Mechanisms of multiple neurotransmitters in the effects of Lycopene on brain injury induced by Hyperlipidemia.

BACKGROUND: Lycopene is a kind of carotenoid, with a strong capacity of antioxidation and regulating the bloodlipid. There has been some evidence that lycopene has protective effects on the central nervous system, but few studies have rigorously explored the role of neurotransmitters in it. Therefore, the present study was designed to investigate the effects of several neurotransmitters as lycopene exerts anti-injury effects induced by hyperlipidemia. METHODS: Eighty adult SD rats, half male and half female, were randomly divided into eight groups on the basis of serum total cholesterol (TC) levels and body weight. There was a control group containing rats fed a standard laboratory rodent chow diet (CD); a hypercholesterolemic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil - this is also called a CCT diet) group; a positive group (CCT + F) fed CCT, supplemented with 10 mg·kg·bw- 1·d- 1 fluvastatin sodium by gastric perfusion; and lycopene groups at five dose levels (CCT + LYCO) fed with CCT and supplied lycopene at doses of 5, 25, 45, 65, and 85 mg·kg·bw- 1·d- 1. The levels of TC, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α), oxidized low density lipoprotein (ox-LDL), low-density lipoprotein receptor (LDLR), nerve growth factor (NGF), glutamic acid (Glu), Gamma aminobutyric acid (GABA), dopamine (DA), 5-hydroxytryptamine (5-HT), N-methyl-D-aspartate (NMDA1R), GABAA, 5-HT1, D1, and apoptosis-related proteins Caspase3, bax, and bcl-2 were measured after the experiment. Nissl staining was adopted to observe the morphological changes in neurons. RESULTS: At the end of the experiment, the levels of TC, TG, LDL-C, IL-1, TNF-α, and ox-LDL in the serum and brain as well as the content of Glu, DA, NMDA, and D1 in the brain of rats in the CCT group were higher than those in the control group (P<0.05); the levels of LDLR, NGF, GABA, 5-HT, GABAA, 5-HT1, and neuron quantities in the hippocampal CA1 and CA3 areas were lower than those in the control group (P<0.05). Compared to the CCT group, levels of TC, TG, LDL-C, IL-1, TNF-α, and ox-LDL in the serum and brain, as well as the content of Glu, DA and the expression of pro-apoptotic Caspase3 in the brain decreased in the rats with lycopene (25 mg to 85 mg) added to the diet (P<0.05); the levels of LDLR, NGF, GABA, 5-HT, GABAA, and 5-HT1 as well as the expression of anti-apoptotic bcl-2 and the neuron quantity in hippocampal CA1 and CA3 areas increased (P<0.05); further, the hippocampal cells were closely arranged. Lycopene dose was negatively correlated with the levels of TC, TG, and LDL-C in the serum and brain as well as levels of IL-1, TNF-α, ox-LDL, Glu/GABA, NMDA1R, and Caspase3 (P<0.05); it was positively correlated with the levels of LDLR, NGF, 5-HT, 5-HT1, GABAA, bcl-2, and the neuron quantity in hippocampal CA1 and CA3 areas (P<0.05). CONCLUSIONS: Lycopene exerts anti-injury effects in the brain as-induced by hyperlipidemia. It can inhibit the elevation of serum TC, TG, and LDL-C in rats with hyperlipidemia while indirectly affecting the levels of TC, TG, and LDL-C in the brain, leading to a reduction in ox-LDL, IL-1, and TNF-α in the brain. This inhibits the release of Glu, which weakens nerve toxicity and downregulates pro-apoptotic Caspase3. Lycopene also plays an anti-injury role by promoting the release of the inhibitory neurotransmitter GABA and 5-HT, which enhances the protective effect, and by upregulating the anti-apoptotic bcl-2.

Knockdown of Indian hedgehog protein induces an inhibition of cell growth and differentiation in osteoblast MC3T3­E1 cells.

Indian hedgehog protein (Ihh) is evolutionarily conserved and serves important roles in controlling the differentiation of progenitor cells into osteoblasts. Ihh null mutant mice exhibit a failure of osteoblast development in endochondral bone. Although studies have demonstrated that Ihh signaling is a potent local factor that regulates osteoblast differentiation, the specific transcription factors that determine osteoblast differentiation remain unclear. Further studies are required to determine the precise mechanism through which Ihh regulates osteoblast differentiation. In the present study, Ihh was knocked down in osteoblast MC3T3­E1 cells using short hairpin RNA, to investigate the function of Ihh in osteoblast proliferation and differentiation and to examine the potential mechanism through which Ihh induces osteoblast apoptosis and cell cycle arrest. It was observed that the knockdown of Ihh induced a marked inhibition of cell growth and increased the apoptosis rate compared with the negative control osteoblasts. Downregulation of Ihh resulted in a cell cycle arrest at the G1 to S phase boundary in osteoblasts. In addition, the knockdown of Ihh decreased the alkaline phosphatase activity and mineral deposition of osteoblasts. The inhibitory roles of Ihh downregulation in osteoblast growth and differentiation may be associated with the transforming growth factor­ß/mothers against decapentaplegic homolog and tumor necrosis factor receptor superfamily member 11B/tumor necrosis factor ligand superfamily member 11 signaling pathways. Manipulating either Ihh expression or its signaling components may be of benefit for the treatment of skeletal diseases.

