Effect of Ganoderma lucidum spore on expression of insulin-like growth factor-1, nuclear factor-kappa B, and neuronal apoptosis in the epileptic rat brain

BACKGROUND：It has been reported that Ganoderma lucidum spore powder, a very well known Chinese traditional medicine, can affect immunoregulation, free radical scavenging, and anti-hypoxia responses. OBJECTIVE： To investigate the effect of Ganoderma lucidum spore powder on expression of insulin-like growth factor-1 （IGF-1）, nuclear factor-κB （NF-κB） and neuronal apoptosis in rats with pentylenetetrazol （PTZ）-induced epilepsy. DESIGN, TIME AND SETTING： A cellular and molecular biology experiment with randomized controlled study design was performed at the Central Laboratory of Basic Medical College of Jiamusi University from June to August 2005. MATERIALS： Thirty healthy, adult, male, Wistar rats were selected and randomly divided into 3 groups （10 rats per group）： control, epilepsy model, and Ganoderma lucidum spore powder. A sub-eclampsia PTZ dose （35 mg/kg） was intraperitoneally injected to induce epilepsy in the latter two groups. Wild Ganoderma lucidum spore powder （30 g/L） was provided by the wild Ganoderma lucidum plant nursery at Jiamusi, China. Immunohistochemical detection and terminal deoxynucleotidyl transferase-mediate dUTP nick end-labeling （TUNEL） kits were purchased from Wuhan Boster Biological Technology Co., Ltd., China. METHODS： Ganoderma lucidum spore powder was intragastrically administered at a dose of 10.0 mL/kg, once a day for 28 days. In the epilepsy and control groups, an equivalent volume of normal saline was intragastrically administered. MAIN OUTCOME MEASURES： Immunoreactivity for IGF-1 and NF-κB/P65 were detected by immunohistochemical staining. Neuronal apoptosis was detected using TUNEL methods. RESULTS： The hippocampus and cerebral cortex of rats with PTZ-induced epilepsy exhibited a higher number of apoptotic cells at high magnification （×400）, compared with the control group. Expression of IGF-1 and NF-κB were higher in the epilepsy group, compared with the control group （P 〈 0.01）. In Ganoderma lucidum spore-treated rats, fewer apoptotic cells were observed in the hippocampus and cerebral cortex, expression of NF-κB/P65 was lower, and immunoreactivity to IGF-1 increased more distinctly, compared with the epilepsy group. In addition, seizure latency was longer on 17, 21, and 25 days post-PTZ treatment in the Ganoderma lucidum spore powder group, compared with the epilepsy group （P 〈 0.05-0.01）. CONCLUSION： Ganoderma lucidum spore powder down-regulated expression of NF-κB in brain tissues of rats with PTZ-induced epilepsy, increased immunoreactivity to IGF-1, and inhibited neuronal apoptosis. These results indicated that Ganoderma lucidum spore powder has a neuroprotective effect.

Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium stocking density, MSD: 8.0 kg/m^3; and high stocking density, HSD: 11.0 kg/m^3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower fi nal body weight and specifi c growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2(IGF-2), while the concentrations of serum growth hormone(GH) and insulin-like growth factor 1(IGF-1) decreased in the HSD group. The full-length cDNAs of G H and IGF-2 genes(995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor( GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively af fects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.

Hepatic Expression of Insulin-Like Growth Factor-1 inUnderfed Pregnant Ewes

The liver is one of the most important visceral organs, which represents a large contribution to whole animal energyexpenditure and the major synthetic site of insulin-like growth factor-I （IGF-1） peptide. Decreased plane of nutrition acts byreducing the metabolic rate and mass of metabolic tissues, such as liver. Also, undernutrition results in the reduced circulating IGF-1concentrations, due to the uncoupled growth hormone-IGF （GH-IGF） axis. This study investigated whether a 22-day period ofundernutrition （half maintenance） could affect liver mass and IGF-1 protein and gene expression. Sixteen pregnant ewes fed all （n =9） or half （n = 7） of their maintenance energy requirements were slaughtered on day 7 of pregnancy （oestrus = day 0）. Body and livermass, IGF-1 plasmatic concentrations and liver IGF-1 mRNA and protein expression were determined. Liver mass and the proportionof liver mass to empty body weight were lower in underfed animals. While IGF-1 plasmatic concentrations were lower inundernourished ewes, no differences in liver mRNA expression were found. This is the first time that differences inimmunohistochemistry intensity and total content are reported in sheep. In summary, the decreased plasma IGF-I concentrationsinduced by undernutrition in ewes was not associated with its reduced hepatic mRNA or protein expression, but to a decrease in livermass.

