scholarly journals Analytical Characterization of an Enzyme-Linked Immunosorbent Assay for the Measurement of Transforming Growth Factor β1 in Human Plasma

2018 ◽  
Vol 3 (2) ◽  
pp. 200-212 ◽  
Author(s):  
Brendan M Giles ◽  
Timothy T Underwood ◽  
Karim A Benhadji ◽  
Diana K S Nelson ◽  
Lisa M Grobeck ◽  
...  
Keyword(s):  
Growth Factor ◽  
Human Plasma ◽  
Patient Selection ◽  
Transforming Growth Factor ◽  
Sandwich Elisa ◽  
Transforming Growth Factor Β ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Individuals ◽  
Tgf Β1 ◽  
Apparently Healthy

Abstract Background The transforming growth factor β (TGF-β)–signaling pathway has emerged as a promising therapeutic target for many disease states including hepatocellular carcinoma (HCC). Because of the pleiotropic effects of this pathway, patient selection and monitoring may be important. TGF-β1 is the most prevalent isoform, and an assay to measure plasma levels of TGF-β1 would provide a rational biomarker to assist with patient selection. Therefore, the objective of this study was to analytically validate a colorimetric ELISA for the quantification of TGF-β1 in human plasma. Methods A colorimetric sandwich ELISA for TGF-β1 was analytically validated per Clinical and Laboratory Standards Institute protocols by assessment of precision, linearity, interfering substances, and stability. A reference range for plasma TGF-β1 was established for apparently healthy individuals and potential applicability was demonstrated in HCC patients. Results Precision was assessed for samples ranging from 633 to 10822 pg/mL, with total variance ranging from 28.4% to 7.2%. The assay was linear across the entire measuring range, and no interference of common blood components or similar molecules was observed. For apparently healthy individuals, the average TGF-β1 level was 1985 ± 1488 pg/mL compared to 4243 ± 2003 pg/mL for HCC patients. Additionally, the TGF-β1 level in plasma samples was demonstrated to be stable across all conditions tested, including multiple freeze–thaw cycles. Conclusions The ELISA described in this report is suitable for the quantification of TGF-β1 in human plasma and for investigational use in an approved clinical study.

scholarly journals Kadar Transforming Growth Factor β-1 Urin pada Berbagai Keadaan Proteinuria

Sari Pediatri ◽  
2019 ◽  
Vol 20 (5) ◽  
pp. 309
Author(s):  
Partini P. Trihono ◽  
Husein Alatas ◽  
Taralan Tambunan ◽  
Sudigdo Sastroasmoro
Keyword(s):  
United Kingdom ◽  
Growth Factor ◽  
Immunosorbent Assay ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immuno Assay ◽  
Tgf Β1

