scholarly journals The Influence of the Preservation Method and Gamma Irradiation Sterilization on TGF-β and bFGF Levels in Freeze-Dried Amnion Membrane (FD-AM) and Amnion Sponge

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Heri Suroto ◽  
Deny M. Aryawan ◽  
Camilla A. Prakoeswa

Background. Amnion grafts can be preserved as freeze-dried amnion membrane (FD-AM) and amnion sponge. Preserved grafts require to be sterilized by gamma irradiation. However, each step of the process could affect its biological properties. Even so, there are only a few studies that report the influence of the preservation method and gamma irradiation on growth factor levels in preserved amniotic grafts. Methods. This was an in vitro experimental study with a pretest-posttest group design using a consecutive sampling technique in one batch of amnion donors at a particular time. The amnion was made into FD-AM and amnion sponge preparations, and they were sterilized with gamma irradiation (15 kGy and 25 kGy). Nonirradiated specimens served as controls, and 20 mg of each specimen was pulverized to evaluate the growth factors levels using ELISA. Results. There were significant decreases in amnion sponge compared to the FD-AM, both in transforming growth factor beta (TGF-β) and basic fibroblast growth factor (bFGF) levels and in the preirradiated and 25 kGy postirradiated preparations ( p ≤ 0.05 ). The growth factor levels in the preirradiated and postirradiated FD-AM (both 15 kGy and 25 kGy) showed significant differences ( p ≤ 0.05 ). Likewise, the preirradiated amnion sponge group’s growth factor levels compared with the postirradiated amnion sponge group also showed a significant decrease ( p ≤ 0.05 ). Conclusion. TGF-β and bFGF levels were lower in amnion sponge than FD-AM. The FD-AM and amnion sponge preparations’ growth factors levels were reduced following gamma irradiation sterilization. Although the decrease in growth factor levels is significant, the number of growth factor levels is still sufficient for tissue healing.

1994 ◽  
Vol 267 (6) ◽  
pp. E990-E1001 ◽  
Author(s):  
M. Slater ◽  
J. Patava ◽  
K. Kingham ◽  
R. S. Mason

Human fetal osteoblast-like cells formed a regular multilayered structure in vitro with an extensive collagen-based extracellular matrix. With colloidal gold immunocytochemistry, labels for alkaline phosphatase and osteocalcin were distributed in a relatively diffuse pattern, in contrast to the bone growth factors, insulin-like growth factors I and II (IGF-I and IGF-II), transforming growth factor-beta 1 (TGF-beta 1), and basic fibroblast growth factor, which were colocalized in the collagenous matrix of the multilayer. The inclusion of 17 beta-estradiol (10(-11) to 10(-9) M) in the culture medium increased multilayer depths, increased labeling for IGF-I, IGF-II, and TGF-beta 1, and resulted in earlier detection of TGF-beta 1 label. In contrast, the increase in multilayer depth resulting from treatment with human platelets, an exogenous source of growth factors, was not accompanied by an increase in matrix IGF-I, IGF-II, or TGF-beta 1 label, suggesting a particular effect of estradiol to facilitate this process. Because growth factors in bone matrix may act as coupling agents when released during resorption, reduced growth factor incorporation in the presence of reduced sex steroid concentrations may lead to uncoupling of resorption and subsequent formation.


Reproduction ◽  
2000 ◽  
pp. 85-91 ◽  
Author(s):  
S Hasthorpe ◽  
S Barbic ◽  
PJ Farmer ◽  
JM Hutson

At birth, the mouse gonocyte does not resume mitotic activity for several days in vivo but, in an in vitro clonogenic system, cell division commences soon after culture. Somatic testis cell underlays had potent inhibitory activity on gonocyte-derived colony formation (23 +/- 15% compared with 84 +/- 1% in controls; P = 0.0001) when added to cultures of gonocytes in vitro. A Sertoli cell line, TM4B, had an even more pronounced effect on gonocyte clonogenic capacity, with 1 +/- 1% compared with 72 +/- 17% colony formation in controls (P = 0.0003). Testis cells appeared to have a direct inhibitory effect since testis-conditioned medium did not show a significant reduction in the number of colonies. The observed reduction in colony formation with the testis cell underlay was not accounted for by decreased attachment of gonocytes as simultaneous addition of a single cell suspension of testis cells was still effective in significantly reducing colony number when compared with controls (P = 0.01). Therefore, the observed inhibition exerted by testis cells appears to be a consequence of decreased proliferation of gonocytes. Growth factors belonging to the transforming growth factor beta superfamily which are known to be expressed in testis, such as transforming growth factor beta and epidermal growth factor, did not exert any inhibitory action on gonocyte-derived colony formation when added together or alone. However, a shift to a smaller colony size occurred in the presence of transforming growth factor beta and transforming growth factor beta plus epidermal growth factor, indicating a reduction in colony cell proliferation. Evidence for the expression of the Mullerian inhibiting substance receptor on newborn gonocytes using in situ hybridization was inconclusive. This finding was in agreement with the lack of a direct action of Mullerian inhibiting substance on the formation of gonocyte-derived colonies in vitro. Leukaemia inhibitory factor, alone or in combination with forskolin, had neither an inhibitory nor an enhancing effect on gonocyte-derived colony formation. An in vitro clonogenic method to assay for the proliferation of gonocytes in the presence of specific growth factors, cell lines, testis cell underlays and cell suspensions was used to identify a somatic cell-mediated inhibitor which may be responsible for the inhibitory action on gonocyte proliferation in vivo shortly after birth.


