Comparison of structural changes in skin and amnion tissue grafts for transplantation induced by gamma and electron beam irradiation for sterilization

Sterilization is an important step in the preparation of biological material for transplantation. The aim of the study is to compare morphological changes in three types of biological tissues induced by different doses of gamma and electron beam radiation. Frozen biological tissues (porcine skin xenografts, human skin allografts and human amnion) were irradiated with different doses of gamma rays (12.5, 25, 35, 50 kGy) and electron beam (15, 25, 50 kGy). Not irradiated specimens served as controls. The tissue samples were then thawn and fixed in 10 % formalin, processed by routine paraffin technique and stained with hematoxylin and eosin, alcian blue at pH 2.5, orcein, periodic acid Schiff reaction, phosphotungstic acid hematoxylin, Sirius red and silver impregnation. The staining with hematoxylin and eosin showed vacuolar cytoplasmic changes of epidermal cells mainly in the samples of xenografts irradiated by the lowest doses of gamma and electron beam radiation. The staining with orcein revealed damage of fine elastic fibers in the xenograft dermis at the dose of 25 kGy of both radiation types. Disintegration of epithelial basement membrane, especially in the xenografts, was induced by the dose of 15 kGy of electron beam radiation. The silver impregnation disclosed nuclear chromatin condensation mainly in human amnion at the lowest doses of both radiation types and disintegration of the fine collagen fibers in the papillary dermis induced by the lowest dose of electron beam and by the higher doses of gamma radiation. Irradiation by both, gamma rays and the electron beam, causes similar changes on cells and extracellular matrix, with significant damage of the basement membrane and of the fine and elastic and collagen fibers in the papillary dermis, the last caused already by low dose electron beam radiation.     

Scanning electron microscopic assessment on surface morphology of preserved human amniotic membrane after gamma sterilisation

Human amniotic membrane that has been processed and sterilised by gamma irradiation is widely used as a biological dressing in surgical applications. The morphological structure of human amniotic membrane was studied under scanning electron microscopy (SEM) to assess effects of gamma radiation on human amniotic membrane following different preservation methods. The amniotic membrane was preserved by either air drying or submerged in glycerol before gamma irradiated at 15, 25 and 35 kGy. Fresh human amniotic membrane, neither preserved nor irradiated was used as the control. The surface morphology of glycerol preserved amnion was found comparable to the fresh amniotic membrane. The cells of the glycerol preserved was beautifully arranged, homogonous in size and tended to round up. The cell structure in the air dried preserved amnion seemed to be flattened and dehydrated. The effects of dehydration on intercellular channels and the microvilli on the cell surface were clearly seen at higher magnifications (10,000×). SEM revealed that the changes of the cell morphology of the glycerol preserved amnion were visible at 35 kGy while the air dried already changed at 25 kGy. Glycerol preservation method is recommended for human amniotic membrane as the cell morphological structure is maintained and radiation doses lower than 25 kGy for sterilization did not affect the appearance of the preserved amnion.     

Effects of ionizing radiation and preservation on biomechanical properties of human costal cartilage

Tissue banks around the world store human cartilage obtained from cadaveric donors for use in diverse reconstructive surgical procedures. To ensure this tissue is sterile at the time of distribution, tissues may be sterilized by ionizing radiation. In this work, we evaluate the physical changes in deep frozen costal cartilage (?70 °C) or costal cartilage preserved in high concentrations of glycerol (>98 %) followed by a terminal sterilization process using ionizing radiation, at 3 different doses (15, 25 and 50 kGy). Tension and compression tests were carried out to determine the mechanical changes related both to the different preservation methods and irradiation doses. For both methods of preservation, tension strength was increased by about 24 %, when cartilage tissue was irradiated with 15 kGy. Deep frozen samples, when irradiated with 25 or 50 kGy, had a decrease in their mechanical performance, albeit to a lesser extent than when tissues were preserved in high concentration of glycerol and equally irradiated. In conclusion, processing in high concentration of glycerol did not increase tissue protection against radiation damage; while cartilage preserved in high concentrations of glycerol withstands radiation up to 25 kGy, deep frozen human costal cartilage may be sterilized with a doses up to 50 kGy without significant mechanical impact.     

