In our first Research Roundup we present five studies. The first four, published this year, may give some Dry Eye patients hope. The fifth, from last year, reveals new insights about demodex mites.
The topics of these studies – lacrimal glands, quality of life, contact lenses, and demodex mites – themselves show how complex Dry Eye really is. There are many different conditions under the Dry Eye umbrella, a lot of potential causes, and numerous possible symptoms.
The first two studies discuss lacrimal glands in mice with Sjogren’s aqueous deficiency. One examines stem/cell progenitor cells as a potential treatment for chronically inflamed human lacrimal glands. The other looks at changes in aging lacrimal glands, and concludes that TSP1 (thrombospondin 1), is necessary for maintaining their health.
The third study is not about Dry Eye, but about vision and social status. It suggests that impaired vision can have a profound impact on quality of life. Dry Eye can affect vision. So clearly, the quality of life for these patients can be affected too. (The same could be said for those with Dry Eye whose vision per se may not be affected, but ocular discomfort has impacted their quality of life). For some, the impact can be devastating.
The fourth study looks at contact lenses and how bacteria can alter eye tissue. It should be of no surprise by now that contact lenses can cause inflammation and ocular discomfort. This study may lead to new therapies for inflammation due to eye infections.
The fifth study may interest you if you think you have demodex mites, and wonder where they came from. The answer is they were around way before humans inhabited the earth, and probably came from someone close to you. No wonder they can be hard to get rid of .
Lacrimal Glands, Quality of Life, Contact Lenses, and Demodex Mites
Lacrimal gland repair using progenitor cells
Gromova A, Voronov DA, Yoshida M, Thotakura S, Meech R, Dartt DA, Makarenkova HP.
Stem Cells Translational Medicine
2016 Aug 15. pii: sctm.2016-0191. [Epub ahead of print]
This study demonstrates, for the first time, that epithelial cell progenitors (EPCPs) can mediate functional recovery of the lacrimal gland in a Sjögren’s syndrome mouse model. These data establish proof of concept that endogenous stem/progenitor cell transplantation may be used to treat human lacrimal gland chronic inflammation.
Alteration in cellular turnover and progenitor cell population in lacrimal glands from thrombospondin 1-/- mice, a model of Dry Eye
Shatos MA, Hodges RR, Morinaga M, McNay DE, Islam R, Bhattacharya S, Li D, Turpie B, Makarenkova HP, Masli S, Utheim TP, Dartt DA.
Experimental Eye Research
2016 Sep 30. pii: S0014-4835(16)30308-6. doi: 10.1016/j.exer.2016.09.011. [Epub ahead of print]
We conclude that thrombospondin 1 (TSP1) is necessary for maintaining normal lacrimal gland (LG) homeostasis. Absence of TSP1 alters cytokine levels and stem cell transcription factors, LG cellular architecture, decreases cell proliferation, and alters amount of stem cell markers.
Visual function, social position, and health and life chances: The UK Biobank study
Cumberland PM, Rahi JS, UK Biobank Eye and Vision Consortium
JAMA Ophthalmology
2016 Sep 1;134(9):959-66. doi: 10.1001/jamaophthalmol.2016.1778.
Impaired vision in adults is common, and even near-normal vision, potentially unrecognized without assessment, has a tangible influence on quality of life.
New mechanism causing eye inflammation
Medical News Today
2016 June 21
According to Medical News Today, “researchers discovered that a common bacterial contaminant of contact lenses and cases can cause the formation of large bubble-like membrane structures on human ocular cells, which can contribute to contact lens wear complications and inflammation.
Contact lens use is a major risk factor for contracting microbial keratitis, yet the reasons for this increased risk are not well understood.
‘Use of contacts lenses is so prevalent, yet until now, we’ve had limited understanding of how bacteria, associated with contacts lenses and cases, damage cells on the surface of the eye. Our study paves the way for new therapies that alleviate inflammation associated with these often serious eye infections,’ said Robert Shanks, PhD, Associate Professor, Charles T. Campbell Laboratory of Ophthalmic Microbiology, Department of Ophthalmology, UPMC Eye Center, University of Pittsburgh.
The researchers observed bacteria including Proteus mirabilis and Serratia marcescens that cause eye and other infections, induce major morphological changes in the surface of epithelial and other cell types. ‘These changes look like large membrane bubbles on the human cell surface, noted here as blebs,’ said Shanks. Cells that experience the blebs do not survive.
Global divergence of the human follicle mite demodex folliculorum: persistent associations between host ancestry and mite lineages
Palopoli MF, Fergus DJ, Minot S, Pei DT, Simison WB, Fernandez-Silva I, Thoemmes MS, Dunn RR, Trautwein M
Proceedings of the National Academy of Sciences of the United States of America
2015 Dec 29;112(52):15958-63. doi: 10.1073/pnas.1512609112. Epub 2015 Dec 14.
Microscopic mites of the genus Demodex live within the hair follicles of mammals and are ubiquitous symbionts of humans… Phylogenetic analyses recovered multiple deep lineages including a globally distributed lineage common among hosts of European ancestry and three lineages that primarily include hosts of Asian, African, and Latin American ancestry… We found that D. folliculorum populations are stable on an individual over the course of years and that some Asian and African American hosts maintain specific mite lineages over the course of years or generations outside their geographic region of birth or ancestry. D. folliculorum haplotypes were much more likely to be shared within families and between spouses than between unrelated individuals, indicating that transmission requires close contact. Dating analyses indicated that D. folliculorum origins may predate modern humans.
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