Soluble Collagen Research Articles

Effect of Heating Methods on Quality Attributes of Culled Saanen Crossbred Goat Meat

The effect of boiling, grilling, and microwaving until reaching temperature of 85 °C on culled Saanen goat meat was evaluated and compared to raw samples. Biceps femoris muscle was used to evaluate the effect of these heating methods on proximate composition, collagen, cook loss, color, and texture profile analysis. Supraspinatus muscle was used to determine the effect of these heating methods on changes in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) of meat during 5 days of chilled storage. Boiled and grilled samples showed lower moisture (63.04 and 63.89 %, respectively) and higher protein (29.20 and 29.59 %, respectively) and fat (5.98 and 4.01 %, respectively) than those of the microwaved sample (68.03 % moisture, 26.72 % protein, and 2.95 % fat) (P < 0.05). Higher total collagen in the grilled sample (14.35 mg/g) and higher soluble collagen percentage (6.57 %) in the microwaved sample were obtained (P < 0.05). Boiled and grilled samples revealed higher cook loss (39.70 and 41.28 %, respectively) compared to microwaved samples (28.82 %) (P < 0.05). Grilled samples exhibited higher hardness (3,730.21 g), gumminess (2,397.76), and chewiness (1,774.71) than those of other heated samples (P < 0.05). Higher lightness (L* = 54.90), lower redness (a* = 4.11) and yellowness (b* = 13.96) in boiled sample were found (P < 0.05). Grilled samples exhibited sharper PV formation while boiled samples revealed sharper TBARS formation during storage (P < 0.05). In summary, variation in remaining moisture, soluble collagen, parallel with types of heating medium led to complexity in the results obtained in total solid, cook loss, color, and texture profile analysis (TPA). Boiled samples were prone to yield higher TBARS formation.

Collagen profile and tenderness of strip loin and silverside originated from polish Holstein-Friesian bulls of the black and white variety

The aim of the study was to determine and compare the collagen profile of two beef carcass cuts: silverside (M. semitendinosus) and strip loin (M. longissimus lumborum), originated from Polish Holstein-Friesian bulls of the black and white variety. Silverside showed higher total, acid-soluble, total soluble, and insoluble collagen content than strip loin. Significant differences between silverside and strip loin were noted in their share of water-soluble and acid-soluble collagen (% total collagen, P<0.05). The thermal treatment caused cooking losses, which reached 38% in strip loin and 40% in silverside. There were no significant differences in shear force values or organoleptic quality between the cuts, which indicates their similar usefulness as meat for roasting. The content and profile of intramuscular collagen did not influence the organoleptic quality or shear force values of silverside and strip loin.

Soluble Collagen VI treatment enhances mesenchymal stem cells expansion for engineering cartilage.

Bone Marrow‐derived mesenchymal stem cells (BM‐MSC) are an attractive source for cell‐based therapies in cartilage injury owing to their efficient differentiation into chondrocytes and their immune‐suppressive abilities. However, their clinical use is hampered by a scarcity of cells leading to compromised efficacy. While expansion of human MSC ex vivo can potentially overcome the scarcity of cells, current methods lead to a rapid loss of the stem cell properties. In this study, we report soluble Collagen VI (cartilage pericellular matrix component) as a potential biologic that can expand the MSC population while maintaining the stem cell phenotype as confirmed by expression of the stem cell markers CD105 and CD90. Short‐term treatment with Collagen VI additionally retains the potential of MSC to differentiate into mature chondrocytes in pellet culture. Cartilage pellets generated from MSC treated with Collagen VI or control express comparable amounts of the chondrogenic markers Collagen II, Aggrecan and Sox9, and the extracellular glycosaminoglycans. Our observations confirm that the use of the endogenous and cartilage‐specific factor Collagen VI is valuable for a rapid and efficient expansion of MSC for potential use in cartilage regeneration and osteoarthritis.

