Inhibition of activator protein 1 activity by paclitaxel suppresses interleukin-1-induced collagenase and stromelysin expression by bovine chondrocytes

Naringin and naringenin counteract taxol-induced liver injury in Wistar rats via suppression of oxidative stress, apoptosis and inflammation

This research aimed to evaluate the preventing effects of naringin, naringenin, and their combination on liver injury induced by Taxol (paclitaxel) in Wistar rats. Male Wistar rats received 2 mg/kg Taxol intraperitoneal injections twice weekly on the second and fifth days of each week for 6 weeks. During the same period as Taxol administration, rats were given naringin, naringenin, or a combination of the two (10 mg/kg b.wt) every other day. Treatment with naringin and/or naringenin reduced the abnormally high serum levels of total bilirubin, aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, and gamma-glutamyl transferase in Taxol-treated rats. It also significantly increased the level of serum albumin, indicating an improvement in the liver. The perturbed histological liver changes were markedly improved due to the naringin and/or naringenin treatment in Taxol-administered rats. Additionally, the treatments reduced high hepatic lipid peroxidation and increased liver glutathione content as well as the activities of superoxide dismutase and glutathione peroxidase. Furthermore, the treatments reduced the levels of alpha-fetoprotein and caspase-3, a pro-apoptotic mediator. The naringin and naringenin mixture appeared more effective in improving organ function and structural integrity. In conclusion, naringin and naringenin are suggested to employ their hepatoprotective benefits via boosting the body's antioxidant defense system, reducing inflammation, and suppressing apoptosis.

Angiographic characteristics of vasculopathy in patients with idiopathic inflammatory myopathies and systemic sclerosis

To describe the peripheral angiographic features of vasculopathy in idiopathic inflammatory myopathies (IIM) and systemic sclerosis (SSc) in comparison to polyarteritis nodosa (PAN). Angiograms of 47 extremities (24 upper and 23 lower) of 11 patients with IIM (n = 5) and SSc (n = 6), and 12 patients with PAN who presented with critical limb ischemia were retrospectively analyzed with regards to the presence of stenosis, occlusion, aneurysms and delayed distal flow, and degree of neovascularization. Diffuse narrowing was more frequent (66.1 vs. 38.0%, p = 0.001), whereas multifocal stenosis (6.5% vs. 26.8%, p = 0.002), abrupt occlusion (11.3% vs. 29.6%, p = 0.010) and aneurysm formation (1.6% vs. 11.3%, p = 0.037) were less frequent in IIM/SSc than PAN. In distal arteries, tapered occlusion (95.5% vs. 76.0%, p = ns) and delayed flow (77.3% vs. 48.0%, p = 0.039) were more common in IIM/SSc than PAN. After 1 year, auto- or surgical amputation tended to be more frequent in IIM/SSc than PAN (36.4% vs. 16.7%, p = ns). In conclusion, diffuse narrowing, tapered occlusion and delayed distal flow on conventional angiograms tend to be more frequent in IIM/SSc than PAN. Further studies are needed to verify these findings in a larger prospective cohort.

Cell-associated type I collagen in nondegenerate and degenerate human articular cartilage

Chondrocytes with abnormal morphology are present in nondegenerate human cartilage suggesting dedifferentiation to a fibroblastic phenotype and production of a mechanically-weakened matrix of unknown composition. We determined the relationship between in situ chondrocyte morphology, chondrocyte clusters, and levels of cell-associated collagen type I. Chondrocyte morphology in fresh femoral head cartilage from 19 patients with femoral neck fracture and collagen type I labelling was identified with Cell Tracker^TM fluorescence and immunofluorescence, respectively, in axial/coronal orientations using confocal microscopy with images analysed by Imaris^TM . In axial images of grade 0 cartilage, 87 ± 8% were normal chondrocytes with a small (10 ± 6%) abnormal population possessing ≥1 cytoplasmic process. More normal chondrocytes (78 ± 11%) were collagen type I negative than those labelling positively (p < 0.001). For abnormal chondrocytes, 81 ± 14% labelled negatively for collagen type I compared to those labelling positively (19 ± 3%; p = 0.007; N(n)=11(3)). Overall, approximately 9% of the cells in normal cartilage labelled for collagen type I. With degeneration, the percentage of normal chondrocytes decreased (p < 0.001) but increased for abnormal cells (p = 0.036) and clusters (p = 0.003). A larger percentage of normal, abnormal and clustered chondrocytes now demonstrated collagen type I labelling (p = 0.004; p = 0.009; p = 0.001 respectively). Coronal images exhibited increased (p = 0.001) collagen type I labelling in the superficial zone of mildly degenerate cartilage with none in the mid or deep zones. These results show that collagen type I was identified around normal and abnormal chondrocytes in nondegenerate cartilage, which increased with degeneration. This suggested the presence of mechanically weak fibro-cartilaginous repair tissue in otherwise macroscopically nondegenerate human cartilage which progressed with degeneration as occurs in osteoarthritis.

Dual Role of Chondrocytes in Rheumatoid Arthritis: The Chicken and the Egg

Rheumatoid arthritis (RA) is one of the inflammatory joint diseases that display features of articular cartilage destruction. The underlying disturbance results from immune dysregulation that directly and indirectly influence chondrocyte physiology. In the last years, significant evidence inferred from studies in vitro and in the animal model offered a more holistic vision of chondrocytes in RA. Chondrocytes, despite being one of injured cells in RA, also undergo molecular alterations to actively participate in inflammation and matrix destruction in the human rheumatoid joint. This review covers current knowledge about the specific cellular and biochemical mechanisms that account for the chondrocyte signatures of RA and its potential applications for diagnosis and prognosis in RA.

