Unconjugated
To explore the repairing effect of combination of adipose stem cells (ASCs) and composite scaffolds on CWR, the electrospun Poly 1, 8-octanediol-co-citric acid (POC)-poly-L-lactide acid (PLA) composite scaffolds were prepared, followed by in vitro and in vivo biocompatibility evaluation of the scaffolds. Afterwards, ASCs were seeded on POC-PLA to construct the POC-PLA-ASCs scaffolds, and the POC-PLA, POC-PLA-ASCs, and traditional materials expanded polytetrafluoroethylene (ePTFE) were adopt for CWR in New Zealand white (NZW) rabbit models. As results, the POC-PLA-ASCs patches possessed good biocompatibility as the high proliferation ability of cells surrounding the patches. Rabbits in POC-PLA-ASCs groups showed better pulmonary function, less pleural adhesion, higher degradation rate and more neovascularization when compared with that in other two groups. The results of western blot indicated that POC-PLA-ASCs patches accelerated the expression of VEGF and Collagen I in rabbit models. From the above, our present study demonstrated that POC-PLA material was applied for CWR successfully, and ASCs seeded on the sheets could improve the pleural adhesions and promote the reparation of chest wall defects.
To investigate the effects of Mg-6Zn alloy on the healing of the common bile duct (CBD), Mg-6Zn alloy stents were implanted into the CBDs of rabbits. Stainless steel stents were transplanted into a second group of rabbits to serve as a control. Computed tomography (CT) scanning was performed and weight loss was recorded to evaluate the in vivo degradation process. Hematoxylin and eosin staining and immunohistochemical analyses were performed to determine the expressions of transforming growth factor (TGF)-β, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) and evaluate CBD healing. The Mg-6Zn stents maintained ~82 and ~50% of the original length, and ~90 and ~43% of the original CT value at 1 and 2 weeks post-operatively, respectively. The residual weights of the Mg-6Zn stents were ~89, ~42 and ~9% of the original weights at 1, 2 and 3 weeks post-operatively, respectively. At 3 weeks post-surgery, the CBD was completely healed, with no wounds observed in the 3 groups. VEGF expression in the Mg-6Zn stent group was lower than that in the stainless steel stent group at 3 weeks post-surgery (P=0.002). No significant differences were observed between the mean expressions of the TGF-β1 and bFGF genes at 1 and 2 weeks post-surgery. The results of the present study suggest that degradation of the Mg-6Zn alloy may not affect healing of the CBD.
Although peroxisome proliferator-activated receptor (PPAR)-α has been reported to be involved in preventing acute lung injury (ALI), the molecular regulation of post‑ALI lung recovery remains to be fully elucidated. The aim of the present study was to characterize the mechanism by which PPAR‑α prevents ALI and examine the role of PPAR‑α in the recovery of lung function following acute respiratory distress syndrome (ARDS). Reverse transcription‑quantitative‑polymerase chain reaction and western blot analyses suggested that PPAR‑α was effective in suppressing transforming growth factor (TGF)‑β1 in HLF cells and RAW 264.7 cells. In an ALI mouse model, PPAR‑α treatment prior to stimulation with lipopolysaccharide (LPS) resulted in a decrease in the expression of TGF‑β1 in bronchoalveolar lavage fluid (BALF), peripheral blood and splenocytes. The injection of a virus expressing short hairpin PPAR‑α into mice following LPS treatment resulted in a dose‑dependent increase in lung resistance index and decrease in dynamic compliance, and a significant increase in BALF protein, which indicated PPAR‑α was essential for the recovery of lung function following ALI. Of note, the serum expression of PPAR‑α was inversely correlated with TGF‑β1 and negatively correlated with disease severity in patients with ARDS. These data suggested that PPAR‑α was essential for the recovery of lung function following ALI by the suppression of TGF‑β1, which reveals a previously unappreciated mechanism controlling post‑ALI lung recovery.
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and fatal fibrotic lung disease characterized by profound changes in stem cell differentiation, epithelial cell phenotypes and fibroblast proliferation. In our study, we found that miR-497-5p was significantly upregulated both during myofibroblast differentiation of lung resident mesenchymal stem cells (LR-MSCs) and in the lung tissues of a pulmonary fibrosis model. In addition, as determined by luciferase assays and Western blot analysis, reversion-inducing cysteine-rich protein with kazal motifs (Reck) was identified to be one of the target genes of miR-497-5p, and Reck could suppress the expression of matrix metalloproteinase-2 (Mmp2) and Mmp9, which could activate latent transforming growth factor-β1 (TGF-β1). To test the potential therapeutic significance of this miRNA, we modulated the expression of miR-497-5p in LR-MSCs and relevant animal models. The results demonstrated that upregulation of miR-497-5p could induce LR-MSCs to differentiate into myofibroblasts and promote pulmonary fibrogenesis, while inhibition of its expression could effectively retard these processes. In conclusion, our work supports that controlling pulmonary fibrogenesis via inhibition of miR-497-5p expression may provide a potential therapeutic strategy for IPF.
