AIM: To research the two homologous predicted proline -rich protein genes, Mus musculus predicted gene 4736 (MP4) and proline-rich protein BstNI subfamily 1 (Prb1) which were significantly upregulated in cultured corneal organs when encountering fungal pathogen preparations. This study was to confirm the expression and potential functions of these two genes in ocular surface. METHODS: A Pseudomonas aeruginosa keratitis model was established in Balb/c mice. One day post infection, mRNA level of MP4 was measured using real-time polymerase chain reaction (PCR), and MP4 protein detected by immunohistochemistry (IHC) or Western blot using a customized polyclonal anti -MP4 antibody preparation. Lacrimal glands from normal mice were also subjected to IHC staining for MP4. An online bioinformatics program, BioGPS, was utilized to screen public data to determine other potential locations of MP4. RESULTS: One day after keratitis induction, MP4 was upregulated in the corneas at both mRNA level as measured using real -time PCR and protein levels as measured using Western blot and IHC. BioGPS analysis of public data suggested that the MP4 gene was most abundantly expressed in the lacrimal glands, and IHC revealed that normal murine lacrimal glands were positive for MP4 staining. CONCLUSION: MP4 and Prb1 are closely related with the physiology and pathological processes of the ocular surface. Considering the significance of ocular surface abnormalities like dry eye, we propose that MP4 and Prb1 contribute to homeostasis of ocular surface, and deserve more extensive functional and disease correlation studies.
Matrix remodeling is a critical process in hematopoiesis.The biology of MXRA7,as a matrix remodeling associated gene,has still not been reported in hematopoietic process.Public databases showed that MXRA7 expressed in hematopoietic stem cells,suggesting that it may be involved in hematopoiesis.We found that the amounts of megakaryocytes were lower in bone marrow and spleen from Mxra7−/−mice compared with that from wild-type mice.Knock-out of MXRA7 also reduced the amount of platelet in peripheral blood and affected the function of platelets.Knock-out of MXRA7 inhibited hematopoietic stem/progenitor cells differentiate to megakaryocytes possibly through down-regulating the expression of GATA-1 and FOG-1.Moreover,knockdown of MXRA7 in MEG-01 cells could inhibit the cell proliferation and cell apoptosis.Knockdown of MXRA7 inhibited the differentiation of MEG-01 cells and proplatelet formation through suppressing the ERK/MAPK signaling pathway and the expression ofβ-tubulin.In conclusion,the current study demonstrated the potential significance of MXRA7 in megakaryocyte differentiation and platelet production.The novel findings proposed a new target for the treatment of platelet-related diseases,and much more investigations are guaranteed to dissect the mechanisms of MXRA7 in megakaryocyte differentiation and platelet production.
Zhenjiang SunBenfang WangYing ShenKunpeng MaTing WangYiqiang WangDandan Lin
