Role of insulin-like growth factor-1 (IGF-1) in regulating cell cycle progression

Aims

Insulin-like growth factor-1 (IGF-1) is a polypeptide protein hormone, similar in molecular structure to insulin, which plays an important role in cell migration, cell cycle progression, cell survival and proliferation. In this study, we investigated the possible mechanisms of IGF-1 mediated cell cycle redistribution and apoptosis of vascular endothelial cells.

Method

Human umbilical vein endothelial cells (HUVECs) were pretreated with 0.1, 0.5, or 2.5 μg/mL of IGF-1 for 30 min before the addition of Ang II. Cell cycle redistribution and apoptosis were examined by flow cytometry. Expression of Ang II type 1 (AT₁) mRNA and cyclin E protein were determined by RT-PCR and Western blot, respectively.

Results

Ang II (1 μmol/L) induced HUVECs arrested at G₀/G₁, enhanced the expression level of AT₁ mRNA in a time-dependent manner, reduced the enzymatic activity of nitric oxide synthase (NOS) and nitric oxide (NO) content as well as the expression level of cyclin E protein. However, IGF-1 enhanced NOS activity, NO content, and the expression level of cyclin E protein, and reduced the expression level of AT₁ mRNA. L-NAME significantly counteracted these effects of IGF-1.

Conclusions

Our data suggests that IGF-1 can reverse vascular endothelial cells arrested at G₀/G₁ and apoptosis induced by Ang II, which might be mediated via a NOS-NO signaling pathway and is likely associated with the expression levels of AT1 mRNA and cyclin E proteins.     

American ginseng (Panax quinquefolius) prevents glucose-induced oxidative stress and associated endothelial abnormalities

Purpose

Ginseng (Araliaceae), demonstrates widespread biological effects because of its purported antioxidant and other properties. The present study was undertaken to investigate the effects of American ginseng root extract on glucose-induced oxidative stress and associated oxidative damage to human umbilical vein endothelial cells (HUVECs).

Methods

Following pretreatment with various concentrations of ginseng (alcoholic extract), HUVECs were incubated with various concentrations of d-glucose ranging from 5 to 25 mmol/l for 24 h. l-Glucose was used at a concentration of 25 mmol/l as a control.

Results

Glucose-induced oxidative stress detected by intracellular reactive oxygen species accumulation, superoxide anion generation and DNA damage in HUVECs were significantly prevented by ginseng. Treatment of HUVECs with ginseng further led to significant prevention of glucose-induced NF-κB activation. Glucose-induced increase in fibronectin (FN), EDB⁺FN (a splice variant of FN), endothelin-1 (ET-1) and vascular endothelial growth factor (VEGF) mRNAs and protein levels were also prevented by ginseng treatment.

Conclusion

These data indicate that American ginseng prevented glucose-induced damage in the HUVECs through its antioxidant properties.     

Glutathione-S-transferase M1 and T1 genes and gastric cancer: a case control study in North Indian population

Background

Difference in the capacity of xenobiotic metabolising enzymes might be an important factor in genetic susceptibility to cancer.

Methods

A case control study involving forty one gastric cancer patients and one hundred and thirty controls was carried out to determine the frequency of GSTM1 and GSTT1 null genotypes. The frequency of GSTM1 and GSTT1 null genotype was observed by carrying out multiplex PCR.

Results

There was no difference in the frequencies of the GSTM1 and GSTT1 null and the combined GSTM1 and GSTT1 null genotype between patients and control.

Conclusions

Our data suggest that GSTM1 and GSTT1 status may not influence the risk of developing gastric cancer.     

Leaf press juice from Bryophyllum pinnatum (Lamarck) Oken induces myometrial relaxation

Aims

The use of preparations from Bryophyllum pinnatum (Lamarck) Oken (Kalanchoe pinnata (Lamarck) Persoon) in tocolysis is supported by clinical evidence. We studied here the effect of B. pinnatum leaf press juice and its chemical fractions on the response of human myometrial strips. No data are available if the influence on myometrial strips of the juice differs from that of its components in the chemical fractions, in order to increase the pharmacological effect.

