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This study assessed the biocompatibility of two types of nanogold composites: fibronectin-gold (FN-Au) and collagen-gold (Col-Au). It consisted of three main parts: surface characterization, in vitro biocompatibility assessments, and animal models. To determine the structural and functional differences between the materials used in this study, atomic force microscopy, Fourier-transform infrared spectroscopy, and ultraviolet-visible spectrophotometry were used to investigate their surface topography and functional groups. The F-actin staining, proliferation, migration, reactive oxygen species generation, platelet activation, and monocyte activation of mesenchymal stem cells (MSCs) cultured on the FN-Au and Col-Au nanocomposites were investigated to determine their biological and cellular behaviors. Additionally, animal biocompatibility experiments measured capsule formation and collagen deposition in female Sprague–Dawley rats. The results showed that MSCs responded better on the FN-Au and Col-AU nanocomposites than on the control (tissue culture polystyrene) or pure substances, attributed to their incorporation of an optimal Au concentration (12.2 ppm), which induced significant surface morphological changes, nano topography cues, and better biocompatibility. Moreover, neuronal, endothelial, bone, and adipose tissues demonstrated better differentiation ability on the FN-Au and Col-Au nanocomposites. Nanocomposites have a crucial role in tissue engineering and even vascular grafts. Finally, MSCs were demonstrated to effectively enhance the stability of the endothelial structure, indicating that they can be applied as promising alternatives to clinics in the future. [ABSTRACT FROM AUTHOR]

Acute and chronic liver failure are clinically significant conditions, and the artificial liver support system (ALSS) is emerging as a novel and effective approach for the clinical management of liver failure. Within this framework, scaffold materials occupy a pivotal position as integral components of the bioreactor. Elevating the performance capabilities of these scaffolds not only augments the therapeutic efficacy of the artificial liver but also lays the groundwork for refining and selecting large-scale hepatocyte culture models. In this study, we introduced a novel hepatocyte scaffold material designated as PET-COL, crafted by coating polyethylene terephthalate (PET) with collagen. This involved a sequence of modifications, including alkaline hydrolysis, EDC/NHS activation and crosslinking, as well as collagen conjugation. The physicochemical attributes of the scaffold were thoroughly characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), second harmonic generation (SHG), water contact angle measurements, and high-performance liquid chromatography–mass spectrometry (HPLC-MS). Furthermore, an investigation into the material's biological properties was conducted that encompassed SEM (HepaRG growth), fluorescence staining (assessment of cell viability), staining by trypan blue (HepaRG counting), CCK-8 (proliferation of cells), biochemical testing, and immunosorbent assay. Our findings revealed that collagen was covalently bonded to the PET surface, leading to a substantial enhancement in the material's hydrophilicity (p < 0.001). The quantity of collagen coating was determined to be precisely 33.30 μg per scaffold. Human liver progenitor HepaRG cells thrived on the PET-COL material. Compared with the untreated group, cell viability, albumin secretion, urea synthesis, and the expression levels of CYP3A4 and CPS1 increased significantly (p < 0.001), demonstrating remarkable biological vitality. The PET-COL scaffold, as developed in this study, holds immense potential for application in bioartificial livers. [ABSTRACT FROM AUTHOR]

Pulsed electrical stimulation (PES) is known to affect cellular activities. We previously found PES to human dermal fibroblasts (HFs) promoted platelet-derived growth factor subunit A (PDGFA) gene expression, which enhanced proliferation. In this study, we investigated PES effects on fibroblast collagen production and differentiation into myofibroblasts. HFs were electrically stimulated at 4800 Hz and 5 V for 60 min. Imatinib, a specific inhibitor of PDGF receptors, was treated before PES. After 6 h of PES, PDGFA, α-smooth muscle actin (α-SMA), and collagen type I α1 chain gene expressions were upregulated in PES group. Imatinib suppressed the promoted expression except for PDGFA. Immunofluorescence staining and enzyme-linked immunosorbent assay showed the production of α-SMA and collagen I was enhanced in PES group but suppressed in PES + imatinib group at 48 h after PES. Therefore, PES promotes the production of α-SMA and collagen I in fibroblasts, which is triggered by PDGFA that is upregulated early after PES. [ABSTRACT FROM AUTHOR]

Abstract Background Very little is known about the characteristics of echocardiographic abnormalities and joint hypermobility in Chinese patients with osteogenesis imperfecta (OI). The aim of our study was to investigate the characteristics, prevalence and correlation of echocardiographic abnormalities and joint hypermobility in Chinese patients with OI. Methods A cross-sectional comparative study was conducted in pediatric and adult OI patients who were matched in age and sex with healthy controls. Transthoracic echocardiography was performed in all patients and controls, and parameters were indexed for body surface area (BSA). The Beighton score was used to evaluate the degree of joint hypermobility. Results A total of 48 patients with OI (25 juveniles and 23 adults) and 129 age- and sex-matched healthy controls (79 juveniles and 50 adults) were studied. Four genes (COL1A1, COL1A2, IFITM5, and WNT1) and 39 different mutation loci were identified in our study. Mild valvular regurgitation was the most common cardiac abnormality: mild mitral and tricuspid regurgitation was found in 12% and 36% of pediatric OI patients, respectively; among 23 OI adults, 13% and 17% of patients had mild mitral and tricuspid regurgitation, respectively, and 4% had mild aortic regurgitation. In multiple regression analysis, OI was the key predictor of left atrium diameter (LAD) (β=-3.670, P