Quantifying the ultrastructure changes of air-dried and irradiated human amniotic membrane using atomic force microscopy: a preliminary study

Air-dried and sterilized amnion has been widely used as a dressing to treat burn and partial thickness wounds. Sterilisation at the standard dose of 25 kGy was reported to cause changes in the morphological structure as observed under the scanning electron microscope. This study aimed to quantify the changes in the ultrastructure of the air-dried amnion after gamma-irradiated at several doses by using atomic force microscope. Human placentae were retrieved from mothers who had undergone cesarean elective surgery. Amnion separated from chorion was processed and air-dried for 16 h. It was cut into 10?×?10 mm, individually packed and exposed to gamma irradiation at 5, 15, 25 and 35 kGy. Changes in the ultrastructural images of the amnion were quantified in term of diameter of the epithelial cells, size of the intercellular gap and membrane surface roughness. The longest diameter of the amnion cells reduced significantly after radiation (p?<?0.01) however the effect was not dose dependent. No significant changes in the shortest diameter after radiation, except at 35 kGy which decreased significantly when compared to 5 kGy (p?<?0.01). The size of the irradiated air-dried amnion cells reduced in the same direction without affecting the gross ultrastructure. At 15 kGy the intercellular gap decreased significantly (p?<?0.01) with Ra and Rq, values reflecting surface roughness, were significantly the highest (p?<?0.01). Changes in the ultrastructure quantified by using atomic force microscope could complement results from other microscopic techniques.     

The influence of the irradiation regime upon mycotoxins production under experimental conditions

The paper handles the problem of the inactivation of the toxinogenic strain Aspergillus flavus following the application of gamma radiation to wheat. The amount of the applied dose and of the absorbed dose of ionizing radiation upon the inhibition of mycelium growth and toxin production were defined. The aflatoxin B1 was determined by extracting in chloroform and developed on Silufol R within the choroform; aceton system. The applied doses of gamma radiation (3-30 kGy) have show that the absorbed dose does not inhibit aflatoxin production. By combining the action of gamma radiation with humidity of the wheat (humidity 13-15%; 25% irradiation 6 kGy) an inactivation was reached. With the help of toxicologico-genetical tests (the Dominant Lethal Mutations Test, the Three Generations Test) the influence was traced of contaminated, irradiated substrates upon the health of experimental animals. It follows from the results obtained that in long-term feeding with contaminated wheat irradiated by gamma rays no positive mutagenic activity has been recorded. It allows to presume that wheat of humidity of 25% contaminated by a weakly toxigenic strain Aspergillus flavus irradiated by a dose of 6 kGy, and wheat of a humidity of 13-15%, contaminated by a strongly toxinogenic strain of Aspergillus flavus, irradiated by a dose of 6 kGy, are no genetic risk for white rats.     

Chondrogenic differentiation of human bone marrow-derived mesenchymal stem cells treated by GSK-3 inhibitors

