Long-term exposure to excessive fluoride causes chronic damage in the body tissues and could lead to skeletal and dental fluorosis. Cartilage damage caused by excessive fluoride intake has gained wide attention, but how fluoride accumulation blocks the development of chondrocytes is still unclear. Here, we report a negative correlation between the length and growth plate width after NaF treatments via apoptosis and autophagy, with shrinkage of cells, nuclear retraction, dissolution of chondrocytes. Whereas, fluoride exposure had no significant effect on the number and distribution of the osteoclasts which were well aligned. More importantly, fluoride exposure induced apoptosis of tibial bone through CytC/Bcl-2/P53 pathways via targeting Caspase3, Caspase9, Bak1, and Bax expressions. Meanwhile, the Beclin1, mTOR, Pakin, Pink, and p62 were elevated in NaF treatment group, which indicated that long-term excessive fluoride triggered the autophagy in the tibial bone and produced the chondrocyte injury. Altogether, fluoride exposure induced the chondrocyte injury by regulating the autophagy and apoptosis in the tibial bone of ducks, which demonstrates that fluoride exposure is a risk factor for cartilage development. These findings revealed the essential role of CytC/Bcl-2/P53 pathways in long-term exposure to fluoride pollution and block the development of chondrocytes in ducks, and CytC/Bcl-2/P53 can be targeted to prevent fluoride induced chondrocyte injury.

To our best knowledge, all of the fungal immunomodulatory proteins (FIPs) have been successfully extracted and identified in Basidomycetes, with only the exception of FIP from ascomycete Nectria haematococca (FIP-nha) discovered through homology alignment most recently. In this work, a gene encoding FIP-nha was synthesized and recombinantly expressed in an Escherichia coli expression system. SDS-PAGE and MALDI-MS analyses of recombinant FIP-nha (rFIP-nha) indicated that the gene was successfully expressed. The yield of the bioactive FIP-nha protein was 42.7 mg/L. In vitro assays of biological activity indicated that the rFIP-nha caused hemagglutination of human and rabbit red blood cells, significantly stimulated mouse spleen lymphocyte proliferation, and enhanced expression of interleukin-2 (IL-2) released from mouse splenocytes, revealing a strong antitumor effect against HL60, HepG2 and MGC823. Through this work, we constructed a rapid and efficient method of FIP production, and suggested that FIP-nha is a valuable candidate for use in future medical care and pharmaceutical products.

Treatment of common pathogens, such as Salmonella species, Escherichia coli, Staphylococcus aureus, etc., is a big challenge for a practitioner. Antibiotics’ side effects during their application for the treatment of infectious diseases should not be underestimated as they have many issues, such as the transfer of antibiotics-resistant genes, dysbiosis, and antibiotic-resistant strains, which is the main hurdle in the eradication of diseases. To avoid these antibiotics complications, in modern countries, the interest of using probiotics in feed supplementation to promote health and prevent or treat intestinal infectious diseases has been increasing. The purpose of the present study was to evaluate the probiotic potential of three Lactobacilli strains isolated from clinically healthy dogs for their further utilization as a dietary supplement for dogs to avoid pathogenic and antibiotic complication. After 16SrRNA sequencing, in vitro tests were conducted to assess the survival potential of Lactobacilli under simulated gastrointestinal conditions and adhesion ability to the MODE-K cell line, effects on epithelial barrier function, anti-inflammatory activities, effects on host defensin peptides (beta-defensin 3), and inhibitory effects on common pathogens. Lactobacilli showed considerable potential to survive in simulated gastrointestinal environmental conditions, low pH, and high bile salt concentrations along with good adhesion properties with MODE-K cells. Pathogenic bacterial growth and their adhesion to MODE-K cells were significantly inhibited by Lactobacilli. Real-time PCR analyses further demonstrated that the L. acidophilus strain AR1 and AR3 inhibit Salmonella-induced proinflammatory cytokine (IL-6, IL-8, IL-1β) production and reinforce the expression of tight junction protein (occludin). None of the strains induce mRNA expression of beta-defensin 3 in MODE-K cells. Based on the in vitro results, the L. acidophilus strain AR1 has the potential to be supplemented in canine feed. However, further in vivo studies investigating health-promoting effects are awaited.