Effect of fluoroquinolones on the expression of matrix metalloproteinase in debrided cornea of rats

Matrix metalloproteinases (MMPs) are implicated in regenerative and healing processes in corneal injuries. Based upon reports that topical fluoroquinolones (FQs) may cause perforations during corneal healing by modulating MMPs, this study evaluated the comparative effects of commercially available FQs eye drops on the expression of MMP-2 and MMP-9 in the cornea after ethanol injury. Uniform corneal epithelial defects were created using 70% ethanol in the right eye of the rats (n?=?6). The groups studied were (I) sham, (II) normal saline with benzalkonium chloride (NS-BKC), (III) norfloxacin 0.3%, (IV) ciprofloxacin 0.3%, (V) lomefloxacin 0.3%, (VI) sparfloxacin 0.3%, (VII) gatifloxacin 0.3%, and (VIII) moxifloxacin 0.5%. Each treatment was instilled six times/day up to 48?h and rats were sacrificed using excess of anesthesia. The corneas were excised to study the expression of MMP-2 and MMP-9 using gelatin zymography and real-time PCR. All the FQs significantly increased the expression of MMP-2 and MMP-9 as compared to the sham and NS-BKC-treated group. NS-BKC did not show a significant effect on MMPs expression compared to the sham group. Among the studied FQs, ciprofloxacin was observed to exhibit maximal induction of MMP-2 and MMP-9, whereas lomefloxacin exhibited an equivocal effect on both MMP-2 and MMP-9 expression. Findings of the present study demonstrate that topical application of FQs may induce the expression of MMP-2 and MMP-9 in debrided corneal epithelium and, therefore, may delay corneal wound healing. Thus, it can be concluded that selecting a FQ for ophthalmic use having minimal effect on MMPs may impact wound healing in injured or vulnerable cornea.     

Fluoroquinolones: place in ocular therapy

The fluoroquinolones have become widely used antibacterial agents in the treatment of ocular infections, with topical, intravitreal and systemic routes of administration being used. In general, fluoroquinolones (such as ciprofloxacin, ofloxacin, lomefloxacin and norfloxacin) have good activity against gram-negative and gram-positive bacteria. Therapeutic concentrations are achieved in the cornea after topical administration so that the fluoroqinolones have largely replaced combination therapy for the treatment of bacterial keratitis. However, a second line agent is needed when resistance is likely, such as in disease caused by streptococcal species. Reversal of resistance to quinolones may not occur with withdrawal of the antibacterial. This stresses the importance of prudent prescribing to reduce the occurrence of resistance to quinolones. When used in therapeutic topical dosages, corneal toxicity does not occur. Similarly, retinal toxicity is not seen when fluoroquinolones are used at therapeutic dosages, systemically or topically. Corneal precipitation occurs, particularly with ciprofloxacin and to a lesser extent norfloxacin, but does not appear to interfere with healing. In the treatment of endophthalmitis there is reasonable penetration of systemic fluoroquinolones into the vitreous but sufficiently high concentrations to reach the minimum inhibitory concentration for 90% of isolates (MIC90) of all important micro-organisms may not be guaranteed. Systemic administration may be useful for prophylaxis after ocular trauma.     

湿润暴露疗法/湿润烧伤膏对慢性创面组织中MMP-2和MMP-9表达的影响

目的探讨湿润暴露疗法/湿润烧伤膏(MEBT/MEBO)作用MMP-2和MMP-9促进慢性创面愈合的机制。方法90只Wistar大鼠随机分为5组:MEBO组、贝复新组、慢性组、急性组和空白组,每组18只,构建慢性难愈合创面模型。采用ELISA、Western blot和qRT-PCR技术,检测d 3、14创面组织中MMP-2和MMP-9表达变化。结果(1)与慢性组相比,MEBO组和贝复新组创面愈合时间明显缩短且愈合率升高(P<0.05);且生长情况及病理形态学改变更好;(2)与慢性组相比,d 3标本匀浆中,MEBO组和贝复新组MMP-2和MMP-9表达均增高(均P<0.05);而d 14,MEBO组和贝复新组MMP-2和MMP-9均降低(P<0.05);(3)与慢性组相比,d 3标本,MEBO组和贝复新组MMP-2和MMP-9表达量均增高(P<0.05);而d 14,MEBO组和贝复新组MMP-2和MMP-9表达均降低(P<0.05)。结论MEBT/MEBO促进慢性创面愈合可能与调控MMP-2和MMP-9,来参与ECM的降解与重塑相关。     