Effects of the duration of hyperlipidemia on cerebral lipids, vessels and neurons in rats.

BACKGROUND: The present study was designed to investigate the effects of hyperlipidemia on the cerebral lipids, vessels and neurons of rats, and to provide experimental evidence for subsequent intervention. METHOD: One hundred adult SD rats, half of which were male and half of which were female, were randomly divided into five groups on the basis of serum total cholesterol (TC) levels. Four groups were fed a hypercholesterolemic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil - this is also called a CCT diet) for periods of 1 week, 2 weeks, 3 weeks and 4 weeks, respectively. A control group was included. The levels of serum lipids, cerebral lipids, free fatty acids (FFA), interleukin-6 (IL-6), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α), vascular endothelial growth factor (VEGF), oxidized low density lipoprotein (ox-LDL), A-beta precursor proteins (APP), amyloid beta (Aß), glial fibrillary acidic protein (GFAP) and tight junction protein Claudin-5 were measured after the experiment. The pathologic changes and apoptosis of the rat brains were evaluated. RESULTS: Compared with the control group, after 1 week of a CCT diet, the levels of serum total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and brain triglycerides had increased by 2.40, 1.29 and 1.75 and 0.3 times, respectively. The serum high density lipoprotein cholesterol (HDL-C) had decreased by 0.74 times (P < 0.05) and the expression of IL-1, TNF-α and GFAP in the brains had increased (P < 0.05). In the second week, the expression of FFA and APP in the brains, and the amount of apoptotic neurons, had increased (P < 0.05). In the third week, the levels of VEGF, Ox-LDL and Aß had increased, and the expression of Claudin-5 had decreased in the brains (P < 0.05). In the fourth week, the levels of TC, LDL-C and the amount of apoptotic neurons had increased (P < 0.05). The correlation analysis showed a positive correlation among FFA, TNF-α, VEGF, ox-LDL, Aß, GFAP and neuronal apoptosis in the rat brains, and they all were negatively correlated with Claudin-5 (P < 0.05). CONCLUSION: Hyperlipidemia may activate astrocytes by means of high levels of TG that will have direct toxic effects on the cerebral vessels and neurons by causing the secretion of TNF-α and IL-1 in the brains of rats. In the metabolic procession, brain tissue was shown to generate FFA that aggravated the biosynthesis of ox-LDL. With the extension of the duration of hyperlipidemia, high levels of cerebral TC and LDL-C were shown to aggravate the deposition of Aß, induce the secretion of VEGF, reduce the expression of tight junction protein Claudin-5 and change the permeability of blood-brain barriers to factors that could damage cerebral vessels and neurons.

Impact of rosiglitazone on the expression of beta3-AR in the stable cell lines expressed beta3-AR gene.

BACKGROUND: The aim of the present study was to investigate the effect of rosiglitazone, a peroxisome proliferator-activated receptor gamma2 (PPAR-gamma2) agonist, on the expression of beta3-adrenergic receptor (beta3-AR) at transcriptional and translational level. METHODS: We cloned the cDNA sequences of human PPAR-gamma2 (hPPAR-gamma2) gene and human wild type and mutant beta3-adrenergic receptor (hbeta3-AR) genes and established their eukaryotic expression vectors. The pcDNA3.1/hbeta3-AR (mutant and wild type) was transfected into SH-SY5Y cells using electroporation method. The expression level of beta3-AR protein was determined by Western blot analysis. RESULTS: Our results showed that the reverse transcription-PCR products were consistent with theoretical fragment sizes of human PPAR-gamma2 (1544 bp) and human beta3-AR genes (1578 bp). The sequence analysis of PPAR-gamma2 and beta3-AR genes showed that the fragment sizes were the same as that of human PPAR-gamma2 and human beta3-AR genes in Genbank. The pcDNA3.1/hbeta3-AR (mutant and wild type) was successfully cloned to SH-SY5Y cells. We found that the expression of beta3-AR protein was significantly inhibited by rosiglitazone in a concentration-dependent manner in SH-SY5Y cell lines stably expressed beta3-AR genes. CONCLUSIONS: The results suggest that rosiglitazone has a concentration-dependent inhibitory effect on the expression of beta3-AR protein, and this inhibitory effect may be due to activation of PPAR-gamma2 receptor.

[Assessing the content of formaldehyde in vermicelli in Changsha market].

In order to better supervise food safety for the residents, the extent of formaldehyde in vermicelli sold on Changsha market was assessed by the acetyl acetone colorimetry method. Results showed that among 106 samples, 61 were formaldehyde positive. The positive rate was 57.55% (61/106). The content of formaldehyde ranged from 0.011 mg/kg to 2.859 mg/kg, indicating severe contamination of vermicellis by formaldehyde in Changsha market and therefore, the food safety supervision work should be strengthened.