Chronic asthma and Mesenchymal stem cells: Hyaluronan and airway remodeling

BackgroundPrevious studies have demonstrated that ovalbumin sensitization promotes chronic asthma phenotype in murine asthma model. Human mesenchymal stem cells (hMSCs) are multipotent cells in vitro that have been shown to decrease inflammation and can reverse airway remodeling when infused into an in vivo chronic asthma model. However, the mechanism by which hMSCs reverse remodeling is still unclear. In this study, we hypothesized that hMSCs influence remodeling by decreasing extracellular matrix (ECM) deposition, more specifically by decreasing collagen I, collagen III, and hyaluronan synthesis.MethodsChronic asthma phenotype was produced in an in vitro model with 3 T3 murine airway fibroblast cells by stimulating with GM-CSF. Collagen I and collagen III gene expression was investigated using RT-PCR and Taqman techniques. Hyaluronan was evaluated using FACE and Western Blots. The chronic asthma phenotype was produced in vivo in murine model using sensitization with ovalbumin with and without hMSC infusion therapy. ECM deposition (specifically trichrome staining, soluble and insoluble collagen deposition, and hyaluronan production) was evaluated. Image quantification was used to monitor trichrome staining changes.ResultsGM-CSF which induced collagen I and collagen III production was down-regulated with hMSC using co-culture. In the in vivo model, Ovalbumin induced enhanced ECM deposition, soluble and insoluble collagen production, and lung elastance. hMSC infusions decreased ECM deposition as evidenced by decreases in soluble and insoluble collagen production.ConclusionhMSCs participate in improved outcomes of remodeling by reversing excess collagen deposition and changing hyaluronan levels.

Effects of moist- and dry-heat cooking on the meat quality, microstructure and sensory characteristics of native chicken meat.

This study investigates the effects of moist- (water-cooking; WC) and dry-heat (oven-cooking; OC) on the quality, microstructure and sensory characteristics of native chicken breast meat. The results revealed that OC meat had a significantly higher cooking time, cooking loss, and shear force values and lower L* values. Protein solubility decreased after cooking in both cooking methods; however, no statistical difference was observed between WC and OC meats, whereas collagen solubility and myofibrillar fragmentation index (MFI) increased after cooking and WC meat exhibited higher collagen solubility and MFI (P<0.05). The fiber diameter and sarcomere length decreased substantially after cooking, and fibril shrinkage was noticeable in OC meat (P<0.05). Descriptive sensory analysis revealed that WC meat exhibited a significantly higher moisture release and lower initial hardness, chewdown hardness and residual loose particles. A darker color and enhanced chickeny flavor were observed for OC meat. Based on the unique sensory and physicochemical characteristics in demand, producers should employ appropriate cooking methods to optimize native chicken meat quality.

Understanding the effect of pulsed electric fields on thermostability of connective tissue isolated from beef pectoralis muscle using a model system

Brisket is a low value/tough meat cut that contains a large amount of connective tissue. Conversion of collagen into gelatin during heating reduces the toughness of the connective tissue however this conversion is slow at low cooking temperatures (around 60°C). The objective of this project was to determine the ability of pulsed electric field (PEF) processing to reduce the thermal stability of connective tissue. To achieve this, a novel model system was designed in which connective tissue obtained from beef deep pectotalis muscle (brisket) was exposed to PEF at combinations of electric field strength (1.0 and 1.5kV/cm) and specific energy (50 and 100kJ/kg) within an agar matrix at electrical conductivities representing the electrical conductivity found in brisket. Differential scanning calorimetry showed that PEF treatment significantly (p<0.05) decreased the denaturation temperature of connective tissue compared to untreated samples. Increasing electric field strength and the specific energy increased the Ringer soluble collagen fraction. PEF treated samples showed higher solubilization compared to the untreated samples at both 60°C and 70°C in heat solubility test. SEM examination of PEF treated (at 1.5kV/cm and 100kJ/kg) and untreated samples revealed that PEF appeared to increase the porosity of the connective tissue structure. These finding suggest that PEF processing is a technology that could be used to improve the tenderness and decrease the cooking time of collagen rich, meat cuts.

AQX-1125, small molecule SHIP1 activator inhibits bleomycin-induced pulmonary fibrosis.