The Role of Chondrocyte Morphology and Volume in Controlling Phenotype-Implications for Osteoarthritis, Cartilage Repair, and Cartilage Engineering

PURPOSE OF REVIEW

Articular chondrocytes are exclusively responsible for the turnover of the extracellular matrix (ECM) of hyaline cartilage. However, chondrocytes are phenotypically unstable and, if they de-differentiate into hypertrophic or fibroblastic forms, will produce a defective and weak matrix. Chondrocyte volume and morphology exert a strong influence over phenotype and a full appreciation of the factors controlling chondrocyte phenotype stability is central to understanding (a) the mechanisms underlying the cartilage failure in osteoarthritis (OA), (b) the rationale for hyaline cartilage repair, and (c) the strategies for improving the engineering of resilient cartilage. The focus of this review is on the factors involved in, and the importance of regulating, chondrocyte morphology and volume as key controllers of chondrocyte phenotype.

RECENT FINDINGS

The visualisation of fluorescently-labelled in situ chondrocytes within non-degenerate and mildly degenerate cartilage, by confocal scanning laser microscopy (CLSM) and imaging software, has identified the marked heterogeneity of chondrocyte volume and morphology. The presence of chondrocytes with cytoplasmic processes, increased volume, and clustering suggests important early changes to their phenotype. Results from experiments more closely aligned to the normal physico-chemical environment of in situ chondrocytes are emphasising the importance of understanding the factors controlling chondrocyte morphology and volume that ultimately affect phenotype. An appreciation of the importance of chondrocyte volume and morphology for controlling the chondrocyte phenotype is advancing at a rapid pace and holds particular promise for developing strategies for protecting the chondrocytes against deleterious changes and thereby maintaining healthy and resilient cartilage.

Paclitaxel-Coated Balloons and Eluting Stents: Is There a Mortality Risk in Patients With Peripheral Artery Disease?

Paclitaxel drug-coated balloons and drug-eluting stents became commercially available for the treatment of intermittent claudication in 2015 and 2012, respectively. Both devices demonstrated superiority in limb revascularization compared with non-paclitaxel-coated devices and were rapidly accepted into clinical practice. In a recent systematic review and study-level meta-analysis, Katsanos et al reported a late all-cause mortality signal for patients in the drug-coated balloon and drug-eluting stent arms of randomized clinical trials for both devices. As a result of this safety signal, Vascular InterVentional Advances Physicians (VIVA), a not-for-profit 501c(3) organization, convened the Vascular Leaders Forum on March 1 and 2, 2019, in Washington, DC, to initiate an open and collaborative process of investigation into this finding. The Vascular Leaders Forum brought together 100 stakeholders, including an international group of representatives of cardiovascular medicine, interventional radiology, vascular medicine, and vascular surgery; oncologists; basic scientists; the Food and Drug Administration; the Centers for Medicare and Medicaid Services; and commercial manufacturers of these products. The Vascular Leaders Forum reviewed the natural history of peripheral arterial disease, the use of paclitaxel in peripheral arterial disease and other conditions, the harm signal noted by Katsanos et al, the impact of the methods chosen by Katsanos et al, possible mechanisms of harm, the role of the Food and Drug Administration in a setting like this one, and guidance for clinicians taking care of patients with symptomatic peripheral arterial disease. This document integrates the most current data to help establish an appropriate path forward to understand the risks and benefits associated with these technologies while ensuring the best treatment paradigm for patients.

Identification of transcription factors responsible for dysregulated networks in human osteoarthritis cartilage by global gene expression analysis

OBJECTIVE

Osteoarthritis (OA) is the most prevalent joint disease. As disease-modifying therapies are not available, novel therapeutic targets need to be discovered and prioritized for their importance in mediating the abnormal phenotype of cells in OA-affected joints. Here, we generated a genome-wide molecular profile of OA to elucidate regulatory mechanisms of OA pathogenesis and to identify possible therapeutic targets using integrative analysis of mRNA-sequencing data obtained from human knee cartilage.

DESIGN

RNA-sequencing (RNA-seq) was performed on 18 normal and 20 OA human knee cartilage tissues. RNA-seq datasets were analysed to identify genes, pathways and regulatory networks that were dysregulated in OA.

RESULTS

RNA-seq data analysis revealed 1332 differentially expressed (DE) genes between OA and non-OA samples, including known and novel transcription factors (TFs). Pathway analysis identified 15 significantly perturbed pathways in OA with ECM-related, PI3K-Akt, HIF-1, FoxO and circadian rhythm pathways being the most significantly dysregulated. We selected DE TFs that are enriched for regulating DE genes in OA and prioritized these TFs by creating a cartilage-specific interaction subnetwork. This analysis revealed eight TFs, including JUN, Early growth response (EGR)1, JUND, FOSL2, MYC, KLF4, RELA, and FOS that both target large numbers of dysregulated genes in OA and are themselves suppressed in OA.

CONCLUSIONS

We identified a novel subnetwork of dysregulated TFs that represent new mediators of abnormal gene expression and promising therapeutic targets in OA.

