Effect of Beclin-1 shRNA on hypoxia-induced autophagy in SH-SY5Y cells / 中国应用生理学杂志

OBJECTIVE@#To observe the effect of hypoxia on autophagy in Beclin-1-knockdown SH-SY5Y cells by constructing a stable transfected SH-SY5Y cell lines of silencing Beclin-1 gene.@*METHODS@#Beclin-1shRNA lentiviral vector and negative control lentiviral vector were constructed; the vector was transfected into SH-SY5Y cells; then the expression of Beclin-1 mRNA was detected by RT-PCR, the level of Beclin-1 protein was detected by Western blot. CCK-8 method was used to determine the effect of Beclin-1 knockdown on the viability of SH-SY5Y cells. Next, the blank control, negative control and transfected cells were cultured under 21% normoxia and 5% hypoxia conditions. The expression of LC3 protein in each group was detected by Western blot and the autophagic bodies were observed by electron microscopy.@*RESULTS@#Beclin-1 shRNA significantly inhibited the expression of Beclin-1 mRNA and protein in SH-SY5Y cells; after silencing Beclin 1 gene, the survival rate of Beclin-1 shRNA group cells was no different from that of negative control (NC) group. After 5% hypoxia treatment, compared with NC group, the ratio of LC3Ⅱ/LC3Ⅰand the number of autophagy bodies were all decreased in Beclin-1 shRNA group.@*CONCLUSIONS@#Beclin-1 knockdown SH-SY5Y cell lines and negative control cell lines were successfully established. Lentivirus-mediated Beclin-1 shRNA has no effect on the viability of SH-SY5Y cells, but can inhibit hypoxia-induced autophagy.

Long-term results of dual anti-collagen membrane in guided tissue regeneration / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the long-term clinical effect of dual anti-collagen membranes in guided tissue regeneration (GTR).</p><p><b>METHODS</b>This randomized clinical trial included 26 teeth in 24 patients, presenting a total of 31 lesions consisting of intrabony defects and furcation defects. Twenty-six teeth were divided into two groups and treated by GTR with dual anti-collagen membranes and atelocollagen membranes, respectively. At baseline, 6 months, 1, 3 and 6 years, the following parameters were recorded: clinical attachment level, probing depth, gingival recession and the quantity of alveolar bone analyzed by computer assisted densitometry image analysis (CADIA).</p><p><b>RESULTS</b>At 1 year after GTR surgery, the gain of clinical attachment in dual anti-collagen membranes group was (3.93 ± 1.74) mm, compared with (2.25 ± 1.90) mm in atelocollagen group (P = 0.044). The increasing of the value of CADIA in dual anti-collagen membrane and atelocollagen group were (53.14 ± 21.35) and (32.96 ± 17.97), P = 0.031. At 3 and 6 years, clinical parameters remained basically stable in both groups, compared to that at 1 year after surgery.</p><p><b>CONCLUSIONS</b>The regeneration of periodontal tissues obtained by GTR with dual anti-collagen membranes could be maintained on a long-term basis.</p>

Protective effect of baicalin on experimental periodontitis in rats and its possible mechanisms / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of baicalin on the experimental periodontitis in rats, as well as the expression of MMP-1, MMP-2, MMP-9.</p><p><b>METHODS</b>Twenty-seven adult male Sprague-Dawley rats were divided into three groups, with 9 rats in each group. A nylon thread was placed around the lower first molars of rats, which were sacrificed after 7 days. Baicalin (200 mg/kg) was administered to the experimental group by oral gavage, starting one day before the induction of periodontitis. The negative control group received vehicle (0.5% carboxymethylcellulose) alone. The blank control group did not get induction of periodontitis. The alveolar bone loss (ABL) and the area fraction (AA% ) occupied by collagen fibers were assessed. MMP-1, MMP-2 and MMP-9 protein expressions in the gingiva were detected by immunohistochemistry.</p><p><b>RESULTS</b>Baicalin treatment significantly decreased ABL compared with the negative control group (P = 0.009). AA% of collagen fibers was significantly higher in baicalin-treated group than in the negative control group (P = 0.047). Baicalin treatment significantly down-regulated the protein expression for MMP-1 (P = 0.023) and MMP-9 (P = 0.042) and decreased the expression for MMP-2 (P = 0.099) compared with the negative control group.</p><p><b>CONCLUSIONS</b>Baicalin protects against tissue damage in ligature-induced periodontitis in rats, which might be mediated in part by its inhibitory effect on the expression of MMP-1, MMP-2 and MMP-9.</p>

