Research progress of the CXCR4 mechanism in Alzheimer's disease.

Alzheimer's disease (AD) is a degenerative brain disease with complex clinical manifestations and pathogeneses such as abnormal deposition of beta-amyloid protein and inflammation caused by the excessive activation of microglia. CXC motif chemokine receptor type 4 (CXCR4) is a type of G protein-coupled receptor that binds to CXC motif ligand 12 (CXCL12) to activate downstream signaling pathways, such as the Janus kinase/signal transducer and activator of transcription and the renin-angiotensin system (Ras)/RAF proto-oncogene serine (Raf)/mitogen-activated protein kinase/extracellular-regulated protein kinase; most of these signaling pathways are involved in inflammatory responses. CXCR4 is highly expressed in the microglia and astrocytes; this might be one of the important causes of inflammation caused by microglia and astrocytes. In this review, we summarize the mechanism and therapeutics of AD, the structures of CXCR4 and the CXCL12 ligand, and the mechanisms of CXCR4/CXCL12 that are involved in the occurrence and development of AD. The possible treatment of AD through microglia and astrocytes is also discussed, with the aim of providing a new method for the treatment of AD.

Lacidipine attenuates TNF-α-induced cardiomyocyte apoptosis.

This study was designed to investigate whether lacidipine elicited a protective role on cardiomyocyte against apoptosis induced by TNF-α. Neonatal rat cardiomyocytes were randomly assigned into different groups. TUNEL staining was utilized to detect apoptosis, and caspase-3 and caspse-12 were determined. To explore the underlying mechanism, Z-ATAD-FMK (a selective caspase-12 inhibitor) was used to identify the key molecule involved. TNF-α increased caspase-3 expression, which was mediated by increased caspase-12 expression. In the meantime, apoptosis was significantly induced by TNF-α. Lacidipine lowered caspase-12 and caspase-3 expression, and cardiomyocyte apoptosis induced by TNF-α. The results suggest that lacidipine attenuates TNF-α -induced apoptosis via inhibition of caspase-12 and caspase-3 successively.

Effect of pomegranate peel polyphenol gel on cutaneous wound healing in alloxan-induced diabetic rats.

BACKGROUND: Pomegranate (punica granatum) belongs to the family Punicaceae, and its peel has been used as a traditional Chinese medicine because of its efficacy in restraining intestine, promoting hemostasis, and killing parasites. Pomegranate peel has been reported to possess wound-healing properties which are mainly attributed to its polyphenol extracts. The purpose of this study was to investigate the effect of pomegranate peel polyphenols (PPP) gel on cutaneous wound healing in diabetic rats. METHODS: Alloxan-induced diabetic rats were given incisional wounds on each side of the mid-back and then treated daily with PPP gel (polyphenol mass fraction = 30%) post-wounding. Rats were sacrificed on days 4, 7, 14, and 21 post-wounding to assess the rates of wound closure, histological characteristics; and to detect the contents of hydroxyproline, production of nitric oxide (NO), and activities of NO synthase (NOS), as well as the expressions of transforming growth factor-ß1 (TGF-ß1), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF) in wound tissue. RESULTS: Wound closure was significantly shortened when PPP gel was applied to the wounds of diabetic rats. Histological examination showed the ability of PPP gel to increase fibroblast infiltration, collagen regeneration, vascularization, and epithelialization in the wound area of diabetic rats. In addition, PPP gel-treated diabetic rats showed increased contents of hydroxyproline, production of NO, and activities of NOS and increased expressions of TGF-ß1, VEGF, and EGF in wound tissues. CONCLUSION: PPP gel may be a beneficial method for treating wound disorders associated with diabetes.

[Plasma glutathione of patients with coronary heart disease measured by fluorospectrophotometer].

The standard samples of reduction form glutathione (GSH) and oxidization form glutathione (GSSG) were scanned with full-wavelength range to determine the excitation wavelength lambda(ex) 334.4 nm, the emission wavelength lambda(em) 424 nm, and the spectral bandwidth 5 nm respectively. Phosphate buffer saline (PBS) of pH 8. 3 served as buffer solution. GSH was incubated for 30 min with 100 microL o-phthaldehyde (OPA) of 10 mmol x L(-1) methyl alcohol solution for derivatization, and then fluorescence intensities were measured. With standard glutathione concentration being independent variable and fluorescence intensity being dependent variable, the linear equations for GSH and GSSG were deduced: Y(GSH) = 6.9 + 8.6X (r2 = 0.994) and Y(GSSG) = 6.2 + 17.2X (r2 = 0.999). Standard curves were done hereby. The plasma glutathione of three groups was then measured, and GSH/ GSSG redox potential was calculated according to Nernst equation. The results indicated that, from normal control group to prophase coronary heart disease group, then to coronary heart disease group, the GSH and GSH/GSSG ratio gradually reduced, GSSG and GSH/GSSG redox potential gradually increased (more positive) (all P < 0.05), and the redox potential shifted to oxidization direction along with the development of coronary heart disease. This fluorospectrophotometry method showed simple operation, and fine precision and accuracy.

