Myricetin Increases Circulating Adropin Level after Activation of Glucagon-like Peptide 1 (GLP-1) Receptor in Type-1 Diabetic Rats.

Myricetin is a common plant-derived flavonoid, considered an agonist of glucagon-like peptide 1 (GLP-1) receptor. It improves glycemic control and helps reduce body weight in diabetic subjects. The potential mechanisms of action of myricetin in this context might be enhancing the secretion of ß-endorphin (BER) to activate peripheral µ-opioid receptors. Moreover, adropin is a nutritionally regulated peptide hormone, which regulates energy metabolism, and plays a role in ameliorating diabetes. Because their mechanisms of insulin sensitivity are closely related, we hypothesized that myricetin may interact with adropin and plasma BER. The present study investigated the glucose-lowering effect of acute and chronic treatments of myricetin in type-1 diabetic rats. Plasma BER and adropin levels were determined by enzyme-linked immunosorbent assay (ELISA). The secretion of BER was measured in rats who received adrenalectomy. The changes in adropin gene (Enho) or mRNA level of GLP-1 receptor were measured using qPCR analysis. The results showed that myricetin dose-dependently increased plasma BER and adropin levels like the reduction of hyperglycemia after bolus injection as acute treatment. In addition, these effects of myricetin were inhibited by the antagonist of GLP-1 receptor. Moreover, in HepG2 cell line, myricetin induced GLP-1 receptor activation, which modulated the expression of adropin. In diabetic rats, the plasma adropin increased by myricetin is mainly through endogenous ß-endorphin after activation of GLP-1 receptor via bolus injection as acute treatment. Additionally, chronic treatment with myricetin increased adropin secretion in diabetic rats. In conclusion, our results provide a new finding that activation of opioid µ-receptor in the liver may enhance circulating adropin in animals.

Major Plant in Herbal Mixture Gan-Mai-Da-Zao for the Alleviation of Depression in Rat Models.

Gan-Mai-Da-Zao (GMDZ) is a well-known product in Chinese traditional medicine and includes three major plants: blighted wheat (Fu Mai), licorice (Gan Cao), and jujube (Da Zao). GMDZ is widely used as an efficacious and well-tolerated prescription for depression in clinics. The present study was designed to investigate the main plant of GMDZ for its antidepressant-like effect using the unpredictable chronic mild stress (UCMS) model on rats who received an injection with p-chlorophenylalanine (PCPA) to produce the chemical model. In rats subjected to the UCMS model, forced swim tests, open field tests, and sucrose preference tests were applied to estimate the chronic effect of GMDZ. We found that the oral administration of GMDZ for 21 days significantly alleviated the behavior in rats with depression induced by either UCMS or PCPA. The expression levels of the serotonin transporter (5-HTT) and brain-derived neurotrophic factor (BDNF) in the hippocampus of the rats with depression were markedly increased by GMDZ. Additionally, rats that received the herbal mixture without licorice showed a markedly lower response than GMDZ. These results suggest that GMDZ may alleviate the depressive-like behaviors in depressive rats, possibly via licorice (Gan Cao), to increase 5-HTT and BDNF signals in the hippocampus. The present study confirmed the antidepressant-like effects of GMDZ. Additionally, licorice (Gan Cao) may play a key role in the effectiveness of GMDZ.

Liraglutide Activates Glucagon-Like Peptide 1 Receptor to Attenuate Hyperglycemia through Endogenous Beta-Endorphin in Diabetic Rats.

Liraglutide, an acylated analog of glucagon-like peptide 1 (GLP-1), could improve glycemic control in diabetes. Moreover, endogenous opioid peptides play a role in blood sugar regulation. Since GLP-1 receptors are also expressed in extra-pancreatic tissues, this study investigates the effect of liraglutide on endogenous opioid secretion in type 1-like diabetes. The endogenous opioid level was determined by enzyme-linked immunosorbent assay. The direct effect of liraglutide on endogenous opioid secretion was determined in the isolated adrenal medulla. Acute treatment with liraglutide dose-dependently attenuated hyperglycemia, and increased the plasma opioid neuropeptide, beta-endorphin (BER) levels in diabetic rats. These effects have been blocked by GLP-1 receptor antagonist, naloxone. Additionally, the effects of liraglutide were markedly reduced in adrenalectomized diabetic rats. In the isolated adrenal medulla, liraglutide induced BER secretion and increased the BER mRNA levels. Subcellular effects of liraglutide on the adrenal gland were further identified to mediate through the exchange proteins directly activated by cAMP, mainly using the pharmacological blockade. After repeatedly administering liraglutide, metabolic changes in diabetic rats were investigated, and genes associated with gluconeogenesis in the liver were downregulated. Naloxone pretreatment inhibited these effects of liraglutide, indicating the involvement of endogenous opioids. The present study indicated that liraglutide had an acute effect of reducing hyperglycemia by regulating endogenous opioid BER and modifying the glucose homeostasis.