Latar belakang. Proteinuria masif pada sindrom nefrotik (SN) akan menginduksi suatu rentetan reaksi biologis di tubular proksimal. Reaksi ini mengaktivasi peptida vasoaktif dan produksi sitokin, seperti TGF-β1. Di dalam urin, TGF-β1 urin merupakan sitokin fibrogenik yang pluripoten, yang melalui beberapa patomekanisme menyebabkan fibrosis interstisial dan glomerulosklerosis yang pada akhirnya menimbulkan gagal ginjal.Tujuan. Mengetahui kadar TGF-β1 urin pada berbagai keadaan proteinuria, yakni pada anak dengan sindrom nefrotik sensitif steroid (SNSS), dalam keadaan remisi maupun relaps, dan pada anak dengan sindrom nefrotik resisten steroid (SNRS). Metode. Penelitian dengan desain potong lintang ini dilakukan di 8 pusat ginjal anak di Indonesia. Subyek penelitian ini terdiri atas 34 anak dengan SNSS steroid remisi, 31 anak dengan relaps, 55 anak dengan SNRS, dan 35 anak tanpa penyakit ginjal sebagai kontrol. Kadar proteinuria dan TGF-β1 urin diperiksa pada sampel urin sewaktu yang diambil pagi hari. Kadar TGF-β1 urin diperiksa dengan metode enzyme-linked immunosorbent assay (Quantikine kit for human TGF-β1 immuno assay; R&D Systems, Mineapolis, MN). Kadar proteinuria kuantitatif diperiksa dengan cara kolorimetri (Randox kit; Randox Laboratories, United Kingdom)Hasil. Kadar proteinuria tertinggi didapatkan pada SN relaps, yang secara bermakna lebih tinggi daripada kadar SNRS. Namun, kadar TGF-β1 urin pada SN relaps sama tinggi dengan kadarnya pada SNRS yang secara bermakna lebih tinggi daripada kadarnya pada SN remisi. Kadar TGF-β1 urin pada SN remisi tidak berbeda dengan kadarnya pada anak tanpa penyakit ginjal. Terdapat korelasi positif antara kadar TGF-β1 dan protein urin (r=0,649 ;p<0,0001).Kesimpulan. Kadar TGF- β1 urin pada anak dengan SN relaps sama tingginya dengan kadar TGF- β1 urin pada SNRS, yang secara bermakna lebih tinggi bila dibandingkan dengan kadar pada anak dengan sindrom nefrotik remisi, maupun anak tanpa penyakit ginjal.

scholarly journals RANSFORMING GROWTH FACTOR-β1 IN PATIENTS WITH BRONCHIAL ASTHMA: PATHOGENETIC, CLINICAL AND THERAPEUTIC ASPECTS (LITERATURE REWIEW AND OWN RESULTS)

2021 ◽  
Vol 2021 (2) ◽  
pp. 34-42
Author(s):  
V. V. Kachkovska ◽  
A. V. Kovchun ◽  
A. M. Bondarkova ◽  
L. N. Prystupa
Keyword(s):  
Growth Factor ◽  
Bronchial Asthma ◽  
Transforming Growth Factor ◽  
Airway Remodeling ◽  
Transforming Growth Factor Β1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Individuals ◽  
Key Words Bronchial Asthma ◽  
Tgf Β1

The goal of our research was to analyze the role of transforming growth factor-β1 (TGF-β1 ) in airway remodeling, inflammation, clinical course, treatment efficacy in patients with bronchial asthma (BA) according to the literature data, as well as determination of this biomarkers level in the blood of BA patients. Material and research methods. The publications is containing the results of studies on the role of TGF-β1 in the course of BA have been analyzed. The level of TGF-β1 in the blood was determined within enzyme-linked immunosorbent assay using kits “IBL International GMBH, Germany” in 553 BA patients and in 95 healthy individuals. Results. The article presents data about TGF-β1 influence on the processes of airway remodeling in BA patients, its role in microcirculation disorders, mucus production, eosinophilic inflammation and severity of clinical symptoms of the disease. The level of TGF-β1 expression was associated with disease control, severity and duration of the disease, despite conflicting data that require further study. In addition, there were presented recent research data about TGF-β1 as a marker of airway remodeling and as a therapeutic target in the treatment of BA patients. Glucocorticoids, tiotropium bromide, methylxanthines, selective inhibitors of TGF-β1 , resveratrol, simvastatin and montelukast and their mechanisms of influence were presented in detail. Significantly higher level of TGF-β1 in the blood of patients with BA was found (38.5 ± 0.7) pg/ml compared with healthy individuals (33.9 ± 1.0) pg /ml, p = 0.007. Conclusion. A significantly higher level of TGF-β1 was revealed in the blood of BA patients. In our opinion, a differentiated analysis of the content of this marker depending on the phenotype of the disease is important, which would explain the conflicting results of different studies, deepen understanding of its pathophysiological and clinical role in order to develop methods for slowing airway remodeling. Key words: bronchial asthma, transforming growth factor-β1 (TGF-β1), airway remodeling.