Interplay between cytoskeletal polymerization and the chondrogenic phenotype in chondrocytes passaged in monolayer culture

Tubulin and actin exist as monomeric units that polymerize to form either microtubules or filamentous actin. As the polymerization status (monomeric/polymeric ratio) of tubulin and/or actin have been shown to be important in regulating gene expression and phenotype in non-chondrocyte cells, the objective of this study was to examine the role of cytoskeletal polymerization on the chondrocyte phenotype. We hypothesized that actin and/or tubulin polymerization status modulates the chondrocyte phenotype during monolayer culture as well as in 3D culture during redifferentiation. To test this hypothesis, articular chondrocytes were grown and passaged in 2D monolayer culture. Cell phenotype was investigated by assessing cell morphology (area and circularity), actin/tubulin content, organization and polymerization status, as well as by determination of proliferation, fibroblast and cartilage matrix gene expression with passage number. Bovine chondrocytes became larger, more elongated, and had significantly (P < 0.05) increased gene expression of proliferation-associated molecules (cyclin D1 and ki67), as well as significantly (P < 0.05) decreased cartilage matrix (type II collagen and aggrecan) and increased fibroblast-like matrix, type I collagen (COL1), gene expression by passage 2 (P2). Although tubulin polymerization status was not significantly (P > 0.05) modulated, actin polymerization was increased in bovine P2 cells. Actin depolymerization, but not tubulin depolymerization, promoted the chondrocyte phenotype by inducing cell rounding, increasing aggrecan and reducing COL1 expression. Knockdown of actin depolymerization factor, cofilin, in these cells induced further P2 cell actin polymerization and increased COL1 gene expression. To confirm that actin status regulated COL1 gene expression in human P2 chondrocytes, human P2 chondrocytes were exposed to cytochalasin D. Cytochalasin D decreased COL1 gene expression in human passaged chondrocytes. Furthermore, culture of bovine P2 chondrocytes in 3D culture on porous bone substitute resulted in actin depolymerization, which correlated with decreased expression of COL1 and proliferation molecules. In 3D cultures, aggrecan gene expression was increased by cytochalasin D treatment and COL1 was further decreased. These results reveal that actin polymerization status regulates chondrocyte dedifferentiation. Reorganization of the cytoskeleton by actin depolymerization appears to be an active regulatory mechanism for redifferentiation of passaged chondrocytes.

Tumor and salivary matrix metalloproteinase levels are strong diagnostic markers of oral squamous cell carcinoma

BACKGROUND

The matrix metalloproteinases (MMP) cause degradation of the extracellular matrix and basement membranes, and thus may play a key role in cancer development.

METHODS

In our search for biomarkers for oral squamous cell carcinomas (OSCC), we compared primary OSCC, oral dysplasia and control subjects with respect to: (i) expression of MMP1, MMP3, MMP10, and MMP12 in oral epithelial tissue using Affymetrix U133 2.0 Plus GeneChip arrays, followed by quantitative reverse transcription-PCR (qRT-PCR) for MMP1, and (ii) determination of MMP1 and MMP3 concentrations in saliva.

RESULTS

MMP1 expression in primary OSCC (n = 119) was >200-fold higher (P = 7.16 × 10(-40)) compared with expression levels in nonneoplastic oral epithelium from controls (n = 35). qRT-PCR results on 30 cases and 22 controls confirmed this substantial differential expression. The exceptional discriminatory power to separate OSCC from controls was validated in two independent testing sets (AUC% = 100; 95% CI: 100-100 and AUC% = 98.4; 95% CI: 95.6-100). Salivary concentrations of MMP1 and MMP3 in OSCC patients (33 stage I/II, 26 stage III/IV) were 6.2 times (95% CI: 3.32-11.73) and 14.8 times (95% CI: 6.75-32.56) higher, respectively, than in controls, and displayed an increasing trend with higher stage disease.

CONCLUSION

Tumor and salivary MMPs are robust diagnostic biomarkers of OSCC.

IMPACT

The capacity of MMP gene expression to identify OSCC provides support for further investigation into MMPs as potential markers for OSCC development. Detection of MMP proteins in saliva in particular may provide a promising means to detect and monitor OSCC noninvasively.

Variation of matrix metalloproteinase 1 and 3 haplotypes and their serum levels in patients with rheumatoid arthritis and osteoarthritis

The matrix metalloproteinases 1 and 3 (MMP1 and MMP3) are thought to be important in destructive joint changes seen in rheumatoid arthritis (RA) and osteoarthritis (OA) diseases. The aim of this study was to analyze whether functional polymorphisms in the promoter region of the MMP1 and MMP3 genes were associated with RA and OA. The MMP1 (-1607 1G/2G) and MMP3 (-1171 5A/6A) polymorphisms were screened by polymerase chain reaction-restriction fragment length polymorphism in 100 patients with (RA), 100 patients with (OA), and 100 controls. Serum MMP1 and MMP3 levels were measured by enzyme-linked immunosorbent assay. The results reported a significant difference between patients with OA and controls regarding allele distributions of MMP1 polymorphism, but not between patients with RA and controls. For MMP3 polymorphism, the 6A/6A genotype was significantly more frequent in patients with RA and OA than in controls. The haplotype 2G-6A, which carries the abnormal alleles, showed higher frequencies in the patients with RA and OA than in controls (28%, 30% and 8%, respectively). There were no significant differences in serum MMP1 and MMP3 levels between all studied groups. In conclusion, the MMP1 and MMP3 haplotypes may represent genetic determinants for RA and OA in the Egyptian population. The results suggest that MMP polymorphism genotypes may be more useful in predicting joint damage than measurement of serum concentrations of MMP1 and MMP3. Moreover, MMP1 and MMP3 polymorphisms may predict the activity and severity of these diseases.

The Taxus drug-eluting stent: a new paradigm in controlled drug delivery

The advent of drug-eluting stents (DES) has provided the medical community with a technology that is transforming the treatment of coronary artery disease. As the newest treatment modality available to the interventional cardiologist, drug-eluting stents have not only significantly reduced the risk of restenosis, but they are also allowing the interventionalists to treat more complex lesions in patients that would otherwise require more invasive bypass surgery. Development of these drug-device combination products has presented considerable challenges to the device industry because it involves a multi-disciplinary approach that combines conventional device design and manufacturing with the principles of controlled local drug delivery. This review article provides an in-depth discussion of the key elements of drug-eluting stents, focusing on the TAXUS paclitaxel-eluting stent as an example of this new class of product. Specific sections will review the drug and polymer matrix components, formulation development and evaluation, pre-clinical studies and clinical trial results.