At present, osteoarthritis stands as one of the most prevalent degenerative musculoskeletal diseases globally. The inherent lack of self-healing capacity in articular cartilage presents a considerable obstacle in treating osteoarthritis. Tissue engineering emerged as a promising strategy for the regeneration of osteochondral defects. Collagen, a primary component of bone and cartilage, stands out as a widely utilized natural material in osteochondral tissue engineering. Among various collagen types, Type I and type II collagen are notably prominent in this field. This review initially summarizes the advantageous and disadvantageous properties of type I/II collagen in osteochondral tissue engineering, proceeds to introduce their applications in this context, and concludes with a prospective outlook on the future development of type I/II collagen's applications.

Collagen-derived peptides have been gaining interest due to their potential to act as DPP-IV inhibitors, which are considered to have antidiabetic effects. This study focused on extracting type I collagen from discarded southern bluefin tuna skin, confirming its structure and properties, and then measuring the ability of its hydrolysates to act as DPP-IV inhibitors. First, type I collagen was purified from southern bluefin tuna skin, and the constituent subunit was found to contain the α3(I) chain. Next, enzymatic hydrolysates were prepared, and their DPP-IV inhibitory activity measurements were examined and compared. Collagenase hydrolysate showed the highest DPP-IV inhibitory activity (71.8 ± 0.3 %), and considering digestive degradation, collagenase-pepsin-trypsin hydrolysate was prepared and separated into fractions via anion exchange chromatography, cartridge column, and HPLC. Notably, the 70 % methanol eluted fraction separated via cartridge column was found to have an IC50 of 0.26 ± 0.01 mg/ml. Subsequently, a novel peptide GPSGGGYDV with the highest DPP-IV inhibitory activity (IC50 value 82±0.0 µM) was purified from this fraction and found to be a competitive inhibitor of DPP-IV. This is the first study to investigate the DPP-IV inhibitory potential of type I collagen hydrolysate from southern bluefin tuna.

BACKGROUND: Abnormal extracellular matrix accumulation and excessive proliferation of fibroblasts are the main manifestations of pathological scars. Excessive proliferation of fibroblasts leads to the production of large amounts of collagen-based extracellular matrix. Therefore, to investigate the role of fibroblast fibrosis in the formation of pathological scar will provide a new idea for revealing the mechanism of pathological scar and biological therapy. OBJECTIVE: To investigate the effect of RAS-selective lethal small molecule 3 (RSL3) on the fibrosis of human pathological scar fibroblasts. METHODS: Then cases of pathological scar tissue and normal skin tissue samples from the same individuals, provided by the Department of Burn Plastic Surgery, General Hospital of Ningxia Medical University, were collected. Fibroblasts of human pathological scar and human normal skin were extracted and used in the following experiments. The general condition of the pathological scar tissue and the normal skin tissue was detected by hematoxylin-eosin staining. The appearance of fibroblasts from pathological scar and normal skin were observed by inverted microscope. The fibroblasts were verified by immunofluorescence assay. The cells were treated with different concentrations of RSL3 (1, 3, 5, 7, 9, 11, 13 μmol/L). The inhibitory concentration of RSL3 on fibroblasts was detected by cell counting kit-8. Control group (without treatment) and RSL3 intervention group (treated with 7 μmol/L RSL3 for 24 hours) were set up. The mRNA and protein expressions of glutathione peroxidase 4, type I collagen, type III collagen and α-smooth muscle actin were detected by qRT-PCR and western blot, respectively. Level of malondialdehyde in cells was detected. The residual scratch area was measured by cell scratch test after 24 hours to calculate the percentage of residual scratch area. RESULTS AND CONCLUSION: The expression of glutathione peroxidase 4 in the pathological scar group was higher than that in the normal skin group (mRNA: t=3.252, P < 0.01; protein: t=5.075, P < 0.01). The expression of glutathione peroxidase 4 in the pathological scar fibroblast group was higher than that in the normal skin fibroblast group (mRNA: t=10.32, P < 0.01; protein: t=26.22, P < 0.01). Compared with the control group, the expression of glutathione peroxidase 4 was decreased (mRNA: t=2.798, P < 0.05; protein: t=4.643, P < 0.01), the content of malondialdehyde was increased (t=2.917, P < 0.05), the expression of type I collagen (mRNA: t=15.84, P < 0.01; protein: t=4.610, P < 0.01), type III collagen (mRNA: t=28.86, P < 0.01; protein: t=7.713, P < 0.01) and α-smooth muscle actin (mRNA: t=2.671, P < 0.05; protein: t=7.417, P < 0.01) were decreased in the RSL3 intervention group. Compared with the control group, the migration ability was weakened in the RSL3 intervention group (t=14.06, P < 0.01). To conclude, RSL3 can inhibit the expression of glutathione peroxidase 4 and then inhibit the ability of fibrosis and migration of pathological scar fibroblasts. [ABSTRACT FROM AUTHOR]