Methodology

In vitro study to test the effect of repeated addition of B. pinnatum leaf press juice (BPJ) and its chemical components in several dilutions (undiluted, 1-10%) on myometrium strips hang up in a myograph chamber. Chemical analysis is including HPLC, MPLC with Sephadex LH-20 and TLC.

Results

All test solutions are inhibiting contractility by reducing the amplitude and the area under the curve (AUC) of the contractions. Undiluted BPJ and its undiluted chemical fraction 4 are reducing most effective these two parameters: the amplitude was at 78% of the baseline (95% CI (77-89); p < 0.05) at the second addition of the BPJ and at 70% (95% CI (50-90); p < 0.05) of the first addition of fraction 4; the AUC was at 82% (95% CI (69-95); p < 0.05) of the baseline at the first addition of the press juice and at 51% (95% CI (27-74); p < 0.05) at the first addition of fraction 4. The BPJ decreased amplitude and AUC significantly faster and increased frequency significantly faster than the control. Fractions could be tentatively assigned to bufadienolids, flavonoids and cinnamic acids. Fraction 4, accounted for flavonoids, increased the frequency of the contractions most effectively: 557% of the baseline (95% CI (316-797); p < 0.05) at the first addition.

Conclusion

Leaf juice of B. pinnatum and its flavonoid fraction are most effective in relaxing myometrial strips by inducing frequency.     

Localization of the Sodium-Taurocholate cotransporting polypeptide in membrane rafts and modulation of its activity by cholesterol in vitro

Background

The relevance of discrete localization of hepatobiliary transporters in specific membrane microdomains is not well known.

Aim

To determine whether the Na⁺/taurocholate cotransporting polypeptide (Ntcp), the main hepatic sinusoidal bile salt transporter, is localized in specific membrane microdomains.

Methods

Presence of Ntcp in membrane rafts obtained from mouse liver was studied by immunoblotting and immunofluorescence. HEK-293 cells stably transfected with rat Ntcp were used for in vitro studies. Expression, localization and function of Ntcp in these cells were assessed by immunoblotting, immunofluorescence and biotinylation studies and Na⁺-dependent taurocholate uptake assays, respectively. The effect of cholesterol depletion/repletion assays on Ntcp function was also investigated.

Results

Ntcp localized primarily to membrane rafts in in vivo studies and localized partially in membrane rafts in transfected HEK-293 cells. In these cells, membrane cholesterol depletion resulted in a shift of Ntcp localization into non-membrane rafts, which correlated with a 2.5-fold increase in taurocholate transport. Cholesterol repletion shifted back part of Ntcp into membrane rafts, and normalized taurocholate transport to values similar to control cells.

Conclusion

Ntcp localizes in membrane rafts and its localization and function are regulated by membrane cholesterol content. This may serve as a novel regulatory mechanism of bile salt transport in liver.     

Perfusion culture system: Synovial fibroblasts modulate articular chondrocyte matrix synthesis in vitro

Objective

To investigate the interactions of chondrocyte metabolism by synovial cells and synovial supernatants in a new perfusion co-culture system.

Methods

Chondrocytes and synovial fibroblasts were obtained from knee joints of slaughtered adult cattle. For experimental studies chondrocytes and synovial fibroblasts were placed together into a perfusion chamber (co-culture) or were placed into two different perfusion culture containers, which were connected by a silicone tube (culturing of chondrocytes with synovial supernatants). A control setup was used without synovial cells. Chondrocyte proliferation was shown by measurement of DNA content. The proteoglycan synthesis was quantified using ³⁵SO₄²⁻-labelling and the dimethylmethylene blue assay. ³H-proline incorporation was used to estimate the protein biosynthesis. Type II collagen synthesis was measured by ELISA, furthermore extracellular matrix deposition was monitored immunohistochemically (collagen types I/II). Regarding to the role of reactive oxygen species LDH release before and after stimulation with hydrogen peroxide was measured.

