Alteration in cellular turnover and progenitor cell population in lacrimal glands from thrombospondin 1 −/− mice, a model of dry eye

Abstract

The purpose of this study was to investigate the changes that occur in the lacrimal glands (LGs) in female thrombospondin 1 knockout (TSP1−/−) mice, a mouse model of the autoimmune disease Sjogren’s syndrome. The LGs of 4, 12, and 24 week-old female TSP1−/− and C57BL/6J (wild type, WT) mice were used. qPCR was performed to measure cytokine expression. To study the architecture, LG sections were stained with hematoxylin and eosin. Cell proliferation was measured using bromo-deoxyuridine and immunohistochemistry. Amount of CD47 and stem cell markers was analyzed by western blot analysis and location by immunofluorescence microscopy. Expression of stem cell transcription factors was performed using Mouse Stem Cell Transcription Factors RT2 Profiler PCR Array. Cytokine levels significantly increased in LGs of 24 week-old TSP1−/− mice while morphological changes were detected at 12 weeks. Proliferation was decreased in 12 week-old TSP1−/− mice. Three transcription factors were overexpressed and eleven underexpressed in TSP1−/− compared to WT LGs. The amount of CD47, Musashi1, and Sox2 was decreased while the amount of ABCG2 was increased in 12 week-old TSP1−/− mice. We conclude that TSP1 is necessary for maintaining normal 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.

Manipulation of Panx1 Activity Increases the Engraftment of Transplanted Lacrimal Gland Epithelial Progenitor Cells

“…Thus, the TSP1 −/− mouse fully mimics the development of chronic autoimmune dry eye disease in humans. 42 , 43 …”

“…As demonstrated previously, inflammation in TSP1 −/− LGs starts at approximately 10 to 12 weeks as periductal lymphocytic infiltrates 14 , 43 and could be found in periacinar regions at 3 to 4 months of age. 42 , 43 Thus, injections were started when TSP-1 −/− mice were around 4 months old and performed once a week for at least 5 weeks. We injected the right LGs of female TSP-1 −/− mice with a Panx1 or Casp4(11) sdRNAi, whereas the LGs on the other side were injected with a control sdRNAi or vehicle.…”

“…The analysis of EPCP engraftment showed a significant and reproducible positive correlation between these treatments and the number of engrafted cells per cross section, with an average increase of engrafted cells of approximately 63% after 10 panx treatment and 169% after Panx1 sdRNAi treatment relative to untreated controls. Similarly, treatment of the LGs of thrombospondin-1–null ( TSP-1 −/− ) mice, a recently reported model of chronic LG inflammation, 9 , 42 , 43 with sdRNAi to either Panx1 or Casp4(11) showed a significant decrease in mRNA level of proinflammatory genes and LG inflammation.…”

Alternativa terapéutica para el tratamiento de la inflamación crónica de la superficie ocular asociada a la reducción de la expresión de la trombospondina-1

“…The activation of these lymphocytes and their homing to the ocular surface play a central role in the effector phase that leads to chronic inflammation. In the main lacrimal gland, inflammatory infiltrates are observed at 12-24 weeks of age Shatos et al, 2016), providing evidence of the effector phase.…”

“…This corneal damage is accompanied by conjunctival inflammation, characterized by increased lymphatic vessels and inflammatory cytokine expression, and decreases in the number of goblet cells and tear mucin (MUC5AC) levels . Also at this age, increased inflammatory cytokine expression occurs in the main lacrimal gland Shatos et al, 2016). These changes trigger the sensitization or induction phase, in which ocular APCs migrate to local lymph nodes and spleen to activate immature T cells.…”