Taurine Attenuates Streptococcus uberis-Induced Bovine Mammary Epithelial Cells Inflammation via Phosphoinositides/Ca2+ Signaling.

Taurine may alleviate the inflammatory injury induced by Streptococcus uberis (S. uberis) infection by regulating intracellular Ca2+ levels. However, the underlying mechanisms remain unclear. Infection leads to subversion of phosphoinositides (PIs) which are closely related to Ca2+ signaling. In order to investigate whether taurine regulates inflammation by means of PIs/ Ca2+ systems, competitive inhibitors of taurine (ß-alanine) siTauT, siPAT1, siPLC, siCaN, siPKC, and inhibitors of PLC (U73122), PKC (RO31-8220), and CaN (FK 506) were used. The results indicate that taurine transfers the extracellular nutrient signal for intercellular innate immunity to phosphoinositides without a need to enter the cytoplasm while regulating intracellular Ca2+ levels during inflammation. Both the Ca2+-PKCα-NF-κB, and Ca2+-CaM-CaN-NFAT signaling pathways of S. uberis infection and the regulatory roles of taurine follow activation of PIs/Ca2+ systems. These data increase our understanding on the mechanisms of multifunctional nutrient, taurine attenuated inflammatory responses caused by S. uberis infection, and provide theoretical support for the prevention of this disease.

Tryptophan Supplementation Increases Reproduction Performance, Milk Yield, and Milk Composition in Lactating Sows and Growth Performance of Their Piglets.

Tryptophan (Trp) can produce bioactive compounds for appetite regulation, calcium mobilization, and mammary gland homeostasis via a serotonin pathway. This study evaluated the effects of Trp supplementation on the reproduction performance, milk yield, and composition of lactating sows, growth performance of their piglets, and the secretion function of porcine mammary epithelial cells (PMECs). The infrared emulsion analyzer and ELISA analyses revealed that feeding sows with a 0.12% Trp addition increased ( P < 0.05) sow average daily feed intake, milk yield, milk calcium concentration, average daily gain of piglets, fatty acid synthase (FAS) and lactose synthase (LS), ß-casein secretion, intracellular Ca2+ level, the expression of calcium binding protein CaM, and the activity of CaMKII. In a cellular experiment of PMECs treated with Trp, ELISA and flow cytometry analyses revealed that the pretreatment of a Trp hydroxylase inhibitor reduced ( P < 0.05) FAS and LS synthesis, the intracellular Ca2+ level, and the activity of CaMKII. In conclusion, Trp supplementation at 0.12% increased sows' reproductive performance, milk yield, and calcium concentration and piglets' growth performance. Milk yield increased by Trp was linked to 5-hydroxytryptamine-mediated synthesis of FAS, LS, and ß-casein in PMECs, while the increase in calcium concentration was attributed to increasing CaM expression and CAMKII activity.

PI3K/Akt/mTOR signaling pathway participates in Streptococcus uberis-induced inflammation in mammary epithelial cells in concert with the classical TLRs/NF-ĸB pathway.

Mammary epithelial cells (MECs) play an important role in debating Streptococcus uberis (S. uberis) infection. Toll like receptor (TLR) engagement leads to the recruitment of phosphatidylinositol 3 kinases (PI3K). In order to investigate the relationship of TLRs/NF-κB and PI3K/Akt/mTOR signaling pathways in S. uberis infection in MECs, we challenged MECs (EpH4-Ev) with S. uberis 0140 J and quantified the adaptor molecules in these two signaling pathways, as-well-as proinflammatory cytokines and cell damage. The results indicate that the host's responses to virulent S. uberis infection are complex. In MECs, both TLR2 and TLR4 are detecting S. uberis infection and TLR2 is the principal receptor. The role of the PI3K/Akt/mTOR pathway in inflammatory regulation is independent of the activation of TLRs/NF-κB. Cross-talk between PI3K/Akt/mTOR and TLRs/NF-κB signaling pathways promote inflammation. This study increases our understanding of the molecular defense mechanisms of MECs in S. uberis mastitis, and provides theoretical support for the prevention of this disease.

[The research of apoptosis and proliferation inhibition of human laryngeal carcinoma cell line Hep-2 induced by Genistein].

OBJECTIVE: To investigate the effect of genistein on cell proliferation and apoptosis in human laryngeal carcinoma cell line Hep-2. METHOD: Cell Counting Kit-8 (CCK-8) assay was used to measure the 50% inhibiting concentration (IC50) value of genistein; cell apoptosis rate and the distribution changes of cell cycle were determined with flow cytometry assay after treatment by gensitein. The morphological changes of tumor cells were evaluated by inverted phase contrast mircroscopy. RESULT: The IC50 of geniste responses to Hep-2 cells for 24 h was 23.64 µg/ml. The apoptotic rates of Hep-2 cells treated by genistein for 24 h were 22.40% ± 1. 65% (at 12 µg/ml genistein) and 30.64% ± 2.94% (at 24 µg/ml genistein) respectively, significantly statistical differences were foundbetween above threated groups and the control group (P < 0.05); the apoptotic rates of Hep-2 cells treated by genistein for 48 h were 30.55% ± 0.72%(at 12 µg/ml genistein) and 48.69% ± 1.06% (at 24 µg/ml genistein) respectively, significantly statistical differences were found between above threated groups and the control group (P < 0.05). When Hep-2 cells exposed to the same concentration of genistein for 24 h, 48 h respectively, the difference in apoptotic rate was statistically significant. CONCLUSION: Genistein inhibited Hep-2 cells growth obviously, meanwhile it could induced apoptosis of Hep-2 cells, the apoptotic rate was increasing with the increase of the time and dose of genistein.