LncRNA A2M-AS1 lessens the injury of cardiomyocytes caused by hypoxia and reoxygenation via regulating IL1R2.

BACKGROUND: Myocardial ischemia and reperfusion injury (MI/RI) is a complex pathophysiological process, which can lead to severe myocardial injury. The long noncoding RNA alpha-2-macroglobulin antisense RNA 1 (A2M-AS1) has been revealed to be abnormally expressed in MI, However, its function in MI and the potential mechanism are still unclear. OBJECTIVE: To evaluate the functional role of A2M-AS1 in hypoxia/reoxygenation (H/R)-induced neonatal cardiomyocytes and its potential molecular mechanism. METHODS: Dataset GSE66360 was obtained from GEO database for analyzing the RNA expression of A2M-AS1 and interleukin 1 receptor type 2 (IL1R2). KEGG pathway enrichment analysis of the genes that co-expressed with A2M-AS1 was performed. Human neonatal cardiomyocytes were subjected to H/R to construct in vitro models. QRT-PCR and Western blot were adopted to test the levels of mRNA and protein. The viability and apoptosis of cardiomyocytes were tested by CCK-8 and flow cytometry assays, respectively. RESULTS: The expression of A2M-AS1 was notably downregulated in H/R-treated cardiomyocytes. Overexpression of A2M-AS1 can notably enhance the cell viability of H/R-damaged cardiomyocytes, whereas knockdown of A2M-AS1 showed the opposite outcomes. Besides, a negative correlation was showed between A2M-AS1 and IL1R2 expression. In H/R-treated cardiomyocytes, overexpression of IL1R2 weakened the promoting proliferation and anti-apoptosis effects caused by overexpressing A2M-AS1, however, IL1R2-knockdown abolished the anti-proliferation and pro-apoptosis effects caused by silencing A2M-AS1. CONCLUSION: This study demonstrates the potential regulatory role of A2M-AS1/ IL1R2 axis in cardiomyocytes suffered from H/R, and provides insight into the protection of MI/RI.

Development of betulinic acid as an agonist of TGR5 receptor using a new in vitro assay.

BACKGROUND: G-protein-coupled bile acid receptor 1, also known as TGR5 is known to be involved in glucose homeostasis. In animal models, treatment with a TGR5 agonist induces incretin secretion to reduce hyperglycemia. Betulinic acid, a triterpenoid present in the leaves of white birch, has been introduced as a selective TGR5 agonist. However, direct activation of TGR5 by betulinic acid has not yet been reported. METHODS: Transfection of TGR5 into cultured Chinese hamster ovary (CHO-K1) cells was performed to establish the presence of TGR5. Additionally, TGR5-specific small interfering RNA was employed to silence TGR5 in cells (NCI-H716 cells) that secreted incretins. Uptake of glucose by CHO-K1 cells was evaluated using a fluorescent indicator. Amounts of cyclic adenosine monophosphate and glucagon-like peptide were quantified using enzyme-linked immunosorbent assay kits. RESULTS: Betulinic acid dose-dependently increases glucose uptake by CHO-K1 cells transfected with TGR5 only, which can be considered an alternative method instead of radioligand binding assay. Additionally, signals coupled to TGR5 activation are also increased by betulinic acid in cells transfected with TGR5. In NCI-H716 cells, which endogenously express TGR5, betulinic acid induces glucagon-like peptide secretion via increasing calcium levels. However, the actions of betulinic acid were markedly reduced in NCI-H716 cells that received TGR5-silencing treatment. Therefore, the present study demonstrates the activation of TGR5 by betulinic acid for the first time. CONCLUSION: Similar to the positive control lithocholic acid, which is the established agonist of TGR5, betulinic acid has been characterized as a useful agonist of TGR5 and can be used to activate TGR5 in the future.