The phosphatase SHIP1 negatively regulates the PI3K pathway, and its predominant expression within cells of the haematopoietic compartment makes SHIP1 activation a novel strategy to limit inflammatory signalling generated through PI3K. AQX-1125 is the only clinical-stage, orally administered, SHIP1 activator. Here, we demonstrate the prophylactic and therapeutic effects of AQX-1125, in a mouse model of bleomycin-induced lung fibrosis. For prophylactic evaluation, AQX-1125 (3, 10 or 30mg·kg-1 ·d-1 , p.o.) or dexamethasone (1mg·kg-1 ·d-1 , i.p.) were given to CD-1 mice starting 3days before intratracheal administration of bleomycin (0.1IU per mouse) and continued daily for 7 or 21 days. Therapeutic potentials of AQX-1125 (3, 10 or 30mg·kg-1 ·d-1 , p.o.) or pirfenidone (90mg·kg-1 ·d-1 , p.o.) were assessed by initiating treatment 13days after bleomycin instillation and continuing until day 28. Given prophylactically, AQX-1125 (10 and 30mg·kg-1 ) reduced histopathological changes in lungs, 7 and 21days following bleomycin-induced injury. At the same doses, AQX-1125 reduced the number of total leukocytes, neutrophil activity, TGF-β immunoreactivity and soluble collagen in lungs. Administered therapeutically, AQX-1125 (10 and 30mg·kg-1 ) improved lung histopathology, cellular infiltration and reduced lung collagen content. At 30mg·kg-1 , the effects of AQX-1125 were similar to those of pirfenidone (90mg·kg-1 ) with corresponding improvements in disease severity. AQX-1125 prevented bleomycin-induced lung injury during the inflammatory and fibrotic phases. AQX-1125, given therapeutically, modified disease progression and improved survival, as effectively as pirfenidone.

Dating Reassembled Collagen from Fossil Bones

AbstractInsoluble bone collagen is one of the most common materials used for high-resolution radiocarbon (14C) dating. Unfortunately, in some bones, poor preservation of the insoluble collagen excludes the possibility of dating. During the burial of the bone the collagen sometimes degrades into peptides. These peptides are soluble in the acid used to dissolve the bone mineral. It is known that under appropriate conditions, collagen has the ability to self-assemble. Here we exploit this capability and present a method for reassembling the soluble collagen peptides in archaeological bones and dating them. We treated the acid fraction generated during the demineralization of the bone by desalting and neutralizing the solution by dialysis. During the dialysis, the soluble collagen peptides reassemble and precipitate in the dialysis bag. We used FTIR spectroscopy to determine that the precipitated material is indeed collagen. The14C dates obtained from the reassembled collagen were compared to the dates of “standard” insoluble collagen, extracted in parallel from the same bone. Although there are some divergences of the dates, 3 out of 10 samples could have been dated only by the reassembled collagen. This shows that collagen peptides reassembly can be a valuable tool for dating bones with little or no insoluble collagen.

Potency of Culled Saanen Crossbred Goat in Supplying Raw Meat for Traditional Thai Butchery

Potency of culled Saanen crossbred goat meat to replace the supply of yearling Boer crossbred goat meat was evaluated. Selected muscles from leg and shoulder cuts were analysed for their nutritional (proximate composition, collagen, amino acids, fatty acids), physicochemical (pH, myoglobin, drip loss, cook loss, shear force, lightness (L*) redness (a*) yellowness (b*), microstructure), and sensory (triangle test, hedonic test) evaluations. Meat samples from culled Saanen crossbred goat exhibited higher values in protein, collagen, and MUFA (P<0.05) than those from Boer crossbred goat, while lower values in ash, soluble collagen, and SFA were obtained (P<0.05). Meat from culled Saanen crossbred goat revealed higher cook loss, shear force, and redness compared to those from a yearling Boer crossbred goat (P<0.05). In addition, thicker perimysium in meat of Saanen crossbred goat was obtained particularly that could be seen on leg part. In sensory evaluation result, the panels could detect the differences between raw meat characteristics of these goat breeds (P<0.05) within the same muscle. However, the panels could not distinguish the difference between breeds in leg meat after being cooked. Shoulder meat of Saanen crossbred goat had less acceptance level compared to the other samples (P<0.05) particularly on its texture and taste quality. In summary, shoulder cut of culled Saanen crossbred goat exhibited a well-intentioned potency to substitute the supply of meat from yearling Boer crossbred goat. Nevertheless, pre-treatment might be applied to leg cut of Saanen crossbred goat to solve the less acceptance level of its textural and taste characteristics.

