Light-focusing human micro-lenses generated from pluripotent stem cells model lens development and drug-induced cataract in vitro

Abstract

Cataracts cause vision loss and blindness by impairing the ability of the ocular lens to focus light onto the retina. Various cataract risk factors have been identified, including drug treatments, age, smoking and diabetes. However, the molecular events responsible for these different forms of cataract are ill-defined, and the advent of modern cataract surgery in the 1960s virtually eliminated access to human lenses for research. Here, we demonstrate large-scale production of light-focusing human micro-lenses from spheroidal masses of human lens epithelial cells purified from differentiating pluripotent stem cells. The purified lens cells and micro-lenses display similar morphology, cellular arrangement, mRNA expression and protein expression to human lens cells and lenses. Exposing the micro-lenses to the emergent cystic fibrosis drug Vx-770 reduces micro-lens transparency and focusing ability. These human micro-lenses provide a powerful and large-scale platform for defining molecular disease mechanisms caused by cataract risk factors, for anti-cataract drug screening and for clinically relevant toxicity assays.

The Development, Growth, and Regeneration of the Crystalline Lens: A Review

“…57 The capsulorhexis technique used by Lin et al is an important advancement in regenerative ophthalmology and by minimizing damage to the capsule allows for the conditions necessary for lens regeneration to take place and opens up avenues of research. 56,57 In addition to the promising clinical trials of Lin et al, 56 a recent in vivo study by Murphy et al 132 opens a new avenue of study for lens regeneration research by producing light focusing micro-lenses from pluripotent stem cells. These micro-lenses provide a new platform with which to study lens regeneration without the complications posed by animal studies while more closely matching the human regenerative response.…”

Modeling ocular lens disease in Xenopus

“…Other compounds could certainly be screened in preclinical approaches to isolate novel molecules with a potential to enter clinical trials against cataracts. A promising tool toward this goal is the “micro‐lens” obtained in vitro by differentiation of human stem cells . However, this organoid does not recapitulate the normal environment or the barriers of the eye (especially the cornea) that may prevent molecules of potential pharmaceutical interest to access to the lens.…”

“…2D cell culture models only recapitulate a tiny part of the molecular events leading to cataracts. A 3D cell culture model (lens organoid) was recently developed as a promising in vitro model . Animal models of cataract are the zebrafish “cloche” mutants, which tend to have lens defects suggestive of cataracts, and mammals like rodents, rabbits or dogs .…”

Inherited cataracts: molecular genetics, clinical features, disease mechanisms and novel therapeutic approaches

“…15 This programme can be mimicked in culture conditions to determine the differentiation pathway of pluripotent cells and their derivatives. 16 The lens placode invaginates to form the lens pit ( figure 1C), which makes a complete circle of cells and detaches from the surface ectoderm to develop into the lens vesicle (figure 1D). By the end of week 4 (Carnegie stages 10-13), the cells from the posterior vesicle start elongating towards the anterior epithelial cell layer to become the primary lens fibres that fill the lens vesicle and later become the embryonic nucleus of the mature lens ( figure 1E).…”

“…In the early optic cup stage, the lens vesicle releases signals that induce the overlying surface ectoderm to differentiate into the corneal epithelium. Around weeks 6-7 (Carnegie stages [16][17][18][19], lens fibres start to develop from the epithelial cells located at the equator where they begin to elongate and differentiate into the secondary lens fibres (fetal nucleus) of the developing lens ( figure 1F). Around week 8 (Carnegie stage 20), the Y-shaped suture appears at the anterior and posterior poles of the embryonic nucleus of the lens as a result of the terminal ends of the secondary lens fibres abutting each other.…”