急性肺损伤大鼠体内明胶酶的活性变化及大豆胰蛋白酶抑制剂的干预效应

目的探讨急性肺损伤大鼠体内基质金属蛋白酶2,9(MMP-2,MMP-9)活性的变化以及大豆胰蛋白酶抑制剂(soybean trypsin protease inhibitor,SBTI)的干预效应。方法90只SD大鼠随机分为假手术组(Sham组,n=30)、内毒素组(LPS组,n=30)、大豆胰蛋白酶抑制剂组(SBTI组,n=30)。向LPS和STBI组大鼠气管内一次性注入0.3ml含LPS(6mg.kg-1)的生理盐水复制ALI模型,假手术组大鼠则在气管内一次性注入等量生理盐水。SBTI组于造模前1天腹腔注射给予100mg.kg-1.d-1SBTI(溶于0.5ml生理盐水),假手术组和LPS组大鼠腹腔注射等量的生理盐水,3组动物同步于气管内LPS灌注后d1、d3、d7分别随机处死10只。收集肺泡灌洗液,冰浴匀浆肺组织制备匀浆液,-80℃冻存。Bradford法测定血浆蛋白含量和肺泡灌洗液中蛋白含量,计算肺通透指数;酶谱法测肺组织匀浆液和支气管肺泡灌洗液上清中MMP-2、MMP-9酶活力及免疫组织化学方法检测肺组织MMP-2、MMP-9蛋白表达情况;并进行肺组织形态学观察。结果酶谱法显示:与LPS组相比,SBTI组大鼠肺组织、支气管肺泡灌洗液中MMP-2、MMP-9活性明显下降,在d7活性变化明显,但MMP-9变化较MMP-2更明显。免疫组化显示MMP-2、MMP-9在LPS组肺组织细胞高表达。SBTI组大鼠肺组织MMP-2、MMP-9表达明显减弱。肺组织病理提示SBTI治疗组肺损伤病变局限且程度较轻,肺泡内渗出明显小于LPS组,PMN和红细胞渗出较少。结论MMP-2、MMP-9在LPS诱导大鼠急性肺损伤中发挥重要的作用,SBTI通过抑制MMPs的分泌及激活,降低基底膜的降解,减轻肺水肿及炎症反应,发挥肺保护的作用。     

A potent,selective inhibitor of matrix metalloproteinase-3 for the topical treatment of chronic dermal ulcers

The pathology of chronic dermal ulcers is characterized by excessive proteolytic activity which degrades extracellular matrix (required for cell migration) and growth factors and their receptors. The overexpression of MMP-3 (stromelysin-1) and MMP-13 (collagenase-3) is associated with nonhealing wounds, whereas active MMPs-1, -2, -9, and -14 are required for normal wound healing to occur. We describe the synthesis and enzyme inhibition profile of (3R)-3-[([(1S)-2,2-dimethyl-1-(([(1S)-2-methoxy-1-phenylethyl]amino)carbonyl)propyl]amino)carbonyl]-6-(3-methyl-4-phenylphenyl)hexanoic acid (UK-370,106, 7), which is a potent inhibitor of MMP-3 (IC(50) = 23 nM) with >1200-fold weaker potency vs MMP-1, -2, -9, and -14. MMP-13, which may also contribute to the pathology of chronic wounds, was inhibited about 100-fold less potently by compound 7. Compound 7 potently inhibited cleavage of [(3)H]-fibronectin by MMP-3 (IC(50) = 320 nM) but not cleavage of [(3)H]-gelatin by either MMP-2 or -9 (up to 100 microM). Compound 7 had little effect, at MMP-3 selective concentrations, on keratinocyte migration over a collagen matrix in vitro, which is a model of the re-epithelialization process. Following iv (rat) or topical administration to dermal wounds (rabbit), compound 7 was cleared rapidly (t(1/2) = 23 min) from plasma, but slowly (t(1/2) approximately 3 days) from dermal tissue. In a model of chronic dermal ulcers, topical administration of compound 7 for 6 days substantially inhibited MMP-3 ex vivo. These data suggest compound 7 is sufficiently potent to inhibit MMP-3-mediated matrix degradation while leaving unaffected cellular migration mediated by MMPs 1, 2, and 9. These properties make compound 7 a suitable candidate for progression to clinical trials in human chronic dermal wounds, such as venous ulcers.     

