Transforming Growth Factor-β1 Release Research Articles

Quantitative assessment of transforming growth factor-β1 release from dentin matrix upon conditioning with ethylene diamine tetra-acetate, doxycycline hydrochloride, and propolis: An in vitro study.

Transforming growth factor-beta 1 (TGF-β1) is a key morphogen in regenerative endodontics that plays a central role in regulating cellular functions. Various chelating agents have been shown to release this growth factor upon conditioning. The objective of the study was to evaluate TGF-β1 release from the dentin matrix upon conditioning with ethylene diamine tetra-acetate (EDTA), doxycycline hydrochloride, and propolis. Forty-two human 3rd molar teeth were collected and coronal portion of the teeth was sectioned to obtain dentin blocks with dimensions 2 mm × 2 mm × 2 mm. The blocks were then randomly divided into three groups depending on the conditioning agent used; Group 1: 17% EDTA, Group 2: doxycycline hydrochloride (100 mg/mL), and Group 3: propolis (250 μg/mL). Conditioned blocks were placed in 0.5 mL of phosphate buffered saline and incubated for 1 week for quantification. Highest TGF-β1 release was noted for propolis (0.21 ng/mL), followed by doxycycline hydrochloride (0.18 ng/mL) and 17% EDTA (0.14 ng/mL). Doxycycline hydrochloride and propolis significantly enhanced the release of TGF-β1 from the dentin matrix compared to EDTA (P < 0.05). No significant difference was observed between doxycycline hydrochloride and propolis (P > 0.05). Doxycycline and propolis can be used as effective alternatives to EDTA during regenerative endodontic procedures.

Effect of benzalkonium chloride addition to EDTA on attachment and proliferation of dental pulp stem cells on dentin and on transforming growth factor-β1 release.

To investigate the effect of benzalkonium chloride (BAC) addition to ethylenediaminetetraacetic acid (EDTA) on transforming growth factor-β1 (TGF-β1) release, as well as attachment and proliferation of dental pulp stem cells (DPSCs) on dentin. A total of standard 268 human dentin disks were prepared and immersed in 1.5% sodium hypochlorite (NaOCl) for 5min. The disks were rinsed with distilled water and randomly divided into seven groups. In control group, the disks received no further treatment. The remaining disks were immersed in following solutions: 17% EDTA or 17% EDTA + 0.008% BAC for 1, 5 or 10min and rinsed with distilled water. DPSCs were seeded in part of the disks since the TGF-β1 release assay was performed with disks with and without cells. The attachment and proliferation of DPSCs on dentin disks were analyzed using lactate dehydrogenase activity and WST-1 assays, respectively. The cell morphology was observed by scanning electron microscopy. The release of TGF-β1 was quantified using ELISA. Data were analyzed using three- and two-way analysis of variance with Bonferroni corrections. Both EDTA solutions increased the attachment and proliferation of DPSCs (p < .05) while there was no significant difference between them (p > .05). The exposure time of both EDTA solutions had no influence on cell attachment, proliferation and TGF-β1 release (p > .05). There was no significant difference in TGF-β1 release between the control and experimental groups (p > .05). The amount of released TGF-β1 from dentin disks was similar whether or not they were seeded with cells (p > .05). Dentin treatment with either of the EDTA solutions had no effect on the amount of TGF-β1 release while both EDTA solutions improved cell attachment and proliferation on dentin surface regardless of exposure time.

Quantification of growth factors in advanced platelet-rich fibrin and concentrated growth factors and their clinical efficacy as adjunctive to the GTR procedure in periodontal intrabony defects.