Effects of aging on the plasma levels of nesfatin-1 and adiponectin.

Gastric and adipose tissue secrete a number of hormones that are involved in energy metabolism. The biological functions of these hormones, including their effects on aging, are currently under investigation. Adiponectin was shown to be directly involved in appetite and the control of body weight. However, the effects of aging of nesfatin-1, an appetite-suppressing peptide that was recently identified, have not yet been fully elucidated. The aim of this study was to determine the effects of aging on the plasma levels of nesfatin-1 and adiponectin. Our results demonstrated no significant differences in the nesfatin-1 plasma levels among three age groups (2, 6 and 24 months) of female BALB/c mice. The plasma nesfatin-1 levels/visceral fat (VF) ratio in the 24-month-old mice was significantly lower compared to that in the 2- and 6-month-old mice. In addition, there were no significant differences in the plasma adiponectin levels among the three age groups. The plasma adiponectin levels/VF ratio in the 24-month-old mice was significantly lower compared to that in the 2- and 6-month-old mice. In conclusion, there were no age-related changes in the plasma levels of nesfatin-1 and adiponectin, although the ratio of plasma levels of nesfatin-1 and adiponectin per VF was decreased with advancing age. Our results indicated that nesfatin-1 and adiponectin may be involved in controlling energy balance during aging.

Silymarin induces insulin resistance through an increase of phosphatase and tensin homolog in Wistar rats.

BACKGROUND AND AIMS: Phosphatase and tensin homolog (PTEN) is a phosphoinositide phosphatase that regulates crucial cellular functions, including insulin signaling, lipid and glucose metabolism, as well as survival and apoptosis. Silymarin is the active ingredient in milk thistle and exerts numerous effects through the activation of PTEN. However, the effect of silymarin on the development of insulin resistance remains unknown. METHODS: Wistar rats fed fructose-rich chow or normal chow were administered oral silymarin to identify the development of insulin resistance using the homeostasis model assessment of insulin resistance and hyperinsulinemic- euglycemic clamping. Changes in PTEN expression in skeletal muscle and liver were compared using western blotting analysis. Further investigation was performed in L6 cells to check the expression of PTEN and insulin-related signals. PTEN deletion in L6 cells was achieved by small interfering ribonucleic acid transfection. RESULTS: Oral administration of silymarin at a dose of 200 mg/kg once daily induced insulin resistance in normal rats and enhanced insulin resistance in fructose-rich chow-fed rats. An increase of PTEN expression was observed in the skeletal muscle and liver of rats with insulin resistance. A decrease in the phosphorylation of Akt in L6 myotube cells, which was maintained in a high-glucose condition, was also observed. Treatment with silymarin aggravated high-glucose-induced insulin resistance. Deletion of PTEN in L6 cells reversed silymarin-induced impaired insulin signaling and glucose uptake. CONCLUSIONS: Silymarin has the ability to disrupt insulin signaling through increased PTEN expression. Therefore, silymarin should be used carefully in type-2 diabetic patients.

Role of musclin in the pathogenesis of hypertension in rat.

Musclin is a novel skeletal muscle-derived secretory factor found in the signal sequence trap of mouse skeletal muscle cDNAs. Musclin possesses a region homologous to the natriuretic peptide family. Thus, musclin is found to bind with the natriuretic peptide clearance receptors. However, the role of musclin in vascular regulation remains unclear. In this study, we aim to investigate the direct effect of musclin on vascular tone and to analyze its role in hypertension using the spontaneously hypertensive rats (SHR). In aortic strips isolated from SHR, musclin induced contractions in a dose-dependent manner. We found that the musclin-induced vasoconstriction was more marked in SHR than in normal rats (WKY). Moreover, this contraction was reduced by blockade of natriuretic peptide receptor C using the ab14355 antibody. Therefore, mediation of the natriuretic peptide receptor in musclin-induced vasoconstriction can be considered. In addition, similar to the natriuretic peptide receptor, expression of the musclin gene in blood vessels was higher in SHR than in WKY. Injection of musclin markedly increased the blood pressure in rats that can be inhibited by anti-musclin antibodies. Musclin-induced vasoconstriction was more pronounced in SHR than in WKY as in its expression. Taken together, these results suggest that musclin is involved in blood pressure regulation. The higher expression of musclin in hypertension indicates that musclin could be used as a new target for the treatment of hypertension in the future.

