Multitasking bamboo leaf-derived compounds in prevention of infectious, inflammatory, atherosclerotic, metabolic, and neuropsychiatric diseases.

Bamboo is a medicinal plant, and has long been used as a traditional/folk medicine and a food preservative in Japan. Bamboo leaf contains many active ingredients with medicinal benefits. In particular, recent studies demonstrated that bamboo leaf extract and its constituents have great potential to prevent infectious, inflammatory, cardiovascular, metabolic, and neurological/neuropsychiatric diseases. In this review, we summarize the prophylactic and possible therapeutic effects of bamboo leaf extract and its constituent compounds against these disorders. The effects of the extract are explainable in part by the effects of some constituent compounds: p-coumaric acid, myricetin, orientin, stachyose, and vitexin. Moreover, coenzyme Q10, an anti-oxidative constituent, alleviates oxidative stress which underlies the common pathogenic mechanisms of the development of diabetic complications, atherosclerosis and periodontal disease. Some flavonoids contained in bamboo leaf, such as orientin and vitexin, have been reported to regulate gut microbiota responsible for maintaining whole-body functions, suggesting a possible interaction between bamboo leaf extract and probiotics. Thus, bamboo leaf is a valuable natural resource for the development of multiple pharmacotherapies.

An open-label, prospective, single-arm study of switching from infliximab to cyclosporine for refractory uveitis in patients with Behçet's disease in long-term remission.

PURPOSE: Although infliximab (IFX) decreases the risk of blindness due to refractory uveitis in patients with Behçet's disease (BD), there are no standard criteria for IFX switching or withdrawal. To evaluate the effect of IFX switching in patients with BD in long-term remission, a prospective, single-arm intervention trial was conducted, switching from IFX to cyclosporine A (CYA). STUDY DESIGN: A prospective open-label study. METHODS: Eligible patients met the following criteria: administration of IFX without concomitant immunosuppressants for more than 5 years with no episodes of ocular attacks, no retinal vasculitis on fluorescein fundus angiography, negative C-reactive protein in serum, and no extraocular lesions at the time of IFX withdrawal. CYA 5 mg/kg/day was administered from 6 weeks after IFX withdrawal. The primary outcome was the rate of readministration of tumor necrosis factor inhibitors at 1 year after IFX withdrawal. RESULTS: Three of 45 BD patients treated with IFX for refractory uveitis were included in the study. At 1 year after withdrawal of IFX, no patient had experienced any ocular attacks or needed readministation of IFX. However, extraocular lesions, such as recurrent oral ulcers, folliculitis, and recurrent fevers, occurred in all patients. Liver or renal dysfunction, which may have been caused by CYA, was also observed in all patients. CONCLUSIONS: Although no ocular attacks were observed for at least 1 year after IFX withdrawal, this prospective study indicates that IFX withdrawal should be considered carefully, even for patients in long term remission of ocular and extraocular lesions.

Genetic control of CCL24, POR, and IL23R contributes to the pathogenesis of sarcoidosis.

Sarcoidosis is a genetically complex systemic inflammatory disease that affects multiple organs. We present a GWAS of a Japanese cohort (700 sarcoidosis cases and 886 controls) with replication in independent samples from Japan (931 cases and 1,042 controls) and the Czech Republic (265 cases and 264 controls). We identified three loci outside the HLA complex, CCL24, STYXL1-SRRM3, and C1orf141-IL23R, which showed genome-wide significant associations (P < 5.0 × 10-8) with sarcoidosis; CCL24 and STYXL1-SRRM3 were novel. The disease-risk alleles in CCL24 and IL23R were associated with reduced CCL24 and IL23R expression, respectively. The disease-risk allele in STYXL1-SRRM3 was associated with elevated POR expression. These results suggest that genetic control of CCL24, POR, and IL23R expression contribute to the pathogenesis of sarcoidosis. We speculate that the CCL24 risk allele might be involved in a polarized Th1 response in sarcoidosis, and that POR and IL23R risk alleles may lead to diminished host defense against sarcoidosis pathogens.

Postoperative refractive error following cataract surgery after the first attack of acute primary angle closure.

