In vitro cellular aging is associated with enhanced proliferative capacity, G1 cell cycle modulation, and matrix metalloproteinase-9 regulation in mouse aortic smooth muscle cells

Extracellular Matrix in Aging Aorta

The aging population is booming all over the world and arterial aging causes various age-associated pathologies such as cardiovascular diseases (CVDs). The aorta is the largest elastic artery, and transforms pulsatile flow generated by the left ventricle into steady flow to maintain circulation in distal tissues and organs. Age-associated structural and functional changes in the aortic wall such as dilation, tortuousness, stiffening and losing elasticity hamper stable peripheral circulation, lead to tissue and organ dysfunctions in aged people. The extracellular matrix (ECM) is a three-dimensional network of macromolecules produced by resident cells. The composition and organization of key ECM components determine the structure-function relationships of the aorta and therefore maintaining their homeostasis is critical for a healthy performance. Age-associated remodeling of the ECM structural components, including fragmentation of elastic fibers and excessive deposition and crosslinking of collagens, is a hallmark of aging and leads to functional stiffening of the aorta. In this mini review, we discuss age-associated alterations of the ECM in the aortic wall and shed light on how understanding the mechanisms of aortic aging can lead to the development of efficient strategy for aortic pathologies and CVDs.

Long non-coding RNA LOC285194 regulates vascular smooth muscle cell apoptosis in atherosclerosis

Long non-coding RNAs (lncRNAs) recently have been implicated in many biological processes and diseases. Atherosclerosis is a major risk factor for cardiovascular disease. However, the functional role of lncRNAs in atherosclerosis is largely unknown. Here we identified LOC285194 as a key regulator of cell proliferation and apoptosis during atherosclerosis. The expression of LOC285194 was dramatically down-regulated in a aortic atherosclerotic plaques of well-defined model of apolipoprotein-E knockout (ApoE^−/-) mice. Moreover, we found that targeting LOC285194 results in neointimal hyperplasia in vivo in carotid artery injury model. We also showed that targeting LOC285194 promotes cell proliferation and inhibits apoptosis in vascular smooth muscle cells (VSMCs) in vitro, and vice versa. In addition, targeting LOC285194 promotes cell invasion and migration in vitro. Our studies identify LOC285194 as a novel regulator of cell proliferation and apoptosis and suggest that this lncRNA could serve as a therapeutic target to treat atherosclerosis and related cardiovascular disorders.

The Role of Vascular Smooth Muscle Cells in Arterial Remodeling: Focus on Calcification-Related Processes

Arterial remodeling refers to the structural and functional changes of the vessel wall that occur in response to disease, injury, or aging. Vascular smooth muscle cells (VSMC) play a pivotal role in regulating the remodeling processes of the vessel wall. Phenotypic switching of VSMC involves oxidative stress-induced extracellular vesicle release, driving calcification processes. The VSMC phenotype is relevant to plaque initiation, development and stability, whereas, in the media, the VSMC phenotype is important in maintaining tissue elasticity, wall stress homeostasis and vessel stiffness. Clinically, assessment of arterial remodeling is a challenge; particularly distinguishing intimal and medial involvement, and their contributions to vessel wall remodeling. The limitations pertain to imaging resolution and sensitivity, so methodological development is focused on improving those. Moreover, the integration of data across the microscopic (i.e., cell-tissue) and macroscopic (i.e., vessel-system) scale for correct interpretation is innately challenging, because of the multiple biophysical and biochemical factors involved. In the present review, we describe the arterial remodeling processes that govern arterial stiffening, atherosclerosis and calcification, with a particular focus on VSMC phenotypic switching. Additionally, we review clinically applicable methodologies to assess arterial remodeling and the latest developments in these, seeking to unravel the ubiquitous corroborator of vascular pathology that calcification appears to be.

Age-related Impairment of Vascular Structure and Functions

Among age-related diseases, cardiovascular and cerebrovascular diseases are major causes of death. Vascular dysfunction is a key characteristic of these diseases wherein age is an independent and essential risk factor. The present work will review morphological alterations of aging vessels in-depth, which includes the discussion of age-related microvessel loss and changes to vasculature involving the capillary basement membrane, intima, media, and adventitia as well as the accompanying vascular dysfunctions arising from these alterations.