Opioid µ-receptors as new target for insulin resistance.

Type-2 diabetes is one of the fastest growing public health problems worldwide resulting from both environmental and genetic factors. Activation of µ-opioid receptor (MOR) could result in reversal of the impairment of insulin-stimulated glucose disposal in genetically obese Zucker rats via exercise training. This improvement of insulin resistance was associated with an elevation of circulating ß-endorphin to ameliorate the post-receptor insulin signaling cascade, including downstream effectors of the phosphatidylinositol 3-kinase (PI3-kinase) signaling pathway. In insulin resistant rats, Loperamide treatment effected on the insulin receptor substrate (IRS)-1/PI3-kinase/Akt signaling cascade and subsequent insulin-stimulated glucose transport trafficking on skeletal muscle, which were all suppressed by MOR antagonism. In addition, induction of insulin resistance by the intake of high fructose is more rapid in MOR knockout mice than in wild-type mice. Improvements in insulin sensitivity through the peripheral MOR activation overcoming defects related to the post-receptor in IRS-1-associated PI3-kinase step have been defined. Opioid receptor activation, especially of the µ-subtype, may provide merits in the amelioration of defective insulin action. Atypical zeta (ζ) isoform of protein kinase C serves as a factor that integrates with peripheral MOR pathway and insulin signals for glucose utilization. The developments call new insights into the chemical compounds and/or herbal products that might enhance opioid peptide secretion and/or stimulate MOR in peripheral insulin-sensitive tissues to serve as potential agents or adjuvants for helping the glucose metabolism. In the present review, we update these topics and discuss the concept of targeting peripheral MOR pathway for the treatment of insulin resistance.

Characterization of preptin-induced insulin secretion in pancreatic ß-cells.

We aimed to characterize the effects of preptin on insulin secretion at the single-cell level, as well as the mechanisms underlying these changes, with respect to regulation by intracellular Ca(2+) [Ca(2+)](i) mobilization. This study assessed the effect of preptin on insulin secretion and investigated the link between preptin and the phospholipase C (PLC)/protein kinase C (PKC) pathway at the cellular level using fura-2 pentakis(acetoxymethyl) ester-loaded insulin-producing cells (Min 6 cells). Our results demonstrate that preptin promotes insulin secretion in a concentration-dependent manner. Using a PLC inhibitor (chelerythrine) or a PKC inhibitor (U73122) resulted in a concentration-dependent decrease in insulin secretion. Also, preptin mixed with IGF2 receptor (IGF2R) antibodies suppressed insulin secretion in a dose-dependent manner, which indicates that activation of IGF2R is mediated probably because preptin is a type of proIGF2. In addition, preptin stimulated insulin secretion to a similar level as did glibenclamide. The activation of PKC/PLC by preptin stimulation is highly relevant to the potential mechanisms for increase in insulin secretion. Our results provide new insight into the insulin secretion of preptin, a secreted proIGF2-derived peptide that can induce greater efficacy of signal transduction resulting from PLC and PKC activation through the IGF2R.

The use of herbal medicine in cancer-related anorexia/ cachexia treatment around the world.

Cancer-related cachexia, a condition in which the body is consumed by deranged carbohydrate, lipid and protein metabolism that is induced by inflammatory cytokines. Cachexia is associated with poor treatment outcome, fatigue and poor quality of life. Pharmacological intervention in the treatment and/or prevention of cachexia has been mainly aimed at the use of appetite enhancers to increase oral nutritional intake so far. Herbal remedies are part of traditional and folk healing methods with long histories of use. In this report, we have assessed which herbal approaches have had associated cancer cachexia case reports. Commonly used herbal medicines in western countries include essiac, iscador, pau d'arco tea, cannabinoids and so on. Some Kampo herbs and formulations are commonly used by cancer patients reduce the side effects and complications during the antitumor therapy. The relevant herbal medicines include ginseng, C. rhizome and radix astragali, and the related herbal remedies, such as TJ-48, TJ-41, PHY906 and Rikkunshito. However, there still have some adverse effects caused or amplified by herb and drug interactions that are difficult to separate. However, randomized effectiveness of herbal medicines shall be further identified in controlled clinical trials involving cancer patients with cachexia.