A study of the cartilage differentiation of mesenchymal stem cells (MSCs) would be of particular interest since one strategy for cell-based treatment of cartilage defects emphasizes the use of cells that are in a differentiated state. The present study has attempted to evaluate the effects of two well-known glycogen synthase kinase-3 inhibitors, including lithium chloride (LiCl) and SB216763 on a human marrow-derived MSC (hMSC) chondrogenic culture. Passaged-3 MSCs were condensed into small pellets and cultivated in the following groups based on the supplementation of chondrogenic medium: transforming growth factor (TGF)-β1, TGF-β1 + LiCl, TGF-β1 + SB216763, TGF-β3, TGF-β3 + LiCl, and TGF-β3 + SB216763. The cultures were maintained for 21 days and then analyzed for expression of Sox9, aggrecan, collagen II, β-catenin, and axin genes. Deposition of glycosaminoglycan (GAG) in the cartilage matrix was also measured for certain cultures. The presence of both LiCl and SB216763 along with TGF-β in the MSC chondrogenic culture led to the up-regulation of cartilage-specific genes. TGF-β3 appeared much better than TGF-β1. Based on our findings, SB216763 was more effective in up-regulation of cartilage-specific genes. These chondrogenic effects appeared to be mediated through the Wnt signaling pathway since β-catenin and axin tended to be up-regulated and down-regulated, respectively. In the culture with SB216763 + TGF-β3, significantly more GAG was deposited (P < 0.05). In conclusion, addition of either SB216763 or LiCl to hMSC chondrogenic culture up-regulates cartilage-specific gene expression and enhances GAG deposition in the culture.     

Structural changes of skin and amnion grafts for transplantation purposes following different doses of irradiation

An important part of the preparation of biological material for transplantation is sterilization. The aim of our study was to assess the impact of ionizing radiation on three types of biological tissues and the impact of different doses on cells and extracellular matrix. Three types of frozen tissues (porcine skin xenografts, human skin allografts and human amnion) were divided into five groups, control and groups according to the dose of radiation to which these samples were exposed (12.5, 25, 35 and 50 kGy). The tissue samples were fixed by formalin, processed by routine paraffin technique and stained with hematoxylin and eosin, alcian blue at pH 2.5, orcein, periodic acid schiff reaction and silver impregnation. The staining with hematoxylin and eosin showed hydropic degeneration of the cells of epidermis in xenografts by the dose of 12.5 kGy, in human skin it was observed by the dose of 35 kGy. The staining for elastic fibers revealed damage of fine elastic fibers in the xenografts dermis by the dose of 12.5 kGy, in the allografts by 35 kGy. Another change was the disintegration of basement membrane of epithelium, especially in the human amnion at the dose of 50 kGy. The silver impregnation visualized nuclear chromatin condensation mainly in human amnion at the dose of 12.5 kGy. Our results have shown that the porcine xenografts and human amnion were more sensitive to irradiation than the human skin. In the next phase of the project we will focus at more detailed changes in the tissues using immunohistochemical techniques.     

Lefty A attenuates the TGF-β1-induced epithelial to mesenchymal transition of human renal proximal epithelial tubular cells

The epithelial to mesenchymal transition (EMT) is a crucial event for renal fibrosis that can be elicited by TGF-β1/Smads signaling and its downstream mediator connective tissue growth factor (CTGF). As a distinct member of the TGF-β superfamily, Lefty A has been shown to be significantly downregulated in the kidneys of patients with severe ureteral obstruction, suggesting its role in renal fibrosis induced by obstructive nephropathy. In order to determine whether Lefty A prevents TGF-β1-induced EMT, human proximal tubule epithelial cells (HK-2) were stably transfected with Lefty A or control vectors and stimulated with 10 ng/ml TGF-β1 for 48 h. The results show that stimulation with TGF-β1 led to EMT including cell morphology changes, Smad2/3 signaling pathway activation, increased α-SMA, collagen type I, and CTGF expression, and decreased E-cadherin expression in mock-transfected HK-2 cells. Overexpression of Lefty A efficiently blocked p-Smad2/3 activation and attenuated all these EMT changes induced by TGF-β1. This finding suggests that Lefty A may serve as a potential new therapeutic target to inhibit or even reverse EMT during the process of renal fibrosis.     

