RESUMEN
The COVID-19 pandemic is a widespread and deadly public health crisis. The pathogen SARS-CoV-2 replicates in the lower respiratory tract and causes fatal pneumonia. Although tremendous efforts have been put into investigating the pathogeny of SARS-CoV-2, the underlying mechanism of how SARS-CoV-2 interacts with its host is largely unexplored. Here, by comparing the genomic sequences of SARS-CoV-2 and human, we identified five fully conserved elements in SARS-CoV-2 genome, which were termed as "human identical sequences (HIS)". HIS are also recognized in both SARS-CoV and MERS-CoV genome. Meanwhile, HIS-SARS-CoV-2 are highly conserved in the primate. Mechanically, HIS-SARS-CoV-2, behaving as virus-derived miRNAs, directly target to the human genomic loci and further interact with host enhancers to activate the expression of adjacent and distant genes, including cytokines gene and angiotensin converting enzyme II (ACE2), a well-known cell entry receptor of SARS-CoV-2, and hyaluronan synthase 2 (HAS2), which further increases hyaluronan formation. Noteworthily, hyaluronan level in plasma of COVID-19 patients is tightly correlated with severity and high risk for acute respiratory distress syndrome (ARDS) and may act as a predictor for the progression of COVID-19. HIS antagomirs, which downregulate hyaluronan level effectively, and 4-Methylumbelliferone (MU), an inhibitor of hyaluronan synthesis, are potential drugs to relieve the ARDS related ground-glass pattern in lung for COVID-19 treatment. Our results revealed that unprecedented HIS elements of SARS-CoV-2 contribute to the cytokine storm and ARDS in COVID-19 patients. Thus, blocking HIS-involved activating processes or hyaluronan synthesis directly by 4-MU may be effective strategies to alleviate COVID-19 progression.
RESUMEN
Objective To understand the dynamic of Oncomelania hupensis snail status in Duchang County at north shore of Poyang Lake so as to provide the evidence for formulating the strategy of schistosomiasis control. Methods The data about the snail status in Duchang County from 2005 to 2012 were collected and the change trend of the snail status was analyzed. Re?sults From 2005 to 2012 all the average density of living snails the occurrence rate of frames with living snails the density of infected snails and the area with infected snails showed a trend of sharp decline and stayed at a low level. Compared to 2005 the above 4 indexes in 2008 decreased by 70.06% 90.33% 79.48% and 37.88% respectively and those in 2012 decreased by 99.35% 98.98% 99.33% and 93.84% respectively. The infection rates of snails fluctuated between 0.06%and 0.53%which showed a trend of first decrease and then increase. The snail area maintained at the level of 2 052.5 hm2 since 2007. Con?clusions Most of the indexes of the snail status in Duchang County have decreased to the lowest level in history since 2012 but the snail area is stable and the infection rate of snails shows a fluctuation trend which suggests that the risks of schistosomia?sis transmission still exist and the snail control still should be strengthened.
RESUMEN
We observed the effects of IKVAV self-assembling peptide nanofiber scaffold (SAPNS) on olfactory ensheathing cells (OECs). The IKVAV molecules were triggered to self-assemble to interconnected nanofibers hydrogel by adjusting pH of solution and adding of DMEM/F12 culture medium. Atomic Force Microscopy (AFM) showed that self-assembly hydrogel was consisted of the interconnected nanofibers, which varied from three nm to five nm in diameter and hundreds nanometer in length. The primary OECs were isolated from rat olfactory bulb and purified by differential adhesion twice. At days 12, the purity of OECs was 85% according to immunostaining of P75 NGFR antibody. OECs were cultured with IKVAV peptide. The adhesion, viability and proliferation of OECs were observed with inverted microscope, Calcein-AM/PI staining and Cell Counting Kit-8. OECs cultured on IKVAV SAPNS grew well and the viable cell count was 95%. IKVAV SAPNS can promote the adhesion of OECs and did no hinder the proliferation of OECs. IKVAV SAPNS nanofiber gel has good biocompatibility and bioactivity for OECs. It can serve as a good nerve tissue engineering scaffold.