[Interleukin-8 monoclonal antibody attenuates smooth muscle cell proliferation and balloon inflation-induced abdominal aorta stenosis in rabbits].

OBJECTIVE: To observe the effects of interleukin-8 monoclonal antibody on smooth muscle cell proliferation and balloon inflation-induced abdominal aorta stenosis in rabbits. METHODS: Thirty-six New Zealand white rabbits were randomly assigned to balloon inflation group (group A, n = 12), interleukin-8 monoclonal antibody pre-treated rabbits (2 mg/kg for 3 days before balloon inflation, group B, n = 12) and sham-operated control group (group C, n = 12). Peripheral blood was collected before experiment and at 4 h, 1, 3, 7, 14, and 28 days post balloon inflation or sham operation and the levels of IL-8 were measured by enzyme linked immunosorbent assay (ELISA). The ratio of positive and negative masculine cells in the high power microscopic field was determined in proliferating cell nuclear antigen (PCNA) stained slide. Histopathologic examination was performed in abdominal aorta and luminal area, intima and tunica media area were measured. RESULTS: Plasma interleukin-8 began to rise at 4 h and peaked at 1 day and remained increased up to 28 days after balloon inflation in rabbits of group A, plasma interleukin-8 level in group A was significantly higher than in group B and C at 4 h and thereafter post operation. The ratio of positive and negative masculine cells was significantly increased in group A compared to group C and was significantly lower in group B than in group A. Abdominal aorta stenosis, luminal area, intima and tunica media area were significantly reduced in group B than in group A. Correlation analysis indicated that there were positive relations between plasma IL-8 level and intima thickness, area of intima and tunica media, respectively (r = 0.894, 0.783, 0.801, 0.912, all P < 0.01). CONCLUSIONS: Plasma IL-8 level is increased in this abdominal aorta stenosis model and is positively correlated to the severity of abdominal aorta stenosis. IL-8 monoclonal antibody could significantly reduce abdominal aorta stenosis in this abdominal aorta stenosis model.

Silymarin inhibits cervical cancer cell through an increase of phosphatase and tensin homolog.

Silymarin is an active constituent contained in the seeds of the milk thistle plant and is widely used as a hepatic protection agent due to its antioxidant-like activity. In the present study we evaluated the potential action of silymarin against cervical cancer and investigated its mechanism of action. Treatment of cervical cancer cells (C-33A) with silymarin resulted in a significant decrease in cell viability. Silymarin induced apoptosis through the modulation of Bcl-2 family proteins and activation of caspase 3. Silymarin also inhibited the phosphorylation of Akt with an increase in expression of phosphatase and tensin homolog (PTEN). We also observed that silymarin suppressed C-33A cell invasion and wound-healing migration in a concentration-dependent manner. Western-blot analysis showed that silymarin significantly inhibited the expression of matrix metalloproteinase-9 (MMP-9) in C-33A cells. Furthermore, we applied siRNA to lower the PTEN gene, which diminished the anticancer actions of silymarin. Taken together, these results show that silymarin has the potential to suppress the survival, migration and invasion of C-33A cancer cells; thus, it could be developed as a promising agent for the treatment of cervical cancer in the future.

Role of Bone Morphogenetic Proteins-7 (BMP-7) in the Renal Improvement Effect of DangGui (Angelica sinensis) in Type-1 Diabetic Rats.

Hyperglycemia induced reactive oxygen species (ROS) generation is believed as major factors leading to diabetic nephropathy (DN). DangGui (Angelica sinensis) is mentioned to show renal protective effect in combination with other herbs. Bone morphogenetic proteins-7 (BMP-7) is produced merit in protection of DN. The role of BMP-7 in DangGui-induced renal improvement is not clear. The present study investigated the effects of DangGui on renal functions, BMP-7 expression and the levels of ROS in streptozotocin (STZ)-induced diabetic rats and high glucose-exposed rat mesangial cells (RMCs). After 1- or 4-week treatment, DangGui improved renal functions and increased renal BMP-7 expression in diabetic rats. The BMP-7 expression in RMCs was reduced by high glucose treatment and this could be reversed by DangGui. Moreover, RMCs exposed to high glucose were expired by BMP-7 RNAi transfection but those cells remained alive by scramble transfection. Thus, we employed regular RMCs to knock down BMP-7 with RNAi and we found that DangGui increased BMP-7 expression in these RMCs. Direct activation of BMP-7 expression by DangGui could be considered. The results of DPPH assay, DHE stain and lucigenin assay indicated that DangGui could inhibit high glucose-induced ROS in RMCs. These results suggest that DangGui has an ability to improve renal functions in STZ-diabetic rats through increasing endogenous BMP-7 expression and decreasing oxidative stress in kidney. The present study suggest that DangGui could be applied to improve renal functions in diabetic disorders.