Vasculopathy in the setting of cardiorenal syndrome: roles of protein-bound uremic toxins

Chronic kidney disease (CKD) often leads to and accelerates the progression of cardiovascular disease (CVD), while CVD also causes kidney dysfunction. This bidirectional interaction leads to the development of a complex syndrome known as cardiorenal syndrome (CRS). CRS not only involves both the heart and the kidney but also the vascular system through a vast array of contributing factors. In addition to hemodynamic, neurohormonal, mechanical, and biochemical factors, nondialyzable protein-bound uremic toxins (PBUTs) are also key contributing factors that have been demonstrated through in vitro, in vivo, and clinical observations. PBUTs are ineffectively removed by hemodialysis because their complexes with albumins are larger than the pores of the dialysis membranes. PBUTs such as indoxyl sulfate and p-cresyl sulfate are key determinate and predictive factors for the progression of CVD in CKD patients. In CRS, both vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) exhibit significant dysfunction that is associated with the progression of CVD. PBUTs influence proliferation, calcification, senescence, migration, inflammation, and oxidative stress in VSMCs and ECs through various mechanisms. These pathological changes lead to arterial remodeling, stiffness, and atherosclerosis and thus reduce heart perfusion and impair left ventricular function, aggravating CRS. There is limited literature about the effect of PBUT on the vascular system and their contribution to CRS. This review summarizes current knowledge on how PBUTs influence vasculature, clarifies the relationship between uremic toxin-related vascular disease and CRS, and highlights the potential therapeutic strategies of uremic vasculopathy in the setting of CRS.

DNA damage-dependent mechanisms of ageing and disease in the macro- and microvasculature

A decline in the function of the macro- and micro-vasculature occurs with ageing. DNA damage also accumulates with ageing, and thus DNA damage and repair have important roles in physiological ageing. Considerable evidence also supports a crucial role for DNA damage in the development and progression of macrovascular disease such as atherosclerosis. These findings support the concept that prolonged exposure to risk factors is a major stimulus for DNA damage within the vasculature, in part via the generation of reactive oxygen species. Genomic instability can directly affect vascular cellular function, leading to cell cycle arrest, apoptosis and premature vascular cell senescence. In contrast, the study of age-related impaired function and DNA damage mechanisms in the microvasculature is limited, although ageing is associated with microvessel endothelial dysfunction. This review examines current knowledge on the role of DNA damage and DNA repair systems in macrovascular disease such as atherosclerosis and microvascular disease. We also discuss the cellular responses to DNA damage to identify possible strategies for prevention and treatment.

Vascular Smooth Muscle Cells in Atherosclerosis

The historical view of vascular smooth muscle cells (VSMCs) in atherosclerosis is that aberrant proliferation of VSMCs promotes plaque formation, but that VSMCs in advanced plaques are entirely beneficial, for example preventing rupture of the fibrous cap. However, this view has been based on ideas that there is a homogenous population of VSMCs within the plaque, that can be identified separate from other plaque cells (particularly macrophages) using standard VSMC and macrophage immunohistochemical markers. More recent genetic lineage tracing studies have shown that VSMC phenotypic switching results in less-differentiated forms that lack VSMC markers including macrophage-like cells, and this switching directly promotes atherosclerosis. In addition, VSMC proliferation may be beneficial throughout atherogenesis, and not just in advanced lesions, whereas VSMC apoptosis, cell senescence, and VSMC-derived macrophage-like cells may promote inflammation. We review the effect of embryological origin on VSMC behavior in atherosclerosis, the role, regulation and consequences of phenotypic switching, the evidence for different origins of VSMCs, and the role of individual processes that VSMCs undergo in atherosclerosis in regard to plaque formation and the structure of advanced lesions. We think there is now compelling evidence that a full understanding of VSMC behavior in atherosclerosis is critical to identify therapeutic targets to both prevent and treat atherosclerosis.