Selective matrix metalloproteinase inhibition increases breaking strength and reduces anastomotic leakage in experimentally obstructed colon.

Colonic obstruction causes loss of collagen and impairment of anastomotic integrity by matrix metalloproteinases (MMPs). Unexpectedly, pharmacological MMP inhibition increased anastomotic leakage (AL) in obstructed colon possibly due to the non-selective nature of these compounds and the experimental model applied. We therefore studied the effects of selective MMP inhibition on the healing of anastomoses in colon obstructed by a novel laparoscopic technique. Left colon was obstructed in 38 male Sprague-Dawley rats (226-284g). After 12h, stenoses were resected and end-to-end anastomoses constructed. Baseline breaking strength was determined in 6 animals on day 0. The remaining 32 rats were randomized to daily treatment with the selective MMP-8, MMP-9, and MMP-12 inhibitor AZD3342 (n=16) or vehicle (n=16). On day 3, anastomoses were evaluated for AL and breaking strength. Isolated anastomotic wound tissue was analyzed on total collagen and pepsin-insoluble and pepsin-soluble collagen by hydroxyproline. The soluble collagens were further differentiated into native, measured by Sircol, and fragmented forms. Baseline breaking strength was maintained with AZD3342 but decreased by 25% (P=0.023) in the vehicle group. The anastomotic breaking strength of AZD3342-treated rats was 44% higher (P=0.008) than the vehicle-treated rats. Furthermore, the AL rate was reduced (P=0.037) with AZD3342 compared with vehicle treatment. AZD3342 treatment influenced neither the total or insoluble collagen concentrations nor the degree of fragmentation of the soluble collagen triple helices. Selective MMP inhibition increased anastomotic breaking strength and reduced AL after resection of colonic obstruction.

Interferon-γ Treatment of Human Laryngotracheal Stenosis–Derived Fibroblasts

Laryngotracheal stenosis (LTS) is a fibroproliferative disorder of the glottis, subglottis, and trachea. In models of fibrosis from other organ systems, the CD4+ T-cell response has been shown to regulate extracellular matrix deposition. Specifically, helper T cell 2 (TH2) promotes fibrosis, whereas TH1 and associated cytokines have been shown to be antifibrotic. However, this antifibrotic effect of the TH1 response has not been demonstrated in LTS. To determine whether the TH1 cytokine interferon-γ inhibits the function of LTS-derived fibroblasts in vitro. This in vitro controlled study included 6 patients with iatrogenic LTS undergoing routine surgical subglottic and tracheal dilation at a single institution. Fibroblasts were isolated from biopsy specimens of laryngotracheal scar and normal-appearing trachea. The presence of fibroblasts was confirmed by an immunohistochemical analysis. Laryngotracheal stenosis-derived fibroblasts were treated with interferon-γ and compared with untreated controls (2 sets of untreated, LTS-derived fibroblasts [media did not contain interferon-γ]) and normal airway fibroblasts (fibroblasts isolated from normal trachea). Data were collected from August 2015 through June 2016. Treatment with interferon-γ, 10 ng/mL. Cellular proliferation, fibrosis gene expression (using quantitative reverse transcription polymerase chain reaction analysis), soluble collagen, and cellular histologic features were assessed. Among the 6 patients (6 women; mean [SD] age, 38.3 [17.2] years), LTS-derived fibroblast proliferation was reduced in patients who received interferon-γ treatment compared with untreated controls on days 3 (mean difference, -6515 cells; 95% CI, -10 630 to -2600 cells) to 6 (mean difference, -47 521 cells; 95% CI, -81 285 to -13 757 cells). Interferon-γ treatment reduced collagen types I and III gene expression by 86% and 68%, respectively, and resulted in lower total collagen production (10.94 vs 14.89 μg/mL). In addition, interferon-γ treatment resulted in a 32% reduction in expression of transforming growth factor β in LTS-derived fibroblasts. Interferon-γ reduced proliferation, soluble collagen production, and collagen expression in LTS-derived fibroblasts while also reducing the expression of the profibrotic cytokine transforming growth factor β. These findings suggest that therapeutics aimed at increasing interferon-γ and the TH1 response could attenuate LTS.

