Corneal stromal regeneration-keratoconus cell therapy: a review.

BACKGROUND: Keratoconus is a corneal ectatic disease caused by stromal thinning leading to astigmatism and progressive loss of vision. Loss of the keratocytes and excessive degradation of collagen fibres by matrix metalloproteinases are the molecular signatures of the disease. Despite several limitations, corneal collagen cross-linking and keratoplasty are the most widely used treatment options for keratoconus. In the pursuit of alternative treatment modalities, clinician scientists have explored cell therapy paradigms for treating the condition. METHODS: Articles pertaining to keratoconus cell therapy with relevant key words were used to search in PubMed, Researchgate, and Google Scholar. The articles were selected based on their relevance, reliability, publication year, published journal, and accessibility. RESULTS: Various cellular abnormalities have been reported in keratoconus. Diverse cell types such as mesenchymal stromal cells, dental pulp cells, bone marrow stem cells, haematopoietic stem cells, adipose-derived stem cells apart from embryonic and induced pluripotent stem cells can be used for keratoconus cell therapy. The results obtained show that there is a potential for these cells from various sources as a viable treatment option. CONCLUSION: There is a need for consensus with respect to the source of cells, mode of delivery, stage of disease, and duration of follow-up, to establish a standard operating protocol. This would eventually widen the cell therapy options for corneal ectatic diseases beyond keratoconus.

Resveratrol for dry eye disease - Hope or Hype?

Dry eye disease (DED) is a multifactorial and common ophthalmic disease that has a tremendous effect on the quality of life. It is now becoming a public health concern because of our changing lifestyle and environment. The current treatment modalities, artificial tear substitutes, and anti-inflammatory therapy are directed at dry eye symptoms. One of the major drivers for DED is oxidative stress, and the polyphenol group of natural compounds has the potential to reduce the same. Resveratrol, widely found in the skin of grapes and nuts, has antioxidative and anti-inflammatory properties. It has been shown to have beneficial effects in glaucoma, age-related macular degeneration, retinopathy of prematurity, uveitis, and diabetic retinopathy. Studies have also explored the beneficial effects of resveratrol in DED, making it as a promising therapeutic molecule. Resveratrol has not yet reached clinical application because of difficulty in deliverability and low bioavailability. In this review, we explore the potential of resveratrol in DED treatment based on various in vitro and in vivo studies.

A class of circadian long non-coding RNAs mark enhancers modulating long-range circadian gene regulation.

Circadian rhythm exerts its influence on animal physiology and behavior by regulating gene expression at various levels. Here we systematically explored circadian long non-coding RNAs (lncRNAs) in mouse liver and examined their circadian regulation. We found that a significant proportion of circadian lncRNAs are expressed at enhancer regions, mostly bound by two key circadian transcription factors, BMAL1 and REV-ERBα. These circadian lncRNAs showed similar circadian phases with their nearby genes. The extent of their nuclear localization is higher than protein coding genes but less than enhancer RNAs. The association between enhancer and circadian lncRNAs is also observed in tissues other than liver. Comparative analysis between mouse and rat circadian liver transcriptomes showed that circadian transcription at lncRNA loci tends to be conserved despite of low sequence conservation of lncRNAs. One such circadian lncRNA termed lnc-Crot led us to identify a super-enhancer region interacting with a cluster of genes involved in circadian regulation of metabolism through long-range interactions. Further experiments showed that lnc-Crot locus has enhancer function independent of lnc-Crot's transcription. Our results suggest that the enhancer-associated circadian lncRNAs mark the genomic loci modulating long-range circadian gene regulation and shed new lights on the evolutionary origin of lncRNAs.