Effect of magnetic microbeads on sustained and targeted delivery of transforming growth factor-beta-1 for rotator cuff healing in a rat rotator cuff repair model.

Structural failure is a well-established complication of rotator cuff repair procedures. To evaluate the effect of magnetic microbeads, designed for precise drug delivery via magnetic force, on sustained transforming growth factor-beta-1 (TGF-ß1) release and rotator cuff healing in a rat rotator cuff repair model. TGF-ß1 laden microbeads were prepared, and baseline in vitro experiments included the magnetization of the microbeads and TGF-ß1 release tests. In an in vivo experiment using a rat rotator cuff repair model on both shoulders, 72 rats were randomly assigned to three groups (24 per group): group A, conventional repair; group B, repair with and simple TGF-ß1 injection; and group C, repair with magnet insertion into the humeral head and TGF-ß1 laden microbead injection. Delivery of TGF-ß1 was evaluated at 1 and 7 days after the intervention using PCR, Western blot, and immunohistochemistry. At 6 weeks post-intervention, rotator cuff healing was assessed using biomechanical and histological analysis. The in vitro experiments confirmed the magnetization property of the microbeads and sustained delivery of TGF-ß1 for up to 10 days. No difference in the TGF-ß1 expression was found at day 1 in vivo. However, at day 7, group C exhibited a significantly elevated expression of TGF-ß1 in both PCR and Western blot analyses compared to groups A and B (all P < 0.05). Immunohistochemical analysis revealed a higher expression of TGF-ß1 at the repair site in group C on day 7. At 6 weeks, biomechanical analysis demonstrated a significantly higher ultimate failure load in group C than in groups A and B (P < 0.05) and greater stiffness than in group A (P = 0.045). In addition, histological analysis showed denser and more regular collagen fibers with complete continuity to the bone in group C than in groups A and B, a statistically significant difference according to the semi-quantitative scoring system (all P < 0.05). The use of the TGF-ß1 laden magnetic microbeads demonstrated sustained delivery of TGF-ß1 to the repair site, improving rotator cuff healing.

miR-29b Regulates TGF-ß1-Induced Epithelial-Mesenchymal Transition by Inhibiting Heat Shock Protein 47 Expression in Airway Epithelial Cells.

Tissue remodeling contributes to ongoing inflammation and refractoriness of chronic rhinosinusitis (CRS). During this process, epithelial-mesenchymal transition (EMT) plays an important role in dysregulated remodeling and both microRNA (miR)-29b and heat shock protein 47 (HSP47) may be engaged in the pathophysiology of CRS. This study aimed to determine the role of miR-29b and HSP47 in modulating transforming growth factor (TGF)-ß1-induced EMT and migration in airway epithelial cells. Expression levels of miR-29b, HSP47, E-cadherin, α-smooth muscle actin (α-SMA), vimentin and fibronectin were assessed through real-time PCR, Western blotting, and immunofluorescence staining. Small interfering RNA (siRNA) targeted against miR-29b and HSP47 were transfected to regulate the expression of EMT-related markers. Cell migration was evaluated with wound scratch and transwell migration assay. miR-29b mimic significantly inhibited the expression of HSP47 and TGF-ß1-induced EMT-related markers in A549 cells. However, the miR-29b inhibitor more greatly induced the expression of them. HSP47 knockout suppressed TGF-ß1-induced EMT marker levels. Functional studies indicated that TGF-ß1-induced EMT was regulated by miR-29b and HSP47 in A549 cells. These findings were further verified in primary nasal epithelial cells. miR-29b modulated TGF-ß1-induced EMT-related markers and migration via HSP47 expression modulation in A549 and primary nasal epithelial cells. These results suggested the importance of miR-29b and HSP47 in pathologic tissue remodeling progression in CRS.

Generation and characterization of cardiac valve endothelial-like cells from human pluripotent stem cells.