Results

The proliferation of chondrocytes shows an increase in monoculture as well as in co-culture or in culture with synovial supernatants more than fivefold within 12 days. ³H-proline incorporation as a marker for chondrocytes biosynthetic activity decreases in co-culture system and in culture with synovial supernatants. A similar effect is seen measuring total proteoglycan content as well as the ³⁵SO₄²⁻ incorporation in chondrocytes. Co-culturing and culturing with synovial supernatants lead to a significant decrease of proteoglycan release and content. Quantification of collagen type II by ELISA shows significant lower amounts of native collagen type II in the extracellular matrix of co-cultured chondrocytes as well as in culture with synovial supernatants. The membrane damage of chondrocytes by hydrogen peroxide is reduced when chondrocytes are co-cultured with synovial fibroblasts.

Conclusion

The co-culture perfusion system is a new tool to investigate interactions of different cell types with less artificial interferences. Our results suggest that synovial supernatants and synovial fibroblasts modulate the biosynthetic activity and the matrix deposition of chondrocytes as well as the susceptibility to radical attack of reactive oxygen species.     

Baseline severity but not gender modulates quantified Crataegus extract effects in early heart failure - A pooled analysis of clinical trials

Objective

The efficacy of quantified Crataegus extract in chronic heart failure (CHF) has been assessed in numerous clinical studies. The present pooled analysis evaluates the impact of baseline severity and gender on objective and patient-reported endpoints and associations between both types of outcomes in patients with early CHF.

Methods

Available data from 687 individual patients treated with quantified Crataegus extract or placebo in ten studies were pooled. Treatment effects on physiologic outcome parameters and on symptoms were analysed for their association with baseline severity and gender. Changes in symptom scores were investigated with respect to their relation to physiologic outcome parameters. Results were compared with observations in a 3-year cohort study.

Results

Physiologic outcome parameters maximal workload (MWL), left ventricular ejection fraction (LVEF) and pressure-heart rate product increase (PHRPI) at 50 W ergometric exercise improved more in active treatment than in placebo patients. Magnitude of improvement was independent from baseline for LVEF but increased for MWL and PHRPI with baseline severity. Improvement of typical symptoms like reduced exercise tolerance, exertional dyspnea, weakness, fatigue, and palpitations improved more with active treatment and in patients with more severe symptoms. A weak association between improvements in MWL, PRHP, and symptoms could be demonstrated. Gender differences in treatment effects could be explained by baseline differences. Results of the pooled analysis are in agreement with observations in the cohort study.

Conclusions

Crataegus extract treatment effects on physiologic outcomes and typical symptoms were modulated by baseline severity. Taking baseline differences into account, benefits were comparable in male and female patients with impaired exercise-tolerance in early chronic heart-failure.     

The effectiveness and efficacy of Rhodiola rosea L.: A systematic review of randomized clinical trials

Objective

To critically assess the current evidence from randomized clinical trials (RCTs) for or against the effectiveness or efficacy of Rhodiola rosea.

Data sources

Systematic literature searches were performed in six electronic databases: AMED (1985-July 2009), CINAHL (1982-July 2009), The Cochrane Library (search in July 2009), EMBASE (1974-July 2009), MEDLINE (1950-July 2009) and Web of Science (searched in July 2009). No language restrictions were imposed. Reference lists of all retrieved articles were searched, and experts and manufacturers were contacted for unpublished RCT.

Review methods

RCTs testing the efficacy or effectiveness of mono-preparations of R. rosea as sole treatment administered orally against a control intervention in any human individual suffering from any condition or healthy human volunteers were included. Studies were selected, data extracted, and quality assessed by two independent reviewers.