Abstract 297: Cyclic GMP Reduces Vascular Smooth Muscle Migration through Inhibition of TGF-ß1/Smad Signaling

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Jackson R Vuncannon ◽  
Joshua D Stone ◽  
Danielle N Martin ◽  
Chintamani N Joshi ◽  
Shaquria P Adderley ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Vascular Smooth Muscle ◽  
Cyclic Gmp ◽  
Transforming Growth Factor ◽  
Soluble Guanylate Cyclase ◽  
Sandwich Elisa ◽  
Cell Lysates ◽  
Tgf Β1

Abnormal vascular smooth muscle (VSM) growth remains an elemental foundation of vasculoproliferative disorders including atherosclerosis and restenosis. Many second messenger, cytokine, and growth factor signals mediate control of VSM growth, and among these is transforming growth factor (TGF)-β1, a pluripotent cytokine with wide-ranging yet often opposite effects in VSM. Cyclic nucleotide signaling also exerts powerful growth control of VSM, and our previous work has helped establish a biological link between cyclic GMP and TGF-β1 in injured carotid arteries. The current study characterized the influence of cyclic GMP on TGF-β1 and its receptor-activated Smad3 in rat primary VSM cells. The heme-dependent soluble guanylate cyclase (sGC) stimulator BAY 41-2272 (BAY41) significantly increased cyclic GMP and site-specific phosphorylation of vasodilator-activated serum phosphoprotein (VASP) in manner indicative of active protein kinase G (PKG) and PKA signaling. Recombinant TGF-β1 (10 ng/ml) significantly stimulated phospho-Smad3 (Ser 423/425 ) and decreased inhibitory Smad7 in VSM cell homogenates, and using flow cytometry significantly increased cells in G 2 /M and expression of cyclins D and E and Cdk2 and Cdk4 while decreasing expression of inhibitory p21 and p27 after 24 hours compared to vehicle controls. TGF-β1 also significantly increased cell numbers compared to controls after 48 hours, thus confirming growth promoting capacities of TGF-β1 in VSM. In cell lysates double-sandwich ELISA revealed that BAY41 significantly reduces total and active TGF-β1, and Western analyses showed it significantly decreases total and phospho-Smad3 Ser423/425 expression and reduces MMP-2 and MMP-9 expression and activity (via column zymography) in both cell lysates and conditioned media after 1 and 48 hours. BAY41 also significantly reduced serum- and PDGF-stimulated cell migration between 6 and 18 hours using an in vitro scrape injury and a transwell assay. In comparison, inclusive effects of BAY41 were replicated by its prototype YC-1 and by the heme-independent sGC activator BAY 60-2770. These data clearly support growth protective capacities of cGMP in VSM and propose it operates through attenuation of TGF-β1/Smad3 signaling.

Platelet-Rich Plasma Powder: A New Preparation Method for the Standardization of Growth Factor Concentrations

2016 ◽  
Vol 45 (4) ◽  
pp. 954-960 ◽  
Author(s):  
Matthias Kieb ◽  
Frank Sander ◽  
Cornelia Prinz ◽  
Stefanie Adam ◽  
Anett Mau-Möller ◽  
...  
Keyword(s):  
Growth Factors ◽  
Growth Factor ◽  
Clinical Application ◽  
Whole Blood ◽  
Sports Medicine ◽  
Transforming Growth Factor ◽  
Platelet Rich Plasma ◽  
Transforming Growth Factor Β1 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tgf Β1

