Effects of endurance racing on horse plasma extracellular particle miRNA

Background: Physical exercise is an essential factor in preventing and treating metabolic diseases by promoting systemic benefits throughout the body. The molecular factors involved in this process are poorly understood. Micro RNAs (miRNAs) are small non-coding RNAs that inhibit mRNA transcription. MiRNAs, which can participate in the benefits of exercise to health, circulate in plasma in extracellular particles (EP). Horses that undergo endurance racing are an excellent model to study the impact of long-duration/low intensity exercise in plasma EP miRNAs. Objectives: To evaluate the effects of 160 km endurance racing on horse plasma extracellular particles and their miRNA population. Study design: Cohort study. Methods: We collected plasma from five Arabian horses during five time-points of an endurance ride. Extracellular particles were purified from plasma and characterised by electron microscopy, resistive pulse sensing (qNano) and western blotting. Small RNAs were purified from horse plasma EP, and sequencing was performed. Results: Endurance racing increased EP concentration and average diameter compared to before the race. Western blotting showed a high concentration of extracellular vesicles proteins 2 hours after the race, which returned to baseline 15 hours after the race. MicroRNA differential expression analysis revealed increasing levels of eca-miR-486-5p during and after the race, and decreasing levels of eca-miR-9083 after the end. Conclusions: This study adds new data about the variation in plasma EP concentrations after long-distance exercise and brings new insights about the roles of exercise-derived EP miRNAs during low-intensity endurance exercise

A representative metalloprotease induces PGE2 synthesis in fibroblast-like synoviocytes via the NF-κB/COX-2 pathway with amplification by IL-1β and the EP4 receptor

Abstract Inflammatory joint conditions are characterized by synovial inflammation, which involves activation of fibroblast-like synoviocytes (FLSs) and production of inflammatory mediators and matrix metalloproteases (MMPs) in joints. This study showed that the snake venom metalloprotease (SVMP) BaP1 activates FLSs to produce PGE2 by a mechanism dependent on COX-2, mPGES-1 and iPLA2s. BaP1 also induces IL-1β release, which up-regulates the production of PGE2 at a late stage of the stimulation. Expression of COX-2 and mPGES-1 are induced by BaP1 via activation of NF-κB pathway. While NF-κB p50 and p65 subunits are involved in up-regulation of COX-2 expression, only p65 is involved in BaP1-induced mPGES-1 expression. In addition, BaP1 up-regulates EP4 receptor expression. Engagement of this receptor by PGE2 triggers a positive feedback loop for its production by up-regulating expression of key components of the PGE2 biosynthetic cascade (COX-2, mPGES-1 and the EP4 receptor), thus contributing to amplification of BaP1-induced effects in FLSs. These data highlight the importance of FLS as a target for metalloproteases in joint inflammation and provide new insights into the roles of MMPs in inflammatory joint diseases. Moreover, our results may give insights into the importance of the catalytic domain, of MMPs for the inflammatory activity of these enzymes

Frequency and hematological alterations of different hemoplasma infections with retrovirusis co-infections in domestic cats from Brazil

Abstract: Mycoplasma haemofelis is the agent of feline infectious anemia, although Candidatus M. haemominutum can also be associated. This study evaluated the frequency and hematological alterations caused by hemoplasma infections and co-infections with FeLV, FIV and Toxoplasma gondii in domestic cats from two distinct areas (urban - G1 and periurban - G2) of Brasília, Brazil. One hundred cats were evaluated, 51 from the G1 area and 49 from G2. No cats were positive for T. gondii. Hemoplasma infection was diagnosed in 33% cats from G1 and 32.6% from G2 (p>0.05). In G1 35.3% of the positive cats were infected with Mycoplasma haemofelis, 47.06% with Candidatus Mycoplasma haemominutum and 17.64% with mixed hemoplasma species infection; 12.5% of the cats identified as PCR positive in G2 were infected with Mycoplasma haemofelis, 18.75% with Candidatus Mycoplasma haemominutum and 68.75% with mixed infection. Cats from the periurban area had higher mixed hemoplasmas infection rates than those from urban area, and most of them were asymptomatic carriers. Cytology results were positive in only 5% of cats from G1. Mycoplasma haemofelis infected cats had normocytic normochromic anemia while the cats infected with Candidatus Mycoplasma haemominutum or with both species did not. 37.2% of G1 cats were co-infected with Mycoplasma haemofelis and FeLV, and presented lower PCV and hemoglobin concentration than those infected only with Mycoplasma haemofelis. The co-infection with Candidatus Mycoplasma haemominutum and FeLV produced lower WBC, segmented cells and platelets, and increased total protein concentration