Long noncoding RNA GAS5 attenuates cardiac fibroblast proliferation in atrial fibrillation via repressing ALK5.

OBJECTIVE: Recently, long noncoding RNAs (lncRNAs) have caught more attention for their role in the progression of many diseases. Among them, lncRNA GAS5 (Growth Inhibition Specificity 5) was studied in this research to identify how it affects the progression of atrial fibrillation (AF). PATIENTS AND METHODS: In 40 patients with AF and 30 patients with sinus rhythm (SR), the GAS5 expression of the right atrial appendage (RAA) tissues was detected by the quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Moreover, the cell proliferation assay was conducted in AC16 cells transfected with GAS5 inhibitor and mimics, respectively. Furthermore, the qRT-PCR was performed to uncover the mechanism. RESULTS: In the research, the expression of GAS5 in RAA tissues was decreased significantly in AF patients than that in SR ones. Moreover, overexpression of GAS5 inhibited cell growth in AC16 cells, while knockdown of GAS5 promoted cell growth in AC16 cells. In addition, further experiments revealed that ALK5 was a target of GAS5 and its expression in AF tissues negatively correlated to GAS5 expression. CONCLUSIONS: These results indicate that GAS5 could inhibit cell proliferation of AF via suppressing ALK5, which may offer a new vision for interpreting the mechanism of AF development.

Effect of early intrajejunal nutrition on pancreatic pathological features and gut barrier function in dogs with acute pancreatitis.

BACKGROUND: In patients with major trauma and burns, total enteral nutrition (TEN) significantly decreases the acute phase response and incidence of septic complications when compared with total parenteral nutrition (TPN). Traditionally, it was believed that early intrajejunal nutrition (EIN) in severe acute pancreatitis (SAP) may exacerbate the clinical pathological features, lead to recurrence of symptoms and delay complications. OBJECTIVE: To compare the effect of EIN vs TPN on the pancreatic pathological features and gut barrier function in dogs with acute pancreatitis (AP). METHODS: Fifteen dogs (surviving over 7 days, the death rate being 32%, 7/22) were divided into parenteral nutrition (PN) group (n=7) and EIN group (n=8). SAP model was induced by injecting 1 ml/kg of combined solution of 2.5% sodium taurocholate and 8000-10000 BAEE units trypsin/ml into the pancreas via the pancreatic duct. Nutrients were delivered to the EIN group by catheter via a jejunostomy feeding 24 h postoperatively. The two groups were isocaloric and isonitrogenous. Systemic blood samples were obtained before and 1, 4, 7 d following AP, and cultured by aerobic as well as anaerobic bacterial growth. Systemic plasma and portal vein endotoxin levels were quantified by the chromogenic limulus amebocyte lysate (LAL) technique. Portal vein blood and specimens of tissue from mesenteriolum and mesocolon lymph nodes, lung, pulmonary portal lymph nodes and pancreas were adopted before the experiment was finished. Aliquots of the homogenata were cultured as blood mentioned above. Serum glucose, calcium, amylase and lysosomal enzymes were determined. All dogs were injected with 50 microCi (125)I-BSA 4 h at the 7th day before being sacrificed. The (125)I-BSA indexes of the pancreas/muscle and pancreas/blood were measured, and pancreatitic pathological scores (PPSs) of the different partial pancreas were observed. The content of mucosa protein, DNA and the villi, the thickness of mucosa and the whole bowel wall of the ileum and transverse colon were measured. RESULTS: The study showed that serum glucose in the PN group was higher than in the EIN group after SAP 3 d; the levels of systemic plasma endotoxin and the magnitude of bacterial translocation to the portal and systemic blood and distant organ reduced significantly in the EIN group P<0.01. There were no differences between the two groups in the data of serum calcium, amylase and lysosomal enzymes, P>0.05; the (125)I-BSA index of pancreas/muscle and pancreas/blood, and PPS of the head, body, tail and total pancreas did not reach significant difference between the two groups, P>0.05. The contents of protein and DNA, the height of villi, the thickness of mucosa and the whole bowel wall of the ileum and transverse colon in the EIN group were higher than that in the PN group,P <0.01. CONCLUSION: Our results suggested that EIN was safe and effective to be adopted by intrajejunal delivery of nutrients in SAP dogs, did not make SAP clinical pathological features deteriorate, and decreased the occurrence rate of endotoxin and gut bacterial translocation.