRISPR) machinery. We illustrate different strategies for the optimization of CDV cargo loading and retargeting, highlighting the versatility and tunability of these vehicles. Nonetheless, the lack of robust and standardized protocols for CDV production, purification, and quality assessment still hinders their widespread adoption to further CRISPR-based therapies as advanced "living drugs." We believe that a collective, multifaceted effort is urgently needed to address these critical issues and unlock the full potential of genome-editing technologies to yield safe, easy-to-manufacture, and pharmacologically well-defined therapies. Finally, we discuss the current clinical landscape of lung-directed gene therapies for cystic fibrosis and explore how CDVs could drive significant breakthroughs in in vivo gene editing for this disease.

Large Language Models in Genomics-A Perspective on Personalized Medicine

Integrating artificial intelligence (AI), particularly large language models (LLMs), into the healthcare industry is revolutionizing the field of medicine. LLMs possess the capability to analyze the scientific literature and genomic data by comprehending and producing human-like text. This enhances the accuracy, precision, and efficiency of extensive genomic analyses through contextualization. LLMs have made significant advancements in their ability to understand complex genetic terminology and accurately predict medical outcomes. These capabilities allow for a more thorough understanding of genetic influences on health issues and the creation of more effective therapies. This review emphasizes LLMs' significant impact on healthcare, evaluates their triumphs and limitations in genomic data processing, and makes recommendations for addressing these limitations in order to enhance the healthcare system. It explores the latest advancements in LLMs for genomic analysis, focusing on enhancing disease diagnosis and treatment accuracy by taking into account an individual's genetic composition. It also anticipates a future in which AI-driven genomic analysis is commonplace in clinical practice, suggesting potential research areas. To effectively leverage LLMs' potential in personalized medicine, it is vital to actively support innovation across multiple sectors, ensuring that AI developments directly contribute to healthcare solutions tailored to individual patients.

Role of the Intestinal Microbiota in the Molecular Pathogenesis of Atypical Parkinsonian Syndromes

The role of the intestinal microbiota and its influence on neurodegenerative disorders has recently been extensively explored, especially in the context of Parkinson's disease (PD). In particular, its role in immunomodulation, impact on inflammation, and participation in the gut-brain axis are under ongoing investigations. Recent studies have revealed new data that could be important for exploring the neurodegeneration mechanisms connected with the gut microbiota, potentially leading to the development of new methods of treatment. In this review, the potential roles of the gut microbiota in future disease-modifying therapies were discussed and the properties of the intestinal microbiota-including its impacts on metabolism and short-chain fatty acids and vitamins-were summarized, with a particular focus on atypical Parkinsonian syndromes. This review focused on a detailed description of the numerous mechanisms through which the microbiota influences neurodegenerative processes. This review explored potentially important connections between the gut microbiota and the evolution and progression of atypical Parkinsonian syndromes. Finally, a description of recently derived results regarding the microbiota alterations in atypical Parkinsonian syndromes in comparison with results previously described in PD was also included.

Lipid Nanoparticles for In Vivo Lung Delivery of CRISPR-Cas9 Ribonucleoproteins Allow Gene Editing of Clinical Targets

In the past 10 years, CRISPR-Cas9 has revolutionized the gene-editing field due to its modularity, simplicity, and efficacy. It has been applied for the creation of in vivo models, to further understand human biology, and toward the curing of genetic diseases. However, there remain significant delivery barriers for CRISPR-Cas9 application in the clinic, especially for in vivo and extrahepatic applications. In this work, high-throughput molecular barcoding techniques were used alongside traditional screening methodologies to simultaneously evaluate LNP formulations encapsulating ribonucleoproteins (RNPs) for in vitro gene-editing efficiency and in vivo biodistribution. This resulted in the identification of a lung-tropic LNP formulation, which shows efficient gene editing in endothelial and epithelial cells within the lung, targeting both model reporter and clinically relevant genomic targets. Further, this LNP shows no off-target indel formation in the liver, making it a highly specific extrahepatic delivery system for lung-editing applications.