The Effect of Ageing on Vascular Smooth Muscle Cell Behaviour--A Mini-Review

Ageing is a prominent risk factor for atherosclerosis and cardiovascular disease. Vascular smooth muscle cells (VSMCs) are an integral part of atherosclerotic plaque formation, progression and subsequent rupture. Emerging evidence suggests that VSMC behaviour is modified by age, which in turn may affect disease outcome in the elderly. In this review, we discuss the effect of age on VSMC behaviour, proliferation, migration, apoptosis, inflammation, extracellular matrix synthesis and calcification. In addition, we discuss the multiple signalling factors underlying these behavioural changes including angiotensin-II, matrix metalloproteinases, monocyte chemotactic protein-1, and transforming growth factor-β1. Understanding the molecular processes underpinning altered VSMC behaviour with age, may lead to the identification of novel therapeutic targets for suppressing atherosclerosis in the elderly population.

MEK drives cyclin D1 hyperelevation during geroconversion

When the cell cycle becomes arrested, MTOR (mechanistic Target of Rapamycin) converts reversible arrest into senescence (geroconversion). Hyperexpression of cyclin D1 is a universal marker of senescence along with hypertrophy, beta-Gal staining and loss of replicative/regenerative potential (RP), namely, the ability to restart proliferation when the cell cycle is released. Inhibition of MTOR decelerates geroconversion, although only partially decreases cyclin D1. Here we show that in p21- and p16-induced senescence, inhibitors of mitogen-activated/extracellular signal-regulated kinase (MEK) (U0126, PD184352 and siRNA) completely prevented cyclin D1 accumulation, making it undetectable. We also used MEL10 cells in which MEK inhibitors do not inhibit MTOR. In such cells, U0126 by itself induced senescence that was remarkably cyclin D1 negative. In contrast, inhibition of cyclin-dependent kinase (CDK) 4/6 by PD0332991 caused cyclin D1-positive senescence in MEL10 cells. Both types of senescence were suppressed by rapamycin, converting it into reversible arrest. We confirmed that the inhibitor of CDK4/6 caused cyclin D1 positive senescence in normal RPE cells, whereas U0126 prevented cyclin D1 expression. Elimination of cyclin D1 by siRNA did not prevent other markers of senescence that are consistent with the lack of its effect on MTOR. Our data confirmed that a mere inhibition of the cell cycle was sufficient to cause senescence, providing MTOR was active, and inhibition of MEK partially inhibited MTOR in a cell-type-dependent manner. Second, hallmarks of senescence may be dissociated, and hyperelevated cyclin D1, a marker of hyperactivation of senescent cells, did not necessarily determine other markers of senescence. Third, inhibition of MEK was sufficient to eliminate cyclin D1, regardless of MTOR.

Aging and atherosclerosis: mechanisms, functional consequences, and potential therapeutics for cellular senescence

Atherosclerosis is classed as a disease of aging, such that increasing age is an independent risk factor for the development of atherosclerosis. Atherosclerosis is also associated with premature biological aging, as atherosclerotic plaques show evidence of cellular senescence characterized by reduced cell proliferation, irreversible growth arrest and apoptosis, elevated DNA damage, epigenetic modifications, and telomere shortening and dysfunction. Not only is cellular senescence associated with atherosclerosis, there is growing evidence that cellular senescence promotes atherosclerosis. This review examines the pathology of normal vascular aging, the evidence for cellular senescence in atherosclerosis, the mechanisms underlying cellular senescence including reactive oxygen species, replication exhaustion and DNA damage, the functional consequences of vascular cell senescence, and the possibility that preventing accelerated cellular senescence is a therapeutic target in atherosclerosis.

Matrix metalloproteinase-9 expression in folliculostellate cells of rat anterior pituitary gland

Folliculostellate (FS) cells of the anterior pituitary gland express a variety of regulatory molecules. Using transgenic rats that express green fluorescent protein specifically in FS cells, we recently demonstrated that FS cells in vitro showed marked changes in motility, proliferation, and that formation of cellular interconnections in the presence of laminin, a component of the extracellular matrix, closely resembled those observed in vivo. These findings suggested that FS cells express matrix metalloproteinase-9 (MMP-9), which assists their function on laminin. In the present study, we investigate MMP-9 expression in rat anterior pituitary gland and examine its role in motility and proliferation of FS cells on laminin. Immunohistochemistry, RT-PCR, immunoblotting, and gelatin zymography were performed to assess MMP-9 expression in the anterior pituitary gland and cultured FS cells. Real-time RT-PCR was used to quantify MMP-9 expression in cultured FS cells under different conditions and treatments. MMP-9 expression was inhibited by pharmacological inhibitor or downregulated by siRNA and time-lapse images were acquired. A 5-bromo-2'-deoxyuridine assay was performed to analyze the proliferation of FS cells. Our results showed that MMP-9 was expressed in FS cells, that this expression was upregulated by laminin, and that laminin induced MMP-9 secretion by FS cells. MMP-9 inhibition and downregulation did not impair FS motility; however, it did impair the capacity of FS cells to form interconnections and it significantly inhibited proliferation of FS cells on laminin. We conclude that MMP-9 is necessary in FS cell interconnection and proliferation in the presence of laminin.