Heat shock protein 47 (HSP47), also known as SERPINH1, functions as a collagen-specific molecular chaperone protein essential for the formation and stabilization of the collagen triple helix. Here, we delved into the regulatory pathways governed by HSP47, shedding light on collagen homeostasis. Our investigation revealed a significant reduction in HSP47 mRNA levels in the skin tissue of older mice as compared to their younger counterparts. The augmented expression of HSP47 employing lentivirus infection in fibroblasts resulted in an increased secretion of type I collagen. Intriguingly, the elevated expression of HSP47 in fibroblasts correlated with increased protein and mRNA levels of type I collagen. The exposure of fibroblasts to IRE1α RNase inhibitors resulted in the reduced manifestation of HSP47-induced type I collagen secretion and expression. Notably, HSP47-overexpressing fibroblasts exhibited increased XBP1 mRNA splicing. The overexpression of HSP47 or spliced XBP1 facilitated the nuclear translocation of β-catenin and transactivated a reporter harboring TCF binding sites on the promoter. Furthermore, the overexpression of HSP47 or spliced XBP1 or the augmentation of nuclear β-catenin through Wnt3a induced the expression of type I collagen. Our findings substantiate that HSP47 enhances type I collagen expression and secretion in fibroblasts by orchestrating a mechanism that involves an increase in nuclear β-catenin through IRE1α activation and XBP1 splicing. This study therefore presents potential avenues for an anti-skin-aging strategy targeting HSP47-mediated processes. [ABSTRACT FROM AUTHOR]

Background: Very little is known about the characteristics of echocardiographic abnormalities and joint hypermobility in Chinese patients with osteogenesis imperfecta (OI). The aim of our study was to investigate the characteristics, prevalence and correlation of echocardiographic abnormalities and joint hypermobility in Chinese patients with OI. Methods: A cross-sectional comparative study was conducted in pediatric and adult OI patients who were matched in age and sex with healthy controls. Transthoracic echocardiography was performed in all patients and controls, and parameters were indexed for body surface area (BSA). The Beighton score was used to evaluate the degree of joint hypermobility. Results: A total of 48 patients with OI (25 juveniles and 23 adults) and 129 age- and sex-matched healthy controls (79 juveniles and 50 adults) were studied. Four genes (COL1A1, COL1A2, IFITM5, and WNT1) and 39 different mutation loci were identified in our study. Mild valvular regurgitation was the most common cardiac abnormality: mild mitral and tricuspid regurgitation was found in 12% and 36% of pediatric OI patients, respectively; among 23 OI adults, 13% and 17% of patients had mild mitral and tricuspid regurgitation, respectively, and 4% had mild aortic regurgitation. In multiple regression analysis, OI was the key predictor of left atrium diameter (LAD) (β=-3.670, P < 0.001) and fractional shortening (FS) (β = 3.005, P = 0.037) in juveniles, whereas for adults, OI was a significant predictor of LAD (β=-3.621, P < 0.001) and left ventricular mass (LVM) (β = 58.928, P < 0.001). The percentages of generalized joint hypermobility in OI juveniles and adults were 56% and 20%, respectively. Additionally, only in the OI juvenile group did the results of the Mann‒Whitney U test show that the degree of joint hypermobility was significantly different between the echocardiographic normal and abnormal groups (P = 0.004). Conclusions: Mild valvular regurgitation was the most common cardiac abnormality in both OI juveniles and adults. Compared with OI adults, OI juveniles had more prevalent and wider joint hypermobility. Echocardiographic abnormalities may imply that the impairment of type I collagen is more serious in OI. Baseline echocardiography should be performed in OI patients as early as possible. [ABSTRACT FROM AUTHOR]

Osteogenesis imperfecta (OI) is a group of genetic disorders of bone formation characterized by soft and shorter brittle bones in affected individuals. OI is generally considered a collagenopathy resulting from abnormal expression of type I collagen. As assay system to detect the cellular level and quality of type I collagen would help in rapid and correct detection of OI from the diagnostic perspectives. Here, we report an immunofluorescence assay for detection of type I collagen in fibroblast models of OI and represented them into two broad categories based on the expression level and aggregation characteristics of pro‐α1(I). Cell phenotypic assays of pro‐α1(I) in OI‐related gene knocked down fibroblasts revealed aggregates of pro‐α1(I) in conditions with knockdown of SERPINF1, CRTAP, P3H1, PPIB, SERPINH1, FKBP10, TMEM38B, MESD, and KDELR2, whereas pro‐α1(I) expression was very low in fibroblasts which had knockdown of IFITM5, SP7, BMP1, WNT1, CREB3L1, MBTPS2, and CCDC134. The expression of pro‐α1(I) showed abundant and non‐aggregated distribution in the fibroblasts with knockdown of non‐OI skeletal disorder‐related genes (RAB33B and IFT52). The in vitro assay accurately detected abnormally expressed pro‐α1(I) levels in cellular models of various types of OI. Thus, this procedure represents a promising point‐of‐detection assay for potential diagnosis and therapeutic decisions in OI. [ABSTRACT FROM AUTHOR]