Multiomics Studies on the Effects of High-Temperature Stress on Male Sterility in Gossypium barbadense

High-temperature (HT) stress has been recognized as one of the main factors restricting the normal growth and development of cotton and severely affects fiber quality and yield. To elucidate the regulatory mechanism of male sterility-related hormones in Gossypium barbadense under HT stress, we explored candidate genes closely related to male sterility in G. barbadense. We studied the expression profiles of hormones and genes in the anthers of G. barbadense GB150 under HT stress by combining transcriptomic and metabolomic analyses. Through a combined analysis of the transcriptional metabolism of the anthers of G. barbadense GB150, we determined the contents of ABA, JA, SA, IAA, tZR, and GA20 and the expression of genes related to biosynthetic pathways and signal transduction pathways. The results revealed that the ABA and JA contents significantly increased after HT; the IAA, tZR, and GA20 contents significantly decreased; and the SA content did not significantly change after HT. We then used weighted gene coexpression network analysis (WGCNA) to further analyze the interactions among hormones, transcription factors, and core genes and constructed hormone coexpression networks and genome-wide coexpression networks. Through these network analyses, we ultimately identified 10 candidate genes closely related to male sterility in G. barbadense. Using qRT-PCR, resequencing data from 221 G. barbadense materials revealed that ALA4 (Arabidopsis thaliana has been proven to be associated with male fertility) and SBP1 (two stop gains in the gene structure) may play important roles in the process of male sterility in G. barbadense. The results of this study provide a theoretical basis for the molecular mechanism of male sterility in G. barbadense.

Effect of RNA Demethylase FTO Overexpression on Biomass and Bioactive Substances in Diatom Phaeodactylum tricornutum

Phaeodactylum tricornutum is rich in bioactive substances, rendering it valuable in nutrition and medicine. Epigenetic editing mediated by human RNA demethylase FTO can significantly increase the yields of rice and potato and offers significant potential for the genetic breeding of microalgae. This study aimed to enhance the production of certain metabolites in P. tricornutum via FTO-mediated epigenetic editing. Phenotypic analysis revealed that transgenic P. tricornutum exhibits significantly reduced RNA m6A modification levels and faster growth, producing markedly higher levels of lipids, proteins, and carotenoids than the wild type. Transcriptome analysis revealed 1009 upregulated genes and 378 downregulated genes. KEGG analysis demonstrated the upregulated expression of multiple key enzymes involved in long-chain fatty acid synthesis (e.g., ACSL, fabF, and fabG), carotenoid synthesis (e.g., crtQ, PDS, and PSY1), and amino acid synthesis (e.g., dapF, glyA, and aroK) in transgenic P. tricornutum, consistent with our phenotypic results. These results indicate that FTO can promote growth and increase the bioactive compound content in P. tricornutum by regulating the m6A modification of RNA, and further suggest that FTO has the potential to serve as a new tool for the epigenetic editing of microalgae.

Unraveling the future of genomics: CRISPR, single-cell omics, and the applications in cancer and immunology

The CRISPR system has transformed many research areas, including cancer and immunology, by providing a simple yet effective genome editing system. Its simplicity has facilitated large-scale experiments to assess gene functionality across diverse biological contexts, generating extensive datasets that boosted the development of computational methods and machine learning/artificial intelligence applications. Integrating CRISPR with single-cell technologies has further advanced our understanding of genome function and its role in many biological processes, providing unprecedented insights into human biology and disease mechanisms. This powerful combination has accelerated AI-driven analyses, enhancing disease diagnostics, risk prediction, and therapeutic innovations. This review provides a comprehensive overview of CRISPR-based genome editing systems, highlighting their advancements, current progress, challenges, and future opportunities, especially in cancer and immunology.

