Human Muse cells-derived neural precursor cells as the novel seed cells for the repair of spinal cord injury.

At present, stem cell transplantation has a significant therapeutic effect on spinal cord injury (SCI), however, it is still challenging for the seed cells selection. In this study, in order to explore cells with wide neural repair potentials, we selected the pluripotent stem cells multilineage-differentiating stress-enduring (Muse) cells, inducing the in vitro differentiation of human Muse cells into neural precursor cells (Muse-NPCs) by applying neural induction medium. Here, we found induced Muse-NPCs expressed neural stem cell markers Nestin and NCAM, capable of differentiating into three types of neural cells (neuron, astrocyte and oligodendrocyte), and have certain biological functions. When Muse-NPCs were transplanted into rats suffering from T10 SCI, motor function was improved. These results provide an insight for application of Muse-NPCs in cell therapy or tissue engineering for the repair of SCI in future.

Lipoic acid attenuates the expression of adhesion molecules by increasing endothelial nitric-oxide synthase activity.

We tried to study the possible effects of lipoic acid (LA) on adhesion molecule expression and its underlying mechanism in the prevention and treatment of cardiovascular disorders. Intercellular adhesion molecule-1 (ICAM-1) expression and endothelial nitric oxide synthase (eNOS) activity were determined after endothelial cells were exposed to high glucose in the absence and presence of LA. Coincubation of endothelial cells with high glucose for 24 h resulted in a significant increase of monocyte-endothelial cell adhesion and the expression of ICAM-1 (P < 0.01). These effects were abolished by LA and LA significantly increased eNOS activities (P < 0.01). These findings suggested that LA may play a role in inhibiting expression of adhesion molecules by increasing eNOS activities.

Protective roles of quercetin in acute myocardial ischemia and reperfusion injury in rats.

Myocardial ischemia and reperfusion (MI/R) is associated with an intense inflammatory reaction, which may lead to myocyte injury. In this study, we investigated the effect of quercetin, an inhibitor of c-Jun N-terminal kinase on ischemia/reperfusion injury in isolated rat hearts. Rat models of MI/R were induced by coronary occlusion followed by reperfusion, treatment of rats with quercetin (1.0 mg/kg, i.v.) induced a significant reduction of infarct volume and improvements in baseline hemodynamic abnormalities (P < 0.05). Quercetin treatment also attenuated the expression of both TNF-alpha (TNF-α) and interleukin-10 (IL-10) and lowered the serum levels of inflammatory cytokine (P < 0.05). These findings suggested that quercetin treatment significantly attenuated MI/R injury primarily through anti-inflammatory effects.

Nitric oxide modulated the expression of DREAM/calsenilin/KChIP3 in inflammatory pain of rats.

Downstream regulatory element antagonistic modulator (DREAM) is a critical transcriptional repressor for pain modulation. The role of nitric oxide (NO) plays in modulating DREAM pain pathway in the periphery is unclear. Therefore, we investigated the role of the NO in modulation of the expression of DREAM in formalin-induced rat inflammatory pain models. Male Sprague-Dawley rats were randomly distributed into four groups: the normal group, formalin test group, Nω-nitro-L-arginine (l-NNA) group, and morphine group. One hundred microliters of 2.5 % formalin was injected into the plantar surface of the right hindpaw of rats. l-NNA (40 nmol/L) and morphine (40 nmol/L) were injected intrathecally in the hindpaw before formalin injection. The nociceptive behavioral reaction was recorded. After the formalin test, the expression of DREAM mRNA and protein in the spinal cord of the four groups were measured. The nociceptive reaction induced by injection of formalin exhibited two phases. Morphine and l-NNA significantly decreased pain scores of the second phase. The expression of DREAM was significantly increased in the rat spinal cord after formalin-induced pain. Morphine significantly upregulated the expression of DREAM, and the formalin-induced upregulation was significantly attenuated by l-NNA. NO may play an important role in the DREAM pathway modulation of inflammatory pain.

Sarpogrelate protects against high glucose-induced endothelial dysfunction and oxidative stress.