Matrix metalloproteinase-9 and cell division in neuroblastoma cells and bone marrow macrophages

Matrix metalloproteinases (MMPs) degrade the extracellular matrix and carry out key functions in cell development, cancer, injury, and regeneration. In addition to its well recognized extracellular action, functional intracellular MMP activity under certain conditions is supported by increasing evidence. In this study, we observed higher gelatinase activity by in situ zymography and increased MMP-9 immunoreactivity in human neuroblastoma cells and in bone marrow macrophages undergoing mitosis compared with resting cells. We studied the pattern of immunoreactivity at the different stages of cell division by confocal microscopy. Immunostaining with different monoclonal antibodies against MMP-9 revealed a precise, dynamic, and well orchestrated localization of MMP-9 at the different stages of cell division. The cellular distribution of MMP-9 staining was studied in relation to that of microtubules. The spatial pattern of MMP-9 immunoreactivity suggested some participation in both the reorganization of the nuclear content and the process of chromatid segmentation. We then used several MMP-9 inhibitors to find out whether MMP-9 might be involved in the cell cycle. These drugs impaired the entry of cells into mitosis, as revealed by flow cytometry, and reduced cell culture growth. In addition, the silencing of MMP-9 expression with small interfering RNA also reduced cell growth. Taken together, these results suggest that intracellular MMP-9 is involved in the process of cell division in neuroblastoma cells and in primary cultures of macrophages.

Protection of vascular smooth muscle cells by over-expressed methionine sulphoxide reductase A: role of intracellular localization and substrate availability

Methionine sulphoxide reductase A (MSRA) that reduces methionine-S-sulphoxide back to methionine constitutes a catalytic antioxidant mechanism to prevent oxidative damage at multiple sub-cellular loci. This study examined the relative importance of protection of the cytoplasm and mitochondria by MSRA using A-10 vascular smooth muscle cells, a cell type that requires a low level of reactive oxygen species (ROS) for normal function but is readily damaged by higher concentrations of ROS. Adenoviral over-expression of human MSRA variants, targeted to either mitochondria or the cytoplasm, did not change basal viability of non-stressed cells. Oxidative stress caused by treatment with the methionine-preferring oxidizing reagent chloramine-T decreased cell viability in a concentration-dependent manner. Cytoplasmic MSRA preserved cell viability more effectively than mitochondrial MSRA and co-application of S-methyl-L-cysteine, an amino acid that acts as a substrate for MSRA when oxidized, further increased the extent of protection. This suggests an important role for an MSRA catalytic antioxidant cycle for protection of the cytoplasmic compartment against oxidative damage.

Inhibitory effect of Uncaria sinensis on human aortic smooth muscle cell migration is based on matrix metalloproteinase-9 inhibitory activity

Medicinal extracts of Cho-Deung-san and Uncaria sinensis Havil. (UR) have previously been shown to have inhibitory effects on migration of vascular smooth muscle cells (VSMC) and matrix metalloproteinase (MMP)-2/9 production, which play key roles in the development of atherosclerosis. In this study, we have more extensively investigated the inhibitory effect of UR on MMP-9 activity and TNF-α induced human aortic smooth muscle cells (HASMC) migration. The result from gelatin zymography showed that UR inhibited MMP-9 activity in a dose-dependent manner (IC(50)=55μg/ml). In addition, UR strongly inhibited the migration of HASMC induced by TNF-α treatment (IC(50)=125μg/ml), although it has very low cytotoxic effect on HASMC (IC(50)>500μg/ml). These results suggest that UR is a potential anti-atherosclerotic agent through inhibition of MMP-9 activity and VSMC migration.