The eating quality of beef from young dairy bulls derived from two breed types at three ages from two different production systems

AbstractExpansion of the Irish dairy herd has led to more dairy breed male calves being available for beef production. This study investigated the physico-chemical and sensory characteristics of beef from Holstein-Friesian (HF) and Jersey × HF (JEX) young bulls fed pasture grass only or pasture grass plus 2 kg concentrate during their first grazing season and slaughtered at 15, 19 or 22 mo of age. Longissimus thoracis (LT) muscles were collected from 67 carcasses. Postmortem pH, ultimate pH (pHu), meat colour, chemical composition, collagen content and solubility were evaluated. After ageing for 21 d, Warner-Bratzler shear force and cooking loss were determined, and assessments by a trained sensory panel were conducted. Meat from older animals was darker. The pHu, moisture and ash contents decreased, while residual roast beef flavour length increased with age. However, increasing age to slaughter did not negatively influence tenderness. JEX beef had lower cooking loss, was darker and redder, in addition to having higher sensory scores for initial tenderness and fattiness than HF beef. Warner-Bratzler variables were positively correlated with cooking loss and chewiness and were negatively correlated with intramuscular fat (IMF) content, soluble collagen and initial tenderness. In summary, most young dairy bull beef samples were acceptably tender after 21 d of ageing and half of them had acceptable IMF content. Slaughter age affected beef colour, pHu, chemical composition and flavour length. The eating quality of meat from the JEX breed type was considered to be superior to that of the HF breed type. Diet during the first season had no effect on meat quality traits.

Assessment of physico-chemical traits related to eating quality of young dairy bull beef at different ageing times using Raman spectroscopy and chemometrics

Raman spectroscopy and chemometrics were investigated for the prediction of eating quality related physico-chemical traits of Holstein-Friesian bull beef. Raman spectra were collected on the 3rd, 7th and 14th days post-mortem. A frequency range of 1300–2800cm−1 was used for partial least squares (PLS) modelling. PLS regression (PLSR) models for the prediction of WBSF and cook loss achieved an R2CV of 0.75 with RMSECV of 6.82 N and an R2CV of 0.77 with RMSECV of 0.97%w/w respectively. For the prediction of intramuscular fat, moisture and crude protein content, R2CV values were 0.85, 0.91 and 0.70 with RMSECV of 0.52%w/w, 0.39%w/w and 0.38%w/w respectively. An R2CV of 0.79 was achieved for the prediction of both total collagen and hydroxyproline content, while for collagen solubility the R2CV was 0.88. All samples (100%) from 15- and 19-month old bulls were correctly classified using PLS discriminant analysis (PLS-DA), while 86.7% of samples from different muscles (longissimus thoracis, semitendinosus and gluteus medius) were correctly classified. In general, PLSR models using Raman spectra on the 3rd day post-mortem had better prediction performance than those on the 7th and 14th days. Raman spectroscopy and chemometrics have potential to assess several beef physical and chemical quality traits.

Lipo-PGE1 suppresses collagen production in human dermal fibroblasts via the ERK/Ets-1 signaling pathway.

