The role of quantitative changes in the epxression of insulin receptor substrate-1 and nuclear ubiquitin in abnormal glycometabolism in the livers of KKay mice and the relative therapeutic mechanisms of Astragalus polysaccharide.

Ubiquitin and the ubiquitination pathway are important regulators of insulin signaling. The insulin receptor substrate‑1 (IRS-1), an ubiquitin-interacting adaptor protein, serves as the key docking protein in insulin signaling. The effects of this dynamic interaction and the changes in ubiquitin expression on hepatic insulin signaling, as well as the relative therapeutic effects of Astragalus polysaccharide (APS) have not yet been elucidated.

Astragalus polysaccharide stimulates glucose uptake in L6 myotubes through AMPK activation and AS160/TBC1D4 phosphorylation.

Aim: To establish the mechanism responsible for the stimulation of glucose uptake by Astragalus polysaccharide (APS), extracted from Astragalus membranaceus Bunge, in L6 myotubes in vitro.

Methods: APS-stimulated glucose uptake in L6 myotubes was measured using the 2-deoxy-[(3)H]-D-glucose method. The adenine nucleotide contents in the cells were measured by HPLC.

Multiple hemodynamic effects of endogenous hydrogen sulfide on central nervous system in rats.

Background: Endogenous hydrogen sulfide is a new neuromodulator which takes part in the regulation of central nervous system physiology and diseases. Whether endogenous hydrogen sulfide in the central nervous system regulates cardiovascular activity is not known. In the present study, we observed the hemodynamic changes of hydrogen sulfide or its precursor by intracerebroventricular injection, and investigate the possible roles of endogenous digitalis like factors and sympathetic activity in the regulation.

[Influences and mechanism of verapamil on ischemia/reperfusion injury in cardiomyocytes of streptozotocin-induced diabetes mellitus rats].

Objective: To investigate the effects and mechanism of verapamil preventing ischemia/reperfusion (I/R) injury by cardiac performance intracellular free [Ca(2+)](i) and L-type calcium current (I(Ca-L)) in cardiomyocytes of diabetes mellitus rats.

Methods: Diabetic rats were streptozotocin-induced and received verapamil (8 mg×kg(-1)×d(-1)) from 6 - 14 weeks old. The in vitro heart models of I/R rats were randomly divided into normal control group diabetes group, verapamil control group.

Differential expression and function of the caveolin-1 gene in non-small cell lung carcinoma.

This study was designed to clarify the function of caveolin-1 (Cav-1) in the development of lung cancer by investigating the mutation and protein expression of the Cav-1 gene in non-small cell lung carcinoma (NSCLC). Quantum dot immunofluorescence histochemistry was used to evaluate Cav-1 protein expression and subcellular localization in the lung cancer tissue microarray including 140 cases of lung cancer and 20 cases of non-cancerous lung tissue. Mutation of the Cav-1 gene in exon 1 and exon 3 was detected by polymerase chain reaction-single strand conformation polymorphism and sequencing.

Astragalus polysaccharides alleviates glucose toxicity and restores glucose homeostasis in diabetic states via activation of AMPK.

Aim: To establish the mechanism underlying the improvement of glucose toxicity by Astragalus polysaccharide (APS), which occurred via an AMP activated protein kinase (AMPK)-dependent pathway.

Methods: In vivo and in vitro effects of APS on glucose homeostasis were examined in a type 2 diabetes mellitus (T2DM) rat model. The T2DM rat model was duplicated by a high-fat diet (58% fat, 25.

Astragalus polysaccharides decreased the expression of PTP1B through relieving ER stress induced activation of ATF6 in a rat model of type 2 diabetes.

Protein tyrosine phosphatase 1B (PTP1B) was considered as a potential therapeutic target of type 2 diabetes (T2DM) because of its negative regulation of insulin signaling. It located on the cytosolic surface of endoplasmic reticulum (ER) and played an essential role in the ER stress signaling. Activating transcription factor 6 (ATF6) was an ER stress regulated transmembrane transcription factor that activated the transcription of ER molecular chaperones.

Dexamethasone attenuated endotoxin-induced acute lung injury through inhibiting expression of inducible nitric oxide synthase.

Application of glucocorticoids in sepsis or severe infection is disputable in clinic. In this experiment, we studied the effect of dexamethasone on nitric oxide synthases and whether dexamethasone could attenuate endotoxin-induced acute lung injury (ALI). SD rats received 5 mg/kg lipopolisaccharide (LPS) injection.

Hypoglycemic effect of polysaccharide enriched extract of Astragalus membranaceus in diet induced insulin resistant C57BL/6J mice and its potential mechanism.