Antihypertension Induced by Tanshinone IIA Isolated from the Roots of Salvia miltiorrhiza.

Tanshinone IIA is one of the active principles in danshen (Salvia miltiorrhiza Bge) widely used in treatment of cardiovascular disorders. We investigated the effect of danshen or tanshinone IIA on blood pressure and its possible mechanisms. An i.p. injection of danshen at 10 mg kg(-1) significantly lowered systolic blood pressure (SBP) of spontaneously hypertensive rats (SHRs) but failed to modify the SBP in normotensive Wistar-Kyoto rats (WKY). Oral administration of tanshinone IIA also decreased SBP in SHR but not in WKY. Tanshinone IIA produced a concentration-dependent relaxation in isolated SHR aortic rings precontracted with phenylephrine (10 nmol l(-1)) or potassium chloride (KCl) (40 mmol l(-1)). The relaxing effect of tanshinone IIA on tonic contraction of phenylephrine in isolated aortic rings without endothelium remained produced. Glibenclamide at concentration sufficient to block adenosine triphosphatase (ATP)-sensitive potassium (K(+)) channel attenuated this tanshinone IIA-induced relaxation that was not influenced by other inhibitors. We further investigated the effect of tanshinone IIA on the changes of intracellular calcium concentration ([Ca(2+)](i)) in cultured aortic smooth muscle (A7r5) cells using fura-2 as indicator. Tanshinone IIA decreased [Ca(2+)](i) elicited by phenylephrine (10 nmol l(-1)) or KCl (40 mmol l(-1)) in a concentration-dependent manner; glibenclamide, but not other inhibitors for K(+) channel, abated this effect. Our results suggest that tanshinone IIA acts as an active principle of danshen showing vasodilation through ATP-sensitive K(+) channel to lower [Ca(2+)](i).

Effect of exercise and high-fat diet on plasma adiponectin and nesfatin levels in mice.

Lifestyle-related diseases are associated with overeating and lack of exercise. The purpose of this study was to investigate the effect of exercise and high-fat diet on plasma adiponectin and nesfatin levels. Mice were housed for 4 weeks in 4 groups, which included the non-exercise and normal diet (SN), exercise and normal diet (EN), non-exercise and high-fat diet (SF) and the exercise and high-fat diet (EF) group. The mice in the exercise groups were housed in cages with a running wheel and were subjected to voluntary exercise. The food intake (Kcal) of the mice in the exercise groups increased compared to that of the mice in the non-exercise groups (P<0.01). Body weight and visceral fat decreased in the mice in the EF group compared to the mice in the SF group (P<0.01 and P<0.05). The temperature of the mice in the EF group increased compared to that of the mice in the SN group (P<0.05). Blood glucose, insulin (P<0.01), cholesterol (P<0.01) and triglyceride concentrations (P<0.01) increased in the SF group compared to the normal diet groups. Furthermore, plasma insulin and cholesterol concentrations increased in the SF group compared to the exercise groups (P<0.01). Plasma adiponectin and nesfatin-1 levels in the SF group decreased compared to the SN group (P<0.05). Exercise under a high-fat diet antagonized the significant decrease in the nesfatin-1 level. Exercise together with a high-fat diet affected the plasma levels of adiponectin and nesfatin. It is therefore suggested that exercise together with a high-fat diet can affect various diseases via adiponectin and nesfatin.

The role of ghrelin in energy homeostasis and its potential clinical relevance (Review).

The novel gastric hormone ghrelin, a 28-amino acid peptide, has been identified as a potent growth-hormone secretagogue. Ghrelin production is regulated by nutritional and hormonal factors. Besides stimulating growth hormone secretion, studies show that ghrelin exerts a number of central and peripheral actions such as the regulation of food intake, the control of energy balance, glucose metabolism and insulin release, cardiovascular actions, the stimulation of gastric acid secretion, and motility. The broad spectrum of biological activities associated with ghrelin continues to expand. In the future, the diverse functions of ghrelin raise the possibility of its clinical application in a large number of pathological conditions.