Preserving a patient's own teeth-even in a difficult situation-is nowadays preferable to surgical intervention and therefore promotes development of suitable dental repair materials. Biodentine®, a mineral trioxide aggregate substitute, has been used to replace dentine in a bioactive and biocompatible manner in both the dental crown and the root. The aim of our study was to evaluate the influence of Biodentine® on pulp fibroblasts in vitro. For this study, one to five Biodentine® discs with a diameter of 5.1mm were incubated in DMEM. To obtain Biodentine® suspensions the media were collected and replaced with fresh medium every 24h for 4 days. Primary pulp cells were isolated from freshly extracted wisdom teeth of 20-23 year old patients and incubated with the Biodentine® suspensions. Proliferation, cell morphology, cell integrity and cell viability were monitored. To evaluate the effect of Biodentine® on collagen type I synthesis, the secretion of the N-terminal domain of pro-collagen type I (P1NP) and the release of transforming growth factor-β1 (TGF-β1) were quantified. None of the Biodentine® suspensions tested influenced cell morphology, proliferation or cell integrity. The cell viability varied slightly depending on the suspension used. However, the concentrations of P1NP of all pulp fibroblast cultures treated for 24h with the moderate to high Biodentine® concentration containing suspensions of day 1 were reduced to 5% of the control. Furthermore, a significant TGF-β1 reduction was observed after treatment with these suspensions. It could be shown that Biodentine® is biocompatible. However, dissolved particles of the moderate to high concentrated Biodentine® suspensions 24h after mixing induce a significant reduction of TGF-β1 release and reduce the secretion of collagen type I of primary pulp fibroblasts.
Tumor-associated macrophages (TAMs) are enriched in gliomas and help create a tumor-immunosuppressive microenvironment. A distinct M2-skewed type of macrophages makes up the majority of glioma TAMs, and these cells exhibit pro-tumor functions. Gliomas contain large hypoxic areas, and the presence of a correlation between the density of M2-polarized TAMs and hypoxic areas suggests that hypoxia plays a supportive role during TAM recruitment and induction. Here, we investigated the effects of hypoxia on human macrophage recruitment and M2 polarization. We also investigated the influence of the HIF inhibitor acriflavine (ACF) on M2 TAM infiltration and tumor progression in vivo. We found that hypoxia increased periostin (POSTN) expression in glioma cells and promoted the recruitment of macrophages. Hypoxia-inducible POSTN expression was increased by TGF-α via the RTK/PI3K pathway, and this effect was blocked by treating hypoxic cells with ACF. We also demonstrated that both a hypoxic environment and hypoxia-treated glioma cell supernatants were capable of polarizing macrophages toward a M2 phenotype. ACF partially reversed the M2 polarization of macrophages by inhibiting the upregulation of M-CSFR in macrophages and TGF-β in glioma cells under hypoxic conditions. Administering ACF also ablated tumor progression in vivo. Our findings reveal a mechanism that underlies hypoxia-induced TAM enrichment and M2 polarization and suggest that pharmacologically inhibiting HIFs may reduce M2-polarized TAM infiltration and glioma progression.
In order to explore the potential effects of interleukin (IL)-35 on IL-10, transforming growth factor-β (TGF-β), interferon-γ (INF)-γ, IL-12 and IL-17, a pcDNA3.1‑IL-35 plasmid was injected into the vitreous cavity of BALB/c mice. Enzyme-linked immunosorbent assay, western blot analysis and quantitative PCR analysis were performed to confirm the successful expression of IL-35. Slit-lamp biomicroscopy, hematoxylin and eosin staining and immunofluorescence were employed to detect the status of eyes, and western blot analysis was performed to examine the expression of corneal graft rejection-related cytokines. There were no abnormalities in the eyes pre-mydriasis or post-mydriasis and no injuries to the cornea or retina following the injection of IL-35-expressing plasmid. An immunofluorescence assay detected the positive expression of IL-35 in corneal epithelial cells from IL-35‑injected mice and negative staining in the control group. Further study revealed that IL-35 enhanced the expression of IL-10 and TGF-β which reached their highest levels at 1 and 2 weeks after injection, respectively (p<0.01). Moreover, the expression of INF-γ and IL-12 was decreased significantly at 2 weeks after the injection of IL-35-expressing plasmid (p<0.05), and the expression of IL-17 was suppressed notably at 4 weeks after the injection (p<0.05). The intravitreal injection of IL-35-expressing plasmid in mice downregulates the expression of pro-inflammatory cytokines and upregulates the expression of anti-inflammatory cytokines. Thus, IL-35 may further be assessed as a potential target for the treatment of corneal graft rejection.
The angiogenic switch is an important oncogenic step that determines whether microtumors remain dormant or progresses further. It has been generally perceived that the primary function of this tumorgenic event is to supply oxygen and nutrients through blood circulation. Using in vivo imaging of zebrafish and mouse tumor models, we showed that endothelial cords aggressively penetrated into microtumors and remained non-circulatory for several days before undergoing vascular blood perfusion. Unexpectedly, we found that initial tumor growth in both models was significantly reduced if endothelial cords were removed by blocking VEGF-VEGFR2 signaling or using a vascular deficient zebrafish mutant. It was further shown that soluble factors including IL-8, secreted by endothelial cells (ECs) were responsible for stimulating tumor cells proliferation. These findings establish that tumor angiogenesis play a much earlier and broader role in promoting tumor growth, which is independent of vascular circulation. Understanding this novel mechanism of angiogenic tumor progression offers new entry points for cancer therapeutics.