Selict-seq profiles genome-wide off-target effects in adenosine base editing

Adenosine base editors (ABEs) facilitate A·T to G·C base pair conversion with significant therapeutic potential for correcting pathogenic point mutations in human genetic diseases, such as sickle cell anemia and β-thalassemia. Unlike CRISPR-Cas9 systems that induce double-strand breaks, ABEs operate through precise deamination, avoiding chromosomal instability. However, the off-target editing effects of ABEs remain inadequately characterized. In this study, we present a biochemical method Selict-seq, designed to evaluate genome-wide off-target editing by ABEs. Selict-seq specifically captures deoxyinosine-containing single-stranded DNA and precisely identifies deoxyadenosine-to-deoxyinosine (dA-to-dI) mutation sites, elucidating the off-target effects induced by ABEs. Through investigations involving three single-guide RNAs, we identified numerous unexpected off-target edits both within and outside the protospacer regions. Notably, ABE8e(V106W) exhibited distinct off-target characteristics, including high editing rates (>10%) at previously unreported sites (e.g. RNF2 and EMX1) and out-of-protospacer mutations. These findings significantly advance our understanding of the off-target landscape associated with ABEs. In summary, our approach enables an unbiased analysis of the ABE editome and provides a widely applicable tool for specificity evaluation of various emerging genome editing technologies that produce intermediate products as deoxyinosine.

Long-offset paired nicking-based efficient and precise strategy for in vivo targeted insertion

Clustered regularly interspaced short palindromic repeat (CRISPR)-based targeted insertion of DNA fragments holds great promise for gene therapy. However, designing highly efficient and precise integration of large DNA segments in somatic cells while avoiding unpredictable products remains challenging. Here, we devised a novel long-offset paired nicking target integration (LOTI) strategy, which enhances the capacity of Cas9 nickase (Cas9n) in targeted gene integration in somatic cells, yielding higher knock-in (KI) efficiency compared with classical nickase-based approaches. The underlying repair mechanism involves the DNA repair proteins Rad51 and Rad52, and Ligase I/III. Moreover, we achieved efficient KI of at least 1.5-kb gene fragments in hepatocytes and recovery 55% FIX activity in a hemophilia B mouse model using only one-dose plasmid DNA delivery. Compared with the Cas9-based strategy, LOTI reduces off-target activity and restricts the formulation of unwanted insertions and deletions (indels) at the target site. Thus, LOTI provides a precise and efficient strategy for gene integration in somatic cells in vivo.

SuperDecode: An integrated toolkit for analyzing mutations induced by genome editing

Genome editing using CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein) or other systems has become a cornerstone of numerous biological and applied research fields. However, detecting the resulting mutations by analyzing sequencing data remains time consuming and inefficient. In response to this issue, we designed SuperDecode, an integrated software toolkit for analyzing editing outcomes using a range of sequencing strategies. SuperDecode comprises three modules, DSDecodeMS, HiDecode, and LaDecode, each designed to automatically decode mutations from Sanger, high-throughput short-read, and long-read sequencing data, respectively, from targeted PCR amplicons. By leveraging specific strategies for constructing sequencing libraries of pooled multiple amplicons, HiDecode and LaDecode facilitate large-scale identification of mutations induced by single or multiplex target-site editing in a cost-effective manner. We demonstrate the efficacy of SuperDecode by analyzing mutations produced using different genome editing tools (CRISPR/Cas, base editing, and prime editing) in different materials (diploid and tetraploid rice and protoplasts), underscoring its versatility in decoding genome editing outcomes across different applications. Furthermore, this toolkit can be used to analyze other genetic variations, as exemplified by its ability to estimate the C-to-U editing rate of the cellular RNA of a mitochondrial gene. SuperDecode offers both a standalone software package and a web-based version, ensuring its easy access and broad compatibility across diverse computer systems. Thus, SuperDecode provides a comprehensive platform for analyzing a wide array of mutations, advancing the utility of genome editing for scientific research and genetic engineering.