Wound healing in ovariectomized rats: effects of chemically modified tetracycline (CMT-8) and estrogen on matrix metalloproteinases -8, -13 and type I collagen expression

Cutaneous wound healing is a complex process involving interactions of various cell types. Skin, in addition to certain other organs, is dependent on estrogen; and estrogen-deficiency is associated with impaired wound healing. Wound healing involves the action of collagenolytic matrix metalloproteinases (MMPs). We investigated the expression and localization of collagenolytic MMPs -8 and -13 by collagenase activity assay, Western immunoblot analysis, in situ hybridization and immunohistochemical staining as well as type I collagen by hydroxyproline content analysis and immunohistochemical staining in cutaneous wounds from aged Sham and ovarioectomized (OVX) rats. After wounding, OVX rats were treated with either placebo, chemically modified tetracycline-8 (CMT-8) or estrogen. We found that MMP-8 and MMP-13 mRNA were expressed in wound epithelium of all samples examined as evidenced by in situ hybridization. Type I collagen, which was abundant in all groups examined, was decreased in OVX rats, but was increased by both CMT-8 and estrogen treatments to the level of Sham group. Hydroxyproline analysis revealed similar results. Western blot data showed that all forms of MMP-8 and MMP-13 were clearly reduced in the CMT-8 treated group compared to OVX. Analysis of collagenolytic activity confirmed the decreased collagenolysis in skin wound extracts from CMT-treated rats when compared with skin wound extracts from OVX rats. Our results show for the first time that MMP-8 mRNA and protein are expressed in rat wound epithelium. We further show that CMT-8 and estrogen have a beneficial effect on skin wound healing in OVX rats by increasing the collagen content and reducing the MMP-mediated collagenolysis.     

姜黄素对压力超负荷兔心肌基质金属蛋白酶表达及胶原重构的作用

目的:观察姜黄素对慢性压力超负荷兔左室肌基质金属蛋白酶 2, 9 (MMP 2,MMP 9 )表达及胶原重构的影响,并探讨其机制。方法: 36只家兔随机分为假手术组、结扎组和姜黄素组,腹主动脉次全结扎制备压力超负荷家兔模型,姜黄素组给予姜黄素(100mg·kg-1·d-1 )的聚乙二醇溶液灌胃,假手术组、结扎组给予等量的聚乙二醇。术后12wk取兔心肌行VG染色及免疫组化染色,观察胶原容积百分比 (CVF)及MMP 2,MMP 9表达情况。结果: 假手术组、结扎组、姜黄素组MMP 2的表达灰度值分别是(68±s5), (153±12), (90±7),MMP 9分别是(64±6), (148±10), (86±6);含小血管的CVF分别是 ( 8. 1±0. 9 ) %, ( 17. 7±0. 6 ) %,(13. 0±0. 8) %。慢性压力超负荷下,兔心室肌MMP 2,MMP 9表达显著增强;姜黄素显著抑制MMP 2,MMP 9的表达,并降低CVF。结论:基质金属蛋白酶(MMPs)是促使慢性压力超负荷下心肌胶原重构的重要因素,姜黄素通过抑制MMPs能够改善胶原重构。     

Effects of Cordyceps militaris extract on angiogenesis and tumor growth

INTRODUCTIONAngiogenesis is the process of new blood vesselformation from existing blood vessels and a natural re-sponse of tissues to ischemia[1]. The steps of angio-genesis involve proteolytic degradation of extracelluarmatrix, endothelial cell-matrix adhesion, migration,proliferation, and differentiation[2]. This biological re-action is often associated with some diseases, such assolid tumor[3], diabetic retinopathy[4], and rheumatoidarthritis[5].Tumor formation requires the developm…     