Human muscle-derived progenitor cells (hMDPCs) offer great promise for muscle cell-based regenerative medicine; however, prolonged ex-vivo expansion using animal sera is necessary to acquire sufficient cells for transplantation. Due to the risks associated with the use of animal sera, the development of a strategy for the ex vivo expansion of hMDPCs is required. The purpose of this study was to investigate the efficacy of using platelet-rich plasma (PRP) for the ex-vivo expansion of hMDPCs. Pre-plated MDPCs, myoendothelial cells, and pericytes are three populations of hMDPCs that we isolated by the modified pre-plate technique and Fluorescence Activated Cell Sorting (FACS), respectively. Pooled allogeneic human PRP was obtained from a local blood bank, and the effect that thrombin-activated PRP-releasate supplemented media had on the ex-vivo expansion of the hMDPCs was tested against FBS supplemented media, both in vitro and in vivo. PRP significantly enhanced short and long-term cell proliferation, with or without FBS supplementation. Antibody-neutralization of PDGF significantly blocked the mitogenic/proliferative effects that PRP had on the hMDPCs. A more stable and sustained expression of markers associated with stemness, and a decreased expression of lineage specific markers was observed in the PRP-expanded cells when compared with the FBS-expanded cells. The in vitro osteogenic, chondrogenic, and myogenic differentiation capacities of the hMDPCs were not altered when expanded in media supplemented with PRP. All populations of hMDPCs that were expanded in PRP supplemented media retained their ability to regenerate myofibers in vivo. Our data demonstrated that PRP promoted the proliferation and maintained the multi-differentiation capacities of the hMDPCs during ex-vivo expansion by maintaining the cells in an undifferentiated state. Moreover, PDGF appears to be a key contributing factor to the beneficial effect that PRP has on the proliferation of hMDPCs.
A number of promising therapies for ischemic cardiomyopathy are emerging, and the role of translational research in testing the efficacy and safety of these agents in relevant clinical models has become important. The goal of this study was to develop a chronic model of ischemic cardiomyopathy in a large animal model. In this study, 40 consecutive pigs were initially enrolled. To induce progressive stenosis, a plastic occluder with a fixed diameter of 1.0 mm fitted with an 18-gauge copper wire was placed around the proximal left anterior descending (LAD) coronary artery. Coronary angiography, hemodynamic measurements, and echocardiography were performed at 2 wk and 1, 2, and 3 mo. Overall mortality was 26% at 3 mo, and up to 80% of the pigs showed total occlusion of LAD at 1 mo. A significant depression of peak LV pressure rate of rise (+dP/dt(max)) was observed in the animals showing total artery occlusion throughout the study. Left ventricular ejection fraction was also impaired, and the left ventricular volumes tended to be larger in the pigs with occlusion. Approximately 10% of scar tissue was found in the LAD occluded pigs, whereas the coronary flow pattern in the rest of the area took the pattern of hibernating myocardium. At the same time, histological and protein analysis established the presence of fibrosis and ongoing apoptosis in the ischemic area. In this model, the timing and incidence of total occlusion and low mortality offer significant advantages over other ischemic cardiomyopathy models in conducting preclinical studies.
BACKGROUND/AIMS:
This study was to investigate whether transforming growth factor-β1 (TGF-β1) plays a role in hyperalgesia in chronic pancreatitis (CP) and the underlying mechanisms.
METHODS:
CP was induced in male adult rats by intraductal injection of trinitrobenzene sulfonic acid (TNBS). Abdominal hyperalgesia was assessed by referred somatic behaviors to mechanical stimulation of rat abdomen. Dil dye injected into the pancreas was used to label pancreas-specific dorsal root ganglion (DRG) neurons. Whole cell patch clamp recordings and calcium imaging were performed to examine the effect of TGF-β1 on acutely isolated pancreas-specific DRG neurons. Western blot analysis was carried out to measure the expression of TGF-β1 and its receptors.
RESULTS:
TNBS injection significantly upregulated expression of TGF-β1 in the pancreas and DRGs, and TGF-β1 receptors in DRGs (T9-T13)in CP rats. Intrathecal injection of TGF-β receptor I antagonist SB431542 attenuated abdominal hyperalgesia in CP rats. TGF-β1 application depolarized the membrane potential and caused firing activity of DRG neurons. TGF-β1 application also reduced rheobase, hyperpolarized action potential threshold, and increased numbers of action potentials evoked by current injection of pancreas-specific DRG neurons. TGF-β1 application also increased the concentration of intracellular calcium of DRG neurons, which was inhibited by SB431542. Furthermore, intrathecal injection of TGF-β1 produced abdominal hyperalgesia in healthy rats.
CONCLUSIONS:
These results suggest that TGF-β1 enhances neuronal excitability and increases the concentration of intracellular calcium. TGF-β1 and its receptors are involved in abdominal hyperalgesia in CP. This and future study might identify a potentially novel target for the treatment of abdominal pain in CP.
BACKGROUND AND PURPOSE:
Renal function can be assessed by measuring albuminuria and glomerular filtration rate, and the latter is often estimated by creatinine clearance rate (Ccr). Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor (VEGF) are two important factors involved in the progressive loss of renal function in diabetic nephropathy (DN), especially in terms of albuminuria. We investigated the effect of urocortin 1 on renal function of rats with DN and the mechanisms involved.
EXPERIMENTAL APPROACH:
A modified rat model of DN (multiple injections of low-dose streptozotocin and complete Freund's adjuvant) and a rat mesangial cell line were used. Albuminuria and Ccr were measured or calculated. Expression and secretion of TGF-beta1 and VEGF were measured by immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) or enzyme-linked immunosorbent assay (R&D System, Inc., Minneapolis, MA, USA). Urocortin 1 and astressin [a non-selective antagonist of corticotrophin-releasing factor (CRF) receptors] were given as daily injections for 8 weeks.
KEY RESULTS:
Treatment of DN rats with urocortin 1 decreased albuminuria, renal weight and overexpression of TGF-beta1 and VEGF but enhanced Ccr. Furthermore, VEGF mRNA was increased in kidneys of DN rats, and this increase was reduced by treatment with urocortin 1. The secretion of VEGF induced by TGF-beta1 in mesangial cells was inhibited by urocortin 1 pretreatment. Astressin given with urocortin 1 prevented most of the effects of urocortin 1, in our models, in vivo or in vitro.
