Aberrant TGF-β1 signaling activation by MAF underlies pathological lens growth in high myopia

High myopia is a leading cause of blindness worldwide. Myopia progression may lead to pathological changes of lens and affect the outcome of lens surgery, but the underlying mechanism remains unclear. Here, we find an increased lens size in highly myopic eyes associated with up-regulation of β/γ-crystallin expressions. Similar findings are replicated in two independent mouse models of high myopia. Mechanistic studies show that the transcription factor MAF plays an essential role in up-regulating β/γ-crystallins in high myopia, by direct activation of the crystallin gene promoters and by activation of TGF-β1-Smad signaling. Our results establish lens morphological and molecular changes as a characteristic feature of high myopia, and point to the dysregulation of the MAF-TGF-β1-crystallin axis as an underlying mechanism, providing an insight for therapeutic interventions.

Phakochronology - The Forgotten Science

A 30 year old male, had history of bomb blast injury to the face 24 months ago with multiple foreign bodies perforating the eye (operated for vitrectomy and foreign body explant). The iris entry wound and the cataract caused by one such foreign body is shown in (Figure 1a). The opacity in the lens substance (Figure 1b) is 156 microns behind the anterior lens capsule (Figure 1c) (meaning growth of these much lens fresh clear lens fibres over the time has pushed the lens opacity backwards which earlier would have been on the surface). Calculating by phakochronology [1], we would like to report the in-vivo lens growth in this patient to be 6.5 microns/month.

Breaking it Down: Mechanical Processes in the Weathering Engine

The vast diversity of landscapes found on Earth results from interplay between processes that break rock down, produce mobile regolith, and transport materials away. Mechanical weathering is fundamental to shaping landscapes, yet it is perhaps less understood at a mechanistic level than chemical weathering. Ubiquitous microfractures in rock propagate and grow through a slow process known as subcritical cracking that operates at the low applied stresses common in the near-surface. Subcritical cracking is the most likely explanation for the mechanical processes associated with thermal stress, ice lens growth, mineral alteration, and root growth. The long timescales over which critical zone architectures develop require an understanding of slow processes, such as subcritical cracking.