Outcomes with the polymer-based paclitaxel-eluting TAXUS stent in patients with diabetes mellitus

OBJECTIVES

We sought to determine the safety and efficacy of polymer-regulated site-specific delivery of paclitaxel in patients with diabetes mellitus undergoing stent implantation.

BACKGROUND

Percutaneous coronary intervention in patients with diabetes is associated with high rates of restenosis and repeat revascularization due to excessive neointimal proliferation, a process that may be blunted with the site-specific delivery of paclitaxel.

METHODS

In the TAXUS-IV trial, 1,314 patients were prospectively randomized to the slow rate-release polymer-based paclitaxel-eluting TAXUS stent or the bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). Medically treated diabetes was present in 318 patients (24%), 105 of whom required insulin.

RESULTS

Among patients with diabetes, the TAXUS stent, compared to the bare-metal stent, reduced the rate of 9-month binary angiographic restenosis by 81% (6.4% vs. 34.5%, p < 0.0001), and reduced the 12-month rates of target lesion revascularization by 65% (7.4% vs. 20.9%, p = 0.0008), target vessel revascularization by 53% (11.3% vs. 24%, p < 0.004), and composite major adverse cardiac events by 44% (15.6% vs. 27.7%, p = 0.01). The one-year rates of cardiac death (1.9% vs. 2.5%), myocardial infarction (3.2% vs. 6.4%), and subacute thrombosis (0.6% vs. 1.2%) were comparable between the paclitaxel-eluting and control stents, respectively. In the insulin-requiring subgroup, the TAXUS stent reduced angiographic restenosis by 82% (7.7% vs. 42.9%, p = 0.0065), and reduced the one-year rate of target lesion revascularization by 68% (6.2% vs. 19.4%, p = 0.07), a relative reduction similar to patients without diabetes.

CONCLUSIONS

The site-specific delivery of paclitaxel after coronary stent implantation is highly effective in reducing clinical and angiographic restenosis in patients with diabetes mellitus.

Mechanical Compression of Cartilage Explants Induces Multiple Time-dependent Gene Expression Patterns and Involves Intracellular Calcium and Cyclic AMP

Chondrocytes are influenced by mechanical forces to remodel cartilage extracellular matrix. Previous studies have demonstrated the effects of mechanical forces on changes in biosynthesis and mRNA levels of particular extracellular matrix molecules, and have identified certain signaling pathways that may be involved. However, the broad extent and kinetics of mechano-regulation of gene transcription has not been studied in depth. We applied static compressive strains to bovine cartilage explants for periods between 1 and 24 h and measured the response of 28 genes using real time PCR. Compression time courses were also performed in the presence of an intracellular calcium chelator or an inhibitor of cyclic AMP-activated protein kinase A. Cluster analysis of the data revealed four main expression patterns: two groups containing either transiently up-regulated or duration-enhanced expression profiles could each be subdivided into genes that did or did not require intracellular calcium release and cyclic AMP-activated protein kinase A for their mechano-regulation. Transcription levels for aggrecan, type II collagen, and link protein were up-regulated approximately 2-3-fold during the first 8 h of 50% compression and subsequently down-regulated to levels below that of free-swelling controls by 24 h. Transcription levels of matrix metalloproteinases-3, -9, and -13, aggrecanase-1, and the matrix protease regulator cyclooxygenase-2 increased with the duration of 50% compression 2-16-fold by 24 h. Thus, transcription of proteins involved in matrix remodeling and catabolism dominated over anabolic matrix proteins as the duration of static compression increased. Immediate early genes c-fos and c-jun were dramatically up-regulated 6-30-fold, respectively, during the first 8 h of 50% compression and remained up-regulated after 24 h.

Micellar paclitaxel improves severe psoriasis in a prospective phase II pilot study

BACKGROUND

Taxanes (eg, paclitaxel) are chemotherapeutic agents that have antiproliferative, antiangiogenic, and antiinflammatory properties.

OBJECTIVE

We sought to explore the safety and efficacy of paclitaxel in individuals with severe psoriasis.

METHODS

An open-label, prospective, phase II pilot study was conducted at the National Institutes of Health Clinical Center, a federal government medical research facility, in Bethesda, Maryland. Twelve patients with severe psoriasis, as defined by a baseline Psoriasis Area and Severity Index (PASI) score of >or= 20), were studied. Initially, patients received 6 intravenous infusions of micellar paclitaxel, 75 mg/m(2), at 4-week intervals (stage I). Later patients received 9 intravenous infusions of micellar paclitaxel at 2-week intervals (37.5 mg/m(2) for 3 doses followed by 50 mg/m(2) for six additional doses) (stage II). The primary end point was the percent change in the PASI from week 0 to week 24 in stage I and from week 0 to week 20 in stage II.

RESULTS

In stage I, all 5 patients improved (mean = 59.7% decrease in PASI, median = 59.6%, range: 40.3%-79.2%). Four of the 7 patients completed stage II and all of these patients improved (mean = 45.9% decrease in PASI, median = 45.0%, range: 14.6%-79.1%). Micellar paclitaxel was well tolerated by most patients.

CONCLUSIONS

Micellar paclitaxel demonstrates therapeutic activity in patients with severe psoriasis.