MMP-2、MMP-9在大鼠皮肤创面愈合过程中的表达

目的探讨基质金属蛋白酶2(MMP-2)、MMP-9在大鼠皮肤创面愈合过程中表达的动态及其相关性。方法 42只大鼠制作大鼠背部皮肤创面模型后按取创面皮肤时间随机均分为七组,即在创面形成后1、12、24h及3、7、14、21d切取背部皮肤创面标本,采用免疫组化法检测标本中MMP-2及MMP-9的表达。另取3只正常大鼠背部皮肤标本作为对照。结果正常大鼠皮肤中MMP-2、MMP-9几无表达;背部皮肤创面形成后,MMP-2逐渐升高,14d达峰,21d仍高于正常水平;MMP-9迅速升高,在24h-7d呈高水平表达,后逐渐降至较低水平;MMP-2与MMP-9的表达水平在12h,3、7、14、21d时呈正相关,在24h时呈负相关。结论在大鼠创面愈合过程中MMP-2和MMP-9的表达有一定规律,并且二者相互影响。     

The non-antibiotic properties of tetracyclines: Clinical potential in ophthalmic disease

IntroductionBeyond their decades of long use as broad-spectrum antibiotics, tetracyclines and their derivatives have been shown to exhibit non-antimicrobial properties including their ability to interact with matrix metalloproteinases (MMP), tissue inhibitors of MMPs, growth factors and cytokines. As such, they are capable of affecting inflammation, immunomodulation, cell proliferation, and angiogenesis. Although they have been used to treat a variety of conditions including acne, cutaneous sarcoid, and rheumatoid arthritis, amongst others, their use in treating ophthalmologic disease is in its infancy.Materials and methodsA literature review on the role of non-antimicrobial properties of tetracyclines, semisynthetic tetracyclines, and chemically modified non-antibacterial tetracyclines (CMTs) and their clinical properties was performed. The effects of these compounds in relation to ophthalmic disease are presented.ResultsDue to their non-antimicrobial properties, tetracyclines and their derivatives are capable of influencing a wide variety of ocular diseases in animal models. By affecting expression of MMP-9 and tumor necrosis factor (TNF)-α, these compounds decrease corneal permeability, improve corneal smoothness, and reduce meibomian gland dysfunction; this improves the tear film which in turn restores the optical quality of the tear film and cornea. Sterile corneal ulceration may be inhibited via anticollagenase activity; this has been demonstrated in both animal models and case reports. CMTs suppress cataractogenesis in a diabetic rat model, possibly by affecting MMPs. With respect to retinal disease, tetracyclines can inhibit both microglial-mediated cell death and retinal cell apoptosis as well as prevent retinal capillary damage via caspase inhibition thus preventing retinal neovascularization. Experimental choroidal neovascularization is reduced by inhibition of MMP-2 and MMP-9, elevation of pigment epithelial derived growth factor (PEDF), and reduction of vascular endothelial growth factor (VEGF) expression via Fas ligand.DiscussionDue to their non-antimicrobial properties, tetracyclines and their derivatives are capable of influencing a wide variety of ocular disease in animal models. Research suggests that they are able to reduce inflammation in the eyelid meibomian glands, improve optical clarity of the cornea, retard cataract formation, and limit ocular angiogenesis. They may have a role in treating the leading causes of vision loss: cataract, age-related macular degeneration, and diabetic retinopathy, all of which are anticipated to increase in incidence due to the aging population.ConclusionsTetracyclines, semisynthetic tetracyclines, and CMTs may have a role in the treatment of several important ophthalmologic diseases; however, further research is required, including prospective multicenter clinical trials.     

Measurement of corneal epithelial healing rates and corneal thickness for evaluation of ocular toxicity of chemical substances

Abstract

The epithelial cells bordering a corneal epithelial wound normally slide across the denuded area to close the wound. This reepithelialization generally occurs at a rate of 0.80 to 1.00 mm²/hr in the rabbit. The cornea also swells after wounding and then returns to normal thickness during the healing process. Because this is a predictable process, it is proposed that measurement of corneal healing rate and corneal thickness be used in the evaluation of potential eye irritants. It is shown that several substances, including methylene blue, isopropanol, and benzalkonium chloride, reduce the healing rate of a standardized, 6-mm diameter corneal epithelial wound as compared to a paired, untreated control. Heptanol and isopropanol cause the wounded cornea to swell to a greater thickness and delay the return to normal thickness. Thus, it is clear that toxic substances can inhibit corneal epithelial healing. Measurement of reepithelialization rate and corneal thickness yield quantitative, statistical data that can be used in addition to standard methods in the testing of chemical substances for ocular toxicity.     