1992 ◽  
Vol 101 (4) ◽  
pp. 349-354 ◽  
Author(s):  
David B. Hom ◽  
Robert H. Maisel

Since their discovery 30 years ago, angiogenic growth factors have been demonstrated to stimulate neovascularization in vitro and in animal studies. Over the last decade, knowledge gained in the field of angiogenic growth factors has grown immensely. These angiogenic growth factors exist in four major families: fibroblast growth factor (FGF), transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF). Each has the ability to induce soft tissue vascularization in microgram quantities. In animal models, FGF, TGF-β, PDGF, and EGF have been shown to enhance soft tissue wound healing. In human clinical trials, EGF and a mixture of PDGFs have been demonstrated to accelerate epidermal regeneration in cutaneous wounds. These factors have considerable therapeutic potential in the areas of soft tissue wound healing and otolaryngology. This article reviews important aspects of angiogenic growth factors and discusses their future potential in soft tissue wound healing.


Development ◽  
1991 ◽  
Vol 112 (4) ◽  
pp. 1095-1101
Author(s):  
A.J. Muslin ◽  
L.T. Williams

The effect of growth factors on the formation of cardiac mesoderm in the urodele, Ambystoma mexicanum (axolotl), has been examined using an in vitro explant system. It has previously been shown that cardiac mesoderm is induced by pharyngeal endoderm during neurula stages in urodeles. In this study, explants of prospective cardiac mesoderm from early neurula stage embryos rarely formed beating cardiac tissue in culture. When transforming growth factor beta-1 (TGF-beta 1) or platelet-derived growth factor BB (PDGF) was added to such explants, the frequency of heart tissue formation increased markedly. The addition of other growth factors to these explants did not enhance cardiac mesoderm formation. The addition of basic fibroblast growth factor (bFGF) to prospective heart mesoderm derived from later stage embryos resulted in a decreased tendency to form cardiac tissue. These results suggest that growth factors analogous to TGF-beta 1, PDGF, and bFGF may regulate the initial stages of vertebrate cardiac development in vivo.


1990 ◽  
Vol 111 (5) ◽  
pp. 2139-2148 ◽  
Author(s):  
R J Shaw ◽  
D E Doherty ◽  
A G Ritter ◽  
S H Benedict ◽  
R A Clark

Adherence is an important initial step in the transition of a circulating monocyte to a tissue macrophage. This differentiation is accompanied by an augmented capacity to generate growth factors. We hypothesized that adherence itself might be an important trigger for a sequence of gene activation culminating in cells with increased mRNA encoding profibrotic growth factors such as platelet-derived growth factor B subunit (PDGF[B]) and transforming growth factor-beta (TGF-beta). After in vitro adherence, human monocytes had a biphasic increase in PDGF(B) mRNA with peaks at 6 h and 13 d. No increase in TGF-beta mRNA was observed. The 6-h increase in PDGF(B) mRNA was adherence dependent, and in addition, was abrogated when the cytoskeletal integrity was compromised by cytochalasin D. The 6-h increase in PDGF(B) mRNA was unaltered by adherence in the presence of the monocyte stimulus lipopolysaccharide. Adherence to either fibronectin or collagen-coated plastic had little consistent effect on PDGF(B) mRNA accumulation. The increased PDGF(B) mRNA observed in adherent monocytes was accompanied by increases in mRNAs of the early growth response genes c-fos (maximal at 20 min), c-jun, and EGR2 (maximal at 6-24 h). The increase in c-jun and EGR2, but not c-fos, mRNA was also abrogated by cytochalasin D. These observations suggest that adherence results in increases of c-fos, c-jun, EGR2, and PDGF(B) mRNA. In addition, the increases in c-jun, EGR2, and PDGF(B) may depend on cytoskeletal rearrangement. Modulation of these events at the time of adherence offers a mechanism by which differential priming of the cells may be accomplished.


2022 ◽  
Vol 23 (2) ◽  
pp. 924
Author(s):  
Julia Hauptstein ◽  
Leonard Forster ◽  
Ali Nadernezhad ◽  
Jürgen Groll ◽  
Jörg Teßmar ◽  
...  

