Changes of selenium and selenoprotein expressions in diabetic nephropathy / 西安交通大学学报(医学版)

Objective To explore the relationship between selenium and diabetic nephropathy (DN)by determining the selenium content in the plasma and whole blood of DN patients and the changes of selenoprotein expressions in human mesangial cells stimulated by high glucose.Methods We collected the samples and clinical indicators of DN patients and healthy controls to determine selenium content by atomic absorption spectrometry method.The mRNA in human mesangial cells was isolated after stimulation with 30 mmol/L of glucose for 24 hours by Trizol method to detect the changes of selenoprotein expressions by Real-time PCR.We analyzed the differences between DN patients and healthy controls and the relationship between clinical indicators by unpaired t-test and Pearson correlation analysis,respectively.Results The selenium contents in the plasma (P＜0.0001)and whole blood (P＜0.001)were significantly lower in DN patients than in the healthy controls.In addition,plasma selenium contents had a significant negative correlation with renal function and a positive correlation with glycosylated hemoglobin in DN patients.Among the 2 1 human selenoproteins,the mRNAs of Gpx1 ,TrxR2 ,TrxR3 ,Dio2 , Dio3 ,SelK,SelN,SelP,SelR,SelT,SelW and SPS2 were significantly lower in the high-glucose group than in the normal-glucose group which produced by human mesangial cells after high glucose stimulation for 24 hours. Conclusion There was obvious selenium deficiency in DN patients.Human mesangial cells have a significantly low expression of some selenoproteins in the high glucose environment.These results provide clinical and experimental evidence for illuminating the role of low selenium-sensitive selenoproteins in the occurrence and development of DN.

Qufeng Tongluo Prescription () inhibits mesangial cell proliferation and promotes apoptosis through regulating cell cycle progression / 中国结合医学杂志

<p><b>OBJECTIVE</b>To study the effects and possible underlying mechanism of Qufeng Tongluo Prescription (, QFTL) on the regulation of mesangial cells (MCs) proliferation and apoptosis.</p><p><b>METHODS</b>The MCs used in this experiment have undergone five passages induced by lipopolysaccharide (LPS). Changes in the proliferation, apoptosis, cell cycle regulatory proteins and mRNA expression levels of the MCs after administration of Benazepril or QFTL were measured by methyl thiazolyl tetrazolium (MTT) reduction assay, flow cytometry, Western blot and quantitative real-time polymerase chain reaction (qRT-PCR), respectively.</p><p><b>RESULTS</b>The addition of Benazepril or QFTL serum inhibited LPS-induced MC proliferation after treatment for 24, 48 and 72 h, respectively (P<0.05 or P<0.01). Moreover, the inhibitory effect is more significant in the QFTL group at 48 h (P<0.05). Compared with the control group, LPS-induced cell proliferation decreased the number of cells in G1 phase versus cells in S and G2/M phases, while the addition of QFTL and Benazepril serum increased the ratio of cells at G1 phase (P<0.05 or P<0.01) to cells at S phase (P<0.01), implicating the cell cycle inhibition effect exerted by QFTL. LPS decreased the level of MC apoptosis, compared with the control group (P<0.05), while QFTL and Benazepril serum increased the level of MC apoptosis (P<0.01). Moreover, the difference between the QFTL group and the Benazepril group was statistically significant (P<0.01). Compared with the control group, the protein and mRNA expression levels of cylinD1, cyclin dependent kinase 2 (CDK2) and p21 were significantly increased (P<0.05 or P<0.01), p27 was decreased but with no statistical significance (P>0.05); After being treated with QFTL and Benazepril serum, the protein and mRNA expression levels of cylinD1, CDK2, p21 were decreased and p27 increased significantly (P<0.05 or P<0.01); Compared with the Benazepril group, QFTL show better effects on protein and mRNA expression levels of cylinD1, CDK2 (P<0.05 or P<0.01) and p21 protein expression (P<0.05).</p><p><b>CONCLUSION</b>QFTL inhibits MCs proliferation, promotes MCs apoptosis through an underlying mechanism of down-regulating the protein and mRNA expression levels of cylinD1, CDK2, p21 and up-regulation of the expression level of p27.</p>

Effect of ghrelin on duodenal migrating myoelectric complex in rats with chronic renal failure / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of ghrelin on duodenal migrating myoelectric complex (MMC) in rats with chronic renal failure (CRF).</p><p><b>METHODS</b>Thirty healthy male SD rats were randomly assigned into sham-operated group (n=6) and CRF group (n=24), and the latter group was divided into 4 subgroups according to ghrelin doses administered with or without pretreatment with the receptor antagonist D-Lys(3)-GHRP-6. After a 18-h fasting, the rats with or without pretreatment with D-Lys(3)-GHRP-6 were given subcutaneous injections of ghrelin at different doses to observe the changes in duodenal MMC recorded using a multi lead physiological recording system.</p><p><b>RESULTS</b>Ghrelin significantly increased the MMC cycle duration and dose-dependently enhanced the frequency, amplitude and percentage of phase III MMC cycle. This effect was inhibited by the pretreatment with ghrelin receptor antagonist D-Lys(3)-GHRP-6.</p><p><b>CONCLUSION</b>Ghrelin can promote gastrointestinal motilities of rats with CRF, and the receptor of ghrelin can regulate the activity of MMC.</p>