Induction of chondrogenic differentiation in mesenchymal stem cells by TGF-beta cross-linked to collagen-PLLA [poly(l-lactic acid)] scaffold by transglutaminase 2

Transglutaminase-mediated cross-linking has been employed to optimize the mechanical properties and stability of tissue scaffolds. We have characterized tissue transglutaminase (TG2)-mediated cross-linking as a useful tool to deliver biologically-active TGF to mesenchymal stem cells (MSCs) and direct their differentiation towards a chondrogenic lineage. TGF-β3 is irreversibly cross-linked by TG2 to collagen type II-coated poly(l-lactic acid) nanofibrous scaffolds and activates Smad phosphorylation and Smad-dependent expression of a luciferase reporter. Human bone marrow-derived MSCs cultured on these scaffolds deposit cartilaginous matrix after 14 days of culture at 50 % efficiency compared to chondrogenesis in the presence of soluble TGF-β3. These findings are significant because they suggest a novel approach for the programming of MSCs in a spatially controlled manner by immobilizing biologically active TGF-β3 via cross-linking to a collagen-coated polymeric scaffold.     

Substantiation of 25 kGy radiation sterilization dose for banked air dried amniotic membrane and evaluation of personnel skill in influencing finished product bioburden

Preparation of amniotic membrane (AM) by air drying method followed by radiation sterilization is simple and valuable approach; sterility and quality of the final AM product are depending on the quality management system at the tissue bank. Validation and substantiation of radiation sterilization dose (RSD) for tissue allografts is an essential step for the development and validation of the standard operating procedures (SOP). Application of SOP is perfectly relying on trained staff. Skills differences among personnel involved in AM preparation could have an effect on microbiological quality of the finished product and subsequently on the RSD required. AM were processed by four different couples of the tissue bank technicians. The AM grafts were randomly selected and subjected to bioburden test to validate and substantiate the 25 kGy RSD. Bioburden test for AM grafts were also useful to evaluate the skill of the tissue bank technicians and thus, to validate the current SOP for air dried AM. Moreover, the effect of placental source on bioburden counts on AM grafts was assessed. Substantiation of the 25 kGy RSD at a sterility assurance level of 10^?1, and sample item portion = 1, was carried out using Method VD _max ²⁵ of the International Organization for Standardization, document no. 11137-2 (ISO in Sterilization of healthcare products—radiation—part 2: establishing the sterilization dose, Method VDmax—substantiation of 25 kGy or 15 kGy as the sterilization dose, International Standard Organization, 2006). The results showed that there were no significant differences in the bioburdens of the four batches (α = 1 %), this means no significant differences in the skill of the four couples of the tissue bank technicians in terms of their ability to process AM according to the air dried AM SOP. The 25 kGy RSD was validated and substantiated as a valid sterilization dose for the AM prepared with the current established SOP at the Biotechnology Research Center experimental tissue bank. The donor’s type of delivery, normal or caesarean, showed no significant effect on the levels of microbial counts on the tested AMs (α = 1 %).     

A novel collagen/platelet-rich plasma (COL/PRP) scaffold: preparation and growth factor release analysis

Platelet-rich plasma (PRP) has been widely used in clinical practice for more than 20 years because it causes the release of many growth factors. However, the burst release pattern and short release period of PRP have become obstacles to its application. An optimal controllable release system is an urgent need for researchers. This study investigated whether collagen/PRP (COL/PRP) scaffolds can serve as a vehicle for the controllable release of growth factors. We fabricated a novel scaffold that integrates PRP activated by thrombin or collagen into type I collagen. The mechanical properties, cytotoxicity, and transforming growth factor β1 (TGF-β1), platelet derived growth factor (PDGF), fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) content were evaluated. Our results demonstrate that the COL/PRP scaffolds were not cytotoxic to L-929 fibroblasts. The PDGF and FGF content in the thrombin group was at a higher level and lasted for a long period of time. Collagen and thrombin played the same role in the release of TGF-β1 and VEGF. These data suggest that the novel COL/PRP scaffolds provide a carrier for the controllable release of growth factors and may be used in tissue- regenerative therapies.     