Dysregulation of collagen production contributes to various pathological processes, including tissue fibrosis as well as impaired wound healing. Lipo-prostaglandin E1 (Lipo-PGE1), a lipid microsphere-incorporated prostaglandin E1, is used as a vasodilator for the treatment of peripheral vascular diseases. Lipo-PGE1 was recently shown to enhance human dermal fibroblast (HDF) migration and in vivo wound healing. No published study has characterized the role of Lipo-PGE1 in collagen regulation in HDFs. Here, we investigated the cellular signaling mechanism by which Lipo-PGE1 regulates collagen in HDFs. Collagen production was evaluated by the Sircol collagen assay, Western blot analysis of type I collagen and real time PCR. Unexpectedly, Lipo-PGE1 decreased mRNA expression of collagen 1A1, 1A2, and 3A1. Lipo-PGE1 markedly inhibited type I collagen and total soluble collagen production. In addition, Lipo-PGE1 inhibited transforming growth factor-β-induced collagen expression via Smad2 phosphorylation. To further investigate whether extracellular signal-regulated kinase (ERK)/Ets-1 signaling, a crucial pathway in collagen regulation, is involved in Lipo-PGE1-inhibited collagen production, cells were pretreated with an ERK-specific inhibitor, PD98059, prior to the addition of Lipo-PGE1. Lipo-PGE1-inhibited collagen mRNA expression and total soluble collagen production were recovered by pretreatment with PD98059. Moreover, Lipo-PGE1 directly induced the phosphorylation of ERK. Furthermore, silencing of Ets-1 recovered Lipo-PGE1-inhibited collagen production and PD98059 blocked Lipo-PGE1-enhanced Ets-1 expression. The present study reveals an important role for Lipo-PGE1 as a negative regulator of collagen gene expression and production via ERK/Ets-1 signaling. These results suggest that Lipo-PGE1 could potentially be a therapeutic target in diseases with deregulated collagen turnover.

Biaxial mechanical properties of bovine jugular venous valve leaflet tissues.

Venous valve incompetence has been implicated in diseases ranging from chronic venous insufficiency (CVI) to intracranial venous hypertension. However, while the mechanical properties of venous valve leaflet tissues are central to CVI biomechanics and mechanobiology, neither stress-strain curves nor tangent moduli have been reported. Here, equibiaxial tensile mechanical tests were conducted to assess the tangent modulus, strength and anisotropy of venous valve leaflet tissues from bovine jugular veins. Valvular tissues were stretched to 60% strain in both the circumferential and radial directions, and leaflet tissue stress-strain curves were generated for proximal and distal valves (i.e., valves closest and furthest from the right heart, respectively). Toward linking mechanical properties to leaflet microstructure and composition, Masson's trichrome and Verhoeff-Van Gieson staining and collagen assays were conducted. Results showed: (1) Proximal bovine jugular vein venous valves tended to be bicuspid (i.e., have two leaflets), while distal valves tended to be tricuspid; (2) leaflet tissues from proximal valves exhibited approximately threefold higher peak tangent moduli in the circumferential direction than in the orthogonal radial direction (i.e., proximal valve leaflet tissues were anisotropic; [Formula: see text]); (3) individual leaflets excised from the same valve apparatus appeared to exhibit different mechanical properties (i.e., intra-valve variability); and (4) leaflets from distal valves exhibited a trend of higher soluble collagen concentrations than proximal ones (i.e., inter-valve variability). To the best of the authors' knowledge, this is the first study reporting biaxial mechanical properties of venous valve leaflet tissues. These results provide a baseline for studying venous valve incompetence at the tissue level and a quantitative basis for prosthetic venous valve design.

Effects of electrospun scaffolds of di-O-butyrylchitin and poly-(ε-caprolactone) on wound healing.