Expression of ghrelin and its receptor GHS-R in the hypothalamus and gastrointestinal tract in rats with chronic renal failure / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of ghrelin and its receptor, growth hormone secretagogue receptor (GHS-R), in the hypothalamus and gastrointestinal tract in rats with chronic renal failure (CRF) and explore their relationship with the disorder of gastrointestinal tract motility.</p><p><b>METHODS</b>SD rats were randomly divided into sham-operated group (n=8) and CRF group (n=16), and in the latter group, the rats were subjected to 5/6 nephrectomy to induce CRF. Real-time PCR and immunohistochemical staining were used to detect the distribution of mRNA and protein of ghrelin and GHS-R in the gastric fundus, duodenum, and hypothalamus.</p><p><b>RESULTS</b>The rats in the CRF group showed a significantly higher expression of ghrelin mRNA and protein in the gastric fundus but a lower expression in the hypothalamus than those in the sham-operated group (P<0.01), but the expression in the duodenum was similar between the two groups (P>0.05). The expression of GHS-R mRNA and protein in the gastric fundus was significantly higher in the CRF group than in the sham-operated group (P<0.01), while in the hypothalamus and duodenum, the expression was significantly lower in the CRF group (P<0.01).</p><p><b>CONCLUSION</b>The different distribution patterns of ghrelin and GHS-R in the tissues may be an important pathological basis of gastrointestinal motility disorder in CRF.</p>

The effect of Levocarnitine on nutritional status and lipid metabolism during long-term maintenance hemodialysis / 西安交通大学学报·英文版

Objective: To investigate the effect of Levocarnitine on lipid metabolism and nutritional status of maintenance hemodialysis (MHD) patients and possible mechanism. Methods: A total of 40 MHD patients [mean age (53.5 ± 7.1) years] who underwent normal hemodialysis more than 6 months were randomly classified into two groups, Levocarnitine supplemented group (LS-G) (n = 20; Levocarnitine supplementation after each normal hemodialysis session, at a dose of 1.0 g/day by intravenous administration) and control group (C-G) (n = 20; normal hemodialysis). Before treatment, one month and three months after treatment we respectively measured or observed the following items, the tolerance to hemodialysis, carnitine level in plasma, C-reactive protein, IL-6, TNF-α, percentage of neutrophil, and some relevant nutritional parameters, such as lipid profile, transferrin, total protein, albumin and prealbumin levels. Comparative analysis was conducted between the two groups. Results: In LS-G three months after treatment, the levels of carnitine, hemoglobin, and prealbumin in plasma were significantly increased (P<0.05), but C-reactive protein, neutrophil percentage, low-density lipoprotein and triglyceride were significantly decreased (P < 0.05) in contrast to those in C-G and before treatment. Transferrin, total protein, and albumin were elevated in LS-G, with no statistical significance. Conclusion: There was a significant improvement of lipid metabolism and nutritional status for the long-term maintenance hemodialysis patients with Levocarnitine supplementation. And this improvement is related to the decrease of inflammatory factors.

Effects of linoleic acid on intracellular calcium concentration in primarily cultured rat pancreatic β-cells and underlying mechanism / 生理学报

In this study, we investigated the mechanism of linoleic acid-stimulated increase in intracellular calcium concentration ([Ca(2+)](i)) in pancreatic islet β-cells. Pancreatic islet cells were primarily isolated from rats and cultured for the experiments. The cells were loaded with Fluo-3/AM, the indicator of [Ca(2+)](i), and the intensity of Fluo-3 was measured using confocal microscope. The islet β-cells were identified by immunocytochemical staining with insulin antibody after recording. The drugs were given by perfusion system. The results showed that linoleic acid (20 μmol/L) stimulated [Ca(2+)](i) increase with the first peak increase and the following plateau increase. Linoleic acid-stimulated [Ca(2+)](i) increase was partly inhibited by removal of extracellular calcium and by transient receptor potential (TRP) channel blocker, La(3+), and it was totally blocked by exhaustion of intracellular calcium stores and inhibition of phospholipase C. It is concluded that linoleic acid stimulates [Ca(2+)](i) increase in islet β-cells through both extracellular calcium influx via TRP channels and calcium release from intracellular calcium stores.