A novel collagen scaffold supports human osteogenesis—applications for bone tissue engineering

Collagen glycosaminoglycan (CG) scaffolds have been clinically approved as an application for skin regeneration. The goal of this study has been to examine whether a CG scaffold is a suitable biomaterial for generating human bone tissue. Specifically, we have asked the following questions: (1) can the scaffold support human osteoblast growth and differentiation and (2) how might recombinant human transforming growth factor-beta (TGF-β₁) enhance long-term in vitro bone formation? We show human osteoblast attachment, infiltration and uniform distribution throughout the construct, reaching the centre within 14 days of seeding. We have identified the fully differentiated osteoblast phenotype categorised by the temporal expression of alkaline phosphatase, collagen type 1, osteonectin, bone sialo protein, biglycan and osteocalcin. Mineralised bone formation has been identified at 35 days post-seeding by using von Kossa and Alizarin S Red staining. Both gene expression and mineral staining suggest the benefit of introducing an initial high treatment of TGF-β₁ (10 ng/ml) followed by a low continuous treatment (0.2 ng/ml) to enhance human osteogenesis on the scaffold. Osteogenesis coincides with a reduction in scaffold size and shape (up to 70% that of original). A notable finding is core degradation at the centre of the tissue-engineered construct after 49 days of culture. This is not observed at earlier time points. Therefore, a maximum of 35 days in culture is appropriate for in vitro studies of these scaffolds. We conclude that the CG scaffold shows excellent potential as a biomaterial for human bone tissue engineering.     

Serum level of transforming growth factor beta 1 is associated with left atrial voltage in patients with chronic atrial fibrillation

Background

Atrial tissue fibrosis can cause electrical or structural remodeling in patients with atrial fibrillation. Transforming growth factor beta 1(TGF-β1) signaling acts as a central role in fibroblast activation. In this report, we aimed to investigate the relationship between serum level of TGF-β1 and mean left atrial voltage in patients with chronic atrial fibrillation (CAF).

In vitro study of nano-HA/PLLA composite scaffold for rabbit BMSC differentiation under TGF-β1 induction

The aim of this study is to investigate the effects of differentiation of rabbit bone marrow mesenchymal stem cells (rBMSCs) into chondrocytes induced by transforming growth factor-beta1 (TCP-β1) composite poly-1actide-co-glycolic acid/nano-hydroxyapatite (PLLA/nano-HA) to the construction of biomimetic artificial cartilage in vitro. In the low-temperature extrusion preparation of PLLA/nano-HA composite porous scaffolds, rBMSCs were isolated and cultured to third generation in vitro, induced by TGF-β1-contained special inducing system into chondrocytes, 14 d later, identified by toluidine blue and type II collagen immunohistochemistry staining, and then the differential chondrocytes composite into the PLLA/nano-HA composite porous scaffolds, using scanning electron microscopy (SEM) to observe the growth conditions and cell attachment on the composite in the 7th,14th, and 21st day and to gather cells on composite in the 7th, 14th, and 21st day of cell. RT-PCR is used to detect the expression of aggrecan (Col2A1 in mRNA) and Western blot for detection of the expression of type II collagen of the attached cells. rBMSCs can differentiate into chondrocytes when induced, and the differentiation of chondrocytes secreting GAG by toluidine blue staining and type II collagen immunohistochemistry staining was positive; SEM confirm the cells distribution evenly, stretching well in composite. RT-PCR of aggrecan, Col2A1 in mRNA, and Western-blot of type II collagen expression in the differentiation of chondrocytes have different levels. Using TGF-β1 containing special inducing system induced rBMSCs into chondrocytes, then into compounds of PLLA/nano-HA composite porous scaffolds, and cell carrier complex proliferated well and secreted the chondrocyte-specific extracellular matrix stably, successfully constructing artificial bionic in vitro.     