Design of CoQ10 crops based on evolutionary history

Coenzyme Q (CoQ) is essential for energy production by mitochondrial respiration, and it is a supplement most often used to promote cardiovascular health. Humans make CoQ10, but cereals and some vegetable/fruit crops synthesize CoQ9 with a side chain of nine isoprene units. Engineering CoQ10 production in crops would benefit human health, but this is hindered by the fact that the specific residues of the enzyme Coq1 that control chain length are unknown. Based on an extensive investigation of the distribution of CoQ9 and CoQ10 in land plants and the associated Coq1 sequence variation, we identified key amino acid changes at the base of the Coq1 catalytic pocket that occurred independently in multiple angiosperm lineages and repeatedly drove CoQ9 formation. Guided by this knowledge, we used gene editing to modify the native Coq1 genes of rice and wheat to produce CoQ10, paving the way for developing additional dietary sources of CoQ10.

Selective targeting of oncogenic KRAS G12D using peptide nucleic acid oligomers attached to cell-penetrating peptides

KRAS is a proto-oncogene that contains activating mutations in up to 30% of tumors. Many conventional therapies inhibit both cancerous and normal cells, which may cause toxicity. Thus, programmable mutant-selective targeted inhibitors are needed. Peptide nucleic acids (PNAs) incorporate base sequences analogous to DNA, with modified peptide backbones instead of ribose-phosphate backbones, allowing PNAs to hybridize with DNA with high avidity to suppress transcription. Here, we developed KRAS G12D-selective PNA oligomers with novel cell-penetrating flanking regions. Fluorescein-labeled PNA oligomers displayed high uptake rates in cells and nuclei. Exposure to PNA-delivery peptide conjugates resulted in repression of KRAS G12D mRNA and protein expression within 2 hours and lasting up to 48 hours. Varying cell-penetrating peptide (CPP) compositions and lengths of complementary KRAS sequences were tested using dose-response cell viability assays. These experiments identified configurations that were effective at selectively preventing growth of on-target KRAS G12D cells, while relatively sparing off-target KRAS G12C cells. Electrophoretic mobility shift assays demonstrated in vitro binding and selectivity for KRAS G12D DNA sequences. CPP-PNA-G12D-1 was effective against a panel of pancreatic ductal adenocarcinoma cell lines and patient-derived xenografts in vivo . These results show promise for an enhanced PNA-delivery peptide conjugate strategy as both a tool for studying tumors driven by oncogenic point mutations and as a potential therapeutic strategy to selectively target mutant cancer cells.

Mapping Binding Domains of Viral and Allergenic Proteins with Dual-Cleavable Cross-Linking Technology

The dual-cleavable nature of the cross-linking technology (DUCCT) enhances the reliable identification of cross-linked peptides via mass spectrometry. The DUCCT approach uses a cross-linking agent that can be selectively cleaved by two different tandem mass spectrometry techniques: collision-induced dissociation (CID) and electron transfer dissociation (ETD). This results in distinct signatures in two independent mass spectra for the same cross-linked precursor, leading to unambiguous identification and the validation of the spectra. In this study, we expanded the application of the DUCCT cross-linker to evaluate the binding domains of a specific cat dander allergen, Fel d 1, which exists as the Fel d 1 A and B protein complex, and a viral spike protein from SARS-CoV-2, which invades host cells. To assess the cross-linked products obtained by DUCCT, we utilized a software tool called Cleave-XL, which effectively identified cross-linked sites using data from CID and ETD. Dual cleavable cross-linking studies identified cross-linked peptides in these complexes, which have been reported in bioinformatics analysis and proposed for immunotherapy using synthetic peptides. A benchmark study was also conducted using a commercial cross-linker disuccinimidyl suberate (DSS). Overall, we expect that DUCCT cross-linking technology will greatly facilitate the rapid screening of binding interfaces, thereby advancing structural biology and cell signaling investigations.