Bovine bone is an animal‐origin matrix rich in type I collagen (COL I) and it necessitates prior demineralization and makes COL I available. This study investigated the ossein–hydroxyapatite physicochemical properties evaluation as a result of processing and solubilization by acids and revealed the bone matrix demineralization and making COL I available. The tibia residue from bovine sources was processed, ground, and transformed into bone matrix powder. The bone matrix was solubilized in acetic acid followed by lactic acid. The bone matrix was evaluated as a result of processing and solubilization by acids: ossein and hydroxyapatite percentages by nitrogen and ash content, mineral content, particle size distribution, Fourier‐transformation infrared spectroscopy, x‐ray diffraction, and scanning electron microscope. For the obtained residual extracts, pH and mineral content were evaluated. The solubilization by acids affected the ossein–hydroxyapatite physicochemical properties, and the bone matrix solubilized by acetic and lactic acid showed the preservation of the ossein alongside the loss of hydroxyapatite. The processing and the solubilization by acids were revealed to be a alternative to bone matrix demineralization and enabling the accessibility of bone COL I. Practical Application: Bovine bone is an abundant type I collagen source, but processing maneuvers and demineralization effect present limitations due to the rigidity of the structural components. Exploring methodologies to process and demineralize will allow type I collagen to be obtained from the bone source, and direct and amplify the potentialities in the chemical and food industries. The research focused on bone sources and collagen availability holds paramount significance, and promotes repurposing agribusiness residues and development of protein–base products. [ABSTRACT FROM AUTHOR]

Besides comprising scaffolding, extracellular matrix components modulate many biological processes including inflammation and cell differentiation. We previously found precoating cell plates with extracellular matrix collagen I, or its denatured product gelatin, causes aggregation of macrophage-like human lymphoma U937 cells, which are induced to differentiation by phorbol myristate treatment. In the present study, we investigated the influence of gelatin or collagen I precoating on the bacteria phagocytosis in PMA-stimulated U937 cells. Colony forming units of phagocytosed bacteria, Giemsa-staining of cells with phagocytosed bacteria, confocal microscopic and flow cytometric analysis of cells with phagocytosed FITC-labeled bacteria and non-bioactive latex beats were conducted. Gelatin precoating enhances the phagocytosis of both Gram-negative and positive bacteria, as shown by the increased colony forming units of bacteria phagocytosed by cells, and increased intracellular bacteria observed after Giemsa-staining. But collagen I has no marked influence. Confocal microscopy reveals that both live and dead FITC-bacteria were phagocytosed more in the cells with gelatin-coating but not collagen-coating. Of note, both gelatin and collagen I coating had no influence on the phagocytosis of non-bioactive latex beads. Since gelatin-coating increases autophagy but collagen I has no such impact, we are curious about the role of autophagy. Inhibiting autophagy reduced the phagocytosis of bacteria, in cells with gelatin-coating, while stimulating autophagy enhanced phagocytosis. This study finds the bacteria-phagocytosis stimulatory effect of gelatin in PMA-treated U937 cells and reveals the positive regulatory role of autophagy, predicting the potential use of gelatin products in anti-bacterial therapy. [ABSTRACT FROM AUTHOR]

Deep second and third degree burns treatment requires fibroblasts, keratinocytes and other skin cells in order to grow new dermis and epidermis. Cells can proliferate, secrete growth factors and extracellular matrix required to repair the damaged tissue. Radiosterilized human amnion and radiosterilized pig skin have been used as natural origin skin dressings for burned patients. Adipose-derived mesenchymal stem cells can differentiate into fibroblasts and keratinocytes and improve wound-healing progress. These cells can stimulate vascular tissue formation, release growth factors, synthetize new extracellular matrix and immunoregulate other cells. In this study, we developed mesenchymal stem cells-cellularized skin substitutes based from radiosterilized human amnion or pig skin. Third-degree burns were induced in mice animal models to evaluate the effect of cellularized skin substitutes on burn wound healing. Mesenchymal phenotype was immunophenotypically confirmed by flow cytometry and cell viability was close to 100%. Skin recovery was evaluated in burned mice after seven and fourteen days post-coverage with cellularized and non-cellularized sustitutes. Histological techniques and immunofluorescence were used to evaluate re-epithelization and type I collagen deposition. We determined that cellularized-human amnion or cellularized-pig skin in combination with mesenchymal stem cells improve extracellular matrix deposition. Both cellularized constructs increase detection of type I collagen in newly formed mouse skin and can be potentially used as skin coverage for further clinical treatment of burned patients. [ABSTRACT FROM AUTHOR]

The creation of biocompatible gels, based on type I collagen is studied. To improve the mechanical properties, 10–30% carboxymethylcellulose (CMC) was added to the collagen gel. It is shown that with an increase in the CMC content up to 30%, the stability of composite gels increases. With the help of scanning electron microscopy it is shown, that the ability of collagen to form native fibrils decreases with the addition of CMC. It was also shown by electrophoresis that the presence of CMC increases the rate of degradation of the composite collagen gel. [ABSTRACT FROM AUTHOR]