We sought to determine the usefulness of electrospun dibutyrylchitin (DBC) or poly-(ε-caprolactone [PCL]), in wound treatment. We investigated the mechanisms of action of these polymers on wound healing. We synthesized DBC, a newly identified ester derivative of chitin, using a patented method comprising the substitution of butyryl groups at positions C-3 and C-6 in chitin molecules. We confirmed the double substitution by the butyric groups using infrared spectrometry. The fibrous scaffolds were obtained using the electrospinning method. A polypropylene net was implanted subcutaneously in the rat and served as a wound model. Both DBC and PCL increased granulation tissue weight in the wound. In contrast to PCL, DBC did not abolish glycosaminoglycan changes in wounds. The tested samples did not impair total collagen synthesis or induce excessive fibrosis. In both PCL- and DBC-treated wounds, we observed a lower level of soluble collagen (compared with controls). The results show better hydration of the wounds in both the DBC and PCL groups. No induction of large edema formation by the tested materials was observed. These polymers induced almost identical macrophage-mediated reactions to foreign-body implantation. The implants increased the blood vessel number in a wound. Both PCL and DBC could be used as scaffolds or dressings for wound treatment. The materials were safe and well tolerated by animals. As DBC did not disturb glycosaminoglycan accumulation in wounds and absorbed twice as much liquid as PCL, it can be considered superior.

Hydrolysates of Fish Skin Collagen: An Opportunity for Valorizing Fish Industry Byproducts.

During fish processing operations, such as skinning and filleting, the removal of collagen-containing materials can account for up to 30% of the total fish byproducts. Collagen is the main structural protein in skin, representing up to 70% of dry weight depending on the species, age and season. It has a wide range of applications including cosmetic, pharmaceutical, food industry, and medical. In the present work, collagen was obtained by pepsin extraction from the skin of two species of teleost and two species of chondrychtyes with yields varying between 14.16% and 61.17%. The storage conditions of the skins appear to influence these collagen extractions yields. Pepsin soluble collagen (PSC) was enzymatically hydrolyzed and the resultant hydrolysates were ultrafiltrated and characterized. Electrophoretic patterns showed the typical composition of type I collagen, with denaturation temperatures ranged between 23 °C and 33 °C. In terms of antioxidant capacity, results revealed significant intraspecific differences between hydrolysates, retentate, and permeate fractions when using β-Carotene and DPPH methods and also showed interspecies differences between those fractions when using DPPH and ABTS methods. Under controlled conditions, PSC hydrolysates from Prionace glauca, Scyliorhinus canicula, Xiphias gladius, and Thunnus albacares provide a valuable source of peptides with antioxidant capacities constituting a feasible way to efficiently upgrade fish skin biomass.

Extraction and Characterization of Pepsin Soluble Collagen from the Body Wall of Sea Cucumber Acaudina leucoprocta

ABSTRACTSea cucumber Acaudina leucoprocta is a potential alternative collagen source. However, the high levels of heavy metals contained in the body wall restricts its utilization. In this work, an efficient method was established to remove the heavy metals accumulated in the body wall of A.leucoprocta by demineralizing with 0.2 M ethylenediaminetetraacetic acid (EDTA). The resulting body wall of A.leucoprocta was then used for extracting pepsin-soluble collagen (PSC) with pepsin proteolysis. The PSC from the body wall of A.leucoprocta was obtained with a yield of 43.99 ± 0.65% (dry weight) and high purity. Maximum and minimum solubility for the isolated PSC in 0.5 M acetic acid was observed at pH 2.66 and 4.43, respectively. The solubility was remarkably decreased in the presence of NaCl. The denaturation temperature of PSC rehydrated in 0.5 M acetic acid was measured as 25.4°C. The PSC was characterized as type I collagen, which consists of three α1 chains without α2 chain. Interestingly, α1 chain in PSC showed two isoforms with the pI values of 4.02 and 4.29. The heavy metals existing in PSC were all below the contaminant limit of edible gelatin. The PSC isolated from the body wall could be an alternative to mammalian collagens.