Background: Platelet-rich plasma (PRP) is widely used in sports medicine. Available PRP preparations differ in white blood cell, platelet, and growth factor concentrations, making standardized research and clinical application challenging. Purpose: To characterize a newly standardized procedure for pooled PRP that provides defined growth factor concentrations. Study Design: Controlled laboratory study. Methods: A standardized growth factor preparation (lyophilized PRP powder) was prepared using 12 pooled platelet concentrates (PCs) derived from different donors via apheresis. Blood samples and commercially available PRP (SmartPrep-2) served as controls (n = 5). Baseline blood counts were analyzed. Additionally, single PCs (n = 5) were produced by standard platelet apheresis. The concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor AB (PDGF-AB), transforming growth factor β1 (TGF-β1), insulin-like growth factor 1 (IGF-1), interleukin (IL)–1α, IL-1β, and IL-1 receptor agonist (IL-1RA) were analyzed by enzyme-linked immunosorbent assay, and statistical analyses were performed using descriptive statistics, mean differences, 95% CIs, and P values (analysis of variance). Results: All growth factor preparation methods showed elevated concentrations of the growth factors VEGF, bFGF, PDGF-AB, and TGF-β1 compared with those of whole blood. Large interindividual differences were found in VEGF and bFGF concentrations. Respective values (mean ± SD in pg/mL) for whole blood, SmartPrep-2, PC, and PRP powder were as follows: VEGF (574 ± 147, 528 ± 233, 1087 ± 535, and 1722), bFGF (198 ± 164, 410 ± 259, 151 ± 99, and 542), PDGF-AB (2394 ± 451, 17,846 ± 3087, 18,461 ± 4455, and 23,023), and TGF-β1 (14,356 ± 4527, 77,533 ± 13,918, 68,582 ± 7388, and 87,495). IGF-1 was found in SmartPrep-2 (1539 ± 348 pg/mL). For PC (2266 ± 485 pg/mL), IGF-1 was measured at the same levels of whole blood (2317 ± 711 pg/mL) but was not detectable in PRP powder. IL-1α was detectable in whole blood (111 ± 35 pg/mL) and SmartPrep-2 (119 ± 44 pg/mL). Conclusion: Problems with PRP such as absent standardization, lack of consistency among studies, and black box dosage could be solved by using characterized PRP powder made by pooling and lyophilizing multiple PCs. The new PRP powder opens up new possibilities for PRP research as well as for the treatment of patients. Clinical Relevance: The preparation of pooled PRP by means of lyophilization may allow physicians to apply a defined amount of growth factors by using a defined amount of PRP powder. Moreover, PRP powder as a dry substance with no need for centrifugation could become ubiquitously available, thus saving time and staff resources in clinical practice. However, before transferring the results of this basic science study to clinical application, regulatory issues have to be cleared.

scholarly journals Transplantation of Telocytes Attenuates Unilateral Ureter Obstruction-Induced Renal Fibrosis in Rats

2018 ◽  
Vol 46 (5) ◽  
pp. 2056-2071 ◽  
Author(s):  
Long Zheng ◽  
Long Li ◽  
Guisheng Qi ◽  
Mushuang Hu ◽  
Chao Hu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Protective Effect ◽  
Renal Fibrosis ◽  
Transforming Growth Factor ◽  
Kidney Tissue ◽  
Collagen I ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Mesenchymal Transition ◽  
Tgf Β1

Background/Aims: Previous studies imply that telocytes may have a protective effect on fibrosis in various organs, including the liver, colon, and heart. The effect of telocytes on renal fibrosis remains unknown. Herein, this study was designed to investigate the effect of telocytes on renal fibrosis and the potential mechanisms involved. Methods: In a unilateral ureteral obstruction (UUO)-induced renal fibrosis model, telocytes were injected via the tail vein every other day for 10 days. The degree of renal damage and fibrosis was determined using histological assessment. The expression of collagen I, fibronectin, epithelial-mesenchymal transition markers, and Smad2/3 phosphorylation was examined by western blot analyses. Real-time PCR and enzyme-linked immunosorbent assay were performed in vivo to detect the levels of transforming growth factor (TGF)-β1 and various growth factors. Results: Telocytes attenuated renal fibrosis, as evidenced by reduced interstitial collagen accumulation, decreased expression of fibronectin and collagen I, upregulation of E-cadherin, and downregulation of α-smooth muscle actin. Furthermore, telocytes decreased serum TGF-β1 levels, suppressed Smad2/3 phosphorylation, and increased the expression of hepatocyte growth factor (HGF) in rat kidney tissue following UUO. Blockage of HGF counteracted the protective effect of telocytes on UUO-treated kidneys. Through the detection of HGF mRNA levels in vitro, we found that telocytes had no effect on HGF expression compared with renal fibroblasts. Conclusion: Telocytes attenuated UUO-induced renal fibrosis in rats, likely through enhancing the expression of HGF in an indirect manner.