Type I collagen is a predominant fibrous protein that makes up the extracellular matrix. Collagen enhances cell attachment and is commonly used in three-dimensional culture systems, to mimic the native extracellular environment, for primary sensory neurons such as dorsal root ganglia (DRG). However, the effects of collagen concentration on adult rat DRG neurite growth have not been assessed in a physiologically relevant, three-dimensional culture. This study focuses on the effects of type I collagen used in a methacrylated hyaluronic acid (MAHA)-laminin-collagen gel (triple gel) on primary adult rat DRG explants in vitro. DRGs were cultured in triple gels, and the neurite lengths and number of support cells were quantified. Increased collagen concentration significantly reduced neurite length but did not affect support cell counts. Mechanical properties, fiber diameter, diffusivity, and mesh size of the triple gels with varying collagen concentration were characterized to further understand the effects of type I collagen on hydrogel property that may affect adult rat DRG explants. Gel stiffness significantly increased as collagen concentration increased and is correlated to DRG neurite length. Collagen concentration also significantly impacted fiber diameter but there was no correlation with DRG neurite length. Increasing collagen concentration had no significant effect on mesh size and diffusivity of the hydrogel. These data suggest that increasing type I collagen minimizes adult rat DRG explant growth in vitro while raising gel stiffness. This knowledge can help develop more robust 3D culture platforms to study sensory neuron growth and design biomaterials for nerve regeneration applications. [ABSTRACT FROM AUTHOR]

Microvesicles (MVs) are a subtype of extracellular vesicles that can transfer biological information over long distances, affecting normal and pathological processes including skin wound healing. However, the diffusion of MVs into tissues can be impeded by the extracellular matrix (ECM). We investigated the diffusion of dermal wound myofibroblast‐derived MVs into the ECM by using hydrogels composed of different ECM molecules such as fibrin, type III collagen and type I collagen that are present during the healing process. Fluorescent MVs mixed with hydrogels were employed to detect MV diffusion using fluorometric methods. Our results showed that MVs specifically bound type I collagen and diffused freely out of fibrin and type III collagen. Further analysis using flow cytometry and specific inhibitors revealed that MVs bind to type I collagen via the α2β1 integrin. These data demonstrate that MV transport depends on the composition of the wound environment. [ABSTRACT FROM AUTHOR]

This study aimed to extract collagen‐I from lamb feet (LF) and examine the effects of ultrasound treatment on the structural and molecular characteristics of the collagen. Compared to ultrasonic bath treatment and conventional extraction methods, ultrasonic probe (USP) treatment significantly increased the collagen content of the extract (p < 0.05). The electrophoretic profiles confirmed the presence of α‐ and β‐chains, indicating it as type I. Furthermore, X‐ray diffraction, Fourier‐transform infrared spectroscopy, and circular dichroism spectra analyses revealed that the extraction method did not adversely affect the triple helix structure of the collagen. Moreover, the fibrillar structure of the collagen samples was verified through scanning electron microscopy analyses. Notably, the LF collagen exhibited a high thermal denaturation temperature owing to its elevated imino acid content. The collagen samples exhibited high solubility in acidic pH but low solubility in high salt concentrations. The present findings signified that sonication with USP can effectively enhance the yield of collagen from LF without compromising its quality. Practical Application: This study showed that ultrasonication enhanced the collagen concentration without disturbing the integrity of lamb feet collagen. We expect that lamb feet collagen can be used for industrial processes and consumer products thanks to unique product properties. [ABSTRACT FROM AUTHOR]

Carcinogenesis is widely recognized to be caused by qualitative and quantitative genetic changes. These changes include abnormalities in gene structure itself and/or in transcriptional mechanisms involved in gene expression in cancer cells and cancer‐associated cells. Emerging evidence has also revealed that the nature of the extracellular matrix (ECM) in the tumor microenvironment actively regulates cancer cell growth, migration, and metastasis. The most abundant protein in the ECM surrounding cancer cells is fibrillar type I collagen that accumulates and stiffens through formation of specific types of covalent intermolecular cross‐links. Alterations in the physicochemical nature of ECM proteins like fibrillar type I collagen can affect cancer cell behavior. This review provides an overview of collagen cross‐linking and its roles in oral cancer as well as possible clinical applications. [ABSTRACT FROM AUTHOR]

Qualitative alterations in type I collagen due to pathogenic variants in the COL1A1 or COL1A2 genes, result in moderate and severe Osteogenesis Imperfecta (OI), a rare disease characterized by bone fragility. The TGF-β signaling pathway is overactive in OI patients and certain OI mouse models, and inhibition of TGF-β through anti-TGF-β monoclonal antibody therapy in phase I clinical trials in OI adults is rendering encouraging results. However, the impact of TGF-β inhibition on osteogenic differentiation of mesenchymal stem cells from OI patients (OI-MSCs) is unknown. The following study demonstrates that pediatric skeletal OI-MSCs have imbalanced osteogenesis favoring the osteogenic commitment. Galunisertib, a small molecule inhibitor (SMI) that targets the TGF-β receptor I (TβRI), favored the final osteogenic maturation of OI-MSCs. Mechanistically, galunisertib downregulated type I collagen expression in OI-MSCs, with greater impact on mutant type I collagen, and concomitantly, modulated the expression of unfolded protein response (UPR) and autophagy markers. In vivo, galunisertib improved trabecular bone parameters only in female oim/oim mice. These results further suggest that type I collagen is a tunable target within the bone ECM that deserves investigation and that the SMI, galunisertib, is a promising new candidate for the anti-TGF-β targeting for the treatment of OI.