The cardiac valvular endothelial cells (VECs) are an ideal cell source that could be used for making the valve organoids. However, few studies have been focused on the derivation of this important cell type. Here we describe a two-step chemically defined xeno-free method for generating VEC-like cells from human pluripotent stem cells (hPSCs). HPSCs were specified to KDR+/ISL1+ multipotent cardiac progenitors (CPCs), followed by differentiation into valve endothelial-like cells (VELs) via an intermediate endocardial cushion cell (ECC) type. Mechanistically, administration of TGFb1 and BMP4 may specify VEC fate by activating the NOTCH/WNT signaling pathways and previously unidentified targets such as ATF3 and KLF family of transcription factors. When seeded onto the surface of the de-cellularized porcine aortic valve (DCV) matrix scaffolds, hPSC-derived VELs exhibit superior proliferative and clonogenic potential than the primary VECs and human aortic endothelial cells (HAEC). Our results show that hPSC-derived valvular cells could be efficiently generated from hPSCs, which might be used as seed cells for construction of valve organoids or next generation tissue engineered heart valves.

Type II alveolar epithelial cell-specific loss of RhoA exacerbates allergic airway inflammation through SLC26A4.

The small GTPase RhoA and its downstream effectors are critical regulators in the pathophysiological processes of asthma. The underlying mechanism, however, remains undetermined. Here, we generated an asthma mouse model with RhoA-conditional KO mice (Sftpc-cre;RhoAfl/fl) in type II alveolar epithelial cells (AT2) and demonstrated that AT2 cell-specific deletion of RhoA leads to exacerbation of allergen-induced airway hyperresponsiveness and airway inflammation with elevated Th2 cytokines in bronchoalveolar lavage fluid (BALF). Notably, Sftpc-cre;RhoAfl/fl mice showed a significant reduction in Tgf-ß1 levels in BALF and lung tissues, and administration of recombinant Tgf-ß1 to the mice rescued Tgf-ß1 and alleviated the increased allergic airway inflammation observed in Sftpc-cre;RhoAfl/fl mice. Using RNA sequencing technology, we identified Slc26a4 (pendrin), a transmembrane anion exchange, as the most upregulated gene in RhoA-deficient AT2 cells. The upregulation of SLC26A4 was further confirmed in AT2 cells of asthmatic patients and mouse models and in human airway epithelial cells expressing dominant-negative RHOA (RHOA-N19). SLA26A4 was also elevated in serum from asthmatic patients and negatively associated with the percentage of forced expiratory volume in 1 second (FEV1%). Furthermore, SLC26A4 inhibition promoted epithelial TGF-ß1 release and attenuated allergic airway inflammation. Our study reveals a RhoA/SLC26A4 axis in AT2 cells that functions as a protective mechanism against allergic airway inflammation.

Immunosuppressive PLGA TGF-ß1 Microparticles Induce Polyclonal and Antigen-Specific Regulatory T Cells for Local Immunomodulation of Allogeneic Islet Transplants.

Allogeneic islet transplantation is a promising cell-based therapy for Type 1 Diabetes (T1D). The long-term efficacy of this approach, however, is impaired by allorejection. Current clinical practice relies on long-term systemic immunosuppression, leading to severe adverse events. To avoid these detrimental effects, poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) were engineered for the localized and controlled release of immunomodulatory TGF-ß1. The in vitro co-incubation of TGF-ß1 releasing PLGA MPs with naïve CD4+ T cells resulted in the efficient generation of both polyclonal and antigen-specific induced regulatory T cells (iTregs) with robust immunosuppressive function. The co-transplantation of TGF-ß1 releasing PLGA MPs and Balb/c mouse islets within the extrahepatic epididymal fat pad (EFP) of diabetic C57BL/6J mice resulted in the prompt engraftment of the allogenic implants, supporting the compatibility of PLGA MPs and local TGF-ß1 release. The presence of the TGF-ß1-PLGA MPs, however, did not confer significant graft protection when compared to untreated controls, despite measurement of preserved insulin expression, reduced intra-islet CD3+ cells invasion, and elevated CD3+Foxp3+ T cells at the peri-transplantation site in long-term functioning grafts. Examination of the broader impacts of TGF-ß1/PLGA MPs on the host immune system implicated a localized nature of the immunomodulation with no observed systemic impacts. In summary, this approach establishes the feasibility of a local and modular microparticle delivery system for the immunomodulation of an extrahepatic implant site. This approach can be easily adapted to deliver larger doses or other agents, as well as multi-drug approaches, within the local graft microenvironment to prevent transplant rejection.