Results

Eleven RCTs met the inclusion criteria; all were placebo-controlled. Six trials investigated the effects of R. rosea on physical performance, four on mental performance, and two in patients diagnosed with mental health condition. The methodological quality of most trials was moderate or good. Only few mild adverse events were reported.

Conclusion

R. rosea may have beneficial effects on physical performance, mental performance, and certain mental health conditions. There is, however, a lack of independent replications of the single different studies. Five of the 10 RCTs reached more than three points on the Jadad score (i.e., good quality). More research seems warranted.     

Association of TNF-α promoter gene G-308A polymorphism with metabolic syndrome, insulin resistance, serum TNF-α and leptin levels in Indian adult women

Background

Tumour necrosis factor alpha is a multifunctional proinflammatory cytokine involved in the pathogenesis of metabolic syndrome, insulin resistance, and obesity. Aim of this study is to investigate in a North Indian female population the impact of the G-308A TNF-α variant on various components of the metabolic syndrome, Insulin Resistance, serum TNF-α and Leptin levels.

Methods

The G-308A TNF-α polymorphism has been studied in 269 females with metabolic syndrome (NCEP ATP III criteria) (age 31.91 ± 6.05) and 272 healthy females without metabolic syndrome (age 30.96 ± 7.01). The G-308A variant was detected by PCR amplification and Nco-1 digestion.

Results

Homozygous mutant genotype (AA) (p = <0.001: OR = 3.24: 95% CI = 2.15-4.89) and mutant allele (A) (p = <0.001: OR = 3.04: 95% CI = 2.08-4.43) of TNF-α was significantly less frequently observed in the control population as compared to study group. Furthermore, on dividing the subjects into two groups according to the absence (TNF-1 allele) or presence of the mutant A (TNF-2) allele, significant results were obtained in most of the metabolic risk factors.

Conclusions

Our results suggest that the G-308A polymorphism of the TNF-α gene may be independently associated with hypertension, leptin level and hypercholesterolemia leading to metabolic syndrome independent of Insulin resistance and hyperglycemia.     

Protective effect of tetramethylpyrazine isolated from Ligusticum chuanxiong on nephropathy in rats with streptozotocin-induced diabetes

Purpose

This study was designed to investigate the protective effect of tetramethylpyrazine isolated from Ligusticum chuanxiong, a traditional Chinese medicine, on diabetic nephropathy in a rat model, and to explore the possible mechanism involved in a protective function.

Materials

Diabetes was induced in male Sprague-Dawley rats by a single intraperitoneal injection of 70 mg/kg of streptozotocin. One week later, 200 mg/kg/day of tetramethylpyrazine was administered intragastric gavage daily for 8 weeks. Renal functions and expression of vascular endothelial growth factor were examined at 4 and 8 weeks after tetramethylpyrazine administration.

Results

Blood glucose and renal function were significantly improved in the tetramethylpyrazine-treated group compared to the untreated diabetic rats. Diabetic nephropathy resulted in an increase in the expression of vascular endothelial growth factor, while tetramethylpyrazine administration greatly decreased the expression.

Conclusions

Our results suggest that administration of tetramethylpyrazine may reduce kidney damage caused by diabetes. This protective effect may be mediated, in part, by downregulated expression of vascular endothelial growth factor in the kidney.     

RANTES gene mRNA expression and its -403 G/A promoter polymorphism in coronary artery disease

Objective

Increased RANTES expression has been described to have a role in atherosclerosis plaque formation. Functional polymorphisms within RANTES promoter region have shown association with increased risk of coronary atherosclerosis (CAD). The aim of this study was to examine the RANTES mRNA expression in patients with CAD compared to patients without CAD and its association with RANTES − 403 G/A polymorphism in an Iranian population.

Methods

The study was performed on 319 patients who underwent coronary artery angiography and patients with > 50% stenosis in vessels considered as case groups (CAD+) N = 191 and normal vessels group as control (CAD−) N = 128. In each group 20 patients were examined for RANTES mRNA expression.RANTES mRNA expression was examined using quantitative real-time PCR. Genotyping of − 403 polymorphism was performed using PCR-RFLP technique.