To investigate differences between preoperative target refraction and postoperative spherical equivalent refraction in eyes with the first attack of acute angle closure glaucoma before and after surgery. We retrospectively examined eyes of 36 patients who suffered the first attack of acute primary angle closure after undergoing cataract extraction and intraocular lens implant. We measured keratometric values (K1, K2) due to medical therapy for high ocular tension and the mean time interval until surgery. We compared the axial length, expected diopter, logMAR visual acuity, K1, K2, refractive spherical equivalent, and intraocular pressure (IOP) before and 6 months after surgery. The average preoperative IOP was 51.3 ± 9.0 mmHg, but it decreased to 14.8 ± 3.6 mmHg after surgery. No corneal edema was observed after surgery. The average axial length was 22.12 ± 1.03 mm and there was no significant change in keratometric values, which were 7.72 ± 0.33 mm (K1) and 7.51 ± 0.31 mm (K2) before surgery and 7.67 ± 0.33 mm (K1) and 7.49 ± 0.29 mm (K2) after surgery. Similarly, no significant difference was observed in average preoperative target refractive error (-0.57 ± 0.53 D) and average postoperative refractive spherical equivalent (-0.67 ± 0.97 D). The inability to accurately determine preoperative refractive error due to corneal edema or other complications is a concern during the first attack of acute angle closure glaucoma. However, our results indicate that no differences should be expected between preoperative refractive error and postoperative refractive spherical equivalent.

Cataract surgery for tilted lens in peters' anomaly type 2.

BACKGROUND: Cases of cataract surgery without penetrating keratoplasty in patients with Peters' anomaly are very rare. We report a case of Peters' anomaly type 2 with tilted lens due to synechia between the lens and iris that was treated with cataract surgery without penetrating keratoplasty. CASE PRESENTATION: A 16-year-old girl had Peters' anomaly in both eyes. Corneal opacity was severe in the left eye due to high-grade dysgenesis of the anterior segment. In the right eye, corneal opacity had spread from the center of the cornea to the inferotemporal side, and there was synechia between the iris and corneal endothelium from the inferonasal side to the inferotemporal side. Opacity was observed in the anterior pole of the lens, and there was synechia between the anterior iris and the lens. Ultrasound biomicroscopy (UBM) revealed that the lens was tilted because of synechia. The tilted lens induced astigmatism, which reduced visual acuity to 20/250, in conjunction with a cataract. Cataract surgery was performed; the synechia between the lens capsule and the iris was severed, an intraocular lens was inserted, and the tilt was repaired. UBM was used postoperatively to confirm that the lens capsule synechia had been corrected and that the intraocular lens was not tilted. As a result, visual acuity improved to 20/100; glaucoma and expansion of corneal opacity were not observed. CONCLUSIONS: Severing of the synechia between the cataract and iris, during cataract surgery, in a patient with Peters' anomaly type 2 resulted in favorable postoperative visual acuity.

Reduction in choroidal thickness of macular area in polypoidal choroidal vasculopathy patients after intravitreal ranibizumab therapy.

BACKGROUND: To evaluate changes in retinal and choroidal thickness changes after three intravitreal ranibizumab (IVR) injections for polypoidal choroidal vasculopathy (PCV) using enhanced depth-imaging-optical coherence tomography (EDI-OCT). METHODS: In this retrospective, observational case series, EDI-OCT was used to measure changes in choroidal thickness at nine points in a lattice shape in the macula before and after introductory-stage IVR. RESULTS: Choroidal thickness was decreased at all nine points in the lattice shape, but was significantly decreased only at the fovea. CONCLUSION: The subfoveal choroidal thickness may be reduced by introductory-stage IVR in patients with PCV. In particular, choroidal thickness at the fovea was reduced during the early stage of treatment.

Preoperative factors associated with improvement in visual acuity after globe rupture treatment.