Aims: Cartilage injuries rarely heal spontaneously and often require surgical intervention, leading to the formation of biomechanically inferior fibrous tissue. This study aimed to evaluate the possible effect of amelogenin on the healing process of a large osteochondral injury (OCI) in a rat model. Methods: A reproducible large OCI was created in the right leg femoral trochlea of 93 rats. The OCIs were treated with 0.1, 0.5, 1.0, 2.5, or 5.0 μg/μl recombinant human amelogenin protein (rHAM+) dissolved in propylene glycol alginate (PGA) carrier, or with PGA carrier alone. The degree of healing was evaluated 12 weeks after treatment by morphometric analysis and histological evaluation. Cell recruitment to the site of injury as well as the origin of the migrating cells were assessed four days after treatment with 0.5 μg/μl rHAM+ using immunohistochemistry and immunofluorescence. Results: A total of 12 weeks after treatment, 0.5 μg/μl rHAM+ brought about significant repair of the subchondral bone and cartilage. Increased expression of proteoglycan and type II collagen and decreased expression of type I collagen were revealed at the surface of the defect, and an elevated level of type X collagen at the newly developed tide mark region. Conversely, the control group showed osteoarthritic alterations. Recruitment of cells expressing the mesenchymal stem cell (MSC) markers CD105 and STRO-1, from adjacent bone marrow toward the OCI, was noted four days after treatment. Conclusion: We found that 0.5 μg/μl rHAM+ induced in vivo healing of injured articular cartilage and subchondral bone in a rat model, preventing the destructive post-traumatic osteoarthritic changes seen in control OCIs, through paracrine recruitment of cells a few days after treatment. Cite this article: Bone Joint Res 2023;12(10):615–623.

The effect of riboflavin-induced collagen photocrosslinking on the scaffold printing accuracy, namely on the area of formed niches and filament thickness, as well as on the degradation time and biocompatibility of scaffolds, has been studied. The thickness of the filaments in the riboflavin-modified scaffolds was 13–29% less and the niche area was 23–40% larger than in the control group without riboflavin. The riboflavin addition reduced weight loss and increased the scaffold degradation time in the buffer solution and collagenase solution by 1.2–1.3, and 1.4–2.0 times, respectively, depending on the time of exposure to UV light. The existence of an optimal illumination interval was established. Cultivation of mesenchymal stem cells on a riboflavin-crosslinked scaffold for a week did not lead to a decrease in their viability and proliferation rate. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) is a refractory tumor with a poor prognosis, and its complex microenvironment is characterized by a fibrous interstitial matrix surrounding PDAC cells. Type I collagen is a major component of this interstitial matrix. Abundant type I collagen promotes its deposition and cross-linking to form a rigid and dense physical barrier, which limits drug penetration and immune cell infiltration and provides drug resistance and metabolic adaptations. In this study, to identify the physical effect of the stroma, type I collagen was used as a 3D matrix to culture Capan-1 cells and generate a 3D PDAC model. Using transcriptome analysis, a link between type I collagen-induced physical effects and the promotion of Capan-1 cell proliferation and migration was determined. Moreover, metabolomic analysis revealed that the physical effect caused a shift in metabolism toward a glycolytic phenotype. In particular, the high expression of proline in the metabolites suggests the ability to maintain Capan-1 cell proliferation under hypoxic and nutrient-depleted conditions. In conclusion, we identified type I collagen-induced physical effects in promoting Capan-1 cells, which cause PDAC progression, providing support for the role of dense stroma in the PDAC microenvironment and identifying a fundamental method for modeling the complex PDAC microenvironment. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive evaluation of novel composite biomaterials designed for dental applications, aiming to potentially address the prevalent challenge of dental and periodontal tissue loss. The composites consisted of biomimetic hydroxyapatite (mHA) enriched with Mg2+, CO32−, and Zn2+ ions, type I collagen, alginate, and, additionally, chitosan and sericin. The granules were loaded with ibuprofen sodium salt. The investigation encompassed a morphology characterization, a porosity analysis, a chemical structure assessment, and an examination of the swelling behavior, drug release kinetics (ibuprofen), and release profiles of zinc and magnesium ions. The granules exhibited irregular surfaces with an enhanced homogeneity in the chitosan-coated granules and well-developed mesoporous structures. The FT-IR spectra confirmed the presence of ibuprofen sodium, despite overlapping bands for the polymers. The granules demonstrated a high water-absorption capacity, with delayed swelling observed in the chitosan-coated granules. Ibuprofen displayed burst-release profiles, especially in the G1 and G3 samples. In the case of the chitosan-coated granules (G2 and G4), lower amounts of ibuprofen were released. In turn, there was a significant difference in the released amount of magnesium and zinc ions from the granules, which was most likely caused by their different location in the hydroxyapatite crystals. The cytotoxicity assays confirmed the non-cytotoxic behavior of the biomaterial. These findings suggest the potential applicability of these biomaterials in dental scenarios, emphasizing their multifunctional and biocompatible nature. [ABSTRACT FROM AUTHOR]