Abstract 17285: A Selective Transforming Growth Factor-β and Growth Differentiation Factor-15 Ligand Trap Attenuates Pulmonary Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Lai-Ming Yung ◽  
Samuel D Paskin-Flerlage ◽  
Ivana Nikolic ◽  
Scott Pearsall ◽  
Ravindra Kumar ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Type I ◽  
Rna Seq ◽  
Differentiation Factor ◽  
Group I ◽  
Tgf Β1

Introduction: Excessive Transforming Growth Factor-β (TGF-β) signaling has been implicated in pulmonary arterial hypertension (PAH), based on activation of TGF-β effectors and transcriptional targets in affected lungs and the ability of TGF-β type I receptor (ALK5) inhibitors to improve experimental PAH. However, clinical use of ALK5 inhibitors has been limited by cardiovascular toxicity. Hypothesis: We tested whether or not selective blockade of TGF-β and Growth Differentiation Factor (GDF) ligands using a recombinant TGFβ type II receptor extracellular domain Fc fusion protein (TGFBRII-Fc) could impact experimental PAH. Methods: Male SD rats were injected with monocrotaline (MCT) and received vehicle or TGFBRII-Fc (15 mg/kg, twice per week, i.p.). C57BL/6 mice were treated with SU-5416 and hypoxia (SUGEN-HX) and received vehicle or TGFBRII-Fc. RNA-Seq was used to profile transcriptional changes in lungs of MCT rats. Circulating levels of GDF-15 were measured in 241 PAH patients and 41 healthy controls. Human pulmonary artery smooth muscle cells were used to examine signaling in vitro . Results: TGFBRII-Fc is a selective ligand trap, inhibiting the ability of GDF-15, TGF-β1, TGF-β3, but not TGF-β2 to activate SMAD2/3 in vitro . In MCT rats, prophylactic treatment with TGFBRII-Fc normalized expression of TGF-β transcriptional target PAI-1, attenuated PAH and vascular remodeling. Delayed administration of TGFBRII-Fc in rats with established PAH at 2.5 weeks led to improved survival, decreased PAH and remodeling at 5 weeks. Similar findings were observed in SUGEN-HX mice. No valvular abnormalities were found with TGFBRII-Fc treatment. RNA-Seq revealed GDF-15 to be the most highly upregulated TGF-β ligand in the lungs of MCT rats, with only modest increases in TGF-β1 and no change in TGF-β2/3 observed, suggesting a dominant role of GDF-15 in the pathophysiology of this model. Plasma levels of GDF-15 were significantly increased in patients with diverse etiologies of WHO Group I PAH. Conclusions: These findings demonstrate that a selective TGF-β/GDF-15 trap attenuates experimental PAH, remodeling and mortality, without causing valvulopathy. These data highlight the potential role of GDF-15 as a pathogenic molecule and therapeutic target in PAH.

scholarly journals Knockdown of Long Noncoding RNA H19 Represses the Progress of Pulmonary Fibrosis through the Transforming Growth Factor β/Smad3 Pathway by Regulating MicroRNA 140

2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Xi Wang ◽  
Zhe Cheng ◽  
Lingling Dai ◽  
Tianci Jiang ◽  
Liuqun Jia ◽  
...  
Keyword(s):  
Growth Factor ◽  
Pulmonary Fibrosis ◽  
Noncoding Rna ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Animal Experiments ◽  
A549 Cells ◽  
Transforming Growth Factor Β ◽  
Tgf Β1