The development of platelet concentrated biomaterials has gained increasing awareness for regenerative medicine. With different protocol, derivatives such as advanced platelet-rich fibrin (A-PRF), injected platelet-rich fibrin, and concentrated growth factor (CGF) have been demonstrated effectively in preclinical and clinical studies. The aim of this study was to compare the level of growth factors releasing from A-PRF and CGF, and their clinical efficacy in the regenerative management of intrabony defects (IBDs). Thirty-two blood samples were collected from eight healthy donors and assessed for platelet-derived growth factor-αβ, vascular endothelial growth factor, bone morphogenetic protein-2, and transforming growth factor-β1 release at indicated times. In addition, the clinical records of 45 patients (15 per group) who had undergone guided tissue regeneration (GTR) with or without A-PRF/CGF were retrieved. The probing depth (PD) and clinical attachment level (CAL) were recorded preoperatively and 6 months postoperatively. Intrabony component (IC) depth, radiographic bone level (RBL), and bone defect filling were assessed radiographically. A-PRF had a looser fibrin network than the CGF but presented larger amounts of growth factors with a more sustained release period. Although there was no difference in PD reduction, CAL gain, RBL height change and defect filling (%) between A-PRF and CGF group, both achieved a more favorable clinical result in IC height reduction and defect filling (%) than the control. A-PRF and CGF have the ability to stimulate a continual and steady release of total growth factors over a 14-day period. A-PRF and CGF show a similar effectiveness in periodontal bone regeneration with a potential benefit of improving GTR outcomes in IBD treatment.

PR448: Local anaesthetic in vitro effect on Transforming growth factor β1 release rate from platelets rich fibrin

PR448: Local anaesthetic in vitro effect on Transforming growth factor β1 release rate from platelets rich fibrin

Role of Non Androgenic Factors in Hair loss and Hair Regrowth

Multiple nutritional, environmental and lifestyle factors can directly affect hair follicles or weaken and make them sensitive to the action of androgens. Patients having hair fall, thinning and poor growth can be in early stages of androgenetic alopecia. Hair loss can be corrected and hair growth can be improved by addressing these nonandrogenic factors. Recent research has shown that androgens inhibit hair growth through release of Transforming Growth Factor (TGF) β1. Further study of this mechanism reveals that generation of Reactive Oxygen Species (ROS) induced by androgens leads to release of TGF β1, explaining benefit of antioxidants in hair growth. The binding of ROS also causes hair loss by altering the cellular proteins and converting them to new antigens targeted by inflammatory and immune systems. Calorie restriction and individual micronutrient deficiencies lead to a new process of intracellular destruction or autophagy before cell apoptosis, which could explain cessation of hair growth. Telogen is not a resting phase but now defined as active conservation of follicles under unfavourable conditions. Thus any stress, trauma, metabolic change or insult causes telogen. Micronutrients zinc, copper, selenium maintain immunity, control inflammation and preserve antioxidant activity of the cells. Vitamins A, C, D have a role in phagocytosis and antibodies maintaining resistance. Vitamin D3 modulates the hair-inductive capacity of dermal papilla cells. Vitamin and micronutrient deficiencies are prevalent among all the population of the world. Some nutritional supplementation is necessary to achieve day to day requirements. Nutritive value of the foods has reduced over the years by 30%. Endocrine Disrupting chemicals are creating further damage to the hormonal balance of the body. All these can be countered by a well-planned nutritional program which will also ensure strengthening and regrowth of hair follicles without the use of Finasteride.

Role of pH Changes on Transforming Growth Factor-β1 Release and on the Fibrin Architecture of Platelet-rich Fibrin When Layered with Biodentine, Glass Ionomer Cement, and Intermediate Restorative Material

IntroductionThe purpose of this study was to evaluate the influence of pH that is due to setting reaction of Biodentine, glass ionomer cement (GIC), and intermediate restorative material (IRM) on transforming growth factor-β1 (TGF-β1) release and on the fibrin architecture of platelet-rich fibrin (PRF). MethodsPRF was obtained from 8 volunteers and layered over the freshly prepared GIC, IRM, and Biodentine mixtures. TGF-β1 release was estimated by using enzyme-linked immunosorbent assay (ELISA), and fibrin structure of PRF was analyzed by using scanning electron microscope at 1 and 5 hours. ResultsBiodentine, GIC, and IRM increased the TGF-β1 release in comparison with that of control group (PRF alone) at both 1 and 5 hours. Biodentine released significantly more TGF-β1 than GIC and IRM at 1 hour. At 5 hours both GIC and Biodentine released significantly more TGF-β1 than IRM. The fibrin architecture of the Biodentine group was similar to that of control group at both 1 and 5 hours. In GIC and IRM groups the fibrillar structure of fibrin was collapsed, ill-defined, and cloudy with very thick fibers and irregularly reduced porosities. ConclusionsBiodentine induces larger amount of TGF-β1 release and also maintains the integrity of fibrin structure when compared with GIC and IRM when layered over PRF.