Engineering an optimized hypercompact CRISPR/Cas12j-8 system for efficient genome editing in plants

The Cas12j-8 nuclease, derived from the type V CRISPR system, is approximately half the size of Cas9 and recognizes a 5'-TTN-3' protospacer adjacent motif sequence, thus potentially having broad application in genome editing for crop improvement. However, its editing efficiency remains low in plants. In this study, we rationally engineered both the crRNA and the Cas12j-8 nuclease. The engineered crRNA and Cas12j-8 markedly improved genome editing efficiency in plants. When combined, they exhibited robust editing activity in soybean and rice, enabling the editing of target sites that were previously uneditable. Notably, for certain target sequences, the editing activity was comparable to that of SpCas9 when targeting identical sequences, and it outperformed the Cas12j-2 variant, nCas12j-2, across all tested targets. Additionally, we developed cytosine base editors based on the engineered crRNA and Cas12j-8, demonstrating an average increase of 5.36- to 6.85-fold in base-editing efficiency (C to T) compared with the unengineered system in plants, with no insertions or deletions (indels) observed. Collectively, these findings indicate that the engineered hypercompact CRISPR/Cas12j-8 system serves as an efficient tool for genome editing mediated by both nuclease cleavage and base editing in plants.

Application of Multiple Base-Editing Mediated by Polycistronic tRNA-gRNA-Processing System in Pig Cells

Gene edited pigs have extensive and important application value in the fields of agriculture and biomedicine. With the increasing demand in medical research and agricultural markets, more and more application scenarios require gene edited pigs to possess two or even more advantageous phenotypes simultaneously. The current production of multi gene edited pigs is inefficient, time-consuming, and costly, and there is an urgent need to develop efficient and accurate multi gene editing application technologies. The polycistronic tRNA-gRNA-processing system (PTG), developed based on endogenous tRNA self-processing systems, has been shown to exhibit efficient multi gene editing in plants. This study aims to combine a PTG strategy with multiple gRNA production functions with an adenine base editor (ABE) to test its feasibility for efficient and precise multi gene base editing in pig cells. The results indicate that the PTG based integrated ABE plasmid can perform efficient base editing at multiple gene loci in pig cells. And while the gene editing efficiency was significantly improved, no indel and sgRNA dependent off target effects caused by DSB were detected. This work permit will provide a solid foundation for the production of multi gene edited pigs with agricultural and medical applications.

Linking CRISPR-Cas9 double-strand break profiles to gene editing precision with BreakTag

Cas9 can cleave DNA in both blunt and staggered configurations, resulting in distinct editing outcomes, but what dictates the type of Cas9 incisions is largely unknown. In this study, we developed BreakTag, a versatile method for profiling Cas9-induced DNA double-strand breaks (DSBs) and identifying the determinants of Cas9 incisions. Overall, we assessed cleavage by SpCas9 at more than 150,000 endogenous on-target and off-target sites targeted by approximately 3,500 single guide RNAs. We found that approximately 35% of SpCas9 DSBs are staggered, and the type of incision is influenced by DNA:gRNA complementarity and the use of engineered Cas9 variants. A machine learning model shows that Cas9 incision is dependent on the protospacer sequence and that human genetic variation impacts the configuration of Cas9 cuts and the DSB repair outcome. Matched datasets of Cas9 and engineered variant incisions with repair outcomes show that Cas9-mediated staggered breaks are linked with precise, templated and predictable single-nucleotide insertions, demonstrating that a scission-based gRNA design can be used to correct clinically relevant pathogenic single-nucleotide deletions.

Efficient Intracellular Delivery of CRISPR-Cas9 Ribonucleoproteins Using Dendrimer Nanoparticles for Robust Genomic Editing