Mechanisms of improvement of left ventricle remodeling by trans-planting two kinds of autologous bone marrow stem cells in pigs.

BACKGROUND: The necrosis of a large number of myocardial cells after acute myocardial infarction (AMI) results in a decrease of cardiac function and ventricle remodeling. Stem cell transplantation could improve cardiac function after AMI, but the involving mechanisms have not been completely understood. The present study aimed to investigate the effects of transplantation of autologous bone marrow mononuclear cells (BM-MNC) and mesenchymal stem cells (MSCs) via the coronary artery on the ventricle remodeling after AMI as well as the mechanisms of the effects of transplantation of different stem cells on ventricle remodeling. METHODS: A total of 36 male pigs were enrolled in this study, which were divided into 4 groups: control group, simple infarct model group, BM-MNC transplantation group, and MSCs transplantation group. At 90 minutes when a miniature porcine model with AMI was established, transplantation of autologous BM-MNC ((4.7 +/- 1.7) x 10(7)) and MSCs ((6.2 +/- 1.6) x 10(5)) was performed in the coronary artery via a catheter. Ultrasound, electron microscope, immunohistochemical examination and real time reverse transcriptase-polymerase chain reaction were used respectively to observe cardiac functions, counts of blood vessels of cardiac muscle, cardiac muscle nuclear factor (NF)-kappaB, myocardial cell apoptosis, and the expression of the mRNA of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in cardiac muscles. Multivariate Logistic regression was used to analyze the correlation factors of left ventricular end-diastolic diameter (EDD). RESULTS: The number of blood vessels in the infarct zone and around its border in the BM-MNC transplantation group was more than those in the infarct model group and MSCs group (P = 0.0001) and there was less myocardial cell apoptosis in the stem cell transplantation group than that in the infarct model group (all P < 0.01). The positive rate of NF-kappaB in the stem cell transplantation group was lower than that in the infarct model group (P = 0.001). The gene expression of VEGF in the infarct border zone of the BM-MNC group was higher than that in the MSCs group (P = 0.0001). The gene expression of bFGF in the infarct border zone in the MSCs transplantation group was higher than that in the infarct model group and the BM-MNC group (P = 0.0001). Left ventricular ejection fraction was inversely proportional to the apoptotic rate of myocardial cells and cardiac muscle NF-kappaB but positively correlated with the number of blood vessels and the expression of VEGF and bFGF in the infarct zone and infarct border zone. The Multivariate Logistic regression analysis on the factors influencing the left ventricular end-diastolic diameter after stem cell transplantation showed that the expression of VEGF mRNA in the cardiac muscles in the infarct zone, the number of apoptotic myocardial cells and the expression of NF-kappaB in the infarct border zone were independent factors for predicting the inhibitory effect on the dilation of left ventricular EDD after stem cell transplantation. CONCLUSIONS: Transplantation of autologous BM-MNC and MSCs in pigs can improve the condition of left ventricular remodeling and recover the cardiac functions after AMI. The improvement of cardiac functions is related to the increase of blood vessels, the increased expression of VEGF and bFGF, the reduction of myocardial cell apoptosis, and the decrease of NF-kappaB level in cardiac muscle tissues after stem cell transplantation.

Activation of opioid mu-receptor by sinomenine in cell and mice.

Sinomenine, one of the alkaloids extracted from roots or stems of Sinomenium acutum, is documented to show antinociceptive action but the action mechanism is still unclear. The present study was aimed to investigate the effect of sinomenine on opioid mu-receptor (OMR). In Chinese Hamster Ovary (CHO) cell transfected with OMR, the binding of [(3)H]naloxone was displaced by sinomenine in a concentration-dependent manner. This compound also raised the phosphorylation of OMR in these cells. In a tail-flick test, sinomenine produced dose-dependent antinociception in mice, which was dose-dependently inhibited by pretreatment of naloxonazine, a selective OMR antagonist. Long-term pretreatment with sinomenine may delay the analgesic tolerance of morphine. The obtained results suggest that sinomenine has an ability to activate OMR, implicating the potential of sinomenine to be applied in clinic.