Purchase this article with an account.
SEUNGWON AN, Eunjae Kim, Disha Varma, ILANGOVAN RAJU, Anubhav Pradeep, Christine Mun, Anna Ahn, Azucena Lopez, Zhiqiang Liu, Sandeep Jain; Semaphorin 7a is differentially expressed in myeloid-derived suppressor cells (MDSCs) under naïve and inflammatory conditions.. Invest. Ophthalmol. Vis. Sci. 2017;58(8):153.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We have previously reported expression of neurotrophic factors (NGF and Sema7a) in the cornea. We also reported that MDSCs migrate into the cornea during nerve regeneration. Here, we determine whether MDSCs are a source of Semaphorin 7a (Sema7a) and nerve growth factors (NGF) under naïve, wound healing and inflammatory condition.
YFP fluorescent MDSCs (YFP-MDSCs) were harvested from bone marrow of Thy1-YFP mice (8-10week old) and sorted using the Legacy MoFlo cell sorter. Sorted YFP-MDSCs (>95% purity) were cultured in DMEM under various conditions (serum free for naïve condition, 10% FBS addition for wound healing condition and 40 ng/ml of GM-CSF addition for inflammatory condition). Cell viability was determined under different culture conditions over 42 hours and Sema7a expression was analyzed by immunofluorescence and flow cytometry. The expression of surface markers on YFP-MDSCs was analyzed by mass cytometry. Similar conditions (naïve, 1M NaOH corneal alkali burn for inflammatory condition, epithelial debridement for wound healing condition, and laser transection of corneal stromal nerves for neurotrophic condition) were created in vivo in Thy1-YFP mouse (n=5/group). The total number of YFP+ cells migration was counted. The gene expression of Sema7a was analyzed by qPCR.
YFP-MDSCs showed significant differential expression of neurotrophic factors (Sema7a and NGF) under various culture conditions. NGF, but not Sema7a, was robustly expressed in serum free condition (naive condition) and after addition of 10% FBS (wound healing condition). Also NGF, but not Sema7a, was robustly expressed after corneal nerve transection (9-fold) and in corneas with epithelial debridement (2-fold). However, in inflammatory condition, Sema7a was much more robustly expressed as compared to NGF. A significant increase of Sema7a expression (78-fold) was noticed after GM-CSF addition (inflammatory condition). Sema7a was also robustly expressed in alkali burn corneas (14.5-fold).
NGF is the predominantly expressed neurotrophic factor in naïve corneas and after wound healing. Sema7a is the predominantly expressed neurotrophic factor in inflammatory condition.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only