Association of a specific haplotype across the genes MMP1 and MMP3 with radiographic joint destruction in rheumatoid arthritis

The genetic background of rheumatoid arthritis (RA) is only partly understood, and several genes seem to be involved. The matrix metalloproteinases MMP1 (interstitial collagenase) and MMP3 (stromelysin 1) are thought to be important in destructive joint changes seen in RA. In the present study, functional relevant promoter polymorphisms of MMP1 and MMP3 were genotyped in 308 patients and in 110 controls, to test whether the polymorphisms contribute to the severity of the disease measured by radiographic progression of joint destruction. For comparison, the shared epitope of HLA DR4 and DR1 (SE) was determined by polymerase chain reaction. There was no association of MMP polymorphisms with susceptibility to RA. However, a strong linkage disequilibrium was observed between the 1G/2G (MMP1) and the 5A/6A (MMP3) polymorphisms (P << 10^-6; linkage disequilibrium index D' = 0.46). In factorial regression, the degree of radiographic joint destruction correlated significantly with the 1G-5A haplotype (P = 0.0001) and the interaction term 'estimated number of 1G-5A haplotypes × duration of disease' (P = 0.0007). This association was phasic, indicating that possession of the 1G-5A haplotype has a protective effect over a period of about 15 years of RA, but might be associated with a more pronounced radiographic progression later on. Similar results were also found with the 1G allele of MMP1 alone (P = 0.015) and with the interaction term 'estimated number of 1G alleles × duration of disease' (P = 0.014). The correlation of SE with the Ratingen score was comparable (0.044). The regression model of MMP haplotypes explained 35% of the variance of the radiographic score, whereas the SE explained 29%. The 1G-5A haplotype across the closely linked MMP1 and MMP3 gene loci is a newly described genetic factor strongly associated with the progression of joint damage in RA. Our findings suggest that there are haplotypes in a MMP cluster region that modify the joint destruction in RA in a phasic manner.

A polymer-based, paclitaxel-eluting stent in patients with coronary artery disease

BACKGROUND

Restenosis after coronary stenting necessitates repeated percutaneous or surgical revascularization procedures. The delivery of paclitaxel to the site of vascular injury may reduce the incidence of neointimal hyperplasia and restenosis.

METHODS

At 73 U.S. centers, we enrolled 1314 patients who were receiving a stent in a single, previously untreated coronary-artery stenosis (vessel diameter, 2.5 to 3.75 mm; lesion length, 10 to 28 mm) in a prospective, randomized, double-blind study. A total of 652 patients were randomly assigned to receive a bare-metal stent, and 662 to receive an identical-appearing, slow-release, polymer-based, paclitaxel-eluting stent. Angiographic follow-up was prespecified at nine months in 732 patients.

RESULTS

In terms of base-line characteristics, the two groups were well matched. Diabetes mellitus was present in 24.2 percent of patients; the mean reference-vessel diameter was 2.75 mm, and the mean lesion length was 13.4 mm. A mean of 1.08 stents (length, 21.8 mm) were implanted per patient. The rate of ischemia-driven target-vessel revascularization at nine months was reduced from 12.0 percent with the implantation of a bare-metal stent to 4.7 percent with the implantation of a paclitaxel-eluting stent (relative risk, 0.39; 95 percent confidence interval, 0.26 to 0.59; P<0.001). Target-lesion revascularization was required in 3.0 percent of the group that received a paclitaxel-eluting stent, as compared with 11.3 percent of the group that received a bare-metal stent (relative risk, 0.27; 95 percent confidence interval, 0.16 to 0.43; P<0.001). The rate of angiographic restenosis was reduced from 26.6 percent to 7.9 percent with the paclitaxel-eluting stent (relative risk, 0.30; 95 percent confidence interval, 0.19 to 0.46; P<0.001). The nine-month composite rates of death from cardiac causes or myocardial infarction (4.7 percent and 4.3 percent, respectively) and stent thrombosis (0.6 percent and 0.8 percent, respectively) were similar in the group that received a paclitaxel-eluting stent and the group that received a bare-metal stent.

CONCLUSIONS

As compared with bare-metal stents, the slow-release, polymer-based, paclitaxel-eluting stent is safe and markedly reduces the rates of clinical and angiographic restenosis at nine months.

Changes in human bladder epithelial cell gene expression associated with interstitial cystitis or antiproliferative factor treatment

Explanted bladder epithelial cells from patients with interstitial cystitis (IC) have been shown to differ from explanted control cells in several ways, including production of an antiproliferative factor (APF), altered production of certain epithelial growth factors, and rate of proliferation. To better understand the role of the APF in abnormal bladder epithelial cell proliferation in IC, we studied gene expression patterns in normal bladder epithelial cells treated with APF vs. mock APF and compared them to expression patterns in IC vs. normal cells using microarray analysis. Oligo-dT-primed total cellular RNA was labeled with [(33)P]dCTP and hybridized to GeneFilter GF211 microarray membranes (Research Genetics) containing cDNA for 3,964 human genes. Thirteen genes that function in epithelial cell proliferation or differentiation were consistently differentially expressed in both IC (compared with control) and APF-treated (compared with mock APF-treated) normal bladder epithelial cells. The general pattern of gene expression in IC and APF-treated cells suggested a less proliferative phenotype, with increased expression of E-cadherin, phosphoribosylpyrophosphate synthetase-associated protein 39, and SWI/SNF complex 170-kDa subunit, and decreased expression of vimentin, alpha2-integrin, alpha1-catenin, cyclin D1, and jun N-terminal kinase 1; these findings were confirmed for the structural gene products (E-cadherin, vimentin, alpha2-integrin, and alpha-catenin) by immunohistochemistry. These results are compatible with the previously noted decreased proliferation rate of IC and APF-treated normal cells, and indicate that the mechanism whereby APF inhibits cell proliferation may involve both downregulation of genes that stimulate cell proliferation along with upregulation of genes that inhibit cell growth.

