Genome engineering using the CRISPR/Cas system

Recently, an epoch-making genome engineering technology using clustered regularly at interspaced short palindromic repeats(CRISPR) and CRISPR associated(Cas) nucleases, was developed. Previous technologies for genome manipulation require the time-consuming design and construction of genome-engineered nucleases for each target and have, therefore, not been widely used in mouse research where standard techniques based on homologous recombination are commonly used. The CRISPR/Cas system only requires the design of sequences complementary to a target locus, making this technology fast and straightforward. In addition, CRISPR/Cas can be used to generate mice carrying mutations in multiple genes in a single step, an achievement not possible using other methods. Here, we review the uses of this technology in genetic analysis and manipulation, including achievements made possible to date and the prospects for future therapeutic applications.

Modulation of mitochondrial bioenergetics as a therapeutic strategy in Alzheimer＇s disease

Alzheimer’s disease （AD） is an increasingly pressing worldwide public-health, social, political and economic concern. Despite significant investment in multiple traditional therapeutic strategies that have achieved success in preclinical models addressing the pathological hallmarks of the disease, these efforts have not translated into any effective disease-modifying therapies. This could be because interventions are being tested too late in the disease process. While existing therapies provide symptomatic and clinical benefit, they do not fully address the molecular abnormalities that occur in AD neurons. The pathophysiology of AD is complex; mitochondrial bioenergetic deficits and brain hypometabolism coupled with increased mitochondrial oxidative stress are antecedent and potentially play a causal role in the disease pathogenesis. Dysfunctional mitochondria accumulate from the combination of impaired mitophagy, which can also induce injurious inflammatory responses, and inadequate neuronal mitochondrial biogenesis. Altering the metabolic capacity of the brain by modulating/potentiating its mitochondrial bioenergetics may be a strategy for disease prevention and treatment. We present insights into the mechanisms of mitochondrial dysfunction in AD brain as well as an overview of emerging treatments with the potential to prevent, delay or reverse the neurodegenerative process by targeting mitochondria.

Gene editing particle system as a therapeutic approach for drug-resistant colorectal cancer

The epidermal growth factor receptor(EGFR)pathway plays an important role in the progression of colorectal cancer(CRC).Anti-EGFR drugs based on antibodies have been widely used for treating CRC through inducing the cell death pathway.However,the majority of CRC patients will inevitably develop drug-resistance during anti-EGFR drug treatment,which is mainly caused by a point mutation in the KRAS oncogene.We developed a nanoliposomal(NL)particle containing the Cas9 protein and a single-guide RNA(sgRNA)complex(Cas9-RNP),for genomic editing of the KRAS mutation.The NL particle is composed of bio-compatible lipid compounds that can effectively encapsulate Cas9-RNP.By modifying the NL particle to include the appropriate antibody,it can specifically recognize EGFR expressing CRC and effectively deliver the gene-editing complexes.The conditions of NL treatment were optimized using a KRAS mutated CRC in vivo mouse model.Mice with KRAS-mutated CRC showed drug resistance against cetuximab,a therapeutic antibody drug.After treating the mice with the KRAS gene-editing NL particles,the implanted tumors showed a dramatic decrease in size.Our results demonstrated that this genomic editing complex has great potential as a therapeutic carrier system for the treatment of drug-resistant cancer caused by a point mutation.