When rawhide fleshing (140–230 kg/ton) wastes from beam houses are disposed of, it substantially negatively influences the environment. Hence, we focus on isolating and characterizing a commercially valuable component, collagen, from tannery wastes and demonstrating its in vitro cytotoxicity and proliferative activity for its biomedical applications. After an alkaline pre-treatment, the extraction process involved treating the fleshing with acid and enzyme. The extracted collagen was further subjected to structural and thermal characterization. The in vitro cytotoxicity and proliferation assay was studied using a 3T3-L1 fibroblast cell line. The percentage yield of pepsin-soluble collagen (PSC) was higher than that of acid-soluble collagen (ASC), 22.16 ± 1.25% and 12.93 ± 1.04%, respectively. Fourier transform infrared (FTIR) spectrum confirmed the presence of amides A, B, I, II, and III with the functional group of N-H, CH2, C=O, C-N, and N-H. The electrophoresis pattern and amino acids analysis showed that the collagen was in its native form. The isolated collagen possessed the native structural integrity which was confirmed by the result of X-ray diffraction (XRD) and differential scanning calorimetry (DSC) studies. The thermal denaturation temperature was at 38 °C for PSC. The morphological study revealed that both ASC and PSC exhibited fibrous structure. In vitro biocompatibility tests revealed that the isolated collagen did not cause significant cytotoxicity, and there was no detectable cell death or growth inhibition. From the above findings substantiate the application of hide waste-derived collagen as a safe and cost-effective substitute in various pharmaceutical and biomedical domains. [ABSTRACT FROM AUTHOR]

Objective Osteogenesis imperfecta (OI) is a rare genetic disorder. Clinical severity is heterogeneous. The purpose of this study was to investigate the genetic characteristics of a fetus with OI by whole exome sequencing (WES) and identify the cause of the disease. Methods In this study, a fetus with osteogenic dysplasia was referred to our hospital. DNA was extracted from the aborted fetal tissue and peripheral blood of the parents. To identify the pathogenic genes, we conducted the trio-WES using DNA. A de novo variant in the COL1A1 gene is suspected to be the cause of the OI phenotype. We used Sanger sequencing for validation and various bioinformatics methods (such as SIFT, PolyPhen2, Mutation Taster, conservative analysis, SWISS Model, glycosylation site prediction, and I-Mutant 2.0) for analysis. Results Both WES and Sanger sequencing identified a novel de novo variant of COL1A1 (c. 1309G>A, p. Gly437Ser) in a fetus with OI. Bioinformatic analysis showed that the affected residue, p. Gly437, was highly conserved in multiple species and predicted that the variant was deleterious and may have an impact on protein function. This variant is present in highly conserved glycine residues of Gly-X-Y sequence repeats of the triple helical region of the collagen type I α chain, which may be the cause of OI. Conclusion This study revealed that the c.1309G>A (p. Gly437Ser) variant in the COL1A1 gene may be the genetic cause of fetal OI in this case. The discovery of this variant enriched the variation spectrum of OI. WES improves the accurate diagnosis of fetal OI, and doctors can provide patients with appropriate genetic counseling. [ABSTRACT FROM AUTHOR]

BACKGROUND: A wide range of studies have demonstrated that microRNA (miR) plays a crucial role in hypertrophic scars development, and type I collagen is closely related to hypertrophic scar fibroblasts. There might be a relationship between miR-2116-3p and occurrence and development of hypertrophic scars. OBJECTIVE: To investigate the expression and role of miR-2116-3p on human hypertrophic scar fibroblasts. METHODS: Hypertrophic scar tissues were collected from six patients from the First Affiliated Hospital of Xinjiang Medical University and normal skin tissues were collected from another six patients after blepharoplasty in the same unit at the same time. The expression of miR-2116-3p and type I collagen was detected by qRT-PCR. Hypertrophic scar tissues were taken and primary cells were cultured to passages 3 to 6. Hypertrophic scar fibroblasts were divided into negative control group, miR-2116-3p mimic group, and miR-2116-3p inhibitor group, and transfected with corresponding sequences. Cell proliferation was detected by cell counting kit-8 and EdU kit. Cell migration was detected by cell scratch assay, and apoptosis was detected by flow cytometry. Expression of type I collagen, type III collagen and α-smooth muscle actin was detected by western blot and qRT-PCR at protein and mRNA levels, respectively. Dual luciferase reporter assay system was used to carry out targeting assays. RESULTS AND CONCLUSION: The mRNA expression of miR-2116-3p and type I collagen in hypertrophic scar tissues was significantly lower than that in normal skin tissues (P < 0.01). After 24, 48, and 72 hours of transfection, the cell viability of the miR-2116-3p mimic group was significantly lower than that of the negative control group (P < 0.05 or P < 0.01), while the cell viability of miR-2116-3p inhibitor group was significantly higher than that of the negative control group (P < 0.05 or P < 0.01). At 48 hours after transfection, the number of EdU positive cells in the miR-2116-3p mimic group was significantly lower than that in the negative control group, while the number of EdU positive cells in the miR-2116-3p inhibitor group was significantly higher than that in the negative control group (P < 0.05). At 24 hours after transfection, the cell scratch area and apoptotic rate of the miR-2116-3p mimic group were significantly higher than those of the negative control group (P < 0.01), and while the cell scratch area and apoptotic rate of the miR-2116-3p inhibitor group werer significantly lower than those of the negative control group (P < 0.01 or P < 0.05). At 24 hours after transfection, the mRMA and protein expression levels of type I collagen, type II collagen and α-smooth muscle actin were significantly decreased in the miR-2116-3p mimic group (P < 0.05 or P < 0.01) and significantly increased in the miR-2116-3p inhibitor group (P < 0.01) compared with the negative control group. Results from the dual luciferase assay showed that miR-2116-3p could bind to type I collagen. To conclude, the expression of miR-2116-3p is down-regulated in human hypertrophic scar. miR-2116-3p may inhibit the proliferation and migration of human hypertrophic scar fibroblasts and promote their apoptosis by targeting the expression of type I collagen. [ABSTRACT FROM AUTHOR]