Insulin-like growth factor binding proteins 7 prevents dental pulp-derived mesenchymal stem cell senescence via metabolic downregulation of p21

Cellular senescence affects the efficacy of mesenchymal stem cells(MSCs)-mediated tissue regeneration.Insulin-like growth factor binding proteins-7(IGFBP7),as a member of the IGF family,is associated with osteogenic differentiation and the senescence of MSCs,but its exact function and mechanism remain unclear.We found IGFBP7 promoted the osteogenic differentiation and prevented the senescence of dental pulp-derived MSCs(DPSCs),as observed in the gain-of-function and lossof-function analyses,the senescence-associated marker p21 showed the most pronounced expression changes.We demonstrated that IGFBP7 activated the biological activity of SIRT1 deacetylase via metabolism,resulting in a deacetylation of H3K36ac and a decrease of the binding affinity of H3K36ac to p21 promoter,thereby reducing the transcription of p21,which ultimately prevents DPSCs senescence and promotes tissue regeneration.The activation of the mitochondrial electron transport chain(ETC)by Coenzyme Q10 could rescue the promotion of DPSC senescence induced by the knockdown of IGFBP7,whereas the inhibition of ETC by rotenone attenuated the prevention of DPSC senescence induced by IGFBP7 overexpression.In conclusion,our present results reveal a novel function of IGFBP7 in preventing DPSC senescence via the metabolism-induced deacetylation of H3K36ac and reduction of p21 transcription,suggesting that IGFBP7 is a potential target for promoting tissue regeneration in an aging environment.

Specific metabolic biomarkers as risk and prognostic factors in colorectal cancer

Advances in genomics,molecular pathology and metabolism have generated many candidate biomarkers of colorectal cancer with potential clinical value.Epidemiological and biological studies suggest a role for adiposity,dyslipidaemia,hyperinsulinemia,altered glucose homeostasis,and elevated expression of insulin-like growth factor(IGF)axis members in the risk and prognosis of cancer.This review discusses some recent past and current approaches being taken by researches in obesity and metabolic disorders.The authors describe three main systems as the most studied metabolic candidates of carcinogenesis:dyslipidemias,adipokines and insulin/IGF axis.However,each of these components is unsuccessful in defining the diseases risk and progression,while their co-occurrence increases cancer incidence and mortality in both men and women.

Relation of the IGF/IGF1R system to autophagy in colitis and colorectal cancer

Metabolic syndrome(Met S), as a chronic inflammatory disorder has a potential role in the development of inflammatory and cancerous complications of the colonic tissue. The interaction of DNA damage and inflammation is affected by the insulin-like growth factor 1 receptor(IGF1 R) signaling pathway. The IGF1 R pathway has been reported to regulate autophagy, as well, but sometimes through a bidirectional context. Targeting the IGF1 R-autophagy crosstalk could represent a promising strategy for the development of new antiinflammatory and anticancer therapies, and may help for subjects suffering from Met S who are at increased risk of colorectal cancer. However, therapeutic responses to targeted therapies are often shortlived, since a signaling crosstalk of IGF1 R with other receptor tyrosine kinases or autophagy exists, leading to acquired cellular resistance to therapy. From a pharmacological point of view, it is attractive to speculate that synergistic benefits could be achieved by inhibition of one of the key effectors of the IGF1 R pathway, in parallel with the pharmacological stimulation of the autophagy machinery, but cautiousness is also required, because pharmacologic IGF1 R modulation can initiate additional, sometimes unfavorable biologic effects.

Effects of IGF-1 and oxLDL on expression of phosphatase PHLPP1 in vascular smooth muscular cells

Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase （MD） activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 （100ug/L） increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL（501xg/ml） elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group （P〈0.01 ）. Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.