This study was designed to investigate the effect of sarpogrelate hydrochloride on impaired endothelium-dependent relaxation (EDR) induced by high glucose in isolated rat aorta. Both acetylcholine-induced EDR and sodium nitroprusside-induced endothelium-independent relaxation (EIR) were measured after the rings were exposed to high glucose in the absence and presence of sarpogrelate hydrochloride. Co-incubation of aortic rings with high glucose for 24h resulted in a significant inhibition of EDR, but had no effects on EIR. After incubation of the rings in the co-presence of sarpogrelate hydrochloride with high glucose for 24h, sarpogrelate hydrochloride significantly attenuated impaired EDR. This protective effect of sarpogrelate hydrochloride was abolished by N(G)-nitro-L-arginine methyl ester. Sarpogrelate hydrochloride significantly decreased superoxide anion (O(2)(-)) production and increased superoxide dismutase (SOD) activity and the nitric oxide (NO) release. These results suggest that sarpogrelate hydrochloride can restore impaired EDR induced by high glucose in isolated rat aorta, which may be related to scavenging oxygen free radicals and enhancing NO production.

KB-R7943 inhibits high glucose-induced endothelial ICAM-1 expression and monocyte-endothelial adhesion.

Hyperglycemia is the major cause of diabetic angiopathy. The aim of our study was to evaluate the impact of KB-R7943, an inhibitor of Na+/Ca2+ exchanger (NCX) on cell growth and function of human "diabetic" endothelial cells (EC). Intercellular adhesion molecule-1 (ICAM-1) expression and NCX activity were determined after EC were exposed to high glucose in the absence and presence of KB-R7943. Coincubation of EC with high glucose for 24 h resulted in a significant increase of monocyte-endothelial cell adhesion and the expression of ICAM-1. These effects were abolished by KB-R7943 and KB-R7943 significantly decreased the activation of NCX induced by high glucose. These findings suggested that KB-R7943 may play a role in inhibiting expression of adhesion molecules by inhibiting the reverse activation of NCX.

[Inhibition of N/OFQ on transient outward potassium currents in acutely dissociated rat cerebral parietal cortical neurons].

AIM: To study the effect of Nociceptin/orphanin FQ (N/OFQ) on transient outward potassium (I(A)) in rat cerebral cortical neurons and its kinetic mechanism. METHODS: The effects of N/OFQ on I(A) were investigated by using the whole cell patch clamp technique in acutely dissociated rat cerebral cortical neurons. RESULTS: (1) At the voltage of + 60 mV, 0.1 micromol/L N/OFQ made I(A) decreased from (5356.1 +/- 361.6) pA to (4113.3 +/- 312.7) pA (P < 0.01, n = 10) and the percent inhibition was 23.2% +/- 2.2%. (2) (N/OFQ made I-V curve of I(A) decreased significantly (P < 0.01, n = 10).(3) 0.1 micromol/L N/OFQ shifted the activation curve of I(A) to positive potential from (-9.2 +/- 2.5)mV to (30.6 +/- 3.7) mV (P < 0.01, n = 8) and changed the slope factor(kappa) of the activation curve from (20.4 +/- 2.3) mV to (22.6 +/- 2.1) mV (P > 0.05, n = 8). (4) 0.1 micromol/L N/OFQ caused a significant hyperpolarizing shift of the inactivation curve from (-64.1 +/- 3.2) mV to (-55.9 +/- 1.9) mV (P < 0.05, n = 5), without significant effect on kappa of the inactivation curve. CONCLUSION: 0.1 micromol/L N/OFQ has a significant inhibition on I(A) and shift the activation and inactivation curve to depolarization in cerebral parietal cortical neurons of rats.

Na+/Ca2+ exchanger inhibitor ameliorates impaired endothelium-dependent Na+ relaxation induced by high glucose in rat aorta.

The present study was designed to investigate the effects of KB-R7943, an inhibitor of the Na+/Ca2+ exchanger, on impaired endothelium-dependent relaxation (EDR) induced by high glucose in rat isolated aorta. Both acetylcholine (ACh)-induced EDR and sodium nitroprusside (SNP)-induced endothelium-independent relaxation (EIR) were measured after aortic rings had been exposed to high glucose in the absence and presence of KB-R7943. Coincubation of aortic rings with high glucose (25 mmol/L) for 24 h resulted in a significant inhibition of EDR, but had no effect on EIR. After incubation of aortic rings in the presence of both KB-R7943 (0.1-10 micromol/L) and high glucose for 24 h, significantly attenuation of impaired EDR was observed. This protective effect of KB-R7943 (10 micromol/L) was abolished by superoxide dismutase (SOD; 200 U/mL) and l-arginine (3 mmol/L), whereas d-arginine (3 mmol/L) had no effect. Similarly, high glucose decreased SOD activity and the release of nitric oxide (NO) and increased superoxide anion (O2(-)) production in aortic tissue. KB-R7943 significantly decreased O2(-) production and increased SOD activity and NO release. These results suggest that KB-R7943 can restore impaired EDR induced by high glucose in rat isolated aorta, which may be related to the scavenging of oxygen free radicals and enhanced NO production.