Oral Salmonella msbB Mutant as a Carrier for a Salmonella-Based Vaccine for Prevention and Reversal of Type 1 Diabetes.

A therapy that includes an oral vaccine for type 1 diabetes (T1D) using live attenuated Salmonella MvP728 (ΔhtrA/ΔpurD), cytokines (IL10 and TGFß) and preproinsulin (PPI) antigen in combination with a sub-therapeutic dose of anti-CD3 mAb was developed by our team. The vaccine combination therapy reduced insulitis and prevented and reversed diabetes in non-obese diabetic (NOD) mice. Here, we show the effectiveness of an alternative Salmonella mutant (ΔmsbB) as a carrier strain, which is anticipated to have lower risks of an inflammatory response and septicemia as a result of modification in the lipopolysaccharide (LPS) via detoxification of lipid A. This mutant strain proved to have highly reduced pathogenic side effects. Salmonella strain ΔmsbB expressed autoantigens and in combination with cytokines and anti-CD3 mAb, successfully prevented and reversed T1D to levels comparable to the previously used carrier strain ΔhtrA/ΔpurD. Additionally, the Salmonella msbB mutant resulted in higher rates of host cell infection. These results further demonstrate the potential of an oral Salmonella-based combined therapy in the treatment of early T1D.

In vitro assessment of anti-fibrotic drug activity does not predict in vivo efficacy in murine models of Duchenne muscular dystrophy.

AIM: Fibrosis is the most common complication from chronic diseases, and yet no therapy capable of mitigating its effects is available. Our goal is to unveil specific signaling regulating the fibrogenic process and to identify potential small molecule candidates that block fibrogenic differentiation of fibro/adipogenic progenitors. METHOD: We performed a large-scale drug screen using muscle-resident fibro/adipogenic progenitors from a mouse model expressing EGFP under the Collagen1a1 promotor. We first confirmed that the EGFP was expressed in response to TGFß1 stimulation in vitro. Then we treated cells with TGFß1 alone or with drugs from two libraries of known compounds. The drugs ability to block the fibrogenic differentiation was quantified by imaging and flow cytometry. From a two-rounds screening, positive hits were tested in vivo in the mice model for the Duchenne Muscular Dystrophy (mdx mice). The histopathology of the muscles was assessed with picrosirius red (fibrosis) and laminin staining (myofiber size). KEY FINDINGS: From the in vitro drug screening, we identified 21 drugs and tested 3 in vivo on the mdx mice. None of the three drugs significantly improved muscle histopathology. SIGNIFICANCE: The in vitro drug screen identified various efficient compounds, none of them strongly inhibited fibrosis in skeletal muscle of mdx mice. To explain these observations, we hypothesize that in Duchenne Muscular Dystrophy, in which fibrosis is a secondary event due to chronic degeneration and inflammation, the drugs tested could have adverse effect on regeneration or inflammation, balancing off any positive effects and leading to the absence of significant results.

A novel intramural TGF ß 1 hydrogel delivery method to decrease murine abdominal aortic aneurysm and rat aortic pseudoaneurysm formation and progression.