Results

We found that RANTES mRNA expression was increased to 1.37 fold in CAD patients compared to the controls but the difference was not statistically significant. Also comparing the RANTES mRNA expression in patients with different RANTES − 403 G/A polymorphism showed that in patients carrying AA genotype RANTES mRNA expression was increased to 1.74 fold compared to patients carrying GG genotype and to 1.51 fold compared to patients carrying GA genotype. No significant difference for allele and genotype frequencies of RANTES − 403 polymorphism was found between cases and controls.

Conclusion

More studies on larger number of samples are required to further evaluate role of RANTES in pathogenesis of CAD.     

Significant associations of the rs2943634 (2q36.3) genetic polymorphism with adiponectin, high density lipoprotein cholesterol and ischemic stroke

Background

rs2943634 C/A single nucleotide polymorphism (SNP), located in a non coding region of chromosome 2q36.3, has been associated with coronary artery disease in two genome wide association studies. Our goal was to investigate its relation with myocardial infarction (MI) and ischemic stroke (IS), as well as with 12 intermediate risk phenotypes, in a population-based prospective cohort study.

Methods

rs2943634 was genotyped in a case-cohort study including a random sample of 1891 individuals (subcohort) and all incident MI (n = 211) and IS (n = 144) cases during a mean follow-up of 8.2 ± 2.2 years, nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort comprising 27,548 middle-aged men and women.

Results

rs2943634 minor allele (A) was associated in an additive fashion with lower risk of IS but not with MI [hazard ratio (HR) = 0.66; 95% confidence interval (CI): 0.50-0.87; P = 0.003; HR = 1.02; 95% CI: 0.82-1.28; P = 0.83 respectively, for the age and sex adjusted model]. Furthermore, it was related to slightly higher levels of plasma adiponectin [CC 6.94, CA 7.27, AA 7.86 μg/ml, P = 0.0002] and high density lipoprotein (HDL)-cholesterol (CC 52.08, CA 53.05 and AA 55.27 mg/dl, P = 0.002), based on additive models. Adjustment for adiponectin and HDL-cholesterol did not attenuate the association between the SNP and IS risk. In contrast, adjustment for adiponectin abolished the association between the SNP and HDL-cholesterol and adjustment for HDL-cholesterol attenuated the association between the SNP and adiponectin.

Conclusions

Our findings suggest that rs2943634 is associated with IS risk and with plasma levels of HDL-cholesterol and adiponectin in this German population. Further investigations are needed to confirm these results and to clarify the mechanisms underlying the association.     

Study of the insulin signaling pathways in the regulation of ACAT1 expression in cultured macrophages

Objective

To determine the signaling pathways and components involved in insulin-mediated regulation of Acyl-CoA: cholesterol acyltransferase1 (ACAT1).

Methods

THP-1 cells were cultured in RPMI 1640 medium and were induced into macrophages in the presence of 160 nM phorbol 12-myristate 13-acetate (PMA). Before insulin was added in, macrophages were preincubated with the inhibitors of the insulin signaling pathway, including wortmannin, phosphatidylinositol 3-kinase (PI3 K) inhibitor; PD98059, extracellular signal-regulated kinase (ERK) inhibitor; SB203580, p38 mitogen-activated protein kinase (p38MAPK) inhibitor; SP600125, c-Jun N-terminal kinase (JNK) inhibitor and U73122, phospholipase C-γ (PLC-γ) inhibitor. ACAT1 mRNA and protein expression level in macrophages were determined by real-time quantitative polymerase chain reaction and western blotting, respectively.

Results

Real-time quantitative polymerase chain reaction and western blotting demonstrated that PD98059, SB203580 or SP600125 down-regulated the expression of ACAT1 in a dose-dependent manner. However, no obvious alteration was found in wortmannin and U73122 groups.