OBJECTIVE: Globe rupture is a serious condition. Despite advancements in vitrectomy, the postoperative prognosis for visual acuity remains poor in many cases. We conducted multiple regression analysis to identify preoperative factors associated with postoperative visual acuity. 
 METHODS: Subjects comprised 24 patients with globe rupture in one eye who had 5 consecutive years of consultation and were followed up for 12 months or longer. Subjects comprised 13 males and 11 females with a mean age of 67.8 ± 17.4 years. Our methods involved performing multiple regression analysis with age, preoperative visual acuity, scope of injury, number of surgeries, hyphema, vitreous hemorrhage, retinal detachment, and subchoroidal hemorrhage as explanatory variables, and postoperative visual acuity as the response variable. 
 RESULTS: Preoperative visual acuity and scope of retinal detachment were explanatory factors found to correlate significantly with postoperative visual acuity after globe rupture. 
 CONCLUSIONS: Our results demonstrate that postoperative visual acuity can be predicted to some degree by preoperative visual acuity and the scope of retinal detachment.

Protective effects of coenzyme Q10 against angiotensin II-induced oxidative stress in human umbilical vein endothelial cells.

Angiotensin II is the major effector in the renin-angiotensin system, and angiotensin II-induced oxidative stress and endothelial dysfunction are profoundly implicated in the pathogenesis of hypertension and cardiovascular disease. In the present study, we investigated the effect of an antioxidant reagent, coenzyme Q10, on angiotensin II-induced oxidative stress in human umbilical vein endothelial cells (HUVEC) to assess its potential usefulness for antioxidant therapy. Treatment of HUVEC with coenzyme Q10 (1-10µM) increased its intracellular levels in a concentration-dependent manner. Coenzyme Q10 (10µM) prevented the actions of angiotensin II (100nM): overproduction of reactive oxygen species, increases in expression of p22(phox) and Nox2 subunits of NADPH oxidase, and inhibition of insulin-induced nitric oxide production. In addition, coenzyme Q10 prevented angiotensin II-induced upregulation of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in HUVEC, and inhibited their adhesion to U937 monocytic cells. Moreover, treatment of HUVEC with coenzyme Q10 effectively ameliorated angiotensin II-induced increases in expression of Nox2 subunit of NADPH oxidase, ICAM-1, and VCAM-1. These results provide the first in vitro evidence that coenzyme Q10 is an efficient antioxidant reagent to improve angiotensin II-induced oxidative stress and endothelial dysfunction, possibly relevant to the causes of cardiovascular disease.

Beta-eudesmol suppresses tumour growth through inhibition of tumour neovascularisation and tumour cell proliferation.

In the present study, we investigated the potential anti-angiogenic mechanism and anti-tumour activity of beta-eudesmol using in vitro and in vivo experimental models. Proliferation of human umbilical vein endothelial cells (HUVEC) stimulated with vascular endothelial growth factor (VEGF, 30 ng/ml) and basic fibroblast growth factor (bFGF, 30 ng/ml) was significantly inhibited by beta-eudesmol (50-100 microM). Beta-eudesmol (100 microM) also blocked the phosphorylation of cAMP response element binding protein (CREB) induced by VEGF (30 ng/ml) in HUVEC. Beta-eudesmol (10-100 microM) inhibited proliferation of HeLa, SGC-7901, and BEL-7402 tumour cells in a time- and dose-dependent manner. Moreover, beta-eudesmol treatment (2.5-5 mg/kg) significantly inhibited growth of H(22) and S(180) mouse tumour in vivo. These results indicated that beta-eudesmol inhibited angiogenesis by suppressing CREB activation in growth factor signalling pathway. This is the first study to demonstrate that beta-eudesmol is an inhibitor of tumour growth.

Ameliorating effects of compounds derived from Salvia miltiorrhiza root extract on microcirculatory disturbance and target organ injury by ischemia and reperfusion.