Our previous studies found that Astragalus polysaccharide (APS) exerts insulin-sensitizing and hypoglycemic activities in type 2 diabetic (T2DM) rats. The present study was designed to further confirm the hypoglycemic effect of APS and to investigate its possible mechanism underlying the improvement of insulin resistance in vivo and in vitro. Diet-induced insulin resistant C57BL/6J mice treated with or without APS (orally, 700 mg/kg/d) for 8 weeks were analyzed and compared.

Human mesenchymal stem cells license adult CD34+ hemopoietic progenitor cells to differentiate into regulatory dendritic cells through activation of the Notch pathway.

The mechanisms underlying the immunomodulatory functions of mesenchymal stem cells (MSC) on dendritic cells (DC) have been shown to involve soluble factors, such as IL-6 or TGF-beta, or cell-cell contact, or both depending on the report referenced. In this study, we intend to clarify these mechanisms by examining the immunosuppressive effect of human adult MSC on adult DC differentiated from CD34(+) hemopoietic progenitor cells (HPC). MSC have been shown to inhibit interstitial DC differentiation from monocytes and umbilical CD34(+) HPC.

Astragalus polysaccharide reduces hepatic endoplasmic reticulum stress and restores glucose homeostasis in a diabetic KKAy mouse model.

Aim: To examine the potential effects of Astragalus polysaccharide (APS) on hepatic endoplasmic reticulum (ER) stress in vivo and in vitro and its link with hypoglycemia activity, thus establishing the mechanism underlying the hypoglycemic action of APS.

Methods: The obese and type 2 diabetic KKAy mouse model, which is the yellow offspring of the KK mice expressed Ay gene (700 mg/kg-1/d-1, 8 weeks) and a high glucose-induced HepG2 cell model (200 microg/mL, 24 h) were treated with APS. The oral glucose tolerance test was measured to reflex insulin sensitivity with the calculated homeostasis model assessment (HOMA-IR) index.

Efficient generation of CD34+ progenitor-derived dendritic cells from G-CSF-mobilized peripheral mononuclear cells does not require hematopoietic stem cell enrichment.

As a result of their potent antigen-presentation function, dendritic cells (DC) are important tools for cell therapy programs. In vitro-generated DC from enriched CD34+ hematopoietic stem cells (HSC; enriched CD34 DC) have already proven their efficiency in Phase I/II clinical trials. Here, we investigated whether enrichment of CD34+ HSC before the onset of culture was absolutely required for their differentiation into DC.

Evaluation of human MSCs cell cycle, viability and differentiation in micromass culture.

Mesenchymal stem cells (MSCs) have the potential to differentiate into distinct mesenchymal tissue cells. They are easy to expand while maintaining their undifferentiated state, which suggests that these cells could be an attractive cell source for tissue engineering of cartilage. In vitro high density micromass culture has been widely used for chondrogenesis induction.

The regulatory role of dendritic cells in the immune tolerance.

Immune homeostasis is important for the protection of a host from pathogen aggression, as well as for preventing autoimmunity. Dendritic cells (DCs), the most potent antigen presenting cells, are critical in innate, adaptive immunity and in central tolerance. Recently, their involvement in peripheral tolerance has been shown.

[Protective effect of tert-butylhydroquinone on bone marrow cells in rats from cytotoxicity induced by benzene in vitro].

Objective: To investigate the protective effect of tert-butylhydroquinone on bone marrow cells in rats from cytotoxicity induced by benzene in vitro.

Methods: The bone marrow cells in rats were divided into two groups randomizedly. Cells of the control group were stimulated by 0, 5, 10, 15, 20 mmol/L benzene for 2, 4, 6 hours respectively.

Effect of protein kinase C alpha, caspase-3, and survivin on apoptosis of oral cancer cells induced by staurosporine.

Aim: To elucidate inhibition of protein kinase C alpha (PKC alpha) activity by staurosporine on apoptosis of oral cancer cell line tongue squamous cell carcinoma (TSCCa) cells and to clarify the role of survivin and caspase-3 in mediating apoptosis.

Methods: TSCCa cell viability was measured by MTT assay after 100 nmol/L staurosporine treatment. Apoptotic cells were identified by using phase contrast microscopy, acridine orange/ethidium bromide staining, and flow cytometry.

[Change of glucose transporter 4 and its influence on glucose and fatty-acid metabolism in type 2 diabetic myocardium].

Objective: To investigate the relationship between sarcolemmal content of glucose transporter 4 (GLUT4) and the myocardial glucose and fatty acid utilization in type 2 diabetes.

Methods: Twenty-four Sprague-Dawley rats were randomized into four groups: control, HFD/STZ, control/RSG and HFD/STZ/RSG. Sprague-Dawley rats were fed with high-fat diet (40% of the calories was supplied by fat) for 4 weeks, intraperitoneally injected with 35 mg/kg streptozotocin to establish type 2 diabetes model, and 24 diabetic rats were randomized into four groups: HFD/STZ/RSG group [fed with high fat food and given rosiglitazone (3 mg.