Effect of ozone produced from antibody-catalyzed water oxidation on pathogenesis of atherosclerosis.

Recent studies have suggested that antibodies can catalyze the generation of unknown oxidants including hydrogen peroxide (H2O2) and ozone (O3) from singlet oxygen (1O2) and water. This study is aimed to detect the effect of antibody-catalyzed water oxidation on atherosclerosis. Our results showed that both H2O2 and O3 were produced in human leukemia THP-1 monocytes incubated with human immunoglobulin G and phorbol myristate acetate. In the THP-1 monocytes incubated with human immunoglobulin G, phorbol myristate acetate and low density lipoprotein, the intracellular total cholesterol, free cholesterol, cholesteryl ester and lipid peroxides clearly increased, and a larger number of foam cells were observed by oil red O staining. The accumulation of all intracellular lipids was significantly inhibited by vinylbenzoic acid, and only slightly affected by catalase. These findings suggested that the production of O3, rather than H2O2, might be involved in the pathogenesis of atherosclerosis through the antibody-catalyzed water oxidation pathway.

[Effect of triptolide on expression of urokinase-type plasminogen activators in vascular endothelial cells].

BACKGROUND & OBJECTIVE: It has been showed that triptolide (T10) has antitumor activities. This study was to observe the inhibitory effects of T10 on proliferation of vascular endothelial cells and expression of urokinase-type plasminogen activator (u-PA), and to elucidate the antiangiogenic mechanism of T10. METHODS: Human umbilical vein endothelial cells were cultured in vitro for 3 generations, and treated with T10 (0, 5, 10, 20, and 30 microg/L), or dexamethasone (300 mg/L) as control. Cell count and 3H-TDR incorporation were used to observe cell proliferation. The chick embryo chorioallantoic membrane (CAM) test was carried out to observe the effect of T10 on angiogenesis. Immunohistochemistry and real-time quantitive reverse transcription-polymerase chain reaction (RT-PCR) were used to detect protein and mRNA levels of u-PA. RESULTS: T10 inhibited the proliferation of umbilical vein endothelial cells in a dose-dependent manner; inhibitory rate of endothelial cells was 28.93% after treatment of 5 microg/L of T10. T10 significantly reduced angiogenesis in CAM, even at the concentration of 5 microg/L (P<0.05). T10 decreased protein and mRNA levels of u-PA in endothelial cells in a dose-dependent manner; the protein level of u-PA was reduced by 41.05% after treatment of 5 microg/L of T10. CONCLUSION: T10 could inhibit the proliferation of human umbilical vein endothelial cells and expression of u-PA, which may contribute to its antiangiogenic activity.

[Effects of triptolide on migration of vascular endothelial cells].

OBJECTIVE: To investigate the inhibitory effects of triptolide on the migration, gene and protein expression of urokinase-type plasminogen activator (u-PA) of endothelial cells (ECs) cultured in vitro and to elucidate the anti-angiogenic mechanism of triptolide. METHODS: Human umbilical vein endothelial cells (HUVECs) were cultured in vitro and the passage 3 cells were treated with triptolide (0, 5, 10, 20, 30 microg/L). Three-dimensional culture system was used to assess the effect of triptolide on the migration of HUVECs. Real time quantitive reverse transcription polymerase chain reaction and immunohistochemical assay were applied to detect gene and protein expression of u-PA. RESULTS: Triptolide decreased the migration activity and suppressed the expression of u-PA of HUVECs at the gene and protein level. CONCLUSION: Triptolide could inhibit the migration of ECs by reducing the gene and protein expression of u-PA. These may contribute to an elucidation of the mechanism by which triptolide inhibits the angiogenesis.

[A novel fluorophotometric method for assaying free glutathione of both reduced and oxidized in plasma].

To investigate the measurement of free glutathione of both reduced or oxidized (i.e. GSH and GSSG) in plasma, and to evaluate the redox state of GGSH/GSSG in human plasma, both GSH and GSSG in plasma were measured by fluorophotometry based on the facts that one molar GSSG can be reduced to two molar GSH by dithiothreitol(DTT) under the condition of the pH being about 6.0, and GSH can provide both primary amine and thiol groups to react with the two carbonyl groups of O-phthaldehyde (OPA) to form a fluorescent ternary isoindole complex at pH 8.0. This method can at least measure 16 picomole GSH and 8 picomole GSSG respectively in the tube. The variation coefficient (CV) for intra-ssay and intera-ssay is about 4. 6% and 3.9% for GSH and 3.5% and 4.1% for GSSG respectively. The recovery of GSH and GSSG added to the plasma is (99.77% +/- 5.70)% and (99.28% +/- 4.73)% respectively. The concentration of GSH and GSSG in the plasma of young healthy volunteer is (16.5 +/- 2.4) nmol x mL(-1) and (1.7 +/- 0.35)nmol x mL(-1) respectively, without significant difference between male and female. This measurement method is simple with great sensitivity and selectivity for rapid measuring GSH and GSSG in human plasma simultaneously.