Ischemia and reperfusion (I/R) exerts multiple insults in microcirculation, frequently accompanied by endothelial cell injury, enhanced adhesion of leukocytes, macromolecular efflux, production of oxygen free radicals, and mast cell degranulation. Since the microcirculatory disturbance results in injury of organ involved, protection of organ after I/R is of great importance in clinic. Salvia miltiorrhiza root has long been used in Asian countries for clinical treatment of various microcirculatory disturbance-related diseases. This herbal drug contains many active water-soluble compounds, including protocatechuic aldehyde (PAl), 3,4-dihydroxyphenyl lactic acid (DLA) and salvianolic acid B (SalB). These compounds, as well as water-soluble fraction of S. miltiorrhiza root extract (SMRE), have an ability to scavenge peroxides and are able to inhibit the expression of adhesion molecules in vascular endothelium and leukocytes. Moreover, lipophilic compounds of SMRE also prevent the development of vascular damage; NADPH oxidase and platelet aggregation are inhibited by tanshinone IIA and tanshinone IIB, respectively, and the mast cell degranulation is blunted by cryptotanshinone and 15,16-dihydrotanshinone I. Thus, the water-soluble and lipophilic compounds of SMRE appear to improve the I/R-induced vascular damage multifactorially and synergically. This review will summarize the ameliorating effect of compounds derived from SMRE on microcirculatory disturbance and target organ injury after I/R and will provide a new perspective on remedy with multiple drugs.

Coenzyme Q10 prevents high glucose-induced oxidative stress in human umbilical vein endothelial cells.

Hyperglycemia-induced oxidative stress plays a crucial role in the pathogenesis of vascular complications in diabetes. Although some clinical evidences suggest the use of an antioxidant reagent coenzyme Q10 in diabetes with hypertension, the direct effect of coenzyme Q10 on the endothelial functions has not been examined. In the present study, we therefore investigated the protective effect of coenzyme Q10 against high glucose-induced oxidative stress in human umbilical vein endothelial cells (HUVEC). HUVEC exposed to high glucose (30 mM) exhibited abnormal properties, including the morphological and biochemical features of apoptosis, overproduction of reactive oxygen species, activation of protein kinase Cbeta2, and increase in endothelial nitric oxide synthase expression. Treatment with coenzyme Q10 strongly inhibited these changes in HUVEC under high glucose condition. In addition, coenzyme Q10 inhibited high glucose-induced cleavage of poly(ADP-ribose) polymerase, an endogenous caspase-3 substrate. These results suggest that coenzyme Q10 prevents reactive oxygen species-induced apoptosis through inhibition of the mitochondria-dependent caspase-3 pathway. Moreover, consistent with previous reports, high glucose caused upregulation of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in HUVEC, and promoted the adhesion of U937 monocytic cells. Coenzyme Q10 displayed potent inhibitory effects against these endothelial abnormalities. Thus, we provide the first evidence that coenzyme Q10 has a beneficial effect in protecting against the endothelial dysfunction by high glucose-induced oxidative stress in vitro.

Novel G423S mutation of human alpha7 nicotinic receptor promotes agonist-induced desensitization by a protein kinase C-dependent mechanism.

The alpha7 nicotinic acetylcholine receptor subunit (CHRNA7) gene harbors a high degree of polymorphism. In this study, we found a novel variant (1267 G to A) in exon 10 of the CHRNA7 gene in a Japanese population. This variant results in glycine-to-serine substitution at position 423 (G423S) located in the large cytoplasmic loop of the protein. To clarify the possibility that the G423S mutation alters the pharmacological properties of alpha7 receptors, acetylcholine (ACh)-elicited current through alpha7-G423S mutant receptors expressed in Xenopus laevis oocytes was measured using the two-electrode voltage-clamp technique. We found that the current elicited by ACh (1 mM, 5 s) through alpha7-G423S receptors, but not through alpha7 receptors, was significantly decreased by treatment with a protein kinase C activator, phorbol-12-myristate-13-acetate (PMA, 10-30 nM). In addition, PMA (10 nM) selectively promoted a progressive decrease in alpha7-G423S current induced by repetitive application of ACh pulses (1 mM, 0.1 s, 0.17-0.33 Hz) compared with alpha7 current. PMA also enhanced the inactivation of alpha7-G423S mutant receptors induced by a prolonged application of choline (30 microM) without affecting alpha7 receptor responses. Western blot analysis showed that the treatment with PMA (30 nM) increased the serine phosphorylation level of the alpha7-G423S mutant receptors but not that of the wild-type receptors. These findings demonstrate that the G423S mutation promotes receptor desensitization by a protein kinase C-dependent mechanism. Thus, we provide the first evidence that a variant in the human CHRNA7 gene alters the function of alpha7 nicotinic receptors.