ABSTRACT Long noncoding RNAs (lncRNAs) are involved in various human diseases. Recently, H19 was reported to be upregulated in fibrotic rat lung and play a stimulative role in bleomycin (BLM)-induced pulmonary fibrosis in mice. However, its expression in human fibrotic lung tissues and mechanism of action remain unclear. Here, our observations showed that H19 expression was significantly upregulated and that of microRNA 140 (miR-140) was markedly reduced in pulmonary fibrotic tissues from idiopathic pulmonary fibrosis (IPF) patients and transforming growth factor β1 (TGF-β1)-induced HBE and A549 cells. Moreover, the expression of H19 was negatively correlated with the expression of miR-140 in IPF tissues. H19 knockdown attenuated TGF-β1-induced pulmonary fibrosis in vitro. Furthermore, animal experiments showed that H19 knockdown attenuated BLM-induced pulmonary fibrosis in mice. The study of molecular mechanisms showed that H19 functioned via reduction of miR-140 expression by binding to miR-140. The increase of miR-140 inhibited TGF-β1-induced pulmonary fibrosis, and H19 upregulation diminished the inhibitory effects of miR-140 on TGF-β1-induced pulmonary fibrosis, which was involved in the TGF-β/Smad3 pathway. Taken together, our findings showed that H19 knockdown attenuated pulmonary fibrosis via the regulatory network of lncRNA H19–miR-140–TGF-β/Smad3 signaling, and H19 and miR-140 might represent therapeutic targets and early diagnostic and prognostic biomarkers for patients with pulmonary fibrosis.

scholarly journals Amelioration of paraquat-induced pulmonary fibrosis in mice by regulating miR-140-5p expression with the fibrogenic inhibitor Xuebijing

2020 ◽  
Vol 34 ◽  
pp. 205873842092391 ◽  
Author(s):  
Min-na Dong ◽  
Yun Xiao ◽  
Yun-fei Li ◽  
Dong-mei Wang ◽  
Ya-ping Qu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Treatment Group ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
Lavage Fluid ◽  
Tissue Growth ◽  
Control Treatment ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Tgf Β1

Intravenous Xuebijing (XBJ) therapy suppresses paraquat (PQ)-induced pulmonary fibrosis. However, the mechanism underlying this suppression remains unknown. This work aimed to analyze the miR-140-5p-induced effects of XBJ injection on PQ-induced pulmonary fibrosis in mice. The mice were arbitrarily assigned to four groups. The model group was administered with PQ only. The PQ treatment group was administered with PQ and XBJ. The control group was administered with saline only. The control treatment group was administered with XBJ only. The miR-140-5p and miR-140-5p knockout animal models were overexpressed. The gene expression levels of miR-140-5p, transglutaminase-2 (TG2), β-catenin, Wnt-1, connective tissue growth factor (CTGF), mothers against decapentaplegic homolog (Smad), and transforming growth factor-β1 (TGF-β1) in the lungs were assayed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis. The levels of TGF-β1, CTGF, and matrix metalloproteinase-9 (MMP-9) in the bronchoalveolar lavage fluid were assessed by enzyme-linked immunosorbent assay (ELISA). Hydroxyproline (Hyp) levels and pulmonary fibrosis were also scored. After 14 days of PQ induction of pulmonary fibrosis, AdCMV-miR-140-5p, and XBJ upregulated miR-140-5p expression; blocked the expressions of TG2, Wnt-1, and β-catenin; and decreased p-Smad2, p-Smad3, CTGF, MMP-9, and TGF-β1 expressions. In addition, Hyp and pulmonary fibrosis scores in XBJ-treated mice decreased. Histological results confirmed that PQ-induced pulmonary fibrosis in XBJ-treated lungs was attenuated. TG2 expression and the Wnt-1/β-catenin signaling pathway were suppressed by the elevated levels of miR-140-5p expression. This inhibition was pivotal in the protective effect of XBJ against PQ-induced pulmonary fibrosis. Thus, XBJ efficiently alleviated PQ-induced pulmonary fibrosis in mice.

scholarly journals Transient changes of transforming growth factor-β expression in the small intestine of the pig in association with weaning