Functional −1562 C-to-T polymorphism in matrix metalloproteinase-9 (MMP-9) promoter is associated with the risk for oral squamous cell carcinoma in younger male areca users

BACKGROUND

Circulating matrix metalloproteinase-9 (MMP-9) is a prognostic factor for gastric cancer and vascular diseases, and has been associated with head and neck cancers. The -1562 C-to-T polymorphism in MMP-9 promoter (abbreviated MMP-9 -1562 C>T polymorphism) leads to differential transcription, and is associated with increased susceptibility to neoplastic and vascular diseases. Thus, our aim was to determine whether a functional MMP-9 polymorphism might also influence the risk or affect the progression of areca-associated oral cancers.

METHODS

Genomic DNAs were obtained from peripheral blood cells of male subjects with areca-associated oral squamous cell carcinoma (OSCC) (n = 192), oral submucosal fibrosis (OSF) (n = 73), and non-diseased areca users (n = 191). The PCR-based restriction fragment length polymorphism analysis was performed for MMP-9 genotyping.

RESULTS

MMP-9 -1562 C>T polymorphism was not associated with the risk of OSCC or OSF. However, when subjects were stratified by the median age, an association with the risk of OSCC was found in younger patients (P = 0.029). The T allele frequency was significantly higher in the subset of older patients with buccal mucosa OSCC than older patients with OSCC in counterpart locations. The joint MMP-9 -1562 C>T and MMP-3 -1171 5A>6A functional polymorphisms were not associated with OSCC risk or patient survival.

CONCLUSION

Aberrant MMP-9 expression is closely related to tumor invasiveness and the prognosis of head and neck cancers. However, functional MMP-9 -1562 C>T polymorphism is associated with OSCC risk only in younger areca chewers. The impact of aging or areca-related effect on this functional polymorphism should be elucidated.

Overexpression of Na(+)/K (+)-ATPase parallels the increase in sodium transport and potassium recycling in an in vitro model of proximal tubule cellular ageing

Na(+)/K(+)-ATPase plays a key role in the transport of Na(+) throughout the nephron, but ageing appears to be accompanied by changes in the regulation and localization of the pump. In the present study, we examined the effect of in vitro cell ageing on the transport of Na(+) and K(+) ions in opossum kidney (OK) cells in culture. Cells were aged by repeated passing, and Na(+)/K(+)-ATPase activity and K(+) conductance were evaluated using electrophysiological methods. Na(+)K(+)-ATPase alpha(1)- and beta(1)-subunit expression was quantified by Western blot techniques. Na(+)/H(+) exchanger activity, changes in membrane potential, cell viability, hydrogen peroxide production and cellular proliferation were determined using fluorimetric assays. In vitro cell ageing is accompanied by an increase in transepithelial Na(+) transport, which results from an increase in the number of Na(+)/K(+)-ATPase alpha(1)- and beta(1)-subunits, in the membrane. Increases in Na(+)/K(+)-ATPase activity were accompanied by increases in K(+) conductance as a result of functional coupling between Na(+)/K(+)-ATPase and basolateral K(+) channels. Cell depolarization induced by both KCl and ouabain was more pronounced in aged cells. No changes in Na(+)/H(+) exchanger activity were observed. H(2)O(2) production was increased in aged cells, but exposure for 5 days to 1 and 10 microM: of H(2)O(2) had no effect on Na(+)/K(+)-ATPase expression. Ouabain (100 nM: ) increased alpha(1)-subunit, but not beta(1)-subunit, Na(+)/K(+)-ATPase expression in aged cells only. These cells constitute an interesting model for the study of renal epithelial cell ageing.