Medical benefits of using natural compounds and their derivatives having multiple pharmacological actions.

The multiple pharmacological actions of a unique compound are a prerequisite for classifying drugs as highly efficacious, because the multiple pharmacological actions offer the possibility of treating various symptoms of chronic diseases as described below. 1) Sustained hyperglycemia induces macrovascular and microvascular complications in type 2 diabetes mellitus. Antihyperglycemic medication and the control of postprandial hyperglycemia are essentially important for normalizing plasma glucose level. Gymnemic acid IV isolated from Gymnema sylvestre (Asclepiadaceae) leaves has antisweet, antihyperglycemic, glucose uptake inhibitory, and gut glycosidase inhibitory effects. Most of these pharmacological effects may synergistically contribute to alleviating type 2 diabetes-related symptoms. 2) Diabetic skeletal and vascular smooth muscles are hypersensitive to chemical transmitters, cytokines and autacoids. The sensitivity of neuromuscular synapses is enhanced in diabetes, which seems to be closely associated with neuropathy as one of the diabetic complications. beta-Eudesmol found in Atractylodes lancea rhizome has a desensitizing channel blocking action to nicotinic acetylcholine receptors, anti-angiogenic action in vascular endothelium, and neuronal differentiation actions. These multiple pharmacological actions are favorable for treating angiogenic diseases possibly including the complications of diabetes, namely, retinopathy and nephropathy, and cancer. 3) Nipradilol is clinically utilized as a topical antiglaucoma drug. The ocular hypotensive effects of this compound are brought about by its alpha1 and beta-adrenergic receptor blocking actions, and nitric oxide (NO) releasing action. NO directly activates cyclooxygenases. All these pharmacologic effects are beneficial for treating glaucoma. The selectivity and specificity of drug action are required for treating acute diseases, infections or for acting as useful reagents. The pleiotropic actions of natural compounds and their derivatives serve as important clues for developing new drugs for various chronic diseases.

Comparative study on the combined effects of bunazosin and nipradilol or timolol on intraocular pressure in normotensive rabbits.

PURPOSE: To compare the ocular hypotensive effect of nipradilol and timolol in combination with bunazosin in rabbits. METHODS: The intraocular pressure (IOP) in normal rabbits was measured using an applanation pneumatonograph. Nipradilol, timolol, and bunazosin were instilled, individually or in combination, into the inferior conjunctival sac. RESULTS: Nipradilol (0.25%), timolol (0.5%), and bunazosin (0.01%) individually lowered IOP. The IOP-lowering effects of both nipradilol and timolol were significantly enhanced by the combined application of bunazosin (0.01%). In the presence of 5% timolol or 0.1% bunazosin, IOP was further lowered by the addition of nipradilol. The IOP-lowering effect of nipradilol was partly inhibited by pretreatment with c-PTIO (10 mM), a nitric oxide (NO)-trapping agent. CONCLUSIONS: The present study demonstrated that the IOP-lowering effects of nipradilol are due to beta- and alpha1-blocking and NO-donating actions, and bunazosin has an additive effect on the IOP-lowering effect of nipradilol or timolol.

Marine alkaloids (-)-pictamine and (-)-lepadin B block neuronal nicotinic acetylcholine receptors.

Ascidians (sea squirts) contain a wealth of alkaloids, but their influence over neuronal nicotinic acetylcholine receptors (nAChRs) has not been evaluated. In this study, we examined the effects of two synthetic compounds, (-)-pictamine, a quinolizidine alkaloid from Clavelina picta, and (-)-lepadin B, a decahydroquinoline alkaloid from Clavelina lepadiformis, on major types of neuronal nicotinic receptors (alpha4beta2 and alpha7) expressed in Xenopus oocytes. We found that these alkaloids are potent blockers at these receptors: acetylcholine-elicited currents through alpha4beta2 and alpha7 receptors were blocked by (-)-pictamine with IC(50) values of 1.5 microM and 1.3 microM, respectively, and by (-)-lepadin B with IC(50) values of 0.9 microM and 0.7 microM, respectively. Interestingly, no recovery was observed after the removal of (-)-pictamine in oocytes expressing alpha4beta2 receptors, whereas the inhibited alpha7 currents quickly recovered after the removal of (-)-pictamine. Since there are few compounds that elicit irreversible blocks of alpha4beta2 receptors, (-)-pictamine will be a novel, valuable tool to remove the alpha4beta2-nAChR action from neuronal activities mediated by these two major types of nAChRs.