CONCLUSION AND IMPLICATIONS:
Our results strongly suggest that urocortin 1 improved renal function in rats with DN by inhibiting the overproduction of TGF-beta1 and VEGF.
Transforming growth factor-β1 (TGF-β1) is an important mediator of atrial fibrosis and atrial fibrillation (AF). But the involved genetic mechanism is unknown. Herein, the TGF-β1 C-509 T polymorphism (rs1800469) was genotyped in a case-control study of 840 patients and 845 controls in Chinese population to explore the association between the polymorphism and susceptibility and prognosis of lone AF. As a result, the CT and/or TT genotypes had an increased lone AF risk [adjusted odds ratio (OR) = 1.50 for CT, OR = 3.72 for TT, and OR = 2.15 for CT/TT], compared with the TGF-β1CC genotype. Moreover, patients carrying CT/TT genotypes showed a higher possibility of AF recurrence after catheter ablation, compared with patients carrying CC genotype. In a genotype-phenotype correlation analysis using 24 normal left atrial appendage samples, increasing gradients of atrial TGF-β1 expression levels positively correlated with atrial collagen volume fraction were identified in samples with CC, CT and TT genotypes. The in vitro luciferase assays also showed a higher luciferase activity of the -509 T allele than that of the -509 C allele. In conclusion, the TGF-β1 C-509 T polymorphism is involved in the etiology of lone AF and thus may be a marker for genetic susceptibility to lone AF and predicting prognosis after catheter ablation in Chinese populations. Therefore, we provide new information about treatment strategies and our understanding of TGF-β1 in AF.
In post-haemorrhagic and other forms of communicating hydrocephalus, cerebrospinal fluid flow and drainage is obstructed by subarachnoid fibrosis in which the potent fibrogenic cytokine transforming growth factor-β has been aetiologically implicated. Here, the hypothesis that the transforming growth factor-β antagonist decorin has therapeutic potential for reducing fibrosis and ventriculomegaly was tested using a rat model of juvenile communicating hydrocephalus. Hydrocephalus was induced by a single basal cistern injection of kaolin in 3-week-old rats, immediately followed by 3 or 14 days of continuous intraventricular infusion of either human recombinant decorin or phosphate-buffered saline (vehicle). Ventricular expansion was measured by magnetic resonance imaging at Day 14. Fibrosis, transforming growth factor-β/Smad2/3 activation and hydrocephalic brain pathology were evaluated at Day 14 and the inflammatory response at Days 3 and 14 by immunohistochemistry and basic histology. Analysis of ventricular size demonstrated the development of hydrocephalus in kaolin-injected rats but also revealed that continuous decorin infusion prevented ventricular enlargement, such that ventricle size remained similar to that in intact control rats. Decorin prevented the increase in transforming growth factor-β1 and phosphorylated Smad2/3 levels throughout the ventricular system after kaolin injection and also inhibited the deposition of the extracellular matrix molecules, laminin and fibronectin in the subarachnoid space. In addition, decorin protected against hydrocephalic brain damage inferred from attenuation of glial and inflammatory reactions. Thus, we conclude that decorin prevented the development of hydrocephalus in juvenile rats by blocking transforming growth factor-β-induced subarachnoid fibrosis and protected against hydrocephalic brain damage. The results suggest that decorin is a potential clinical therapeutic for the treatment of juvenile post-haemorrhagic communicating hydrocephalus.
Hypoplastic left heart syndrome (HLHS) is a severe cardiac malformation characterized by left ventricle (LV) hypoplasia and abnormal LV perfusion and oxygenation. We studied hypoxia-associated injury in fetal HLHS and human pluripotent stem cells during cardiac differentiation to assess the effect of microenvironmental perturbations on fetal cardiac reprogramming. We studied LV myocardial samples from 32 HLHS and 17 structurally normal midgestation fetuses. Compared with controls, the LV in fetal HLHS samples had higher nuclear expression of hypoxia-inducible factor-1α but lower angiogenic growth factor expression, higher expression of oncogenes and transforming growth factor (TGF)-β1, more DNA damage and senescence with cell cycle arrest, fewer cardiac progenitors, myocytes and endothelial lineages, and increased myofibroblast population (P < 0.05 versus controls). Smooth muscle cells (SMCs) had less DNA damage compared with endothelial cells and myocytes. We recapitulated the fetal phenotype by subjecting human pluripotent stem cells to hypoxia during cardiac differentiation. DNA damage was prevented by treatment with a TGF-β1 inhibitor (P < 0.05 versus nonhypoxic cells). The hypoplastic LV in fetal HLHS samples demonstrates hypoxia-inducible factor-1α up-regulation, oncogene-associated cellular senescence, TGF-β1-associated fibrosis and impaired vasculogenesis. The phenotype is recapitulated by subjecting human pluripotent stem cells to hypoxia during cardiac differentiation and rescued by inhibition of TGF-β1. This finding suggests that hypoxia may reprogram the immature heart and affect differentiation and development.