Regulation of Smooth Muscle Cell Proliferation by β-Catenin/T-Cell Factor Signaling Involves Modulation of Cyclin D1 and p21 Expression

We previously observed that stimulation of vascular smooth muscle cell (VSMC) proliferation with growth factors is associated with dismantling of cadherin junctions and nuclear translocation of β-catenin. In this study we demonstrate directly that growth factors stimulate β-catenin/T-cell factor (TCF) signaling in primary VSMCs. To determine whether β-catenin/TCF signaling regulates VSMC proliferation via modulation of the β-catenin/TCF responsive cell cycle genes, cyclin D1 and p21, we inhibited β-catenin/TCF signaling by adenoviral-mediated over-expression of N-Cadherin, ICAT (an endogenous inhibitor of β-catenin/TCF signaling), or a dominant negative (dn) mutant of TCF-4. N-cadherin, ICAT or dnTCF-4 over-expression significantly reduced proliferation of isolated human VSMCs by approximately 55%, 80%, and 45% respectively. Similar effects were observed in human saphenous vein medial segments where proliferation was reduced by approximately 55%. Transfection of dnTCF-4 in the ISS10 human VSMC line significantly lowered TCF and cyclin D1 reporter activity but significantly elevated p21 reporter activity, indicating regulation of these genes by β-catenin/TCF signaling. In support of this, over-expression of N-cadherin, ICAT or dnTCF-4 in isolated human VSMCs significantly lowered levels of cyclin D1 mRNA and protein levels. In contrast, over-expression of N-Cadherin, ICAT or dnTCF4 significantly elevated p21 mRNA and protein levels. In summary, we have demonstrated that increasing N-cadherin and inhibiting β-catenin/TCF signaling reduces VSMC proliferation, decreases the expression of cyclin D1 and increases levels of the cell cycle inhibitor, p21. We therefore suggest that the N-cadherin and β-catenin/TCF signaling pathway is a key modulator of VSMC proliferation via regulation of these 2 β-catenin/TCF responsive genes.

Cryptotanshinone from Salvia miltiorrhiza BUNGE has an inhibitory effect on TNF-α-induced matrix metalloproteinase-9 production and HASMC migration via down-regulated NF-κB and AP-1

Matrix metalloproteinases (MMP-9 and MMP-2) production and smooth muscle cell (SMC) migration may play key roles in the phathogenesis of neointima formation and atherosclerosis. Especially inducible MMP-9 expression was directly involved in the cancer cell invasion and SMC migration through vascular wall. In this study, we reveal that cryptotanshinone (CT) purified from Salvia miltiorrhiza BUNGE had an inhibitory effect on MMP-9 production and migration of human aortic smooth muscle cells treated with TNF-alpha in a dose-dependent manner. The down regulation of transcription of MMP-9 mRNA was evidenced by RT-PCR and MMP-9 promoter assay using luciferase reporter gene. Eletrophoretic mobility shift assay showed NF-kappaB and AP-1 nuclear translocations were suppressed. In addition, Western blot analysis indicated that extracellular signal regulated kinase 1 and 2, p38 and JNK MAP kinase signaling pathways were inhibited. From the results, it is suggested that CT has anti-atherosclerosis and anti-neointimal formation activity.

Inhibitory effect of Salvia miltiorrhia BGE on matrix metalloproteinase-9 activity and migration of TNF-α-induced human aortic smooth muscle cells

The migration and matrix metalloproteinases (MMPs) production of vascular smooth muscle cells (VSMC) may play a key role in the development of atherosclerosis. The Radix of Salvia miltiorrhiza Bunge (Labiatae) (SM), an eminent herb, is often included as an ingredient in various herbal remedies recommended for vascular therapies and has been used to treat vascular diseases for many centuries. In this study, we investigated the inhibitory effect of SM on TNF-alpha induced human aortic smooth muscle cells (HASMC) migration and MMP-9 activity. Various extracts prepared from stems of SM were tested for cytotoxic activity on HASMC using the XTT assay method. The ethanol extract (IC50 > 100 microg/ml), water extract (IC50 > 100 microg/ml) and chloroform (IC50 = 90 microg/ml) fraction exhibited weak cytotoxic activity. However, buthanol (IC50 = 80 microg/ml) and ethyl acetate (EtOAc; IC50 = 70 microg/ml) fraction exhibited strongly cytotoxic activity. Also, the extracts and fractions were investigated the inhibitory effects on MMP-9 activity using gelatin zymography. Gelatin zymography showed that the TNF-alpha-treated HASMC secreted MMP, probably including MMP-9, which may be involved in HASMC migration. The EtOAc fraction showed stronger inhibitory effect of proteolytic activity than other fractions. The EtOAc fraction was able to decrease the proteolytic activity of MMP-9 in a concentration-dependent manner on zymography. The Matrigel migration assay showed that SM effectively inhibited the TNF-alpha induced migration of HASMC as compared with the control group in a dose-dependent manner (IC50 = 65 microg/ml) and that the EtOAc fraction effectively inhibited the migration of HASMC, as compared with the control group in a dose-dependent manner. These results suggest that SM could be used as potential anti-atherosclerotic agent for anti-migration in TNF-alpha treated HASMC.