Antiangiogenic activity of beta-eudesmol in vitro and in vivo.

Abnormal angiogenesis is implicated in various diseases including cancer and diabetic retinopathy. In this study, we examined the effect of beta-eudesmol, a sesquiterpenoid alcohol isolated from Atractylodes lancea rhizome, on angiogenesis in vitro and in vivo. Proliferation of porcine brain microvascular endothelial cells and human umbilical vein endothelial cells (HUVEC) was inhibited by beta-eudesmol (50-100 microM). It also inhibited the HUVEC migration stimulated by basic fibroblast growth factor (bFGF) and the tube formation by HUVEC in Matrigel. beta-eudesmol (100 microM) blocked the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 induced by bFGF or vascular endothelial growth factor. Furthermore, beta-eudesmol significantly inhibited angiogenesis in subcutaneously implanted Matrigel plugs in mice and in adjuvant-induced granuloma in mice. These results indicate that beta-eudesmol inhibits angiogenesis, at least in part, through the blockade of the ERK signaling pathway. We considered that beta-eudesmol may aid the development of drugs to treat angiogenic diseases.

Impact of SRC homology 2-containing inositol 5'-phosphatase 2 gene polymorphisms detected in a Japanese population on insulin signaling.

Src homology 2-containing 5'-inositol phosphatase 2 (SHIP2) is known to be one of lipid phosphatases converting PI(3,4,5)P3 to PI(3,4)P2 in the negative regulation of insulin signaling with the fundamental impact on the state of insulin resistance. To clarify the possible involvement of SHIP2 in the pathogenesis of human type 2 diabetes, we examined the relation of human SHIP2 gene polymorphisms to type 2 diabetes in a Japanese population. We identified 10 polymorphisms including four missense mutations. Among them, single nucleotide polymorphism (SNP)3 (L632I) was located in the 5'-phosphatase catalytic region, and SNP5 (N982S) was adjacent to the phosphotyrosine binding domain binding consensus motif in the C terminus. SNP3 was found more frequently in control subjects than in type 2 diabetic patients, suggesting that this mutation might protect from insulin resistance. Transfection study showed that expression of SNP3-SHIP2 inhibited insulin-induced PI(3,4,5)P3 production and Akt2 phosphorylation less potently than expression of wild-type SHIP2 in CHO-IR cells. Insulin-induced tyrosine phosphorylation of SNP5-SHIP2 was decreased compared with that of wild-type SHIP2, resulting in increased Shc/Grb2 association and MAPK activation. These results indicate that the polymorphisms of SHIP2 are implicated, at least in part, in type 2 diabetes, possibly by affecting the metabolic and/or mitogenic insulin signaling in the Japanese population.

Inhibitory effect of nifedipine on tumor necrosis factor alpha-induced neovascularization in cultured choroidal explants of streptozotocin-diabetic rat.

We have previously reported that the Nepsilon (carboxymethyl)lysine (CML) adduct, a major structure of an advanced glycation end product, facilitates proliferation of CD34+ endothelial progenitor cells budded from cultured choroidal explants and produces immature vessel-like structures in fibrin gel. The CML adduct is accumulated and facilitates immature neovascularization in cultured choroidal explants of streptozotocin (STZ)-induced diabetic rat. The CML-enhanced neovascularization activity is associated with the actions of tumor necrosis factor (TNF) alpha, vascular endothelial growth factor and platelet-derived growth factor released from the choroidal explant (Kobayashi et al., Biol. Pharm. Bull., 27, 1382-1387 (2004); 27, 1565-1571 (2004)). The present study was investigated an inhibitory effect of a dihydropyridine calcium antagonist nifedipine on TNF alpha-induced choroidal neovascularization in the STZ-diabetic rat. TNF alpha (1-100 ng/ml) increased neovascularization of cultured choroidal explants in the age-matched normal rat but did not increase it in the diabetic rat. Anti-TNF alpha antibody (1 : 1000) decreased the neovascularization in the diabetic rat but not in the normal rat. Nifedipine (1 microM) inhibited TNF alpha-induced neovascularization of the normal choroidal explant in a non-competitive manner. Nifedipine (1 microM) also inhibited the diabetic state-induced neovascularization and its inhibitory action was reversed by TNF alpha (1-10 ng/ml). In conclusion, STZ-diabetic state facilitated choroidal neovascularization through the release of TNF alpha. Nifedipine inhibited the action of TNF alpha probably by blocking voltage-dependent Ca2+ channels in the endothelial progenitor cells of the diabetic choroid.