Effect of hypoxic preconditioning on the learning and memory ability and expressions of survivin and HSP-70 proteins in rats with focal cerebral ischemia/reperfusion injury / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the neuroprotective effect of hypoxic preconditioning on reperfusion injury following ischemia and its molecular mechanism.</p><p><b>METHODS</b>Forty-eight rats were randomized into 3 groups, namely the sham operated group, ischemia/reperfusion (I/R) group, and I/R following hypoxic preconditioning group (HP+I/R). In the latter two groups, the rats were subjected to middle cerebral artery occlusion (MACO) for 3 h followed by reperfusion for 24 h to induce cerebral I/R injury. The learning and memory ability of the rats 24 h after reperfusion was assessed using Y-maze test. Immunohistochemistry was performed to quantify the expressions of survivin and HSP-70 proteins in the rat brain tissues.</p><p><b>RESULTS</b>The number of survivin- and HSP-70-positive cells in the brain tissues was significantly different between HP+I/R group and IR and the sham operated groups (P<0.05), and following I/R injury, the rats in HP+I/R group showed much better performance in the Y-maze test than those in I/R group.</p><p><b>CONCLUSION</b>Hypoxic preconditioning can protect the ischemic brain against reperfusion injury, promote recovery of the learning and memory ability and neurological functions following the injury. Up-regulation of the expressions of survivin and HSP-70 proteins might be one of the molecular mechanisms for this neuroprotective effect.</p>

Expression of Scleraxis in human periodontal ligament cells and gingival fibroblasts / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To study if Scleraxis, a basic helix-loop-helix type transcription factor, could be expressed in human periodontal ligament cells (hPDLC), bone marrow cells (hBMSC) and gingival fibroblasts (hGF), and to investigate if Scleraxis was involved in hPDLC differentiation.</p><p><b>METHODS</b>hPDLC, hBMSC and hGF were cultured. Expression of Scleraxis in hPDLC from different passages and in hBMSC and hGF was analyzed by reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>Scleraxis expression in hPDLC, hBMSC and hGF were significantly different (P < 0.05). The A values of Scleraxis/beta-actin in these kinds of cells were 0.877 +/- 0.024, 0.438 +/- 0.031, 0.313 +/- 0.083, respectively. The expression of Scleraxis was the highest in hPDLC and lowest in hGF. Scleraxis expression of hPDLC decreased with increase of passages in culture.</p><p><b>CONCLUSIONS</b>Scleraxis was expressed in hPDLC, hBMSC and hGF in vitro, and may play an important role in differentiation of hPDLC.</p>

Effects of baicalin on the expression of pro-MMP-1 and MMP-3 in human gingival fibroblasts and periodontal ligament cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the influence of baicalin on the IL-1beta induced pro-MMP-1 in HGF and the effects of baicalin on MMP-3 expression in periodontal ligament cells (PDLCs).</p><p><b>METHODS</b>The amount of secreted pro-MMP-1 and MMP-3 expression was detected by ELISA and cell immunochemistry.</p><p><b>RESULTS</b>(1) The amount of secreted pro-MMP-1 (3.333 +/- 0.123) microg/L increased significantly following 1 microg/L of IL-1beta, compared with control group (1.960 +/- 0.180) microg/L. Addition of baicalin to cell culture medium for 1 hour following IL-1beta decreased pro-MMP-1 secretion in a dose-dependent manner in the range of 10 approximately 1,000 microg/L. (2) 1 microg/L IL-1beta could significantly stimulate the synthesis and secretion of MMP-3 in PDLCs. (3) The baicalin could not interfere the synthesis of MMP-3, but could inhibit the release of MMP-3 from PDLCs.</p><p><b>CONCLUSIONS</b>Baicalin could inhibit the secretion of pro-MMP-1 and MMP-3 expression in IL-1beta induced HGF and PDLCs, which suggests that baicalin may play an important role in preventing and treating periodontal disease.</p>