Association between shear stress and platelet-derived transforming growth factor-β1 release and activation in animal models of aortic valve stenosis.

Aortic valve stenosis (AS) is characterized by fibrosis and calcification of valves leading to aortic valve narrowing, resulting in high wall shear stress across the valves. We previously demonstrated that high shear stress can activate platelet-derived transforming growth factor-β1 (TGF-β1), a cytokine that induces fibrosis and calcification. The aim of this study was to investigate the role of shear-induced platelet release of TGF-β1 and its activation in AS. We studied hypercholesterolemic Ldlr(-/-)Apob(100/100)/Mttp(fl/fl)/Mx1Cre(+/+) (Reversa) mice that develop AS on Western diet and a surgical ascending aortic constriction mouse model that acutely simulates the hemodynamics of AS to study shear-induced platelet TGF-β1 release and activation. Reversa mice on Western diet for 6 months had thickening of the aortic valves, increased wall shear stress, and increased plasma TGF-β1 levels. There were weak and moderate correlations between wall shear stress and TGF-β1 levels in the progression and reversed Reversa groups and a stronger correlation in the ascending aortic constriction model in wild-type mice but not in mice with a targeted deletion of megakaryocyte and platelet TGF-β1 (Tgfb1(flox)). Plasma total TGF-β1 levels correlated with collagen deposition in the stenotic valves in Reversa mice. Although active TGF-β1 levels were too low to be measured directly, we found (1) canonical TGF-β1 (phosphorylated small mothers against decapentaplegic 2/3) signaling in the leukocytes and canonical and noncanonical (phosphorylated extracellular signal-regulated kinases 1/2) TGF-β1 signaling in aortic valves of Reversa mice on a Western diet, and (2) TGF-β1 signaling of both pathways in the ascending aortic constriction stenotic area in wild-type but not Tgfb1(flox) mice. Shear-induced, platelet-derived TGF-β1 activation may contribute to AS.

Sericin–carboxymethyl cellulose porous matrices as cellular wound dressing material

In this study, porous three-dimensional (3D) hydrogel matrices are fabricated composed of silk cocoon protein sericin of non-mulberry silkworm Antheraea mylitta and carboxymethyl cellulose. The matrices are prepared via freeze-drying technique followed by dual cross-linking with glutaraldehyde and aluminum chloride. The microstructure of the hydrogel matrices is assessed using scanning electron microscopy and biophysical characterization are carried out using Fourier transform infrared spectroscopy and X-ray diffraction. The transforming growth factor β1 release from the cross-linked matrices as a growth factor is evaluated by immunosorbent assay. Live dead assay and 3-[4,5-dimethylthiazolyl-2]-2,5-diphenyl tetrazolium bromide assay show no cytotoxicity of blended matrices toward human keratinocytes. The matrices support the cell attachment and proliferation of human keratinocytes as observed through scanning electron microscope and confocal images. Gelatin zymography demonstrates the low levels of matrix metalloproteinase 2 (MMP-2) and insignificant amount of MMP-9 in the culture media of cell seeded matrices. Low inflammatory response of the matrices is indicated through tumor necrosis factor alpha release assay. The results indicate that the fabricated matrices constitute 3D cell-interactive environment for tissue engineering applications and its potential use as a future cellular biological wound dressing material.

TGF Beta1 and TGF Beta2 and Their Role in Posthemorrhagic Hydrocephalus Following SAH and IVH