TAXUS I: six- and twelve-month results from a randomized, double-blind trial on a slow-release paclitaxel-eluting stent for de novo coronary lesions

BACKGROUND

The TAXUS NIRx stent (Boston Scientific Corp) provides local delivery of paclitaxel via a slow-release polymer coating. The TAXUS I trial was the first in-human experience evaluating safety and feasibility of the TAXUS NIRx stent system compared with bare NIR stents (control) (Boston Scientific Corp) for treatment of coronary lesions.

METHODS AND RESULTS

METHODS AND RESULTS

The TAXUS I trial was a prospective, double-blind, three-center study randomizing 61 patients with de novo or restenotic lesions (< or =12 mm) to receive a TAXUS (n=31) versus control (n=30) stent (diameter 3.0 or 3.5 mm). Demographics, lesion characteristics, clinical outcomes were comparable between the groups. The 30-day major adverse cardiac event (MACE) rate was 0% in both groups (P=NS). No stent thromboses were reported at 1, 6, 9, or 12 months. At 12 months, the MACE rate was 3% (1 event) in the TAXUS group and 10% (4 events in 3 patients) in the control group (P=NS). Six-month angiographic restenosis rates were 0% for TAXUS versus 10% for control (P=NS) patients. There were significant improvements in minimal lumen diameter (2.60+/-0.49 versus 2.19+/-0.65 mm), diameter stenosis (13.56+/-11.77 versus 27.23+/-16.69), and late lumen loss (0.36+/-0.48 versus 0.71+/-0.48 mm) in the TAXUS group (all P<0.01). No evidence of edge restenosis was seen in either group. Intravascular ultrasound analysis showed significant improvements in normalized neointimal hyperplasia in the TAXUS (14.8 mm3) group compared with the control group (21.6 mm3) (P<0.05).

CONCLUSIONS

In this feasibility trial, the TAXUS slow-release stent was well tolerated and showed promise for treatment of coronary lesions, with significant reductions in angiographic and intravascular ultrasound measures of restenosis.

Differentiation-dependent activation of the extracellular fatty acid binding protein (Ex-FABP) gene during chondrogenesis

Chicken hypertrophic chondrocytes secrete the extracellular fatty acid binding protein (Ex-FABP), a lipocalin not expressed by their undifferentiated precursors. Genomic clones coding for the full protein are here structurally and functionally analyzed. We first determined that the promoter sequence markedly differs from that reported for the homologous p20K, and we confirmed by genomic DNA Southern analysis the exactness of our sequence. This is of relevance since we have identified another lipocalin gene within the region of discrepancy, indicating thereby the existence of a lipocalin cluster within the same chromosomal locus. By transient transfections with 5'-deletions and the chloramphenicol acetyl transferase (CAT) reporter gene, the region between nt -926 and nt -629 was shown to be strongly active, specifically in hypertrophic chondrocytes and not in dedifferentiated cells. Responsive elements for several potential transcription factors lay within this sequence. Among those, activating protein-1 (AP-1) was shown to be involved in the regulation of the Ex-FABP gene during chondrocyte differentiation, as indicated by electrophoretic mobility shift assay, AP-1 site mutagenesis and functional interference assays.

Initial experience with paclitaxel-coated stents

Local delivery of immunosuppressive or antiproliferative agents using a drug-eluting stent is a new technology that is supposed to inhibit in-stent restenosis, thus providing a biological and mechanical solution. This technique is a very promising. To date, several agents have been used, including paclitaxel, QP-2, rapamycin, actinomycin D, dexamethason, tacrolimus, and everolimus. Several studies, published recently or still ongoing, have evaluated these drugs as to their release kinetics, effective dosage, safety in clinical practice, and benefit. These studies include: SCORE (paclitaxel derivative), TAXUS I-VI, ELUTES, ASPECT, DELIVER (paclitaxel), RAVEL, SIRIUS (sirolimus), ACTION (actinomycin), EVIDENT, PRESENT (tacrolimus), EMPEROR (dexamethason), and FUTURE (everolimus). Paclitaxel was one of the first stent-based antiproliferative agents under clinical investigation that provided profound inhibition of neointimal thickening depending on delivery duration and drug dosage. The randomized, multicenter SCORE trail (Quanam stent, paclitaxel-coated) enrolled 266 patients at 17 sites. At 6-month's follow-up, a drop of 83% in stent restenosis using the drug-eluting stent could be achieved (6.4% drug-eluting stent vs 36.9% control group), which was attributable to a remarkable decrease in intimal proliferation. Unfortunately, due to frequent stent thrombosis and side-branch occlusions, the reported 30-day MACE rate was 10.2%. The randomized TAXUS-I safety trial (BSC, NIRx, paclitaxel-coated) also demonstrated beneficial reduction of restenotic lesions at 6-month's follow-up (0% vs 10%) but was associated with the absence of thrombotic events presumably due to less drug dosage. The ongoing TAXUS II-VI trials are addressing additional insight regarding the efficacy of the TAXUS paclitaxel-eluting stent. ASPECT and ELUTES evaluated paclitaxel-coated stents (i.e., Cook and Supra G), including subgroups with different drug dosages. With respect to stent restenosis and neointimal proliferation, both studies demonstrated a clear dose response. The RAVEL and the SIRIUS trials evaluated sirolimus-coated stents (i.e., Cordis, Johnson & Johnson, and Bx VELOCITY stents). Results confirmed the beneficial findings regarding reduction of renarrowing using a drug-eluting stent without any major adverse effects. Although parameters such as drug toxicity, optimal drug dosage, or delayed endothelial healing still need to be evaluated, today's clinical experience indicates that drug-coated stents are extremely beneficial in the interventional treatment of coronary lesions.

