MMPs comprise a family of proteolytic enzymes that degrade pericellular substances, which may result in the destabilization of vessels and related to the development of brain arteriovenous malformations (BAVM). MMP3 is a key member of this family, overexpressed in BAVM tissues, and a single nucleotide polymorphism within MMP3, −709A>G (rs522616), is significantly associated with the risk of BAVM. In this study, we aimed to investigate the mechanism through which the polymorphism rs522616 regulates the expression of MMP3. Our results showed that −709A led to a over 2-fold higher transcriptional activity compared with the G allele (P<0.05) and this transcriptional activity can be depressed by co-transfecting cells with competitive DNA fragments containing −709A but not −709G. Bioinformatics analyses suggested that the transcription factor C-MYB might bind to the area around rs522616. Overexpressed C-MYB significantly increased the transcriptional activity of −709A compared with −709G or controls that did not overexpress c-myb (P<0.01) in HEK293 and HUVEC cells. ChIP assays indicated that C-MYB bound to the SNP region in the two cell lines and three BAVM tissue samples. Together, these data indicated that C-MYB can bind to the −709A allele of the MMP3 promoter, activate its transcription and lead to a higher expression of this gene. This novel hypothesis, supported by molecular evidence, explains how this SNP affects MMP3 promoter function and results in a risk of BAVM development.

The results of our previous study showed that impaired cellular energy metabolism contributes to duck enteritis virus-induced autophagy via the 5`-adenosine monophosphate-activated protein kinase (AMPK)/tuberous sclerosis complex 2/mammalian target of rapamycin pathway in duck embryo fibroblast (DEF) cells. However, it remains unknown whether any other underlying mechanisms of AMPK activation are involved in autophagy induction. The activity of CaMKKβ and AMPK in DEF cells infected with DEV were evaluated.The Effect of inhibitory activity of CaMKKβ on DEV-induced autophagy was investigated. In addtion to, the cytosolic calcium level in DEF cells infected with DEV were evaluated.The Effect of inhibitory cytosolic calcium level on DEV-induced autophagy was investigated. In this study, duck enteritis virus (DEV) infection activated CaMKKβ and its substrate molecule AMPK at 36, 48, and 60 h post-infection (hpi). STO-609, a CaMKKβ inhibitor, or CaMKKβ siRNA significantly inhibited the activation of DEV to AMPK, LC3I to LC3II transformation, and GFP-LC3 puncta distribution. In addition, inhibition of CaMKKβ activity also significantly reduced progeny DEV titer and gB protein expression. Besides, cytosolic calcium (Ca2+) was higher in DEV-infected cells than mock controls at 36, 48, and 60 hpi, respectively. Treatment of DEV-infected cells with 1,2-Bis (2-aminophenoxy) ethane-N, N, N′, N-tetraacetic acid (BAPTA-AM) significantly reduced intracellular Ca2+ ion concentrations, as well as CaMKKβ and AMPK activities, and subsequent autophagy, in addition to viral protein synthesis and viral titer. These results showed that elevated [Ca2+]cyto-mediated activation of CaMKKβ managed the activation of AMPK, which then positively regulated autophagy, thereby providing further insight into DEV–host interactions.

Aleutian mink disease (AMD), which is caused by Aleutian mink disease virus (AMDV), is an important contagious disease for which no effective vaccine is yet available. AMD causes major economic losses for mink farmers globally and threatens some carnivores such as skunks, genets, foxes and raccoons. Aptamers have exciting potential for the diagnosis and/or treatment of infectious viral diseases, including AMD. Using a magnetic beads-based systemic evolution of ligands by exponential enrichment (SELEX) approach, we have developed aptamers with activity against AMDV after 10 rounds of selection. After incubation with the ADVa012 aptamer (4 μM) for 48 h, the concentration of AMDV in the supernatant of infected cells was 47% lower than in the supernatant of untreated cells, whereas a random library of aptamers has no effect. The half-life of ADVa012 was ~ 32 h, which is significantly longer than that of other aptamers. Sequences and three dimensions structural modeling of selected aptamers indicated that they fold into similar stem-loop structures, which may be a preferred structure for binding to the target protein. The ADVa012 aptamer was shown to have an effective and long-lasting inhibitory effect on viral production in vitro.