Altered expressions of MMP-2, MMP-9, and TIMP-2 in placentas from women exposed to lead

Experimental studies have shown that prenatal exposure to lead (Pb) produces morphological changes related to extracellular matrix remodelling. To analyse whether the matrix metalloproteinases (MMPs), particularly MMP-2, MMP-9, and the tissue inhibitor of metalloproteinases-2 (TIMP-2), are associated with morphological alterations found in placentas, the expression of these enzymes was evaluated by immunohistochemical and image analyses in placentas of women with histories of environmental exposure to Pb. The median maternal concentration of Pb in blood was 4.68 μg/dL (x = 5.85 ± 6.48 μg/dL). Significant differences related to the exposure to Pb were not detected in newborn or placenta weight. MMP-2, MMP-9, and TIMP-2 were expressed in the syncytiotrophoblast layer of placental villi. A significant increase in both MMP-2 and MMP-9 was observed in placentas of women with concentrations of Pb in blood ≥4.68 μg/dL (p = 0.01 and 0.03 for MMP-2 and MMP-9, respectively) and decrease in TIMP-2 expression (p = 0.01) resulted in a significant increase in MMP-2/TIMP-2 ratio (p < 0.01). Increased expression of MMPs may be induced to aid in repairing placental tissue damaged by the exposure to Pb and that TIMP-2 decreases its expression to permit tissue repair. Increased expression of MMPs may be important to consider as a mechanism for generating placental abnormalities and in the induction of preterm delivery or abortion.     

Immunohistochemical analysis of radiation-induced non-healing dermal wounds of the head and neck

Persistent, poorly healing wounds are a significant clinical problem in patients who have had previous irradiation. The pathology of chronic dermal ulcers is characterised by excessive proteolytic activity which degrades the extracellular matrix (required for cell migration) and growth factors and their receptors. Interestingly, the molecular basis of radiation-induced dermal wounds is poorly understood. The aim of this study was to investigate, by immunohistochemistry, the expression of the endothelial marker vWF, of angiogenic bFGF, VEGF and IL-8, of collagenases MMP-2 and MMP-9 and their inhibitors TIMP-1 and TIMP-2, in tissue samples from radiation-induced chronic dermal wounds and healthy control skin. Performing immunohistochemical detection of microvessels, an equivalent density of microvessels was observed within tissue samples from normal healthy skin and from radiation-induced non-healing cutaneous wounds. Investigation of angiogenic bFGF and VEGF demonstrated a decreased expression of both factors in the radiation-induced dermal wounds. The expression of angiogenic IL-8 was weak in both the healthy skin samples and the radiation-induced wounds. In addition, an increased expression of collagenases MMP-2 and MMP-9 protein within the radiation-induced wounds was demonstrated. While the expression of TIMP-1 showed no difference of expression between normal control skin and tissue samples from radiation-induced wounds, TIMP-2 expression was slightly increased compared to healthy controls. Our data suggest that radiation-induced dermal injuries often fail to heal because of decreased angiogenesis and persistently high concentrations of MMPs with an imbalance of their tissue inhibitors. The basic mechanisms of wound healing in radiation-induced dermal wounds at the molecular level need to be understood further for the development of innovative treatment strategies.     

Fluoroquinolones, the cornerstone of treatment of drug-resistant tuberculosis: a pharmacokinetic and pharmacodynamic approach

Fluoroquinolones (FQs) are important drugs to treat drug-resistant tuberculosis. In this review we integrated pharmacokinetic properties (PK) and microbiological susceptibility against M. tuberculosis and eventually evaluated the pharmcodynamic (PD) properties, as well as the influence of co-administered agents on these characteristics, for the currently used FQs (ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin and moxifloxacin) in TB treatment. Future FQs that are being developed may overcome the problems with FQs that are used in daily practice. Therefore PK and pharmacodynamic (PD) properties of novel FQs (clinafloxacin, garenoxacin, lomefloxacin, sitafloxacin, sparfloxacin, trovafloxacin, gemifloxacin, grepafloxacin and DC-159a) were evaluated in TB treatment as well. Integrating both excellent PK and PD properties, moxifloxacin, possibly at a higher dosage, may fulfil a far more important role in the treatment of multi-drug and early-generation FQ resistant TB than proposed in the current WHO guideline. Sparfloxacin, trovafloxacin and sitafloxacin are upcoming novel FQs that may be useful for drug-resistant TB based on their favourable PK properties or microbiological susceptibility against M. tuberculosis. Finally, the 8-methoxy moiety, as present in the chemical structure of MFX, will possibly provide DC- 159a with promising PK/PD characteristics and consequently this FQ may develop into a key FQ in future drug resistant TB treatment.     