Bone morphogenetic protein-mediating receptor-associated Smads as well as common Smad are expressed in human articular chondrocytes but not up-regulated or down-regulated in osteoarthritic cartilage

Bone morphogenetic proteins (BMPs) are supposed to be important for cartilage matrix anabolism. In this study, we investigated whether the intracellular mediators of BMP activity, Smads 1, 4, 5, and 8, are expressed in normal human articular chondrocytes in vivo and in vitro and whether alterations in expression and distribution pattern are found in osteoarthritic cartilage or in vitro after stimulation with interleukin (IL)-1, because down-regulation of these mediators could be responsible for the decrease of anabolic activity in osteoarthritic cartilage. RNA was isolated from normal and osteoarthritic human knee cartilage and analyzed by (quantitative) polymerase chain reaction (PCR) technology. Articular chondrocytes were cultured in alginate beads and short-term high-density monolayer cultures with and without stimulation by IL-1. In addition, immunolocalization of the receptor-associated Smads (R-Smads) was performed on sections of normal and diseased articular cartilage. Reverse-transcription (RT)-PCR analysis showed a moderate expression of all Smads investigated in normal, early degenerative, and late stage osteoarthritic cartilage. Immunolocalization detected the R-Smads in most chondrocytes on the protein level in all specimen groups investigated. In vitro, the Smads were also expressed and partly up-regulated by Il-1beta in alginate bead culture. Of note, for Smad 1, two truncated splice variants were expressed by articular chondrocytes missing exon 4 as well as exons 3 and 4. Our study showed that BMP-receptor Smads 1, 5, and 8 as well as common Smad (C-Smad) 4 are expressed and present in human normal and osteoarthritic articular chondrocytes corroborating the importance of BMPs and BMP signaling for articular cartilage. This study is the first to describe splicing variants for Smad 1. Smads 1, 4, and 5 are up-regulated in vitro by Il-1beta, suggesting a linkage of the Il-1 and BMP-signaling pathways within the chondrocytes. None of the Smads were grossly up- or down-regulated in osteoarthritic chondrocytes, suggesting that differences in overall expression levels of the investigated Smad proteins are not relevant for metabolic activity of articular chondrocytes in vivo.

Functional genomics of osteoarthritis

Functional genomics is a challenging new way to address a complex disease like osteoarthritis on a molecular level. Despite osteoarthritis being ultimately a biochemical problem, mainly characterized by an imbalanced cartilage matrix turnover, a deeper understanding of molecular events within the tissue cells (i.e., the chondrocytes) will provide not only a better understanding of pathogenetic mechanisms but also new diagnostic markers and cellular targets for therapeutic intervention. This innovative technology represents a challenging approach complementing (not replacing) classical research in previously described and new disease-relevant genes: large-scale functional genomics will open up new areas of so far unrecognized molecular networks. This will include as yet unidentified players in the anabolic-catabolic balance of matrix turnover of articular cartilage as well as disease-relevant intracellular signaling cascades so far hardly investigated in articular chondrocytes. However, care must be taken not to over or misinterpret results and some major challenges must be overcome in order to properly utilize the potential of this technology in the field of osteoarthritis.

Paclitaxel (Taxol) attenuates clinical disease in a spontaneously demyelinating transgenic mouse and induces remyelination

Treatment with paclitaxel by four intraperitoneal injections (20 mg/kg) 1 week apart attenuated clinical signs in a spontaneously demyelinating model, if given with onset of clinical signs. If given at 2 months of age (1 month prior to clinical signs), disease was almost completely prevented The astrogliosis, prominent in our model, was reversed by paditaxel as determined by astrocyte counts and quantitation of GFAP. Electron microscopic examination of affected regions at 2.5 months demonstrated that the myelin was generally normal. By 4 months of age, demyelination was common in the superior cerebellar peduncle, maximal at 6 months, but continued to 8 months. In addition to myelin vacuolation and nude axons, the presence of many thin myelin sheaths suggested remyelination or partial demyelination. Although no evidence of oligodendrocyte loss was seen, nuclear changes were observed. To substantiate that remyelination was occurring, we measured MBP (18.5 kDa), MBP-exon II, Golli-MBP, TP8, Golli-MBP-J37, platelet-derived growth factor alpha (PDGFR alpha) and sonic hedgehog (SHH). Of these TP8, PDGFR alpha and SHH were up-regulated in the untreated transgenic. After paditaxel treatment, MBP-Exon II, TP8, PDGFR alpha and SHH were further up-regulated. We concluded that some of the effects of paditaxel were to stimulate proteins involved in early myelinating events possibly via a signal transduction mechanism.

15-Deoxy-delta12,14-PGJ2, but not troglitazone, modulates IL-1beta effects in human chondrocytes by inhibiting NF-kappaB and AP-1 activation pathways

The activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to inhibit the production and the effects of proinflammatory cytokines. Since interleukin-1beta (IL-1beta) directly mediates cartilage degradation in osteoarthritis, we investigated the capability of PPARgamma ligands to modulate IL-1beta effects on human chondrocytes. RT-PCR and Western blot analysis revealed that PPARgamma expression was decreased by IL-1beta. 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), in contrast to troglitazone, was highly potent to counteract IL-1beta-induced cyclooxygenase-2 and inductible nitric oxide synthase expression, NO production and the decrease in proteoglycan synthesis. Western blot and gel-shift analyses demonstrated that 15d-PGJ2 inhibited NF-kappaB activation, while troglitazone was ineffective. Although 15d-PGJ2 attenuated activator protein-1 binding on the DNA, it potentiated c-jun migration in the nucleus. The absence or the low effect of troglitazone suggests that 15d-PGJ2 action in human chondrocytes is mainly PPARgamma-independent.