CRISPR-Cas9, a flexible and efficient genome editing technology, is currently limited by the challenge of delivering the large ribonucleoprotein complex intracellularly and into the nucleus. Existing delivery techniques/vectors are limited by their toxicity, immunogenicity, scalability, and lack of specific cell-targeting ability. This study presents a neutral, non-toxic dendrimer conjugate construct that shows promise in overcoming these limitations. We covalently-conjugated S. pyogenes Cas9-2NLS (Cas9-nuclear localization sequence) endonuclease to a hydroxyl PAMAM dendrimer through a glutathione-sensitive disulfide linker via highly specific inverse Diels-alder click reaction (IEDDA), and a single guide RNA (sgRNA) was complexed to the Cas9-dendrimer conjugate nano-construct (D-Cas9). D-Cas9- RNP produces robust genomic deletion in vitro of GFP in HEK293 cells (~100%) and VEGF in a human pigmental epithelium cell line (ARPE-19) (20%). The uptake of the D-Cas9-RNP constructs on similar timescales as small molecules highlights the robustness of the biophysical mechanisms enabling the dendrimer to deliver payloads as large as Cas9, while retaining payload functionality. This promising conjugation approach enabled better stability to the neutral construct. Combined with recent advances in hydroxyl dendrimer delivery technologies in the clinic, this approach may lead to advances in 'neutral' dendrimer-enabled non-toxic, cell-specific, highly efficient in vitro and in vivo genome editing.

Engineering Mice to Study Human Immunity

Humanized mice, which carry a human hematopoietic and immune system, have greatly advanced our understanding of human immune responses and immunological diseases. These mice are created via the transplantation of human hematopoietic stem and progenitor cells into immunocompromised murine hosts further engineered to support human hematopoiesis and immune cell growth. This article explores genetic modifications in mice that enhance xeno-tolerance, promote human hematopoiesis and immunity, and enable xenotransplantation of human tissues with resident immune cells. We also discuss genetic editing of the human immune system, provide examples of how humanized mice with humanized organs model diseases for mechanistic studies, and highlight the roles of these models in advancing knowledge of organ biology, immune responses to pathogens, and preclinical drugs tested for cancer treatment. The integration of multi-omics and state-of-the art approaches with humanized mouse models is crucial for bridging existing human data with causality and promises to significantly advance mechanistic studies.

Discussion on the treatment of diabetic kidney disease based on the "gut-fat-kidney" axis

Diabetic kidney disease is the main cause of end-stage renal disease, and its prevention and treatment are still a major clinical problem. The human intestine has a complex flora of hundreds of millions of microorganisms, and intestinal microorganisms, and their derivatives are closely related to renal inflammatory response, immune response, and material metabolism. Brown adipose tissue is the main part of adaptive thermogenesis. Recent studies have shown that activating brown fat by regulating intestinal flora has good curative effects in diabetic kidney disease-related diseases. As an emerging medical concept, the "gut-fat-kidney" axis has received increasing attention in diabetic kidney disease and related diseases. However, the specific mechanism involved needs further study. A new theoretical basis for the prevention and treatment of diabetic kidney disease is presented in this article, based on the "gut-fat-kidney" axis.

Research advances CRISPR gene editing technology generated models in the study of epithelial ovarian carcinoma

Epithelial ovarian carcinoma (EOC), the most lethal gynecologic cancer, is often diagnosed at advanced stages, which urge us to explore the novel therapeutic strategies. Mouse models have played a crucial role in elucidating the molecular mechanisms for the development ovarian cancer and its therapeutic strategies. However, there are still various challenges in modeling the genetic drivers of ovarian cancer in animal models. Here, we provided an overview of the research advances for the molecular mechanisms underlying EOC development, therapeutic strategies, the CRISPR genome editing technology and its generated EOC models. The review also comprehensively discussed the advantages and obstacles of CRISPR in generating EOC mouse models and the promising therapeutic approach by correcting the oncogenes of EOC through in vivo delivery of gene-edited components. The development of more precise animal models, along with a deeper understanding of EOC molecular mechanisms, will dramatically benefit the investigation and treatment of EOC.