Consistent alterations of circulating matrix metalloproteinases levels in untreated hypertensives and in spontaneously hypertensive rats: a relevant pharmacological target

Inconsistent matrix metalloproteinases (MMPs) levels have been reported in hypertension, with higher, similar and lower MMPs levels reported in hypertensives compared with normotensives. Differences between studies may reflect lack of control of drug effects, accompanying diseases and pre-analytical issues. We compared MMP-2, MMP-8 and MMP-9 levels in 38 untreated hypertensive patients (with no other diseases) with those found in 33 normotensive controls. We also studied endogenous MMPs inhibitors (TIMP-1, TIMP-2 and alpha-2-macroglobulin-A2M). Additionally, we assessed MMPs and A2M levels in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. We hypothesized that similar MMPs/endogenous inhibitors' profiles would be found in this animal model of hypertension and in clinical hypertension. MMPs, TIMPs and A2M were measured in plasma samples with commercially available ELISA and gelatin zymography. We found unaltered MMP-2, MMP-8, TIMP-1, TIMP-2 and A2M levels in hypertension. However, hypertensives had higher MMP-9 levels and MMP-9/A2M ratios than normotensives. Moreover, while we found similar MMP-2 and A2M levels in SHR and WKY rats, we found higher MMP-9 levels and MMP-9/A2M ratios in SHR versus WKY rats. These findings show consistent abnormal net plasma MMP-9 (but not MMP-2) activity in clinical and experimental hypertension. These parallel alterations in clinical hypertension and in SHR suggest an important role for MMPs in hypertension. While MMPs may be a relevant pharmacological target, antihypertensive drugs that down-regulate MMPs may offer advantages in the management of this disease.     

Gelatin hydrogel/contact lens composites as rutin delivery systems for promoting corneal wound healing

Corneal wound healing is a highly regulated biological process that is of importance for reducing the risk of blinding corneal infections and inflammations. Traditional eye drop was the main approach for promoting corneal wound healing. However, its low bioavailability required a high therapeutic concentration, which can lead to ocular or even systemic side effects. To develop a safe and effective method for treating corneal injury, we fabricated rutin-encapsulated gelatin hydrogel/contact lens composites by dual crosslinking reactions including in situ free radical polymerization and carboxymethyl cellulose/N-hydroxysulfosuccinimide crosslinking. In vitro drug release results evidenced that rutin in the composites could be sustainedly released for up to 14 days. In addition, biocompatibility assay indicated nontoxicity of the composites. Finally, the effect of rutin-encapsulated composites on the healing of the corneal injury in rabbits was investigated. The injury was basically cured in corneas using rutin-encapsulated composites (healing rate, 98.3% ± 0.7%) at 48 h post-operation, while the damage was still present in corneas using the composite (healing rate, 87.0% ± 4.5%). Further proteomics analysis revealed that corneal wound healing may be promoted by the ERK/MAPK and PI3K/AKT signal pathways. These results inform a potential intervention strategy to facilitate corneal wound healing in humans.     

Matrix metalloproteinase-9/gelatinase B is a putative therapeutic target of chronic obstructive pulmonary disease and multiple sclerosis