TGF-beta/Smad3 signals repress chondrocyte hypertrophic differentiation and are required for maintaining articular cartilage

Endochondral ossification begins from the condensation and differentiation of mesenchymal cells into cartilage. The cartilage then goes through a program of cell proliferation, hypertrophic differentiation, calcification, apoptosis, and eventually is replaced by bone. Unlike most cartilage, articular cartilage is arrested before terminal hypertrophic differentiation. In this study, we showed that TGF-beta/Smad3 signals inhibit terminal hypertrophic differentiation of chondrocyte and are essential for maintaining articular cartilage. Mutant mice homozygous for a targeted disruption of Smad3 exon 8 (Smad3(ex8/ex8)) developed degenerative joint disease resembling human osteoarthritis, as characterized by progressive loss of articular cartilage, formation of large osteophytes, decreased production of proteoglycans, and abnormally increased number of type X collagen-expressing chondrocytes in synovial joints. Enhanced terminal differentiation of epiphyseal growth plate chondrocytes was also observed in mutant mice shortly after weaning. In an in vitro embryonic metatarsal rudiment culture system, we found that TGF-beta1 significantly inhibits chondrocyte differentiation of wild-type metatarsal rudiments. However, this inhibition is diminished in metatarsal bones isolated from Smad3(ex8/ex8) mice. These data suggest that TGF-beta/Smad3 signals are essential for repressing articular chondrocyte differentiation. Without these inhibition signals, chondrocytes break quiescent state and undergo abnormal terminal differentiation, ultimately leading to osteoarthritis.

Inhibition of experimental allergic encephalomyelitis in the Lewis rat by paclitaxel

Experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis (MS), is useful for preclinical testing for agents to be considered for treatment for this human demyelinating disease. Microtubules in lymphocytes play an important role in the cascade of human T cell activation, and paclitaxel (PTX), a microtubule stabilizer, can inhibit T cell function. A new formulation of micellar PTX, free of Cremophor and ethanol, was tested for its effect on the induction of EAE in Lewis rats. Adoptive EAE was induced with an encephalitogenic T cell line activated with guinea pig myelin basic protein (GP MBP) peptide 68-88. PTX (10 mg/kg) was administered 24 and 72 h after cell transfer. The clinical signs, fulminating in controls, were completely blocked by PTX, but mild CNS inflammation remained unaltered. A similar dose of PTX, given on days 6 and 8 to animals developing active EAE after immunization with GP MBP peptide 68-88 in complete Freund's adjuvant, greatly reduced the severity of paralysis and delayed the onset of disease by 8-9 days. Marked weight loss and severe toxicity were noted with higher and more prolonged administration. In vitro micellar PTX inhibited activation of encephalitogenic T cells by both specific antigen and mitogen. Lower doses and longer treatment programs may provide effective treatment with acceptable adverse effects with this agent in the treatment of inflammatory demyelinating disease.

Pregnancy affects cellular activity, but not tissue mechanical properties, in the healing rabbit medial collateral ligament

Recently, evidence has been accumulating that ligament and joint laxity is altered in women and rabbits during pregnancy. Furthermore, many female adolescents injure ligaments through participation in athletics and other activities. Therefore, to determine whether pregnancy has different effects on the injured and uninjured medial collateral ligament of the rabbit knee, we investigated cellular changes (mRNA levels) and alterations in tissue properties (biomechanics) accompanying pregnancy in animals with the medial collateral ligament injured during adolescence and bred for their primigravid pregnancy as young adults. Assessment of mRNA levels for matrix molecules, matrix metalloproteinases and tissue inhibitor of metalloproteinase-1, growth factors and sex hormone receptors, inflammatory cytokines, inducible nitric oxide synthase, and cyclooxygenase-2 by semiquantitative reverse transcription-polymerase chain reaction revealed that pregnancy had different impacts on scar and uninjured tissue for six of 15 genes assessed. A pregnancy-associated increase in laxity of the medial collateral ligament was observed for rabbits in the uninjured primigravida group; however, no increase was observed for injured rabbits during pregnancy. The injured ligament was already significantly more lax than the normal counterpart, and pregnancy did not lead to additional laxity or prevent the normal decline in laxity as the scar matured in nonpregnant animals. These results indicate that the impact of pregnancy on laxity and cell activity of the medial collateral ligament is dependent on whether the ligament is uninjured or injured. Pregnancy had no significant effect on structural (stiffness and failure load), material (stress at failure and Young's modulus), or viscoelastic (cyclic and static relaxation) properties of tissue from uninjured or injured medial collateral ligament. Therefore, the properties of the healing ligament were not adversely affected during pregnancy in this experimental model. However, it remains to be determined if these results with an injured medial collateral ligament can be extrapolated to the injured anterior cruciate ligament.

Defining therapeutic targets by using adenovirus: blocking NF-kappaB inhibits both inflammatory and destructive mechanisms in rheumatoid synovium but spares anti-inflammatory mediators

The role of the transcription factor NF-kappaB in the pathogenesis of rheumatoid arthritis has long been a subject of controversy. We used an adenoviral technique of blocking NF-kappaB through overexpression of the inhibitory subunit IkappaBalpha, which has the advantage that it can be used in the diseased tissue itself, with >90% of the synovial macrophages, fibroblasts, and T cells infected. We found that the spontaneous production of tumor necrosis factor alpha and other pro-inflammatory cytokines is NF-kappaB-dependent in rheumatoid synovial tissue, in contrast to the main anti-inflammatory mediators, like IL-10 and -11, and the IL-1 receptor antagonist. Of even more interest, IkappaBalpha overexpression inhibited the production of matrix metalloproteinases 1 and 3 while not affecting their tissue inhibitor. Blocking NF-kappaB in the rheumatoid joint thus has a very beneficial profile, reducing both the inflammatory response and the tissue destruction. The adenoviral technique described here has widespread applicability, allowing rapid testing of the effects of blocking a potential therapeutic target in either cultures of normal cells or in the diseased tissue itself.