Posthemorrhagic hydrocephalus (pHC) is a serious complication following subarachnoid hemorrhage (SAH) and intraventricular hemorrhage (IVH). Besides known clinical predictors, different cytokines have drawn attention to the development of chronic hydrocephalus. Transforming growth factor (TGF) β1 and TGF β2 are involved in fibrogenesis, scar formation, cell survival, and tissue differentiation and may play a role in the occurrence of pHC. TGF β1 is stored in platelets in large amount and is released in the cerebrospinal fluid (CSF) after SAH and IVH. Both TGF β1 and TGF β2 can be expressed by various intracranial cells. TGF β1 and β2 were measured in CSF and blood samples of 42 patients with SAH or IVH with acute hydrocephalus during the first 10 days after ictus. Furthermore, albumin was measured in CSF as an indicator for the amount of blood. Patients were categorized as developing pHC requiring shunt treatment or not-developing pHC within 6 months. After adjusting for age, SAH resulted significantly more often in pHC than did IVH. Plasma levels of TGF β1 showed a marked increase over time, whereas CSF levels of TGF β1 constantly decreased. The time course of TGF β1 and albumin in CSF was paralleled and did not correlate with the development of shunt dependent pHC. Also, TGF β1 plasma concentrations did not correlate with shunt dependent pHC. TGF β2 concentrations in plasma showed stable values over time without any variations. TGF β2 in CSF described a parabolic course with a peak at day 6 after ictus. No correlation was found concerning TGF β2 in plasma or CSF and shunt dependent pHC. TGF β1 in CSF is derived by platelets from the cisternal or ventricular clot. TGF β2 in CSF is derived as a general reaction of traumatized brain tissue. These data do not confirm a crucial role of TGF β1 and TGF β2 release in the development of pHC.

Erratum to “Factors Influencing Oxidative Imbalance in Pulmonary Fibrosis: An Immunohistochemical Study”

The authors of the paper would like to apologize for the following errors contained in the original paper. 1. The exact Figure 1 in the original paper has to be corrected as Figure 1 in this paper. Figure 1 2. References in the original paper have to be corrected by adding the following: M. D. Oldfield, L. A. Bach, J. M. Forbes et al., “Advanced glycation end products cause epithelial-myofibroblast transdifferentiation via the receptor for advanced glycation end products (RAGE),” Journal of Clinical Investigation, vol. 108, no. 12, pp. 1853–1863, 2001. M. P. Wautier, O. Chappey, S. Corda, D. M. Stern, A. M. Schmidt, and J. L. Wautier, “Activation of NADPH oxidase by AGE links oxidant stress to altered gene expression via RAGE,” American Journal of Physiology, vol. 280, no. 5, pp. E685–E694, 2001. J. Zhao,W. Shi, Y. L.Wang et al., “Smad3 deficiency attenuates bleomycin-induced pulmonary fibrosis in mice,” American Journal of Physiology, vol. 282, no. 3, pp. L585–L593, 2002. V. J. Thannickal and B. L. Fanburg, “Activation of an H2O2-generating NADH oxidase in human lung fibroblasts by transforming growth factor β1,” Journal of Biological Chemistry, vol. 270, no. 51, pp. 30334–30338, 1995. A. Bellocq, E. Azoulay, S. Marullo et al., “Reactive oxygen and nitrogen intermediates increase transforming growth factor-β1 release from human epithelial alveolar cells through two different mechanisms,” American Journal of Respiratory Cell and Molecular Biology, vol. 21, no. 1, pp. 128–136, 1999. M. H. Barcellos-Hoff and T. A. Dix, “Redox-mediated activation of latent transforming growth factor-β1,” Molecular Endocrinology, vol. 10, no. 9, pp. 1077–1083, 1996. C. L. Fattman, “Apoptosis in pulmonary fibrosis: too much or not enough?” Antioxidants and Redox Signaling, vol. 10, no. 2, pp. 379–385, 2008. A. Bierhaus, T. Illmer, M. Kasper et al., “Advanced glycation end product (AGE)-mediated induction of tissue factor in cultured endothelial cells is dependent on RAGE,” Circulation, vol. 96, no. 7, pp. 2262–2271, 1997. V. Nilakantan, N. L. N. Halligan, T. K. Nguyen et al., “Post-translational modification of manganese superoxide dismutase in acutely rejecting cardiac transplants: role of inducible nitric oxide synthase,” Journal of Heart and Lung Transplantation, vol. 24, no. 10, pp. 1591–1599, 2005. H. M. Lander, J. M. Tauras, J. S. Ogiste, O. Hori, R. A. Moss, and A. M. Schmidt, “Activation of the receptor for advanced glycation end products triggers a p21(ras)-dependent mitogen-activated protein kinase pathway regulated by oxidant stress,” Journal of Biological Chemistry, vol. 272, no. 28, pp. 17810–17814, 1997. R. J. Folz and J. D. Crapo, “Extracellular superoxide dismutase (SOD3): tissue-specific expression, genomic characterization, and computer-assisted sequence analysis of the human EC SOD gene,” Genomics, vol. 22, no. 1, pp. 162–171, 1994. L. I. Wang, D. P. Miller, Y. Sai et al., “Manganese superoxide dismutase alanine-to-valine polymorphism at codon 16 and lung cancer risk,” Journal of the National Cancer Institute, vol. 93, no. 23, pp. 1818–1821, 2001.