OBJECTIVES: Aneurysms are generally the result of dilation of all 3 layers of the vessel wall, and pseudoaneurysms are the result of localized extravasation of blood that is contained by surrounding tissue. Since there is still no recommended protocol to decrease aneurysm formation and progression, we hypothesised that intramural delivery of TGF ß1 hydrogel can decrease aneurysm and pseudoaneurysm formation and progression. MATERIALS: Male C57BL/6 J mice (12-14 wk), SD rats (200 g) and pig abdominal aortas were used, and hydrogels were fabricated by the interaction of sodium alginate (SA), hyaluronic acid (HA) and CaCO3. METHODS: A CaCl2 adventitial incubation model in mice and a decellularized human great saphenous vein patch angioplasty model in rats were used. TGF ß1 hydrogel was intramurally delivered after CaCl2 incubation in mice; at day 7, the abdomen in some mice was reopened, and TGF ß1 hydrogel was injected intramurally into the aorta. In rats, TGF ß1 hydrogel was delivered intramurally after patch angioplasty completion. Tissues were harvested at day 14 and analysed by histology and immunohistochemistry staining. The pig aorta was also intramurally injected with hydrogel. RESULTS: In mice, rhodamine hydrogel was still found between the medium and adventitia at day 14. In the mouse aneurysm model, there was a thicker wall and smaller amount of elastin breaks in the TGF ß1 hydrogel-delivered groups both at day 0 and day 7 after CaCl2 incubation, and there were larger numbers of p-smad2- and TAK1-positive cells in the TGF ß1 hydrogel-injected groups. In the rat decellularized human saphenous vein patch pseudoaneurysm model, there was a higher incidence of pseudoaneurysm formation when the patch was decellularized using 3% SDS, and delivery of TGF ß1 hydrogel could effectively decrease the formation of pseudoaneurysm formation and increase p-smad2 and TAK1 expression. In pig aortas, hydrogels can be delivered between the medium and adventitia easily and successfully. CONCLUSIONS: Intramural delivery of TGF ß1 hydrogel can effectively decease aneurysm and pseudoaneurysm formation and progression in both mice and rats, and pig aortas can also be successfully intramurally injected with hydrogel. This technique may be a promising drug delivery method and therapeutic choice to decrease aneurysm and pseudoaneurysm formation and progression in the clinic.

[High-frequency ultrasonography for evaluation of the urethral stricture model in rats].

OBJECTIVE: To explore the methodology for the establishment of the urethral stricture model in rats, the methods of end-point imaging evaluation of the model establishment and their efficiency. METHODS: Twenty-four adult male rats were randomly divided into a blank control (n = 6) and a model group (n = 18), and the model was established by cutting the penile segment of the urethra to induce incomplete urethral rupture. Then the model rats were treated by injection of transforming growth factor-ß1 (the TGF group, n = 6) or mesenchymal stem cells (the MSC group, n = 12) into the urethral cavernosum. At 4 weeks after modeling, the urethral condition of all the rats was evaluated blindly using high-frequency ultrasound combined with water bath, followed by comparison among different groups. RESULTS: Compared with the blank controls, the model rats showed evident urethral stricture, with more significant urethral fibrous tissue hyperplasia in the TGF than in the MSC group. Ultrasonography revealed significantly narrowed echo strips (P < 0.01), decreased echo intensity and blurred echoes in some strips. The grouping of the model rats according to the assigned values to the ultrasonographic changes was consistent with the actual condition. The area under the ROC curve for distinguishing between the TGF and MSC groups was 0.972, with a sensitivity of 100.0% and a specificity of 83.3% when ultrasound assignment score was 7.5. CONCLUSIONS: High-frequency ultrasonography combined with water bath is effective for evaluating urethral stricture in rats and may give some guidance in the establishment of the urethral stricture model.

Development of a microfluidic approach for the real-time analysis of extrinsic TGF-ß signalling.

Autocrine and paracrine signalling are traditionally difficult to study due to the sub-micromolar concentrations involved. This has proven to be especially limiting in the study of embryonic stem cells that rely on such signalling for viability, self-renewal, and proliferation. Microfluidics allows to achieve local concentrations of ligands representative of the in vivo stem cell niche, gaining more precise control over the cell microenvironment, as well as to manipulate ligands availability with high temporal resolution and minimal amount of reagents. Here we developed a microfluidics-based system for monitoring the dynamics of TGF-ß pathway activity by means of a SMAD2/3-dependent luciferase reporter. We first validated our system by showing dose-dependent transcriptional activation. We then tested the effects of pulsatile stimulation and delayed inhibition of TGF-ß activity on signalling dynamics. Finally, we show that our microfluidic system, unlike conventional culture systems, can detect TGF-ß ligands secreted in the conditioned medium from hESCs.