Dose dependent effect of C-type natriuretic peptide signaling in glycosaminoglycan synthesis during TGF-β1 induced chondrogenic differentiation of mesenchymal stem cells

Recent investigations credited important roles to C-type natriuretic peptide (CNP) signaling during chondrogenesis. This study investigated the putative role of CNP in transforming growth factor (TGF)-β1 induced in vitro chondrogenic differentiation of mesenchymal stem cells (MSCs) in pellet culture. MSCs were derived from human trabecular bone and were characterized on the basis of their cell surface antigens and adipogenic, osteogenic, and chondrogenic differentiation potential. TGF-β1 induced chondrogenic differentiation and glycosaminoglycan (GAG) synthesis was analyzed on the basis of basic histology, collagen type II, Sox 9 and aggrecan expressions, and Alcian blue staining. Results revealed that human trabecular bone-derived MSCs express CNP and NPR-B analyzed on the basis of RT-PCR and immunohistochemistry. In pellet cultures of MSCs TGF-β1 successfully induced chondrogenic differentiation and GAG synthesis. RT-PCR analyses of both CNP and NPR-B during this process revealed an activation of this signaling pathway in response to TGF-β1. Similar cultures induced with TGF-β1 and treated with different doses of CNP showed that CNP supplementation at 10^?8 and 10^?7 M concentrations significantly increased GAG synthesis in a dose dependent manner, whereas at 10^?6 M concentration this stimulatory effect was diminished. In conclusion, CNP/NPR-B signaling pathway is activated during TGF-β1 induced chondrogenic differentiation of human trabecular bone-derived MSCs and may strongly be involved in GAG synthesis during this process. This effect is likely to be a dose-dependent effect.     

The evaluation of cartilage differentiations using transforming growth factor beta3 alone and with combination of bone morphogenetic protein-6 on adult stem cells

In our quest to standardize our formula for a clinical trial, transforming growth factor-beta3 (TGF-β3) alone and in combination with bone morphogenetic protein-6 (BMP-6) were evaluated for their effectiveness in cartilage differentiation. Bone Marrow Stem Cells (BMSCs) and Adipose Derived Stem Cells (ADSCs) were induced to chondrogenic lineage using two different media. Native chondrocytes served as positive control. ADSCs and BMSCs proved multipotency by tri-lineage differentiations. ADSC has significantly higher growth kinetics compare to Chondrocyte only p ≤ 0.05. Using TGF-β3 alone, BMSC revealed higher expressions for hyaline cartilage genes compare to ADSCs. Chondrocyte has significantly higher early chondrogenic markers expression to ADSCs and BMSCs, while BMSCs was only higher to ADSC at chondroadherin, p ≤ 0.0001. On mature chondrogenic markers, chondrocytes were significantly higher to ADSCs and BMSCs for aggrecan, collagen IX, sry (sex determining region y)-box9, collagen II and fibromodullin; and only to ADSC for collagen XI. BMSC was higher to ADSC for aggrecan and collagen IX, p ≤ 0.0001. The combination of TGF-β3 + BMP-6 revealed increased gene expressions on both BMSCs and ADSCs for early and mature chondrogenic markers, but no significance difference. For dedifferentiation markers, ADSC was significantly higher to chondrocyte for collagen I. Glycosaminoglycan evaluations with both formulas revealed that chondrocytes were significantly higher to ADSCs and BMSCs, but none was significant to each other, p ≤ 0.0001. Combination of 10 ng TGF-β3 with 10 ng of BMP-6 enhanced chondrogenic potentials of BMSCs and ADSCs compare to TGF-β3 alone. This could be the ideal cocktail for either cell’s chondrogenic induction.     

