Knockout of Sirt2 alleviates traumatic brain injury in mice

Sirtuin 2(SIRT2)inhibition or Sirt2 knocko ut in animal models protects against the development of neurodegenerative diseases and cerebral ischemia.However,the role of SIRT2 in traumatic brain injury(TBI)remains unclear.In this study,we found that knockout of Sirt2 in a mouse model of TBI reduced brain edema,attenuated dis ruption of the blood-brain barrie r,decreased expression of the nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)inflammasome,reduced the activity of the effector caspase-1,reduced neuroinflammation and neuronal pyroptosis,and improved neurological function.Knoc kout of Sirt2 in a mechanical stretch injury cell model in vitro also decreased expression of the NLRP3 inflammasome and pyroptosis.Our findings suggest that knockout of Sirt2 is neuro protective against TBI;therefore.Sirt2 could be a novel to rget for TBI treatment.

Interleukin-6, desmosome and tight junction protein expression levels in reflux esophagitis-affected mucosa

AIM： To investigate the correlation between the expression levels of interleukin （IL）-6 and proteins in tight junctions （TJs） in the esophageal mucosa of rats modeling different types of reflux esophagitis （RE）, and the ability of aluminum phosphate to protect against RE-induced mucosal damage via these proteins. METHODS： Male SPF Wistar rats aged 56 d were divided randomly into acid RE, alkaline RE, mixed RE, and control groups. Various surgical procedures were performed to establish rat models of acid RE. At 14 d after the procedure, some of the rats started aluminum phosphate treatment. Transmission electron microscopy （TEM） was used to observe the morphological features of TJs and desmosomes in the esophageal epithelium. Immunohistochemical methods and Western blotting were used to measure expression of claudin 1, occludin, ZO-1, JAM-l, DSG-1 and IL-6; reverse transcription polymerase chain reaction （RT- PCR） was used to measure expression of mRNA of claudin 1, occludin, ZO-1, JAM-1, DSG-1 and IL-6. RESULTS： At day 14 alter the procedures, an RE model was established in all subsequently sacrificed rats of groups A, B and C. By both gross and microscopic observation, the mucosa was damaged and thickened as the disease progressed. With TEM observation, a widened intercellular space was noticed, with significantly fewer desmosomes. Immunohistochemistry showed significantly higher levels of all proteins in all RE models compared to control rats at 3 d after operation （65.5% ± 25.6% vs 20.5% ± 2.1%, P 〈 0.05, respectively）. At 14 d after operation, along with continuing hyperplasia in the basal layer, the expression of TJ proteins in individual cells gradually decreased （12.4% ± 2.1% vs 20.5% ± 2.1%, P 〈 0.05, respectively）. Western blottings and RT-PCR showed a directly proportional increase in IL-6 levels in relation to TJ proteins, as compared to controls （0.878 ± 0.024 vs 0.205 ± 0.021 and 0.898±0.022 vs 0.205 ± 0.021, P 〈 0.05, respectively）. Upon treatment with aluminum phosphate, however, these protein levels were restored to normal gradually over 30-60 d in rats with acid RE （30.4% ± 2.1% vs 20.5% ± 2.1%, P 〉 0.05, treated vs untreated, respectively）. These levels increased in the rat with alkaline RE, and this increase was accompanied by continued hyperplasia in comparison with controls （85.5% ± 25.6% vs 20.5% ± 2.1%, P 〈 0.05, respectively）. Furthermore, the expression of TJ proteins was not correlated significantly with that of IL-6 in this group. CONCLUSION： These findings indicate that TJ proteins are highly expressed as an early molecular event involved in RE development, and that IL-6 is an inflammatory factor in this process,

Scutellaria barbata attenuates diabetic retinopathy by preventing retinal inflammation and the decreased expression of tight junction protein

AIM： To observe the attenuation of ethanol extract of Herba Scutellaria barbata （SE） against diabetic retinopathy （DR） and its engaged mechanism. METHODS： C57BL/6J mice were intraperitoneally injected with streptozotocin （STZ, 55 mg/kg） for 5 consecutive days to induce diabetes, The diabetic mice were orally given with SE （100, 200 mg/kg） for lmo at lmo after STZ injection. Blood-retinal barrier （BRB） breakdown was detected by using Evans blue permeation assay. Real-time polymerase chain reaction （RT-PCR）, Western blot and immunofiuorescence staining were used to detect mRNA and protein expression. Enzyme-linked immunosorbent assay （ELISA） was used to detect serum contents of tumor necrosis factor-e （TNF-a） and interleukin （IL）-II. RESULTS： SE （100, 200 mg/kg） reversed the breakdown of BRB in STZ-induced diabetic mice. The decreased expression of retinal claudin-1 and claudin-19, which are both tight junction （T J） proteins, was reversed by SE. SE decreased the increased serum contents and retinal mRNA expression of TNF-a and IL-113. SE also decreased the increased retinal expression of intercellular cell adhesion molecule-1 （ICAM-1）. SE reduced the increased phosphorylation of nuclear factor kappa B （NFKB） p65 and its subsequent nuclear translocation in retinas from STZ- induced diabetic mice. Results of Western blot and retinal immunofluorescence staining of ionized calcium-binding adapter molecule 1 （Ibal） demonstrated that SE abrogated the activation of microglia cells in STZ-induced diabetic mice. CONCLUSION： SE attenuates the development of DR by inhibiting retinal inflammation and restoring the decreased expression of TJ proteins including claudin-1 and claudin-19.