Conclusion

These results suggest that the ERK, p38MAPK and JNK signaling pathways may be involved in insulin-mediated regulation of ACAT1, but no PI3K and PLC-γ signaling pathways were involved in the present study.     

Gaseous persufflation with carbon monoxide during ischemia protects the isolated liver and enhances energetic recovery

Background

The benefit of carbon monoxide as applied by controlled, continuous gaseous persufflation during liver preservation on postischemic graft recovery was investigated in an isolated rat liver model.

Methods

Livers from male Wistar rats were retrieved 30 min after cardiac arrest of the donor and subjected to 18 h of cold storage. Some grafts were subjected to gaseous persufflation with carbon monoxide (CO, dissolved in nitrogen) during static cold storage at a concentration of 50 ppm or 250 ppm. Graft viability was assessed thereafter upon warm reperfusion in vitro.

Results

CO-persufflation significantly reduced cellular enzyme loss (maximal at 50 ppm) and functional recovery (bile production and energy charge) upon reperfusion by about 50%. The effect was associated with a reduction of free radical-induced lipid peroxidation, lower vascular perfusion resistance, and improved mitochondrial ultrastructure.

Conclusion

Viability of cold stored liver grafts can be notably augmented by gaseous ex vivo application of low dose CO to the isolated organ.     

Chemical composition and therapeutic effects of Lippia alba (Mill.) N. E. Brown leaves hydro-alcoholic extract in patients with migraine

Background

There is no universally accepted and effective prophylaxis of migraine headache episodes. Thus we aimed to investigate the effects of Lippia alba (Mill.) N. E. Brown, an herb with many effects on central nervous system, on pain frequency and intensity of migraine patients.

Methods

Patients were enrolled in a prospective, phase 2, non-controlled cohort study to orally receive hydro-alcoholic extract of L. alba leaves. Headache intensity and frequency of episodes were recorded before and after 30-60 days of treatment. We also studied the chemical composition of its essential oil by gas chromatography-mass spectrometry.

Results

We described for the first time a particular L. alba chemotype with geranial and carvenone as major compounds. With treatment, both frequency and intensity of pain episodes significantly decreased from baseline to first reassessment date. More than 80% of patients experienced a minimum 50% reduction on pain intensity and frequency. No side effects were reported.

Conclusions

Treatment with a geranial plus carvenone chemotype of L. alba hydro-alcoholic extract is a cheap, widely available, highly effective therapy to reduce both the intensity and the frequency of headache episodes of migraine patients with no side effects.     

Efectos del entrenamiento en estrategias de regulación emocional en el bienestar de cuidadores de enfermos de Alzheimer

Introduction

The present research shows the results of a psychoeducational intervention programme centered on the regulation of the emotion among Alzheimer patients’ caregivers.

Materials and methods

52 informal caregivers of Alzheimer's patients participated. These caregivers were distributed into two groups: the experimental group (n = 20) and the control group (n = 32). All the participants were evaluated before and after the intervention programme through the application of different measurement tools measuring variables related to the care giving process; stressors, modulation variables and care giving consequences.

Results

In the inter group contrast, the experimental group, when compared with the control condition, obtained higher scores in positive affect, subjective well-being, regulation of emotions, and satisfaction with caregiving. However, the experimental group recorded lower values in perceived stress and negative affect. With reference to the intragroup contrast, the experimental group showed a significant decrease in dysfunctional thoughts and emotional attention. The control group registered higher levels of psychosocial support and lower satisfaction with caregiving.

Conclusions

The training programme, that we both developed and conducted, has contributed to a greater feeling of emotional well-being amongst the its participant caregivers, who now take more adequate care of their emotions and suffer fewer dysfunctional thoughts in relation to caregiving. In future studies, the stability of the results presented in this investigation should be established due to the progressive character of the skills learned during the programme, and the changing needs associated with the caregiving process.