Systematic high-throughput evaluation reveals FrCas9's superior specificity and efficiency for therapeutic genome editing

CRISPR-Cas9 systems have revolutionized genome editing, but the off-target effects of Cas9 limit its use in clinical applications. Here, we systematically evaluate FrCas9, a variant from Faecalibaculum rodentium, for cell and gene therapy (CGT) applications and compare its performance to SpCas9 and OpenCRISPR-1. OpenCRISPR-1 is a CRISPR system synthesized de novo using large language models (LLMs) but has not yet undergone systematic characterization. Using AID-seq, Amplicon sequencing, and GUIDE-seq, we assessed the on-target activity and off-target profiles of these systems across multiple genomic loci. FrCas9 demonstrated higher on-target efficiency and substantially fewer off-target effects than SpCas9 and OpenCRISPR-1. Furthermore, TREX2 fusion with FrCas9 reduced large deletions and translocations, enhancing genomic stability. Through screening of 1903 sgRNAs targeting 21 CGT-relevant genes using sequential AID-seq, Amplicon sequencing, and GUIDE-seq analysis, we identified optimal sgRNAs for each gene. Our high-throughput screening platform highlights FrCas9, particularly in its TREX2-fused form, as a highly specific and efficient tool for precise therapeutic genome editing.

BGC heteroexpression strategy for production of novel microbial secondary metabolites

Biosynthetic gene clusters (BGCs) in microbial genomes play a crucial role in the biosynthesis of diverse secondary metabolites (SMs) with pharmaceutical potential. However, most BGCs remain silent under conventional conditions, resulting in the frequently repeated discovery of known SMs. Fortunately, in the past two decades, the heterologous expression of BGCs in genetically tractable hosts has emerged as a powerful strategy to awaken microbial metabolic pathways for making novel microbial SMs. In this review, we comprehensively delineated the development and application of this strategy, highlighting various BGC cloning and assembly techniques and their technical characteristics. We also summarized 519 novel SMs from BGC hetero-expression-derived strains and described their occurrence, bioactivity, mode of action, and biosynthetic logic. Lastly, current challenges and future perspectives for developing more efficient BGC hetero-expression strategies were discussed in this review.

Specific and efficient RNA A-to-I editing through cleavage of an ADAR inhibitor

RNA editing can be a promising therapeutic approach. However, ectopic expression of RNA editing enzymes has been shown to trigger off-target editing. Here we identified adenosine deaminase acting on RNA (ADAR) inhibitors (ADIs) that suppress the activity of the fused ADAR2 deamination domain (ADAR2DD). Using these specific ADIs, we develop an RNA transformer adenosine base editor (RtABE) with high specificity. Fusing ADI to ADAR2DD, RtABE remains inactive until it binds to its target site. After binding to the target site, ADI is cleaved from ADAR2DD, and RtABE becomes active. RtABE can induce efficient editing in broad sequence contexts, including UAN, AAN, CAN and GAN. Using an adeno-associated virus for delivery of RtABE enables therapeutic RNA correction and restoration of α-L-iduronidase activity in Hurler syndrome mice with no substantial off-target editing. RtABE is a specific and efficient RNA editing system with a broad scope that may be a better alternative to existing RNA editing tools.

Directed evolution expands CRISPR-Cas12a genome editing capacity

CRISPR-Cas12a enzymes are versatile RNA-guided genome-editing tools with applications encompassing viral diagnosis, agriculture and human therapeutics. However, their dependence on a 5'-TTTV-3' protospacer-adjacent motif (PAM) next to DNA target sequences restricts Cas12a's gene targeting capability to only ∼1% of a typical genome. To mitigate this constraint, we used a bacterial-based directed evolution assay combined with rational engineering to identify variants of Lachnospiraceae bacterium Cas12a (LbCas12a) with expanded PAM recognition. The resulting Cas12a variants use a range of non-canonical PAMs while retaining recognition of the canonical 5'-TTTV-3' PAM. In particular, biochemical and cell-based assays show that the variant Flex-Cas12a utilizes 5'-NYHV-3' PAMs that expand DNA recognition sites to ∼25% of the human genome. With enhanced targeting versatility, Flex-Cas12a unlocks access to previously inaccessible genomic loci, providing new opportunities for both therapeutic and agricultural genome engineering.