Accumulating evidence suggests that colorectal cancer (CRC) should be viewed as a heterogeneous disease, with proximal and distal CRCs showing multiple biological and clinical differences. The aim of this study was to develop a clinicopathological, molecular and protein profile for CRCs based on their region and thus providing insight into their heterogeneity. CRC patients (n=399) were evaluated for clinicopathologic and molecular features including K-RAS, BRAF and MSI status. Tumors were also screened for expression of 50 immunohistochemical markers linked to major signaling pathways involved in tumor-progression or immune response. Proximally located tumors show significantly larger tumor size, higher T-stage, higher tumor grade and more frequent mucinous histologic subtype compared to the distal colon and rectum. The frequency of BRAF mutation and MSI-high phenotype were significantly higher in proximal colon cancers. There is a significant difference in regional expression of 10 tumor-associated markers (CDX2, CD44v6, CD44s, TOPK, nuclear beta-catenin, pERK, APAF-1, E-cadherin, p21 and bcl2) and 4 immune response markers (CD68, CD163, FoxP3 and TIA-1). In multivariate analysis CD44s, CD44v6, nuclear beta-catenin and CD68 expression was found to best discriminate left- versus right-sided colon cancers. Tumor diameter, pT stage and MSI status best distinguish right-sided colon cancers from rectal cancers and pT stage and E-cadherin best discriminate left-sided colon cancers and rectal cancers. These data along with existing evidence for the presence of distinct regional embryological origin and gene expression profile are highly supportive of the concept that proximal and distal CRCs are distinct clinicopathologic entities.
The aim of this paper is to study the myocardial damage secondary to long-term streptozotocin-induced type 1 diabetes mellitus (DM1). Normotensive and spontaneously hypertensive rats (SHR) received either streptozotocin injections or vehicle. After 22 or 6 wk, DM1, SHR, DM1/SHR, and control rats were killed, and the left ventricles studied by histology, quantitative PCR, Western blot, ELISA, and electromobility shift assay. Cardiomyocyte cultures were also performed. The expression of profibrotic factors, transforming growth factor-beta (TGF-beta1), connective tissue growth factor, and matrix proteins was increased, and the TGF-beta1-linked transcription factors phospho-Smad3/4 and activator protein-1 were activated in the DM1 myocardium. Proapoptotic molecules FasL, Fas, Bax, and cleaved caspase-3 were also augmented. Myocardial injury in long-term hypertension shared these features. In addition, hypertension was associated with activation of NF-kappaB, increased inflammatory cell infiltrate, and expression of the mediators [interleukin-1beta (IL-1beta), tumor necrosis factor-alpha, monocyte chemoattractant protein 1, vascular cell adhesion molecule 1, angiotensinogen, and oxidants], which were absent in long-term DM1. At this stage, the combination of DM1 and hypertension resulted in nonsignificant additive effects. Moreover, the coexistence of DM1 blunted the inflammatory response to hypertension. Anti-inflammatory IL-10 and antioxidants were induced in long-term DM1 and DM1/SHR hearts. Myocardial inflammation was, however, observed in the short-term model. In cultured cardiomyocytes, IL-10, TGF-beta1, and catalase blocked the glucose-stimulated expression of proinflammatory genes. Fibrosis and apoptosis are features of long-term myocardial damage in experimental DM1. Associated hypertension does not induce additional changes. Myocardial inflammation is present in hypertension and short-term DM1, but is not a key feature in long-term DM1. Local reduction of proinflammatory factors and expression of anti-inflammatory and antioxidant molecules may underlie this effect.
TGF-beta is a well-described immunoregulatory molecule that is produced by most cell types. Many studies have been aimed at investigating the role played by TGF-beta in different cell types and situations. Most methods of measuring TGF-beta have previously relied on enzyme-linked immunosorbent assay (ELISA) or assays of its anti-proliferative effects on various cell lines. Both assays, though useful, cannot be used to effectively identify the cells that are producing TGF-beta in a mixture of cells. It is especially important to know the source and dynamics of TGF-beta secretion in cell culture studies since most cell types are known to be capable of producing TGF-beta. We describe here a technique of qualitative and quantitative measurement of TGF-beta production using flow cytometry. Previous work by others has led to the production of polyclonal and monoclonal antibodies to human and other mammalian TGF-beta. We have developed an intracellular cytokine staining for human TGF-beta using a monoclonal antibody, TB21.
A hybridoma TB 21 clone was derived from fusion between Sp 2/0-Ag 14 myeloma cells and spleen cells of BALB/c mice immunized with transforming growth factor-beta 1 (TGF-beta 1) purified from human platelets. The TB 21 clone was identified to produce monoclonal antibody with IgG1 subclass and had sufficient titer for immunoreactivity to both human platelets-derived TGF-beta 1 and recombinant human TGF-beta 1 by enzyme-linked immunosorbent assay (ELISA). Western blotting studies demonstrated that two immunoreactive bands corresponding to 25 Kda and 12.5 Kda molecules were observed in the sample of acid/ethanol extracts from human platelets. The affinity constant (Kaff) was determined as 1.47 x 10(8) M-1 with non-competitive ELISA. Moreover, using bioassay for the effects of TGF-beta 1 on the growth of mink lung epithelial cells (CCL/64 cell line) and fibroblast cells (NRK 49 F cell line), TB 21 IgG was shown to be able to neutralize the action of TGF-beta 1 on the growth of these target cells. Therefore, this monoclonal antibody may be a useful probe for studying the growth modulatory activity of TGF-beta 1 in a variety of cells and tissues.
BACKGROUND:
In dilated cardiomyopathy (DCM), cardiac failure is accompanied by profound alterations of extracellular matrix associated with the progression of cardiac dilation and left ventricular (LV) dysfunction. Recently, we reported alterations of non-fibrillar collagen expression in ischemic cardiomyopathy linked to fibrosis and cardiac remodeling. We suspect that expression changes in genes coding for non-fibrillar collagens may have a potential role in DCM development.