Assessment of transporter-mediated efflux of nintedanib using in vitro cell line models of idiopathic pulmonary fibrosis.

Objective: We aimed to investigate the involvement of efflux transporters, including multidrug resistant protein 1 (MDR1), multidrug resistance-associated protein 1 (MRP1), MRP2, and breast cancer resistance protein (BCRP), in the intracellular accumulation of the antifibrotic agent nintedanib in fibrotic lung cells. Methods: We used transforming growth factor-ß1 (TGF-ß1)-treated human lung fibroblasts (WI-38) and alveolar epithelial cells (A549) as in vitro models. The expression and activities of efflux transporters in TGF-ß1-treated WI-38 and A549 cells were evaluated using immunoblotting and flow cytometry. Cells were treated with nintedanib and then incubated with inhibitors of these transporters. The intracellular concentration of nintedanib was determined. Results: MDR1, MRP1, MRP2, and BCRP were found to be expressed in WI-38 and A549 cells with or without TGF-ß1 stimulation, with the exception of MRP2 in WI-38 cells. The efflux activities of these transporters were observed in these cells. MDR1 inhibitors significantly increased the intracellular accumulation of nintedanib, whereas MRP inhibitors did not show an effect. The BCRP inhibitor significantly increased the transporter activity in A549 cells but not in WI-38 cells. Conclusion: This study suggests that the efflux via MDR1 and BCRP is involved in the intracellular accumulation of nintedanib in fibrotic lung cells.

MiR-200b/c family inhibits renal fibrosis through modulating epithelial-to-mesenchymal transition via targeting fascin-1/CD44 axis.

BACKGROUND: Renal fibrosis is the characteristic of all kinds of chronic kidney diseases (CKDs). Fascin-1 plays an important role in tumor development, but the roles of fascin-1 in renal fibrosis have not been studied. Here, we explored the role of fascin-1 in renal fibrosis and the potential mechanisms. METHODS: Kidney unilateral ureteral obstruction (UUO) mouse model was used as an in vivo model, and proximal tubule epithelial cell lines treated with TGF-ß1 were used as in vitro model of renal fibrosis. Cell transfection was performed to manipulate the expression of miR-200b/c, fascin-1 and CD44. Western blotting, qRT-PCR, immunohistochemistry or immunofluorescence assays were used to measure levels of miR-200b/c, fascin-1, CD44, and fibrosis and EMT-related markers. H&E and Masson stainings were used to examine the degree of injury and fibrosis in kidneys. Dual luciferase assay was used to examine the interaction between miR-200b/c family and fascin-1. RESULTS: Fascin-1 and CD44 levels were both significantly up-regulated while miR-200b/c family was reduced in models of renal fibrosis. Furthermore, overexpression of miR-200b/c family and inhibition of fascin-1 or CD44 ameliorated renal fibrosis through suppressing EMT process. Mechanistically, miR-200b/c family directly and negatively regulated the expression of fascin-1. Overexpression of fascin-1 could reverse the effects of miR-200b/c family on renal fibrosis, and fascin-1 regulated renal fibrosis by activating CD44. CONCLUSION: Our study is the first to show that fascin-1 plays a critical role in renal fibrosis. MiR-200b/c family could inhibit renal fibrosis through modulating EMT process by directly targeting fascin-1/CD44 axis.

The anti-fibrotic and anti-inflammatory effects of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b] pyriine-3-carbonitrile in corneal fibroblasts.