Pharmacological actions of sodium ferulate in cardiovascular system.

Sodium ferulate (SF) or 3-methoxy-4-hydroxy-cinamate sodium is an active principle from Angelica sinensis, Cimicifuga heracleifolia, Lignsticum chuangxiong, and other plants. It has been used in traditional Chinese medicine and is approved by State Drugs Administration of China as a drug for treatment of cardiovascular and cerebrovascular diseases. SF has antithrombotic, platelet aggregation inhibitory and antioxidant activities in animals and humans.

Rosiglitazone ameliorates abnormal expression and activity of protein tyrosine phosphatase 1B in the skeletal muscle of fat-fed, streptozotocin-treated diabetic rats.

Protein tyrosine phosphatase 1B (PTP1B) acts as a physiological negative regulator of insulin signaling by dephosphorylating the activated insulin receptor (IR). Here we examine the role of PTP1B in the insulin-sensitizing action of rosiglitazone (RSG) in skeletal muscle and liver. Fat-fed, streptozotocin-treated rats (10-week-old), an animal model of type II diabetes, and age-matched, nondiabetic controls were treated with RSG (10 micromol kg(-1) day(-1)) for 2 weeks.

The effects of Chinese herb Angelica in focal cerebral ischemia injury in the rat.

This experiment was designed to study the therapeutic mechanisms of Angelica on the focal cerebral ischemia injury of the rat. The ischemic area was determined by TTC stain. And terminal deoxynucleotidyl transferase (TDT) mediated DUTP-biotin nick end labeling (TUNEL) method was applied to detect neuronal apoptosis.

Hypoglycemic effect of Astragalus polysaccharide and its effect on PTP1B.

Aim: To examine the effects of Astragalus polysaccharide (APS), a component of an aqueous extract of Astragalus membranaceus roots, on protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin-receptor (IR) signal transduction, and its potential role in the amelioration of insulin resistance.

Methods: Ten-week-old fat-fed streptozotocin (STZ)-treated rats, an animal model of type II diabetes mellitus (TIIDM), were treated with APS (400 mg/kg p.o.

[Changes of VASP in shear stress induced cytoskeleton reorganization in endothelial cells].

Aim: To investigate the effects of different level of laminar shear stresses on the vasodilator-stimulated phosphoprotein (VASP) location and expression changes associated with actin reorganization and it's mechanism.

Methods: A parallel-plate flow chamber device was used to create laminar shear stress in vitro on cultured human umbilical endothelial cells (HUVECs). The distribution of VASP and microfilament were observed by double immunofluorescence staining.

Mechanism of improving effect of losartan on insulin sensitivity of non-insulin-dependent diabetes mellitus rats.

The specific inhibition of angiotensin II action at AT(1) receptors by losartan has been shown to decrease peripheral insulin resistance in type 2 diabetic patients and animal models. We examined the effect of losartan on the expression of insulin receptor substrate 1 (IRS-1), protein kinase B (PKB) and glucose transporter 4 (GLUT4), as well as the phosphorylation status of IRS-1 and the association between IRS-1 and phosphatidylinositol (PI) 3-kinase in skeletal muscle from fat-fed and-streptozotocin (STZ)-treated rats, an animal model of type 2 diabetes mellitus. In addition, the effects of losartan on GLUT4 translocation in muscle cells and on insulin sensitivity were also evaluated.

[Effect of thyroid hormone on protein kinase C signal pathway in cardiac myocytes and fibroblasts of rats in vitro].

Aim: To study the effect of thyroid hormone on protein kinase C activity and isoprotein expressions in cardiac myocytes and fibroblasts of rats in vitro.

Methods: Cardiac myocytes and fibroblasts were cultured according to the method of Simpson. Cells were pretreated with 1% newborn calf serum (NCS) or Angiotensin II (Ang II) for 24 hours, then Triiodothyronine (T3) was added to the culture medium and the culture was kept for another 48 hours.

Changes of vasodilator-stimulated phosphoprotein (VASP) and its phosphorylation in endothelial cells exposed to laminar flow.

Vasodilator-stimulated phosphoprotein (VASP), an actin filaments-associated protein expressed mainly in focal adhesions and dynamic membrane regions of endothelial cells (ECs), serves as a substrate for cAMP and cGMP-dependent protein kinases. In this work, we studied the effect of laminar shear stress in vitro on the location and expression of the VASP as well as its phosphorylation associated with actin reorganisation in human umbilical endothelial cells (HUVECs). The distributions of VASP and microfilaments were observed by a fluorescent double staining.