Matrix mechanics regulate the polarization state of bone marrow-derived neutrophils through the JAK1/STAT3 signaling pathway.

Matrix mechanics regulate essential cell behaviors through mechanotransduction, and as one of its most important elements, substrate stiffness was reported to regulate cell functions such as viability, communication, migration, and differentiation. Neutrophils (Neus) predominate the early inflammatory response and initiate regeneration. The activation of Neus can be regulated by physical cues; however, the functional alterations of Neus by substrate stiffness remain unknown, which is critical in determining the outcomes of engineered tissue mimics. Herein, a three-dimensional (3D) culture system made of hydrogels was developed to explore the effects of varying stiffnesses (1.5, 2.6, and 5.7 kPa) on the states of Neus. Neus showed better cell integrity and viability in the 3D system. Moreover, it was shown that the stiffer matrix tended to induce Neus toward an anti-inflammatory phenotype (N2) with less adhesion molecule expression, less reactive oxygen species (ROS) production, and more anti-inflammatory cytokine secretion. Additionally, the aortic ring assay indicated that Neus cultured in a stiffer matrix significantly increased vascular sprouting. RNA sequencing showed that a stiffer matrix could significantly activate JAK1/STAT3 signaling in Neus and the inhibition of JAK1 ablated the stiffness-dependent increase in the expression of CD182 (an N2 marker). Taken together, these results demonstrate that a stiffer matrix promotes Neus to shift to the N2 phenotype, which was regulated by JAK1/STAT3 pathway. This study lays the groundwork for further research on fabricating engineered tissue mimics, which may provide more treatment options for ischemic diseases and bone defects. STATEMENT OF SIGNIFICANCE.

[The relationship among congenital Toxoplasma gondii infection, pregnancy outcome and T lymphocyte subsets in umbilical cord blood].

OBJECTIVE: To reveal the relationship among congenital Toxoplasma gondii (T. gondii) infection, T lymphocyte cell subsets in umbilical cord blood and pregnancy outcome. METHODS: 784 umbilical cord blood samples were collected and information of pregnancy outcomes was collected in a hospital of Hefei city, Anhui province during March 2009 to May 2010. T. gondii IgM antibodies in the sera were detected by ELISA. For all neonates infected with T. gondii and 10 healthy neonates, T lymphocyte cell subsets were detected by flow cytometry. RESULTS: According to the detection results of T. gondii IgM antibodies, 784 neonates were divided into infection group (21 neonates) and control group (763 neonates). The body weight and 1 min Apgar score of infection group were (3116.4 ± 352.6) g and (8.21 ± 1.26) points, respectively, which were statistically lower than control group ((3220.1 ± 242.3) g and (8.77 ± 1.61) points, respectively) (P < 0.01). The proportion of adverse pregnancy outcome of infection group was 19.0% (4/21), which was statistically greater than control group (4.8%, 37/763) (P < 0.01). The percentage of CD(3)(+) T lymphocyte cells in umbilical cord blood in infection group with and without adverse pregnancy outcomes were (64.51 ± 5.27)% and (64.32 ± 4.56)%, respectively, which were statistically lower than control group ((69.32 ± 4.32)%) (P < 0.01). The ratio value of CD(4)(+)/CD(8)(+) in infection group with, without adverse pregnancy outcomes and control group are 1.39 ± 0.24, 1.64 ± 0.28 and 2.34 ± 0.46, respectively, which showed statistical difference between any 2 groups (P < 0.01). CONCLUSION: T. gondii infection leads to adverse pregnancy outcomes and disorder of cellular immunity while T lymphocyte cell subsets are closely associated with adverse pregnancy outcome.

[Modulation of cell proliferation and collagen synthesis of porcine Tenon's fibroblasts by extracts of lens and vitreous with treatment of dexamethasone].

OBJECTIVE: To demonstrate the effects of lens extract (LE), vitreous extract (VE) and dexamethasone on the modulating of the proliferation and collagen synthesis of Tenon's capsule fibroblast. METHODS: Cell proliferation and collagen synthesis of Tenon's fibroblast were measured using MTT and reverse transcription polymerase chain reaction techniques in the presence or absence of LE, VE, or dexamethasone, respectively. RESULTS: The growth of Tenon's fibroblasts was stimulated by LE and VE in dose and time-dependent manners. Dexamethasone significantly inhibited the proliferation of the cells either in the presence or absence of LE and VE. Similarly, LE and VE significantly stimulated the collagen synthesis of the cells. However, dexamethasone showed no significant effect on the LE or VE-enhanced collagen synthesis of the cells. CONCLUSION: These results suggested that there might be some ingredients in LE or VE that could stimulate the cell proliferation and collagen synthesis of Tenon's capsule fibroblasts. These ingredients, if released, may affect the success rate of filtration surgery for glaucoma. The application of glucocorticoid itself might not be sufficient to retard the scar formation following the filtering surgery in refractory glaucoma after cataract surgery or vitrectomy.

[Receptor mediated endocytosis of retinal pigment epithelial cell].

OBJECTIVE: To evaluate the possibility and mechanism of the turnover of the negatively charged macromolecule by retinal pigment epithelial (RPE) cells. METHODS: Cultured porcine RPE eye cups were incubated with fluorescence labeled formaldehyde treated serum albumin (F-FSA), a classical ligand for scavenger receptors. The endocytosis of F-FSA by RPE cells under different conditions was evaluated systematically by fluorescent microscopy and electron microscopy. RESULTS: The amount of F-FSA ingested by RPE cells depends on the incubation time and the concentration of ligand. Similar ligands compete for the binding site of RPE cells. Small vesicles containing F-FSA are noticed in the cytosol of RPE cells as demonstrated by electron microscopy. CONCLUSION: The RPE cells can effectively ingest negatively charged macromolecules, possibly by scavenger receptor mediated endocytosis.