OBJECTIVES:
This study sought to analyze changes in the expression profile of non-fibrillar collagen genes in patients with DCM and to examine relationships between cardiac remodeling parameters and the expression levels of these genes.
METHODS AND RESULTS:
Twenty-three human left ventricle tissue samples were obtained from DCM patients (n = 13) undergoing heart transplantation and control donors (n = 10) for RNA sequencing analysis. We found increased mRNA levels of six non-fibrillar collagen genes, such as COL4A5, COL9A1, COL21A1, and COL23A1 (P < 0.05 for all), not previously described in DCM. Protein levels of COL8A1 and COL16A1 (P < 0.05 for both), were correspondingly increased. We also identified TGF-β1 significantly upregulated and related to both COL8A1 and COL16A1. Interestingly, we found a significant relationship between LV mass index and the gene expression level of COL8A1 (r = 0.653, P < 0.05).
CONCLUSIONS:
In our research, we identified new non-fibrillar collagens with altered expression in DCM, being COL8A1 overexpression directly related to LV mass index, suggesting that they may be involved in the progression of cardiac dilation and remodeling.
BACKGROUND:
This study assessed the effects of inhaled corticosteroid (ICS) on airway vascular remodeling in chronic obstructive pulmonary disease (COPD).
METHODS:
Thirty-four subjects with mild-to-moderate COPD were randomly allocated 2:1 to ICS or placebo treatment in a double-blinded clinical trial over 6 months. Available tissue was compared before and after treatment for vessel density, and expression of VEGF, TGF-β1, and TGF-β1-related phosphorylated transcription factors p-SMAD 2/3. This clinical trial has been registered and allocated with the Australian New Zealand Clinical Trials Registry (ANZCTR) on 17/10/2012 with reference number ACTRN12612001111864.
RESULTS:
There were no significant baseline differences between treatment groups. With ICS, vessels and angiogenic factors did not change in hypervascular reticular basement membrane, but in the hypovascular lamina propria (LP), vessels increased and this had a proportionate effect on lung air trapping. There was modest evidence for a reduction in LP vessels staining for VEGF with ICS treatment, but a marked and significant reduction in p-SMAD 2/3 expression.
CONCLUSION:
Six-month high-dose ICS treatment had little effect on hypervascularity or angiogenic growth factors in the reticular basement membrane in COPD, but normalized hypovascularity in the LP, and this was physiologically relevant, though accompanied by a paradoxical reduction in growth factor expression.
OBJECTIVE:
To determine whether delayed administration of a single dose of suramin, a drug that has been used extensively in humans to treat trypanosomiasis, attenuates renal injury in a leptin receptor deficient C57BLKS/J db/db type 2 diabetic nephropathy (T2DN) mouse model.
RESEARCH DESIGN AND METHODS:
Groups of female non-diabetic (control) db/m and diabetic db/db mice of 8 and 16 weeks of age, respectively, were treated with suramin (10 mg/kg) or saline i.v. All animals were euthanized one week later. Measurements in mice 1 week following treatment included the following: body weight; blood glucose; urinary protein excretion; pathological lesions in glomeruli and proximal tubules; changes in protein expression of pro-inflammatory transcription factor nuclear factor κB (NF-κB) and intracellular adhesion molecule-1 (ICAM-1), profibrotic transforming growth factor-β1 (TGF-β1), phospho-SMAD-3 and alpha-smooth muscle actin (α-SMA); and immunohistochemical analysis of leukocyte infiltration and collagen 1A2 (COL1A2) deposition.
RESULTS:
Immunoblot analysis revealed increased NF-κB, ICAM-1, TGF-β1, phospho-SMAD-3, and α-SMA proteins in both 9 and 17 week db/db mice as compared to db/m control mice. Immunohistochemical analysis revealed moderate leukocyte infiltration and collagen 1A2 (COL1A2) deposition in 9 week db/db mice that was increased in the 17 week db/db mice. Importantly, suramin significantly decreased expression of all these markers in 9 week db/db mice and partially decreased in 17 week db/db mice without altering body weight, blood glucose or urinary protein excretion. There was no difference in creatinine clearance between 9 week db/m and db/db mice ± suramin. Importantly, in the 17 week db/db mice suramin intervention reversed the impaired creatinine clearance and overt histological damage.
CONCLUSIONS:
Delayed administration of a single dose of suramin in a model of T2DN attenuated inflammation and fibrosis as well as improved renal function, supporting the use of suramin in T2DN.
RATIONALE:
Recently it has been shown that long-term intensive exercise practice is able to induce myocardial fibrosis in an animal model. Angiotensin II is a profibrotic hormone that could be involved in the cardiac remodeling resulting from endurance exercise.
OBJECTIVE:
This study examined the antifibrotic effect of losartan, an angiotensin II type 1 receptor antagonist, in an animal model of heart fibrosis induced by long-term intense exercise.
METHODS AND RESULTS:
Male Wistar rats were randomly distributed into 4 experimental groups: Exercise, Exercise plus losartan, Sedentary and Sedentary plus losartan. Exercise groups were conditioned to run vigorously for 16 weeks. Losartan was orally administered daily before each training session (50 mg/kg/day). Time-matched sedentary rats served as controls. After euthanasia, heart hypertrophy was evaluated by histological studies; ventricular collagen deposition was quantified by histological and biochemical studies; and messenger RNA and protein expression of transforming growth factor-β1, fibronectin-1, matrix metalloproteinase-2, tissue inhibitor of metalloproteinase-1, procollagen-I and procollagen-III was evaluated in all 4 cardiac chambers. Daily intensive exercise caused hypertrophy in the left ventricular heart wall and originated collagen deposition in the right ventricle. Additionally long-term intensive exercise induced a significant increase in messenger RNA expression and protein synthesis of the major fibrotic markers in both atria and in the right ventricle. Losartan treatment was able to reduce all increases in messenger RNA expression and protein levels caused by exercise, although it could not completely reverse the heart hypertrophy.