2005 ◽  
Vol 93 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Jie Mei ◽  
Ruo-Jun Xu
Keyword(s):  
Small Intestine ◽  
Growth Factor ◽  
Western Blot ◽  
Intestinal Mucosa ◽  
Blot Analysis ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Intestinal Villus ◽  
Weaning Pigs ◽  
Tgf Β1

It is well known that early weaning causes marked changes in intestinal structure and function, and transforming growth factor-β (TGF-β) is believed to play an important regulatory role in post-weaning adaptation of the small intestine. The present study examined the distribution and expression intensity of TGF-β in the small intestinal mucosa of pre- and post-weaning pigs using a specific immunostaining technique and Western blot analysis. The level of TGF-β in the intestinal mucosa, as estimated by Western blot analysis, did not change significantly during weaning. However, when examined by the immunostaining technique, TGF-β1 (one of the TGF-β isoforms dominantly expressed in the tissue) at the intestinal villus epithelium, particularly at the apical membrane of the epithelium, decreased significantly 4 d after weaning, while the staining intensity increased significantly at the intestinal crypts compared with that in pre-weaning pigs. These changes were transient, with the immunostaining intensity for TGF-β1 at the intestinal villi and the crypts returning to the pre-weaning level by 8 d post-weaning. The transient decrease in TGF-β1 level at the intestinal villus epithelium was associated with obvious intestinal villus atrophy and marked reduction of mucosal digestive enzyme activities. Furthermore, the number of leucocytes staining positively for TGF-β1 increased significantly in the pig intestinal lamina propria 4 d after weaning. These findings strongly suggest that TGF-β plays an important role in the post-weaning adaptation process in the intestine of the pig.

scholarly journals Interactions between Growth Factors and Integrins: Latent Forms of Transforming Growth Factor-β Are Ligands for the Integrin αvβ1

1998 ◽  
Vol 9 (9) ◽  
pp. 2627-2638 ◽  
Author(s):  
John S. Munger ◽  
John G. Harpel ◽  
Filippo G. Giancotti ◽  
Daniel B. Rifkin
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
A549 Cells ◽  
Transforming Growth Factor Β ◽  
Mutant Form ◽  
Rgd Sequence ◽  
Β Receptor ◽  
Coated Surfaces ◽  
Β Function ◽  
Tgf Β1

The multipotential cytokine transforming growth factor-β (TGF-β) is secreted in a latent form. Latency results from the noncovalent association of TGF-β with its processed propeptide dimer, called the latency-associated peptide (LAP); the complex of the two proteins is termed the small latent complex. Disulfide bonding between LAP and latent TGF-β–binding protein (LTBP) produces the most common form of latent TGF-β, the large latent complex. The extracellular matrix (ECM) modulates the activity of TGF-β. LTBP and the LAP propeptides of TGF-β (isoforms 1 and 3), like many ECM proteins, contain the common integrin-binding sequence RGD. To increase our understanding of latent TGF-β function in the ECM, we determined whether latent TGF-β1 interacts with integrins. A549 cells adhered and spread on plastic coated with LAP, small latent complex, and large latent complex but not on LTBP-coated plastic. Adhesion was blocked by an RGD peptide, and cells were unable to attach to a mutant form of recombinant LAP lacking the RGD sequence. Adhesion was also blocked by mAbs to integrin subunits αv and β1. We purified LAP-binding integrins from extracts of A549 cells using LAP bound to Sepharose. αvβ1 eluted with EDTA. After purification in the presence of Mn2+, a small amount of αvβ5 was also detected. A549 cells migrated equally on fibronectin- and LAP-coated surfaces; migration on LAP was αvβ1 dependent. These results establish αvβ1 as a LAP-β1 receptor. Interactions between latent TGF-β and αvβ1 may localize latent TGF-β to the surface of specific cells and may allow the TGF-β1 gene product to initiate signals by both TGF-β receptor and integrin pathways.

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