Matrix metalloproteinases (MMPs) are a large family of proteolytic enzymes involved in an array of physiological and pathological processes from development, morphogenesis, reproduction, wound healing, and aging to inflammation, angiogenesis, neurological disorders, and cancer cell invasion and metastasis. The imbalance between MMP activity and the inhibitory action of tissue inhibitors of metalloproteinases (TIMPs) are implicated in multiple diseases. Secreted in the body in a latent form, upon activation MMP-9 (gelatinase B) acts on many inflammatory substrates, and thus is suspected of contributing to the progression of cardiovascular disease, rheumatoid arthritis, and the subjects of this review, chronic obstructive pulmonary disease (COPD) and multiple sclerosis (MS). COPD is the fourth most common cause of death in the United States. In COPD, increased expression of MMP-9 by inflammatory cells e.g. neutrophils and macrophages is correlated with a variety of processes that cause lung damage. MMP-9 is also important in cytokine and protease modulation; it degrades the serine protease inhibitor alpha(1)-antitrypsin, which thus may lead to lung destruction. MS affects approximately 400,000 Americans and over a million people worldwide. Upregulation of MMP-9 increases the permeability of the blood brain barrier (BBB), facilitates the infiltration of leukocytes into the central nervous system, and causes myelin sheath degradation and neuronal damage. Early stage clinical trials have shown promising results when MMP-9 is inhibited in MS. These observations lead to the hypothesis that MMP-9 is a potential drug target for both COPD and MS and further development of highly potent and specific MMP-9 inhibitors is warranted.     

Activation of latent transforming growth factor beta 1 and inhibition of matrix metalloprotease activity by a thrombospondin-like tripeptide linked to elaidic acid

Impaired wound healing and skin aging are characterized by neutral protease-mediated destruction of matrix macromolecules associated with disturbance in tissue repair. We synthesized a fatty acyl-peptide derivative at aims to simultaneously activate latent TGF-beta through its peptide domain, KFK, and inhibit MMPs through its lipophilic moiety, elaidic acid. Elaidyl-KFK as well as KFK were shown to activate LAP-TGF-beta both in vitro, using a solid phase assay with immobilized LAP-TGF-beta, and ex vivo using human dermal fibroblasts cultures. In both assays, as much as up to 10% of LAP-TGF-beta added could be recovered as active form. KQK, KQFK as well as their lipopeptide counterparts were inactive. Elaidyl-KFK-mediated LAP-TGF-beta activation led to up-regulation of collagen and TIMP-1 production and down regulation of PMA-induced MMP-1 expression in fibroblasts cultures. Those effects could be suppressed by supplementing cell culture medium with blocking TGF-beta antibody. Elaidyl-KFK inhibited MMP-2, MMP-9, MMP-3, MMP-1, in vitro with IC(50) equal to 1.2, 1.0, 0.24 and 8.9 microM, respectively. Its ex vivo inhibitory capacity, as assessed using skin tissue sections, towards the elastin-degrading capacity of MMP-9 was even more pronounced. At a 1 microM concentration, the lipopeptide decreased by up to 80% enzyme activity. Thus, "Lipospondin," i.e. elaidyl-KFK might be considered as a promising model compound to prevent age-associated dermal alterations.     

Michelia alba extract attenuates UVB-induced expression of matrix metalloproteinases via MAP kinase pathway in human dermal fibroblasts

Solar ultraviolet (UV) radiation can cause skin photoaging by inducing secretion of matrix metalloproteinases (MMPs). It has been reported that MMPs, especially MMP-1, -3 and -9, reduce elasticity of the dermis by degrading collagen. Polyphenols are a group of compounds that exist mainly in glycosides in the plants and they may transform to aglycone after hydrolysis. Polyphenols can inhibit MMP expression and elastase activity. In this study, we investigated the effects of Michelia alba extract (MAE) on expression and activity of MMPs in human skin fibroblast cultures after UVB exposure. The results showed that MAE and its hydrolysates (MAH) inhibited collagenase and elastase activities. In addition, MAE exhibited antioxidant activity, elevated hyaluronic acid content and inhibited UVB-induced MMP-1, MMP-3 and MMP-9 expression. In addition, the zymography assay revealed that MAE also inhibited MMP-9 activity. We also found that MAE inhibited UVB-induced ERK and JNK kinase but not p38 kinase expression, suggesting that MAE may regulate the UVB-induced expression of MMP-1, MMP-3 and MMP-9 via the ERK and JNK kinase pathway. MAE could restore total collagen synthesis reduced by UVB. The results also suggest that MAE treatment may prevent UVB-induced extracellular matrix damage by inhibiting the expression of MMP-1, MMP-3 and MMP-9 through the MAP kinase pathway. Our findings imply that MAE is an effective agent against UVB-induced photodamage.