Effect of various methods of platelet-rich plasma gel preparation on transforming growth factor-β1 release

Effect of various methods of platelet-rich plasma gel preparation on transforming growth factor-β1 release

Eotaxin-2/CCL24 and eotaxin-3/CCL26 exert differential profibrogenic effects on human lung fibroblasts

Eotaxin-2/CCL24 and eotaxin-3/CCL26 play an important role in eosinophil chemotaxis and activation in asthma. We previously demonstrated that eotaxin/CCL11 is profibrogenic for human lung fibroblasts. The effect of eotaxin-2/ CCL24 and eotaxin-3/CCL26 on lung fibroblasts has not yet been investigated. To evaluate whether eotaxin-2/CCL24 and eotaxin-3/CCL26 modulate fibrotic properties of lung fibroblasts. Fibroblast proliferation was evaluated by means of 3-hydroxythymidine incorporation. Collagen production was assessed by means of 3-hydroxyproline incorporation and biochemical staining. Chemotaxis was determined using Boyden chambers. Expression of alpha-smooth muscle actin was evaluated by means of immunostaining. Transforming growth factor beta1 release was assessed using enzyme-linked immunosorbent assay. Parametric analysis of variance, followed by the Tukey-Kramer multiple comparisons test, was used to calculate statistical significance. Eotaxin-2/CCL24 but not eotaxin-3/CCL26 stimulated human lung fibroblast proliferation and collagen synthesis. In contrast, eotaxin-3/CCL26 but not eotaxin-2/CCL24 promoted fibroblast migration. Neither eotaxin-2/CCL24 nor eotaxin-3/ CCL26 induced the expression of alpha-smooth muscle actin or transforming growth factor beta1 from lung fibroblasts. Eotaxin-2/CCL24 and eotaxin-3/CCL26 have differential profibrogenic effects on human lung fibroblasts. These CC chemokines may, therefore, contribute to airway remodeling in asthma.

Characterization of regulatory T cells identified as CD4+CD25highCD39+ in patients with active tuberculosis

Forkhead box P3 (FoxP3) is a transcription factor whose expression characterizes regulatory T cells (T(reg)), but it is also present on activated T cells, thus hindering correct T(reg) identification. Using classical markers for T(reg) recognition, discordant results were found in terms of T(reg) expansion during active tuberculosis (TB) disease. Recently CD39 has been shown to be an accurate marker for T(reg) detection. The objectives of this study were: (i) to identify T(reg) expressing CD39 in patients with TB and to compare the results with those obtained by the standard phenotypic markers; (ii) to evaluate if T(reg) are expanded in vitro by exogenous interleukin (IL)-2 or by antigen-specific stimulation; and (iii) to characterize T(reg) function on the modulation of antigen-specific responses. We enrolled 13 patients with pulmonary TB and 12 healthy controls. T(reg) were evaluated by flow cytometry ex vivo and after antigen-specific in vitro stimulation using CD25, FoxP3, CD127 and CD39 markers. Results indicate that CD39(+) cells within the CD4(+)CD25(high) cells have T(reg) properties (absence of interferon-gamma production and transforming growth factor-beta1 release upon stimulation). Ex vivo analysis did not show significant differences between TB patients and controls of T(reg) by classical or novel markers. In contrast, a significantly higher percentage of T(reg) was found in TB patients after antigen-specific stimulation both in the presence or absence of IL-2. Depletion of CD39(+) T(reg) increased RD1-specific responses significantly. In conclusion, CD39 is an appropriate marker for T(reg) identification in TB. These results can be useful for future studies to monitor Mycobacterium tuberculosis-specific response during TB.

