Generation of a Hutchinson-Gilford progeria syndrome monkey model by base editing

Many human genetic diseases, including Hutchinson-Gilford progeria syndrome (HGPS), are caused by single point mutations. HGPS is a rare disorder that causes premature aging and is usually caused by a de novo point mutation in the LMNA gene. Base editors (BEs) composed of a cytidine deaminase fused to CRISPR/Cas9 nickase are highly efficient at inducing C to T base conversions in a programmable manner and can be used to generate animal disease models with single amino-acid substitutions. Here, we generated the first HGPS monkey model by delivering a BE mRNA and guide RNA (gRNA) targeting the LMNA gene via microinjection into monkey zygotes. Five out of six newborn monkeys carried the mutation specifically at the target site. HGPS monkeys expressed the toxic form of lamin A, progerin, and recapitulated the typical HGPS phenotypes including growth retardation, bone alterations, and vascular abnormalities. Thus, this monkey model genetically and clinically mimics HGPS in humans, demonstrating that the BE system can efficiently and accurately generate patient-specific disease models in non-human primates.

Differential stem cell aging kinetics in Hutchinson-Gilford progeria syndrome and Werner syndrome

Hutchinson-Gilford progeria syndrome (HGPS) and Werner syndrome (WS) are two of the best characterized human progeroid syndromes. HGPS is caused by a point mutation in lamin A (LMNA) gene, resulting in the production of a truncated protein product-progerin. WS is caused by mutations in WRN gene, encoding a loss-of-function RecQ DNA helicase. Here, by gene editing we created isogenic human embryonic stem cells (ESCs) with heterozygous (G608G/+) or homozygous (G608G/G608G) LMNA mutation and biallelic WRN knockout, for modeling HGPS and WS pathogenesis, respectively. While ESCs and endothelial cells (ECs) did not present any features of premature senescence, HGPS- and WS-mesenchymal stem cells (MSCs) showed aging-associated phenotypes with different kinetics. WS-MSCs had early-onset mild premature aging phenotypes while HGPS-MSCs exhibited late-onset acute premature aging characterisitcs. Taken together, our study compares and contrasts the distinct pathologies underpinning the two premature aging disorders, and provides reliable stem-cell based models to identify new therapeutic strategies for pathological and physiological aging.

Effects of rapamycin induced cellular autophagy in aging-related diseases / 中国药理学通报

Mammalian target of rapamycin( mTOR) is a key reg-ulator of aging and aging-related diseases. Rapamycin ( RAPA) induces and promotes the process of cell autophagy through in-hibiting mTOR pathway. Autophagy exerts a crucial role in main-taining the cellular meostasis, which provides essential materials for cell reconstruction, regeneration and repair via degradating the redundant, damaged, or senescent proteins and organelles. Hutchinson Gilford progeria syndrome ( HGPS ) patients are al-ways accompanied with abnormally accumulated progerin in cells. Similar to HGPS, abnormal protein accumulation is the common pathological feature of neurodegenerative diseases, in-cluding Huntington′s disease, Parkinson′s disease, Alzheimer′s disease and so on. Degradation of these abnormal proteins pre-dominantly depends on cell autophagy. Thus, rapamycin is a po-tential anti-aging drug for HGPS and aging-related diseases thera-py. This view focuses on the effects of rapamycin on cell autoph-agy and clinical application in HGPS and neurodegenerative dis-eases.

Progeria.

Hutchinson Gilford Progeria Syndrome (HGPS) is a rare, sporadic, autosomal dominant syndrome that involves premature ageing and death at early age due to myocardial infarction or stroke. A 30-year-old male with clinical and radiologic features highly suggestive of HGPS is presented here with description of differential diagnosis, dental considerations and review of literature.