Study of tensiometric properties,microbiological and collagen content in nile tilapia skin submitted to different sterilization methods

Tissue bioengineering development is a global concern and different materials are studied and created to be safe, effective and with low cost. Nile Tilapia skin had shown its biological potential as covers for the burn wound. This study evaluates the tilapia skin histological, collagen properties and tensiometric resistance, after treatment by different sterilization methods. Tilapia skin samples were submitted to two sterilization processes: (1) chemical, which consisted in two 2% chlorhexidin baths, followed by sequential baths in increasing glycerol concentrations; and (2) radiation, when glycerolized skin samples were submitted to gamma radiation at 25, 30 and 50 kGy. Microscopic analyzes were performed through Haematoxylin–eosin and Picrosirius Red under polarized light. For tensiometric analysis, traction tests were performed. Glycerol treated skin presented a discrete collagen fibers disorganization within the deep dermis, while irradiated skin did not show any additional change. Throughout the steps of chemical sterilization, there was a higher proportion of collagen with red/yellow birefringence (type I) in the skin samples up to the first bath in chlorhexidin, when compared to samples after the first two glycerol baths (P < 0.005). However, there was no difference in relation to total collagen between groups. In irradiated skin, there was a larger total collagen preservation when using until 30 kGy (P < 0.005). Tensiometric evaluation did not show significant differences in relation to maximum load in the groups studied. We concluded that chemical and radiation (25 and 30 kGy) are efficient methods to sterilize Nile Tilapia skin without altering its microscopic or tensiometric characteristics.     

FT-IR investigations on effect of high doses of gamma radiation-induced damage to polystyrene and mechanism of formation of radiolysis products

The present article focuses on the influence of gamma irradiation and post-irradiation storage conditions on FT-IR spectra of 1 mm thick polystyrene irradiated with 51, 77 and 129 kGy. The increase in amplitude corresponding to 3600, 3400 and 2100 cm^??1 stretching frequencies clearly showing the formation of O–H and C=O bonds (~?25%). On prolonged storage (2160 h) in the dark, there is an increase in O–H group (~?28%). The electron cloud facilitates the formation of hydroxyl group in irradiated polystyrene. The post-irradiation treatment with heat conversely showed a reduction of O–H, C–H and C=O (9–16%) groups due to radical–radical recombination at higher temperatures and light intensities. This investigation finds its applications in memory devices, optical sensors, radiation dosimetry and different space and radiation facilities.     

Expression,purification, and evaluation of in vivo anti-fibrotic activity for soluble truncated TGF-β receptor II as a cleavable His-SUMO fusion protein

Excessive production of transforming growth factor-β1 (TGF-β1) and its binding to transforming growth factor-β receptor type II (TGF-βRII) promotes fibrosis by activation of the TGF-β1-mediated signaling pathway. Thus, the truncated extracellular domain of TGF-βRII (tTβRII) is a promising anti-fibrotic candidate, as it lacks the signal transduction domain. In this work, the native N-terminal tTβRII was prepared as a His-SUMO fusion protein (termed His-SUMO-tTβRII) in Escherichia coli strain BL21 (DE3). His-SUMO-tTβRII was expressed as a soluble protein under optimal conditions (6 h of induction with 0.5 mM IPTG at 37 °C). His-SUMO-tTβRII was purified by Ni–NTA resin chromatography, and then cleaved with SUMO protease to release native tTβRII, which was re-purified using a Ni–NTA column. Approximately 12 mg of native tTβRII was obtained from a one liter fermentation culture with no less than 95% purity. In vivo studies demonstrated that tTβRII prevented CCl₄-induced liver fibrosis, as evidenced by the inhibition of fibrosis-related Col I and α-SMA protein expression in C57BL/6 mice. In addition, tTβRII downregulated phosphorylation of SMAD2/3, which partly repressed TGF-β1-mediated signaling. These data indicate that the His-SUMO expression system is an efficient approach for preparing native tTβRII that possesses anti-liver fibrotic activity, allowing for the large-scale production of tTβRII, which potentially could serve as an anti-fibrotic candidate for treatment of TGF-β1-related diseases.