Effect of Sulodexide on Plasma Transforming Growth Factor-β1 in Healthy Volunteers

It is unknown whether the glycosaminoglycan drug sulodexide interferes with transforming growth factor-beta1--a member of heparin-binding family and a potent regulator of human biology and diseases. Hence, a 2-week pilot study was performed in 11 healthy men. Sulodexide was initially administered intravenously in a single dose, then--orally for 12 days and--again intravenously on study completion. Initial injection had no effect on activated form of the growth factor measured in plasma after 10 and 120 min; no change was also observed after 120 min from drug ingestion on day 7. On final intravenous administration, the growth factor levels increased by almost 60% after 10 min and remained elevated; the 120-min levels directly correlated with sulodexide dosage. Baseline cytokine levels decreased during the 2-week trial by more than 50%. In conclusion, transforming growth factor-beta1 release and likely downregulation of its expression may constitute novel pharmacological effects of sulodexide.

Transforming Growth Factor-β1 Release from a Porous Electrostatic Spray Deposition–Derived Calcium Phosphate Coating

This study evaluated the utilization of a porous coating, derived with electrostatic spray deposition (ESD), as a carrier material for transforming growth factor-beta1 (TGF-beta1). A porous beta-tricalcium phosphate coating was deposited with ESD, and 10 ng of (125) I-labeled TGF-beta1 was loaded on the substrates. A burst release during the first hour of incubation of >90% was observed, in either culture medium or phosphate-buffered saline (PBS). Ninety-nine percent of the growth factor was released after 10 days of incubation. All samples were able to inhibit epithelial cell growth, indicating that the growth factor had remained bioactive after release. Thereafter, osteoblast-like cells were seeded upon substrates with or without 10 ng of TGF-beta1. While proliferation of osteoblast-like cells was increased on TGF-beta1-loaded substrates, differentiation was inhibited or delayed. In conclusion, a porous ESD-derived calcium phosphate coating can be used as a carrier material for TGF-beta1, when a burst release is desired.

Transforming Growth Factor β1 release by human adipose tissue is enhanced in obesity

The present studies examined the effect of obesity in humans on the release of transforming growth factor β1 (TGF- β1) by human adipose tissue. The regulation of TGF- β1 release by adipose tissue as well as the question of whether its release is due to the adipocytes or the nonfat cells in adipose tissue was also examined. There was a statistically significant ( r = 0.50) correlation between the body mass index of the fat donors and the subsequent release of TGF- β1 release by subcutaneous adipose tissue. There was also a positive correlation between total TGF- β1 release by adipose tissue explants and body fat content ( r = 0.69). The question of whether tumor necrosis factor α (TNF- α) and/or interleukin 1 β (IL-1 β) regulate the release of TGF- β1 was investigated by incubation of adipose tissue explants with a soluble human TNF- α receptor (etanercept) and a neutralizing antihuman IL-1 β antibody. The release of TGF- β1 over 48 hours by adipose tissue explants was significantly enhanced in the presence of both the inhibitor of TNF- α and of IL-1 β. It is of interest, in view of the elevated circulating insulin in blood of morbidly obese women, that the release of TGF- β1 by adipose tissue was enhanced in the presence of insulin. The question of whether the release of TGF- β1 by human adipose tissue explants was primarily due to adipocytes, as is the case for leptin, or the nonfat cells present in human adipose tissue, as is the case for IL-8 and prostaglandin E 2, was examined. The release of TGF- β1 was primarily by the nonfat cells of human adipose tissue because release by adipocytes was less than 10% of that by the nonfat cells of adipose tissue.

Transforming growth factor-β1 release from oligo(poly(ethylene glycol) fumarate) hydrogels in conditions that model the cartilage wound healing environment