In 3D bioprinting for cartilage regeneration, bioinks that support chondrogenic development are of key importance. Growth factors covalently bound in non-printable hydrogels have been shown to effectively promote chondrogenesis. However, studies that investigate the functionality of tethered growth factors within 3D printable bioinks are still lacking. Therefore, in this study, we established a dual-stage crosslinked hyaluronic acid-based bioink that enabled covalent tethering of transforming growth factor-beta 1 (TGF‑β1). Bone marrow-derived mesenchymal stromal cells (MSCs) were cultured over three weeks in vitro, and chondrogenic differentiation of MSCs within bioink constructs with tethered TGF‑β1 was markedly enhanced, as compared to constructs with non-covalently incorporated TGF‑β1. This was substantiated with regard to early TGF‑β1 signaling, chondrogenic gene expression, qualitative and quantitative ECM deposition and distribution, and resulting construct stiffness. Furthermore, it was successfully demonstrated, in a comparative analysis of cast and printed bioinks, that covalently tethered TGF‑β1 maintained its functionality after 3D printing. Taken together, the presented ink composition enabled the generation of high-quality cartilaginous tissues without the need for continuous exogenous growth factor supply and, thus, bears great potential for future investigation towards cartilage regeneration. Furthermore, growth factor tethering within bioinks, potentially leading to superior tissue development, may also be explored for other biofabrication applications.


2021 ◽  
Vol 24 (4) ◽  
pp. 478-486
Author(s):  
S. Saini ◽  
R. A. Bhat

The growth factors platelet derived growth factor (PDGF), transforming growth factor alpha (TGF-α) and transforming growth factor beta (TGF-β) have been demonstrated to stimulate the in vitro prolife­ration of theca and granulosa cells in different animals. The present study was conducted to localise the growth factors PDGF, TGF-α and TGF-β in different types of interstitial cells and stromal cells of normal cycling goat ovaries. Tissue fixed in formalin was processed through a graded series of alcohols and embedded in paraffin wax. The sections were immunohistochemically stained with antibo­dies against PDGF, TGF-α and TGF-β. The binding affinity of interstitial cells and stromal cells were observed and photographed. The staining pattern of PDGF, TGF-α and TGF-β was mild to strong in stromal cells. The primary and secondary interstitial cells exhibited varied staining patterns for all studied growth factors. These findings in goat suggests that PDGF, TGF-α, TGF-β were potentially an important autocrine regulator of different cell functions and possibly a paracrine regulator of ovarian cell function at various development stages.


1993 ◽  
Vol 264 (6) ◽  
pp. F996-F1002 ◽  
Author(s):  
S. A. Rogers ◽  
G. Ryan ◽  
A. F. Purchio ◽  
M. R. Hammerman

Development of the metanephric kidney during embryogenesis is regulated by a number of polypeptide growth factors of renal origin. We have defined previously a role for insulin-like growth factors (IGF) I and II and for transforming growth factor (TGF)-alpha. To delineate the effect of TGF-beta 1, on renal organogenesis, we cultured metanephroi surgically dissected from 13-day-old rat embryos in serum-free chemically defined media. TGF-beta 1 mRNA was present in kidneys from 13-day-old rat embryos, and positive immunostaining for TGF-beta 1 could be demonstrated in cultured metanephroi. However, TGF-beta bioactivity could not be detected in media obtained from the metanephroi. Addition of 10(-9) M TGF-beta 1 to cultures inhibited tubulogenesis, but had no effect on synthesis of IGF-I or -II. Addition of anti-TGF-beta 1 antibodies to cultures accelerated tubulogenesis within the metanephric blastema. These findings establish the potential for TGF-beta 1 production within the rat metanephros during development in vivo. It is possible that this peptide exerts a negative control on the process of tubulogenesis within metanephric blastema and in this manner acts to shape the architecture of mature kidney.


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 679
Author(s):  
Benedict-Uy Fabia ◽  
Joshua Bingwa ◽  
Jiyeon Park ◽  
Nguyen-Mihn Hieu ◽  
Jung-Hoon Ahn

Pseudomonas fluorescens, a gram-negative bacterium, has been proven to be a capable protein manufacturing factory (PMF). Utilizing its ATP-binding cassette (ABC) transporter, a type I secretion system, P. fluorescens has successfully produced recombinant proteins. However, besides the target proteins, P. fluorescens also secretes unnecessary background proteins that complicate protein purification and other downstream processes. One of the background proteins produced in large amounts is FliC, a flagellin protein. In this study, the master regulator of flagella gene expression, fleQ, was deleted from P. fluorescens Δtp, a lipase and protease double-deletion mutant, via targeted gene knockout. FleQ directs flagella synthesis, so the new strain, P. fluorescens ΔfleQ, does not produce flagella-related proteins. This not only simplifies purification but also makes P. fluorescens ΔfleQ an eco-friendly expression host because it will not survive outside a controlled environment. Six recombinant growth factors, namely, insulin-like growth factors I and II, beta-nerve growth factor, fibroblast growth factor 1, transforming growth factor beta, and tumor necrosis factor beta, prepared using our supercharging method, were successfully secreted by P. fluorescens ΔfleQ. Our findings demonstrate the potential of P. fluorescens ΔfleQ, combined with our supercharging process, as a PMF.


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