Role of epithelial-mesenchymal transition (EMT) and fibroblast function in cerium oxide nanoparticles-induced lung fibrosis

The emission of cerium oxide nanoparticles (CeO2) from diesel engines, using cerium compounds as a catalyst to lower the diesel exhaust particles, is a health concern. We have previously shown that CeO2 induced pulmonary inflammation and lung fibrosis. The objective of the present study was to investigate the modification of fibroblast function and the role of epithelial-mesenchymal transition (EMT) in CeO2-induced fibrosis. Male Sprague-Dawley rats were exposed to CeO2 (0.15 to 7mg/kg) by a single intratracheal instillation and sacrificed at various times post-exposure. The results show that at 28days after CeO2 (3.5mg/kg) exposure, lung fibrosis was evidenced by increased soluble collagen in bronchoalveolar lavage fluid, elevated hydroxyproline content in lung tissues, and enhanced sirius red staining for collagen in the lung tissue. Lung fibroblasts and alveolar type II (ATII) cells isolated from CeO2-exposed rats at 28days post-exposure demonstrated decreasing proliferation rate when compare to the controls. CeO2 exposure was cytotoxic and altered cell function as demonstrated by fibroblast apoptosis and aggregation, and ATII cell hypertrophy and hyperplasia with increased surfactant. The presence of stress fibers, expressed as α-smooth muscle actin (SMA), in CeO2-exposed fibroblasts and ATII cells was significantly increased compared to the control. Immunohistofluorescence analysis demonstrated co-localization of TGF-β or α-SMA with prosurfactant protein C (SPC)-stained ATII cells. These results demonstrate that CeO2 exposure affects fibroblast function and induces EMT in ATII cells that play a role in lung fibrosis. These findings suggest potential adverse health effects in response to CeO2 nanoparticle exposure.

Effects of anabolic implants and ractopamine-HCl on muscle fiber morphometrics, collagen solubility, and tenderness of beef longissimus lumborum steaks.

The objective of this study was to examine the effects of growth-promoting technologies (GP) and postmortem aging on longissimus lumborum muscle fiber cross-sectional area (CSA), collagen solubility, and their relationship to meat tenderness. Two groups of black-hided crossbred feedlot heifers (group 1: = 33, initial BW 430 ± 7 kg; group 2: = 32, initial BW 466 ± 7 kg) were blocked by BW and assigned to 1 of 3 treatments consisting of: no implant and no ractopamine hydrochloride (CON; = 21); implant, no ractopamine hydrochloride (IMP; = 22); implant and ractopamine hydrochloride (COMBO; = 22). Heifers that received an implant were administered an implant containing 200 mg trenbolone acetate and 20 mg estradiol on d 0 of the study, and heifers in the COMBO group received 400 mg∙head∙d of ractopamine hydrochloride for 28 (Group 1) or 29 d (Group 2) at the end of 90- (Group 1) or 106-d (Group 2) feeding period. Following harvest, strip loins were collected and further fabricated into 5 roasts for postmortem aging (DOA) periods of 2, 7, 14, 21, or 35 d. After aging, Warner-Bratzler shear force (WBSF), muscle fiber CSA, and collagen solubility were measured. There was no treatment × DOA interaction for WBSF ( = 0.86), but treatment and DOA impacted WBSF ( < 0.01). Over the entire aging study, COMBO steaks had greater ( < 0.01) shear force values when compared to CON steaks. The IMP steaks tended to have decreased ( = 0.07) shear force when compared to the COMBO steaks, but did not differ ( = 0.11) from CON steaks. The IMP and COMBO treatments had increased type IIA fiber CSA when compared to CON ( < 0.01). When compared to each other, the IMP and COMBO type IIA fiber CSA did not differ ( = 0.76). Type I and IIX fiber CSA tended to be greater than CON for IMP and COMBO treatments ( < 0.10). There was no treatment × DOA interaction for all collagen measures ( > 0.33). Collagen amounts were not impacted by GP treatment ( > 0.72), but DOA increased the concentration of soluble collagen ( = 0.04). Fiber CSA of all fiber types were positively correlated ( < 0.05; = 0.21 to 0.28) with WBSF only on d 2 of aging, while soluble collagen amount tended to negatively correlate with WBSF on d 7 and 14 of aging ( < 0.10; = -0.24 and -0.23, respectively). Administration of GP during heifer finishing resulted in greater steak WBSF over 35 d of aging, which was not due to collagen characteristics and only minimally affected by fiber CSA.