This research demonstrates that controlled material degradation and transforming growth factor-β1 (TGF-β1) release can be achieved by encapsulation of TGF-β1-loaded gelatin microparticles within the biodegradable polymer oligo(poly(ethylene glycol) fumarate) (OPF), so that these microparticles function as both a digestible porogen and a delivery vehicle. Release studies performed with non-encapsulated microparticles confirmed that at normal physiological pH, TGF-β1 complexes with acidic gelatin, resulting in slow release rates. At pH 4.0, this complexation no longer persists, and TGF-β1 release is enhanced. However, by encapsulating TGF-β1-loaded microparticles in a network of OPF, release at either pH can be diffusionally controlled. For instance, after 28 days of incubation at pH 4.0, final cumulative release from non-encapsulated microparticles crosslinked in 10 and 40 mM glutaraldehyde (GA) was 75.4±1.6% and 76.6±1.1%, respectively. However, when either microparticle formulation was encapsulated in an OPF hydrogel (noted as OPF-10 mM and OPF-40 mM, respectively), these values were reduced to 44.7±14.6% and 47.4±4.7%. More interestingly, release studies, in conditions that model the expected collagenase concentration of injured cartilage, demonstrated that by altering the microparticle crosslinking extent and loading within OPF hydrogels, TGF-β1 release, composite swelling, and polymer loss could be systematically altered. Composites encapsulating less crosslinked microparticles (OPF-10 mM) exhibited 100% release after only 18 days and were completely degraded by day 24 in collagenase-containing phosphate-buffered saline (PBS). Hydrogels encapsulating 40 mM GA microparticles did not exhibit 100% release or polymer loss until day 28. Hydrogels with no microparticle component demonstrated only 79.3±9.2% release and 89.2±3.4% polymer loss after 28 days in enzyme-containing PBS. Accordingly, these studies confirm that the rate of TGF-β1 release and material degradation can be controlled by altering key parameters of these novel, in situ crosslinkable biomaterials, so that TGF-β1 release and scaffold degradation may be tailored to optimize cartilage repair.

LPS-sensory peptide communication in experimental cystitis.

Stimulation of sensory nerves can lead to release of peptides such as substance P (SP) and consequently to neurogenic inflammation. We studied the role of bacterial lipopolysaccharide (LPS) in regulating SP-induced inflammation. Experimental cystitis was induced in female mice by intravesical instillation of SP, LPS, or fluorescein-labeled LPS. Uptake of fluorescein-labeled LPS was determined by confocal analysis, and bladder inflammation was determined by morphological analysis. SP was infused into the bladders of some mice 24 h after exposure to LPS. In vitro studies determined the capacity of LPS and SP to induce histamine and cytokine release by the bladder. LPS was taken up by urothelial cells and distributed systemically. Twenty-four hours after instillation of LPS or SP, bladder inflammation was characterized by edema and leukocytic infiltration of the bladder wall. LPS pretreatment enhanced neutrophil infiltration induced by SP, increased in vitro release of histamine, tumor necrosis factor-alpha, and interferon-gamma, and significantly reduced transforming growth factor-beta1 release. These findings suggest that LPS amplifies neurogenic inflammation, thereby playing a role in the pathogenesis of neurogenic cystitis.

Inhibitory Effect of Tranilast on Hypertrophic Collagen Production in the Spontaneously Hypertensive Rat Heart

Tranilast, N-(3,4-dimethoxycinnamoyl) anthranilic acid, a widely used antiallergy drug in Japan, has been shown to inhibit transforming growth factor-β1 release from fibroblasts and reduce collagen synthesis in keloid cells. In the present study, we have investigated the effect of this drug on cardiac hypertrophy in spontaneously hypertensive rats (SHR), with a focus on the cardiac collagen matrix, which is associated with myocardial stiffness. Twenty-four-week-old SHRs and Wistar Kyoto rats (WKYs) were administered tranilast (300 mg/kg) orally once a day for 4 weeks. This treatment significantly suppressed increases in left ventricular collagen concentration (P<0.05) and the left ventricular weight / body weights ratios (P<0.05) in SHRs, and tranilast was ineffective on collagen concentration and ventricular weight / body weights ratios in WKYs. Tranilast did not affect systolic or diastolic blood pressure, end-diastolic left ventricular pressure and heart rate in both SHRs and WKYs, and the agent did not change positive dp/dt or cardiac output in SHRs. The pressure-volume relationship curve was shifted to the left by the drug; the slope (k) of the logarithm of the pressure-volume relationship curve was significantly increased (P<0.05) in SHRs. It is concluded that the suppression of increases in cardiac collagen and left ventricular mass by tranilast results in a corresponding prevention of cardiac stiffness as studied in the SHR.