A comparison of p21 and p27 immunoexpression in benign glands, prostatic intraepithelial neoplasia and prostate adenocarcinoma

OBJECTIVE

To assess the immunoexpression of p21 and p27 proteins in consecutive areas of benign glands, prostatic intraepithelial neoplasia (PIN) and prostate adenocarcinoma.

PATIENTS AND METHODS

Tissue from 91 patients who had a radical prostatectomy was assessed by immunohistochemistry to evaluate the expression of p21 and p27 in adjacent areas of benign glands, PIN and prostate adenocarcinoma. The results were correlated with various clinicopathological variables, e.g. age, total prostate-specific antigen level, tumour stage, Gleason score, surgical margin involvement, extraprostatic extension, seminal vesicle invasion, and perineural invasion.

RESULTS

The p27 score in PIN was lower than that in benign glands (P = 0.04) but there was no significant difference between the scores for PIN and tumour. By contrast, p21 expression was almost undetectable in benign glands, although there was substantially more in PIN and tumour (P < 0.01). Some patients had no expression of p21 in tumour tissue, and had lower p21 scores in benign glands and PIN areas (P < 0.05). Interestingly, these patients had a lower frequency of negative prognostic variables. The tumour p21 score was higher in patients with extraprostatic extension (P = 0.045) and tumour p27 expression was inversely correlated with seminal vesicle invasion (P = 0.028). Tumour and PIN p27 expression appeared to decrease with advancing age (P = 0.008 and 0.012, respectively).

CONCLUSION

Higher p21 and lower p27 expression is correlated with adverse prognostic factors. The decline in p27 with advancing age in tumour and PIN areas may be a possible explanation of the greater frequency of prostate adenocarcinoma in older men. A p21-negative tumour subgroup with a lower frequency of adverse prognostic factors was identified, which needs to be further explored.

The expression of matrix metalloproteinase-9 in human follicular fluid is associated with in vitro fertilisation pregnancy

OBJECTIVE

To investigate the role of matrix metalloproteinase-9 (MMP-9) in the pre-ovulatory follicular fluid and culture media during in vitro fertilisation (IVF) cycle and to develop the zymographic pre-diagnosis marker for successful implantation and pregnancy in human IVF.

DESIGN

Controlled clinical study.

SETTING

IVF Laboratory, Women's Hospital Infertility Clinic and Dongguk University, Korea.

SAMPLE

Women undergoing in vitro fertilisation treatment.

METHODS

Experiments were designed for controlled clinical study with women undergoing IVF treatment. MMP-9 expressions in follicular fluid and culture media samples that had been collected during transvaginal oocyte retrieval were measured using zymography. MMP-9 activities and expressions were strongly correlated to a higher rate of fertilisation and pregnancy.

MAIN OUTCOME MEASURES

Fertilisation rates and ultrasonic evidence of intrauterine pregnancy by four weeks after embryo transfer.

RESULT

MMP-9 activity was significantly higher in the pregnant group than in the non-pregnant group (P < 0.01). In contrast, MMP-2 activity was present in the follicular fluid and culture media of all women, and no difference in its expressions was found between the pregnant and non-pregnant groups. No correlation was found between the MMP-9 expression in follicular fluid and culture media and the fertilisation rates.

CONCLUSION

The expression of MMP-9 in the follicular fluid and culture media is a prerequisite for successful pregnancy in IVF cycle. The zymography of MMP-9 activity in follicular fluids of human and culture media was developed as a pre-diagnostic method and zymographic diagnosis marker for successful fertilisation, implantation and pregnancy in human IVF.