BACKGROUND: Although several studies had addressed the anti-inflammatory effects of derivatives of 4H-chromene and chromeno[2,3-b]pyridine in the different types of cells, whether these derivatives would exert beneficial anti-fibrotic effects during corneal fibrotic scar formation was unclear. METHODS: We examined the cyclooxygenase-2 (COX-2) expression of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile (N1) in the human corneal fibroblasts (HCFs) under the treatment TGF-ß1. Signaling pathways underlying the mechanism of the N1 effect on the HCFs were determined. RESULTS: Application of N1 significantly decreased COX-2 expression after 2 h and 4 h in the HCFs stimulated with TGF-ß1. Notably, reduced production of extracellular matrix proteins under N1 treatment was found, including fibronectin, collagen I, and matrix metallopeptidase 9. Immunoblot analysis showed that treatment with N1 significantly attenuated phosphorylation of both STAT3 and Smad 2 in the TGF-ß1-stimulated HCFs. Upregulated mRNA of Smad2 and downregulated mRNA of Smad3 were observed using the quantitative real-time polymerase chain reaction. In addition, N1 induced significant increases in HO-1 and Nrf2 expression, but inhibited phosphorylation of NF-κB in the HCFs treated with TGF-ß1. CONCLUSIONS: Our findings show for the first time that N1 exerts anti-fibrotic and anti-inflammatory effects through suppression of COX-2, Smad2, STAT3, iNOS and NF-κB expressions as well as upregulation of Nrf2 and HO-1 expressions, which suggests they are potential therapeutic targets in the treatment of corneal fibrosis.

Airway epithelial specific deletion of Jun-N-terminal kinase 1 attenuates pulmonary fibrosis in two independent mouse models.

The stress-induced kinase, c-Jun-N-terminal kinase 1 (JNK1) has previously been implicated in the pathogenesis of lung fibrosis. However, the exact cell type(s) wherein JNK1 exerts its pro-fibrotic role(s) remained enigmatic. Herein we demonstrate prominent activation of JNK in bronchial epithelia using the mouse models of bleomycin- or AdTGFß1-induced fibrosis. Furthermore, in lung tissues of patients with idiopathic pulmonary fibrosis (IPF), active JNK was observed in various regions including type I and type II pneumocytes and fibroblasts. No JNK activity was observed in adjacent normal tissue or in normal control tissue. To address the role of epithelial JNK1, we ablated Jnk1 form bronchiolar and alveolar type II epithelial cells using CCSP-directed Cre recombinase-mediated ablation of LoxP-flanked Jnk1 alleles. Our results demonstrate that ablation of Jnk1 from airway epithelia resulted in a strong protection from bleomycin- or adenovirus expressing active transforming growth factor beta-1 (AdTGFß1)-induced fibrosis. Ablation of the Jnk1 allele at a time when collagen increases were already present showed a reversal of existing increases in collagen content. Epithelial Jnk1 ablation resulted in attenuation of mesenchymal genes and proteins in lung tissue and preserved expression of epithelial genes. Collectively, these data suggest that epithelial JNK1 contributes to the pathogenesis of pulmonary fibrosis. Given the presence of active JNK in lungs from patients with IPF, targeting JNK1 in airway epithelia may represent a potential treatment strategy to combat this devastating disease.

Role of hypoxia in skeletal muscle fibrosis: Synergism between hypoxia and TGF-ß signaling upregulates CCN2/CTGF expression specifically in muscle fibers.

Several skeletal muscle diseases are characterized by fibrosis, the excessive accumulation of extracellular matrix. Transforming growth factor-ß (TGF-ß) and connective tissue growth factor (CCN2/CTGF) are two profibrotic factors augmented in fibrotic skeletal muscle, together with signs of reduced vasculature that implies a decrease in oxygen supply. We observed that fibrotic muscles are characterized by the presence of positive nuclei for hypoxia-inducible factor-1α (HIF-1α), a key mediator of the hypoxia response. However, it is not clear how a hypoxic environment could contribute to the fibrotic phenotype in skeletal muscle. We evaluated the role of hypoxia and TGF-ß on CCN2 expression in vitro. Fibroblasts, myoblasts and differentiated myotubes were incubated with TGF-ß1 under hypoxic conditions. Hypoxia and TGF-ß1 induced CCN2 expression synergistically in myotubes but not in fibroblasts or undifferentiated muscle progenitors. This induction requires HIF-1α and the Smad-independent TGF-ß signaling pathway. We performed in vivo experiments using pharmacological stabilization of HIF-1α or hypoxia-induced via hindlimb ischemia together with intramuscular injections of TGF-ß1, and we found increased CCN2 expression. These observations suggest that hypoxic signaling together with TGF-ß signaling, which are both characteristics of a fibrotic skeletal muscle environment, induce the expression of CCN2 in skeletal muscle fibers and myotubes.