Potent reduction of intraocular pressure by nipradilol plus latanoprost in ocular hypertensive rabbits.

The present study was performed to evaluate the intraocular pressure (IOP)-lowering effect of nipradilol in combination with latanoprost on ocular normotensive and hypertensive rabbits. IOP was measured using an applanation pneumatonograph under topical application of 0.4% oxybuprocaine hydrochloride for corneal anesthesia. Ocular hypertension was induced by injection of 0.1 ml hypertonic saline (5% NaCl) into the vitreous body. Saline, nipradilol, latanoprost, sodium nitroprusside (SNP) or indomethacin was then instilled just after 5% NaCl injection. All drugs were instilled in the inferior conjunctival sac, using 50 microl drops. If more than two drugs were used, they were applied 5 min apart. Nipradilol lowered IOP in both ocular normotensive rabbits and ocular hypertensive rabbits, whereas latanoprost did not lower IOP in either. When nipradilol was applied in combination with latanoprost, the reduction in ocular hypertension was significantly enhanced, compared to the effect of nipradilol alone. A significantly potent reduction in ocular hypertension was also observed by the SNP-latanoprost combination. The IOP-lowering effects of SNP in combination with latanoprost were abolished by treatment with indomethacin. These results indicate that the IOP-lowering effect of latanoprost was enhanced when applied in combination with nipradilol or SNP, both of which have nitric oxide (NO)-donating actions. Since both combined effects were abolished by treatment with indomethacin, the mechanisms by which nipradilol combined with latanoprost lowered ocular hypertension may be related, at least in part, to the production of prostaglandins via the NO-donating action of nipradilol.

Nicotinic enhancement of proliferation in bovine and porcine cerebral microvascular endothelial cells.

Nicotinic acetylcholine receptors are found in microvascular endothelial cells. To reveal the functional role in cerebral angiogenic processes, we studied the nicotinic modulation of proliferation activity in cultured bovine and porcine cerebral microvascular endothelial cells. The proliferation activity was determined by an increase in the number of cells present in culture dishes. When the bovine cerebral endothelial cells at different passages were cultured in the presence of nicotine (10 nM), the proliferation activities were significantly increased in the cells at passage 1 and passage 3, but not at passage 4. Reverse transcriptase-polymerase chain reaction studies demonstrated that the expression of mRNAs coding for alpha3 nicotinic receptor subunit was significantly reduced in the bovine cerebral endothelial cells at passage 4, compared with that at passage 1. The proliferation of porcine cerebral endothelial cells (passage 1) was enhanced by acetylcholine (10 nM-100 microM) in the presence of atropine, a muscarinic antagonist, and this enhancing effect was inhibited by hexamethonium (100 microM, a nicotinic antagonist). The stimulation by acetylcholine (1 microM, with atropine) or nicotine (10 nM) induced the phosphorylation of a mitogen-activated protein (MAP) kinase (extracellular-signal regulated kinase: ERK) in the serum-starved endothelial cells. In the presence of PD98059 (2 microM, a MAP kinase kinase inhibitor) and atropine, acetylcholine (1 microM) failed to enhance the proliferation of porcine cerebral endothelial cells. These results demonstrate that nicotinic stimulation promotes the proliferation of bovine and porcine cerebral microvascular endothelial cells, at least in part, through the MAP kinase activation.