[Effects of interferon-gamma and tumor necrosis factor-alpha on the fertilizing capacity of human sperm and their mechanisms].

OBJECTIVE: To investigate the effects of interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-gamma) on the sperm acrosin activity and the rate of acrosome reaction and to probe into their mechanisms. METHODS: Thirty-six nearly normal semen samples were treated with IFN-gamma and/or TNF-alpha after isolated by 75% Percoll. The sperm acrosin activity was tested by the method of BAEE/ADH Unity, the rate of acrosome reaction observed by Triple-stain technique, the NO concentration measured by HPLC and the activities of Na+ -K+ -ATPase, Ca2+ -ATPase and SOD assayed by kit method. RESULTS: Both IFN-gamma and TNF-gamma could decrease sperm acrosin activity and acrosome reaction (P < 0.05 or P < 0.01). TNF-alpha showed stronger inhibiting effect, IFN-gamma markedly reduced the activities of Na+ -K+ -ATPase, Ca2+ -ATPase and SOD in sperm (P < 0.01), and their synergistic action was weaker. However TNF-alpha produced hardly any effect on Na+ -K+ -ATPase and Ca2+ -ATPase. The NO concentration in sperm was significantly increased by IFN-gamma and/or TNF-alpha (P < 0.01). CONCLUSION: IFN-gamma and TNF-alpha have some inhibiting effect on sperm acrosin activity and the rate of acrosome reaction, which could be attributed to their influence on the activities of Na+ -K+ -ATPase, Ca2+ -ATPase and SOD, the NO concentration and so on.

[Inhibition of ACh on the delayed rectifier-like potassium current in acutely isolated cerebral cortical neurons of rats].

The modulation of ACh on delayed rectifier-like potassium currents (I(K)) was studied in freshly dissociated cerebral cortical neurons using the whole-cell patch-clamp technique. Wistar rats between 10- and 14-day old of both sexes were used. After rats were decapitated, their brains were quickly removed, iced, and then manually cut into 400 mum slices. Slices were then incubated for 0.5 h at 32 degrees C in a buffered artificial cerebrospinal fluid (ACSF) bubbled with 95% O2, 5% CO2. Slices were then removed into buffered ACSF containing protease (0.5 mg/ml) at 32 degrees C. After 30 min of enzyme digestion, tissue was rinsed three times in the buffered saline. Then the enzyme-treated slices were mechanically dissociated with a graded series of fire-polished Pasteur pipettes. The cell suspension was then plated into a 35 mm dish and placed on the stage of a Olympus inverted microscope. For whole-cell recordings of currents, standard voltage-clamp techniques were used. Neurons were held at -80 mV, and the I(K) was evoked by 2 000 ms depolarizing voltage commands to potential between -40 mV and +60 mV in 10 mV steps applied at a frequency of 0.5 Hz. It was found that the inhibitory effect of ACh (0.1, 1, 10, 100 mumol/L) on I(K) was dose-dependent. It was also found that ACh affected the activation process of I(K) significantly, i.e., the activation curve of I(K) was characterized by half-activation potential of (-41.8+/-9.7) mV and a slope factor of (30.7+/-7.2) mV in the cortical neurons and they were changed to (-122.4+/-38.6) mV and (42.4+/-7.0) mV, respectively, after giving ACh (10 mumol/L). Tubocurarine (100 mumol/L) antagonized the inhibitory effect of ACh on I(K), and the drop of currents varied from the control value of (36.5+/-7..8)% to (16.9+/-13.8)% (n=8, P<0.01). 4-DAMP (10 mumol/L) blocked the inhibitory effect of ACh on I(K), and the currents reduced from the control value of (36.5+/-7.8)% to (26.8+/-4.7) % (n=6, P<0.05). Pirenzepin did not antagonize the inhibition of ACh on I(K) (n=7, P>0.05). Chelerythrine (20 mumol/L) blocked the inhibitory effect of ACh on I(K) and the currents reduced from the control value of (36.5+/-7.8)% to (11.7+/-17.3)% (n=6, P<0.05). On the contrary, PDBu (10 mumol/L) strengthened the inhibition of ACh on I(K) and the drop of currents changed from the control value of (36.5+/-7.8)% to (59.2+/-14.0)% (n=5, P<0.05). PDBu abolished the antagonism of chelerythrine on ACh in cortical neurons. It is suggested that the ACh-induced depolarization of neurons in the cortex is attributed to the inhibition of I(K) that is most likely evoked by the activation of nicotinic ACh receptors and muscarinic M3 receptor via protein kinase C (PKC) signal transduction pathway.