CONCLUSIONS:
Losartan treatment prevents the heart fibrosis induced by endurance exercise in training animals.
BACKGROUND:
Transforming growth factor beta (TGFβ) is upregulated in chronic inflammation, where it plays a key role in wound healing and promoting fibrosis. However, little is known about the peripheral effects of TGFβ on nociception.
METHODS:
We tested the in vitro effects of TGFβ1 on the excitability of dorsal root ganglia (DRG) neurons and the function of potassium (K) channels. We also studied the effects of TGFβ1 infusion on pain responses to noxious electrical stimulation in healthy rats as well as the effects of neutralization of TGFβ1 on evoked pain behaviors in a rat model of chronic pancreatitis.
RESULTS:
Exposure to TGFβ1 in vitro increased sensory neuronal excitability, decreased voltage-gated A-type K(+) currents (IA) and downregulated expression of the Kv1.4 (KCNA4) gene. Further TGFβ1 infusion into the naïve rat pancreas in vivo induces hyperalgesia and conversely, neutralization of TGFβ1 attenuates hyperalgesia only in rats with experimental chronic pancreatitis. Paradoxically, TGFβ1 neutralization in naïve rats results in pancreatic hyperalgesia.
CONCLUSIONS:
TGFβ1 is an important and complex modulator of sensory neuronal function in chronic inflammation, providing a link between fibrosis and nociception and is a potentially novel target for the treatment of persistent pain associated with chronic pancreatitis.
BACKGROUND:
Huangqi decoction was first described in Prescriptions of the Bureau of Taiping People's Welfare Pharmacy in Song Dynasty (AD 1078), and it is an effective recipe that is usually used to treat consumptive disease, anorexia, and chronic liver diseases. Transforming growth factor beta 1 (TGFβ1) plays a key role in the progression of liver fibrosis, and Huangqi decoction and its ingredients (IHQD) markedly ameliorated hepatic fibrotic lesions induced by ligation of the common bile duct (BDL). However, the mechanism of IHQD on hepatic fibrotic lesions is not yet clear. The purpose of the present study is to elucidate the roles of TGFβ1 activation, Smad-signaling pathway, and extracellular signal-regulated kinase (ERK) in the pathogenesis of biliary fibrosis progression and the antifibrotic mechanism of IHQD.
METHODS:
A liver fibrosis model was induced by ligation of the common bile duct (BDL) in rats. Sham-operation was performed in control rats. The BDL rats were randomly divided into two groups: the BDL group and the IHQD group. IHQD was administrated intragastrically for 4 weeks. At the end of the fifth week after BDL, animals were sacrificed for sampling of blood serum and liver tissue. The effect of IHQD on the TGFβ1 signaling pathway was evaluated by western blotting and laser confocal microscopy.
RESULTS:
Decreased content of hepatic hydroxyproline and improved liver function and histopathology were observed in IHQD rats. Hepatocytes, cholangiocytes, and myofibroblasts in the cholestatic liver injury released TGFβ1, and activated TGFβ1 receptors can accelerate liver fibrosis. IHQD markedly inhibited the protein expression of TGFβ1, TGFβ1 receptors, Smad3, and p-ERK1/2 expression with no change of Smad7 expression.
CONCLUSION:
IHQD exert significant therapeutic effects on BDL-induced fibrosis in rats through inhibition of the activation of TGFβ1-Smad3 and TGFβ1-ERK1/2 signaling pathways.
BACKGROUND:
Recent clinical studies suggest that endurance sports may promote cardiac arrhythmias. The aim of this study was to use an animal model to evaluate whether sustained intensive exercise training induces potentially adverse myocardial remodeling and thus creates a potential substrate for arrhythmias.
METHODS AND RESULTS:
Male Wistar rats were conditioned to run vigorously for 4, 8, and 16 weeks; time-matched sedentary rats served as controls. Serial echocardiograms and in vivo electrophysiological studies at 16 weeks were obtained in both groups. After euthanasia, ventricular collagen deposition was quantified by histological and biochemical studies, and messenger RNA and protein expression of transforming growth factor-β1, fibronectin-1, matrix metalloproteinase-2, tissue inhibitor of metalloproteinase-1, procollagen-I, and procollagen-III was evaluated in all 4 cardiac chambers. At 16 weeks, exercise rats developed eccentric hypertrophy and diastolic dysfunction, together with atrial dilation. In addition, collagen deposition in the right ventricle and messenger RNA and protein expression of fibrosis markers in both atria and right ventricle were significantly greater in exercise than in sedentary rats at 16 weeks. Ventricular tachycardia could be induced in 5 of 12 exercise rats (42%) and only 1 of 16 sedentary rats (6%; P=0.05). The fibrotic changes caused by 16 weeks of intensive exercise were reversed after an 8-week exercise cessation.
CONCLUSIONS:
In this animal model, we documented cardiac fibrosis after long-term intensive exercise training, together with changes in ventricular function and increased arrhythmia inducibility. If our findings are confirmed in humans, the results would support the notion that long-term vigorous endurance exercise training may in some cases promote adverse remodeling and produce a substrate for cardiac arrhythmias.