TGF-ß1 promoted the infection of bovine mammary epithelial cells by Staphylococcus aureus through increasing expression of cells' fibronectin and integrin ß1.

Mastitis is a disease that affects dairy cattle and causes a decline in milk quality as well as economic loss worldwide. TGF-ß1 levels are usually increased during mastitis; however, it is unknown whether TGF-ß1 is involved in bovine mastitis. Therefore, this study evaluated the effects of TGF-ß1 on the susceptibility of bovine mammary epithelial cells (BMECs) to Staphylococcus aureus (S. aureus). The results revealed that S. aureus adhesion to and invasion of BMECs was significantly increased after cells were treated with TGF-ß1. Adhesion of S. aureus to BMECs was increased dramatically by upregulation of fibronectin (Fn) and integrin ß1 (ITGB1), while the increase in the susceptibility of BMECs to S. aureus was blocked by specific antibodies against either Fn or ITGB1. These results indicated that adhesion and invasion were increased by TGF-ß1-induced upregulation of both Fn and ITGB1. Furthermore, TGF-ß1 treatment prior to S. aureus infection significantly increased S. aureus colonization as well as Fn and ITGB1 expression in the mammary glands of mice. These results suggest that TGF-ß1 promoted the expression of Fn and ITGB1 on the surface of BMECs and contributed to mammary gland infection in vitro and in vivo. The results of this study imply that Fn and ITGB1 may be useful therapeutic targets for the treatment of mastitis in dairy cows.

An injectable heparin-conjugated hyaluronan scaffold for local delivery of transforming growth factor ß1 promotes successful chondrogenesis.

Cartilage lacks basic repair mechanisms and thus surgical interventions are necessary to treat lesions. Minimally-invasive arthroscopic procedures require the development of injectable biomaterials to support chondrogenesis of implanted cells. However, most cartilage tissue engineering approaches rely on pre-culture of scaffolds in media containing growth factors (GFs) such as transforming growth factor (TGF)-ß1, which are crucial for cartilage formation and homeostasis. GFs media-supplementation is incompatible with injectable approaches and has led to a knowledge gap about optimal dose of GFs and release profiles needed to achieve chondrogenesis. This study aims to determine the optimal loading and release kinetics of TGF-ß1 bound to an engineered GAG hydrogel to promote optimal cartilaginous matrix production in absence of TGF-ß1 media-supplementation. We show that heparin, a GAG known to bind a wide range of GFs, covalently conjugated to a hyaluronan hydrogel, leads to a sustained release of TGF-ß1. Using this heparin-conjugated hyaluronan hydrogel, 0.25 to 50 ng TGF-ß1 per scaffold was loaded and cell viability, proliferation and cartilaginous matrix deposition of the encapsulated chondroprogenitor cells were measured. Excellent chondrogenesis was found when 5 ng TGF-ß1 per scaffold and higher were used. We also demonstrate the necessity of a sustained release of TGF-ß1, as no matrix deposition is observed upon a burst release. In conclusion, our biomaterial loaded with an optimal initial dose of 5 ng/scaffold TGF-ß1 is a promising injectable material for cartilage repair, with potentially increased safety due to the low, locally administered GF dose. STATEMENT OF SIGNIFICANCE: Cartilage cell-based products are dependent on exogenous growth factor supplementation in order for proper tissue maturation. However, for a one-step repair of defects without need for expensive tissue maturation, an injectable, growth factor loaded formulation is required. Here we show development of an injectable hyaluronan hydrogel, which achieves a sustained release of TGF-ß1 due to covalent conjugation of heparin. These grafts matured into cartilaginous tissue in the absence of growth factor supplementation. Additionally, this system allowed us to screen TGF-ß1 concentrations to determine the mimimum amount of growth factor required for chondrogenesis. This study represents a critical step towards development of a minimally-invasive, arthroscopic treatment for cartilage lesions.