Cortical spreading depression activates and upregulates MMP-9

Cortical spreading depression (CSD) is a propagating wave of neuronal and glial depolarization and has been implicated in disorders of neurovascular regulation such as stroke, head trauma, and migraine. In this study, we found that CSD alters blood-brain barrier (BBB) permeability by activating brain MMPs. Beginning at 3-6 hours, MMP-9 levels increased within cortex ipsilateral to the CSD, reaching a maximum at 24 hours and persisting for at least 48 hours. Gelatinolytic activity was detected earliest within the matrix of cortical blood vessels and later within neurons and pia arachnoid (> or =3 hours), particularly within piriform cortex; this activity was suppressed by injection of the metalloprotease inhibitor GM6001 or in vitro by the addition of a zinc chelator (1,10-phenanthroline). At 3-24 hours, immunoreactive laminin, endothelial barrier antigen, and zona occludens-1 diminished in the ipsilateral cortex, suggesting that CSD altered proteins critical to the integrity of the BBB. At 3 hours after CSD, plasma protein leakage and brain edema developed contemporaneously. Albumin leakage was suppressed by the administration of GM6001. Protein leakage was not detected in MMP-9-null mice, implicating the MMP-9 isoform in barrier disruption. We conclude that intense neuronal and glial depolarization initiates a cascade that disrupts the BBB via an MMP-9-dependent mechanism.

Cortical spreading depression activates and upregulates MMP-9

Cortical spreading depression (CSD) is a propagating wave of neuronal and glial depolarization and has been implicated in disorders of neurovascular regulation such as stroke, head trauma, and migraine. In this study, we found that CSD alters blood-brain barrier (BBB) permeability by activating brain MMPs. Beginning at 3-6 hours, MMP-9 levels increased within cortex ipsilateral to the CSD, reaching a maximum at 24 hours and persisting for at least 48 hours. Gelatinolytic activity was detected earliest within the matrix of cortical blood vessels and later within neurons and pia arachnoid (> or =3 hours), particularly within piriform cortex; this activity was suppressed by injection of the metalloprotease inhibitor GM6001 or in vitro by the addition of a zinc chelator (1,10-phenanthroline). At 3-24 hours, immunoreactive laminin, endothelial barrier antigen, and zona occludens-1 diminished in the ipsilateral cortex, suggesting that CSD altered proteins critical to the integrity of the BBB. At 3 hours after CSD, plasma protein leakage and brain edema developed contemporaneously. Albumin leakage was suppressed by the administration of GM6001. Protein leakage was not detected in MMP-9-null mice, implicating the MMP-9 isoform in barrier disruption. We conclude that intense neuronal and glial depolarization initiates a cascade that disrupts the BBB via an MMP-9-dependent mechanism.

Inhibitory effect of Cho-Deung-San on human aortic smooth muscle cell migration induced by TNF-α through inhibition of matrix metalloproteinase-2 and -9 activity

The migration and matrix metalloproteinases (MMPs) production of vascular smooth muscle cells (VSMC) may play a key role in the development of atherosclerosis. A Korean traditional herbal formulation, Cho-Deung-San (CDS), which is composed of 11 herbal ingredients, has been used to treat vascular diseases for many centuries. In this study, we investigated the inhibitory effect of CDS on tumor necrosis factor-alpha (TNF-alpha)-induced human aortic smooth muscle cells (HASMC) migration and MMP-2 and -9 activity. The cytotoxocity of CDS on HASMC was very low (IC(50)>500 microg/ml) as measured by the XTT assay method. The Matrigel migration assay showed that CDS effectively inhibited the TNF-alpha-induced migration of HASMC as compared with the control group in a dose-dependent manner (IC(50)=85 microg/ml). To explain this inhibitory effect, the extracts prepared from CDS and its herbal ingredients were assayed for gelatin zymography. The results showed that CDS inhibited MMP-2 and -9 activity (IC(50)=180 and 75 microg/ml, respectively). Among the herbal ingredients of CDS, the hooks and stems of Uncaria sinensis (Oliv.) Havil (UR) has shown significant inhibition against MMP-2 and -9 activity. In addition, the inhibitory effect of UR against gelatinolytic activity of MMP-2 and -9 was higher than that of catechin and lower than that of epigallocatechin gallate. These results suggest that CDS could be used as potential antiatherosclerotic agent, and UR is major component of CDS for antimigration in TNF-alpha treated HASMC.