PURPOSE:
Transforming growth factor-beta (TGF-beta) is a potent immunosuppressor that has been associated with tumor evasion from the host immune surveillance and, thus, tumor progression. We tested a novel immunotherapy for human renal cell cancer (RCC) using a technique that involves the adoptive transfer of autologous tumor-reactive, TGF-beta-insensitive CD8(+) T cells into human RCC-challenged immunodeficient mice to identify its potent antitumor responses.
EXPERIMENTAL DESIGN:
The present study was conducted using a one-to-one adoptive transfer strategy to treat tumor-bearing severe combined immunodeficient (SCID/beige) mouse. The SCID/beige mice were humanized with peripheral blood mononuclear cells from patients with RCC (Hu-PBMC-SCID) before adoptive transfer. Autologous CD8(+) T cells were expanded ex vivo using autologous patient's dendritic cells pulsed with the tumor lysate and rendered TGF-beta insensitive by dominant-negative TGF-beta type II receptor. In addition, human RCC cell lines were generated using patients' tumor cells injected into SCID/beige mice.
RESULTS:
Using flow cytometry analysis, we confirmed the expression of the tumor-reactive, TGF-beta-insensitive CD8(+) T cells were the effector CD8(+) cells (CD27(-)CDRA(+)). Adoptive transfer of autologous TGF-beta-insensitive CD8(+) T cells into tumor-bearing Hu-PBMC-SCID mice induced robust tumor-specific CTL responses in vitro, were associated with tumor apoptosis, suppressed lung metastasis, and prolonged survival times in vivo.
CONCLUSION:
The one-to-one adoptive transfer strategy is an ideal in vivo murine model for studying the relationship between TGF-beta and immunosurveillance in RCC in vivo. Furthermore, this technique may offer the promise of a novel therapeutic option for the treatment of human patients with RCC.
PURPOSE:
Pancreatic stellate cells (PSC) drive desmoplasia in pancreatic cancer. Our study analyzed both tumor and PSC, since interaction of these cell types may promote tumor progression.
RESULTS:
SPARC was expressed predominantly in the peritumoral and distal stroma. SPARC in distal stroma correlated inversely with overall survival of the patients with LAPC (p = 0.013) with a relative hazard of 2.23 (95% CI, 1.05 to 4.72; p = 0.036). TGFbeta1 in the tumor was also a negative prognostic factor (p = 0.03). Within the tumor cells, phospho-Akt correlated with TGFbeta1, SPARC and survivin. Tumor phospho-Akt correlated with stroma phospho-Akt, tumor TGFbeta1 correlated with stroma TGFbeta1 and alpha-SMA, tumor survivin correlated with stroma survivin and distal SPARC. Within the stroma, SPARC and TGFbeta1 correlated with alpha-SMA. Peritumoral SPARC correlated with distal SPARC. In vitro, SPARC was highly expressed in hPSC but not in Panc-1 cells. Exogenous SPARC did not change radiation resistance but increased the invasion of Panc-1 cells both in monoculture and in coculture with hPSC.
EXPERIMENTAL DESIGN:
Immunohistochemical expression of SPARC, CTGF, TGFbeta1, phospho-Akt, survivin and alpha-SMA was analyzed prior to chemoradiation in 58 locally advanced pancreatic cancer (LAPC) biopsy specimens. Fisher's exact test served to detect associations between tumor and PSC expression of markers. Kaplan-Meier analysis and multivariate analysis were used to evaluate the association of marker expression with overall survival. SPARC expression was analyzed in human pancreatic cancer cells (Panc-1) and in human PSC (hPSC) and the effect of SPARC on the invasion of Panc-1 cells was measured in monoculture or in coculture with hPSC.
CONCLUSIONS:
Our hypothesis of a detrimental effect of PSC on patient survival in LAPC after chemoradiation is supported by the inverse correlation of SPARC in distal stromal cells with patients survival. Furthermore in vitro data indicate that paracrine SPARC from PSC increases the invasion of pancreatic cancer cells.
PURPOSE:
To identify independent clinicopathologic factors and protein markers leading to the identification of colorectal cancer (CRC) patients with mismatch repair proficiency at risk of developing metastasis and, consequently, more likely to benefit from combined modality therapy.
EXPERIMENTAL DESIGN:
Immunohistochemistry for 22 tumor markers was done using a tissue microarray. A subset of 387 CRC patients with complete clinicopathologic data and TNM stage was analyzed. Univariate and multivariate analyses were done to identify independent predictive markers of metastasis. The results were validated on 810 CRC patients.
RESULTS:
In univariate analysis, T stage (P < 0.001), N stage (P < 0.001), tumor grade (P = 0.005), vascular invasion (P < 0.001), tumor budding (P < 0.001), positive expression of beta-catenin (P = 0.015), overexpression of RHAMM (P = 0.008), negative expression of Raf-1 kinase inhibitor protein (RKIP; P = 0.001), and absence of intraepithelial lymphocytes (P = 0.017) were significantly associated with the presence of distant metastasis. In multivariate analysis, higher N stage (P < 0.001), presence of vascular invasion (P = 0.009), and RKIP loss (P = 0.003) independently predicted distant metastatic disease. A subgroup of node-negative patients was identified as high risk for distant metastasis and showed a similar probability of metastatic risk and nearly identical survival times as node-positive patients with absence of vascular invasion and positive RKIP expression (metastatic risk, 24% and 22%; median survival time, 45.0 and 47.0 months, respectively).
CONCLUSION:
The combined analysis of N stage, vascular invasion, and RKIP expression is highly predictive of distant metastasis in patients with mismatch repair--proficient CRC. Additionally, a subgroup of more aggressive N(0) tumors can be identified by evaluating vascular invasion and RKIP expression.