Dendrimer-Based Platform for Effective Capture of Tumor Cells after TGFß1-Induced Epithelial-Mesenchymal Transition.

Detection of circulating tumor cells (CTCs) relying on their expression of epithelial cell markers, such as epithelial cell adhesion molecule (EpCAM), has been commonly used. However, this approach unlikely captures CTCs that have undergone the process of epithelial-mesenchymal transition (EMT). In this study, we have induced EMT of in vitro prostate (PCa) and breast cancer (BCa) cell lines by treatment of transforming growth factor ß 1 (TGFß1), a pleiotropic cytokine with transition-regulating activities. We found that the TGFß1-treated, post-EMT cells exhibited up to a 45% reduction in binding affinity to antibodies against EpCAM (aEpCAM). To overcome this limitation, we designed our capture platform that integrates a unique combination of biomimetic cell rolling, dendrimer-mediated multivalent binding, and antibody cocktails of aEpCAM/aEGFR/aHER-2. Our capture surfaces resulted in up to 98% capture efficiency of post-EMT cells from mixtures of TGFß1-treated and untreated cancer cells spiked in culture media and human blood. In a clinical pilot study, our CTC device was also able to capture rare CTCs from PCa patients with significantly enhanced capture sensitivity and purity compared to the control surface with aEpCAM only, demonstrating its potential to provide a reliable detection solution for CTCs regardless of their EMT status.

Circulating transforming growth factor-ß1 facilitates remyelination in the adult central nervous system.

Oligodendrocyte maturation is necessary for functional regeneration in the CNS; however, the mechanisms by which the systemic environment regulates oligodendrocyte maturation is unclear. We found that Transforming growth factor (TGF)-ß1, which is present in higher levels in the systemic environment, promotes oligodendrocyte maturation. Oligodendrocyte maturation was enhanced by adult mouse serum treatment via TGF-ß type I receptor. Decrease in circulating TGF-ß1 level prevented remyelination in the spinal cord after toxin-induced demyelination. TGF-ß1 administration promoted remyelination and restored neurological function in a multiple sclerosis animal model. Furthermore, TGF-ß1 treatment stimulated human oligodendrocyte maturation. These data provide the therapeutic possibility of TGF-ß for demyelinating diseases.

Microcarriers Based on Glycosaminoglycan-Like Marine Exopolysaccharide for TGF-ß1 Long-Term Protection.

Articular cartilage is an avascular, non-innervated connective tissue with limited ability to regenerate. Articular degenerative processes arising from trauma, inflammation or due to aging are thus irreversible and may induce the loss of the joint function. To repair cartilaginous defects, tissue engineering approaches are under intense development. Association of cells and signalling proteins, such as growth factors, with biocompatible hydrogel matrix may lead to the regeneration of the healthy tissue. One current strategy to enhance both growth factor bioactivity and bioavailability is based on the delivery of these signalling proteins in microcarriers. In this context, the aim of the present study was to develop microcarriers by encapsulating Transforming Growth Factor-ß1 (TGF-ß1) into microparticles based on marine exopolysaccharide (EPS), namely GY785 EPS, for further applications in cartilage engineering. Using a capillary microfluidic approach, two microcarriers were prepared. The growth factor was either encapsulated directly within the microparticles based on slightly sulphated derivative or complexed firstly with the highly sulphated derivative before being incorporated within the microparticles. TGF-ß1 release, studied under in vitro model conditions, revealed that the majority of the growth factor was retained inside the microparticles. Bioactivity of released TGF-ß1 was particularly enhanced in the presence of highly sulphated derivative. It comes out from this study that GY785 EPS based microcarriers may constitute TGF-ß1 reservoirs spatially retaining the growth factor for a variety of tissue engineering applications and in particular cartilage regeneration, where the growth factor needs to remain in the target location long enough to induce robust regenerative responses.