This study assessed the biocompatibility of two types of nanogold composites: fibronectin-gold (FN-Au) and collagen-gold (Col-Au). It consisted of three main parts: surface characterization, in vitro biocompatibility assessments, and animal models. To determine the structural and functional differences between the materials used in this study, atomic force microscopy, Fourier-transform infrared spectroscopy, and ultraviolet-visible spectrophotometry were used to investigate their surface topography and functional groups. The F-actin staining, proliferation, migration, reactive oxygen species generation, platelet activation, and monocyte activation of mesenchymal stem cells (MSCs) cultured on the FN-Au and Col-Au nanocomposites were investigated to determine their biological and cellular behaviors. Additionally, animal biocompatibility experiments measured capsule formation and collagen deposition in female Sprague–Dawley rats. The results showed that MSCs responded better on the FN-Au and Col-AU nanocomposites than on the control (tissue culture polystyrene) or pure substances, attributed to their incorporation of an optimal Au concentration (12.2 ppm), which induced significant surface morphological changes, nano topography cues, and better biocompatibility. Moreover, neuronal, endothelial, bone, and adipose tissues demonstrated better differentiation ability on the FN-Au and Col-Au nanocomposites. Nanocomposites have a crucial role in tissue engineering and even vascular grafts. Finally, MSCs were demonstrated to effectively enhance the stability of the endothelial structure, indicating that they can be applied as promising alternatives to clinics in the future.

Acute and chronic liver failure are clinically significant conditions, and the artificial liver support system (ALSS) is emerging as a novel and effective approach for the clinical management of liver failure. Within this framework, scaffold materials occupy a pivotal position as integral components of the bioreactor. Elevating the performance capabilities of these scaffolds not only augments the therapeutic efficacy of the artificial liver but also lays the groundwork for refining and selecting large-scale hepatocyte culture models. In this study, we introduced a novel hepatocyte scaffold material designated as PET-COL, crafted by coating polyethylene terephthalate (PET) with collagen. This involved a sequence of modifications, including alkaline hydrolysis, EDC/NHS activation and crosslinking, as well as collagen conjugation. The physicochemical attributes of the scaffold were thoroughly characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), second harmonic generation (SHG), water contact angle measurements, and high-performance liquid chromatography–mass spectrometry (HPLC-MS). Furthermore, an investigation into the material’s biological properties was conducted that encompassed SEM (HepaRG growth), fluorescence staining (assessment of cell viability), staining by trypan blue (HepaRG counting), CCK-8 (proliferation of cells), biochemical testing, and immunosorbent assay. Our findings revealed that collagen was covalently bonded to the PET surface, leading to a substantial enhancement in the material’s hydrophilicity (p < 0.001). The quantity of collagen coating was determined to be precisely 33.30 μg per scaffold. Human liver progenitor HepaRG cells thrived on the PET-COL material. Compared with the untreated group, cell viability, albumin secretion, urea synthesis, and the expression levels of CYP3A4 and CPS1 increased significantly (p < 0.001), demonstrating remarkable biological vitality. The PET-COL scaffold, as developed in this study, holds immense potential for application in bioartificial livers.

The treatment of critical-size bone defects remains a complicated clinical challenge. Recently, bone tissue engineering has emerged as a potential therapeutic approach for defect repair. This study examined the biocompatibility and repair efficacy of hydroxyapatite-mineralized bionic polylactic acid (PLA) scaffolds, which were prepared through a combination of 3D printing technology, plasma modification, collagen coating, and hydroxyapatite mineralization coating techniques. Physicochemical analysis, mechanical testing, and in vitro and animal experiments were conducted to elucidate the impact of structural design and microenvironment on osteogenesis. Results indicated that the PLA scaffold exhibited a porosity of 84.1% and a pore size of 350 μm, and its macrostructure was maintained following functionalization modification. The functionalized scaffold demonstrated favorable hydrophilicity and biocompatibility and promoted cell adhesion, proliferation, and the expression of osteogenic genes such as ALP, OPN, Col-1, OCN, and RUNX2. Moreover, the scaffold was able to effectively repair critical-size bone defects in the rabbit radius, suggesting a novel strategy for the treatment of critical-size bone defects. [ABSTRACT FROM AUTHOR]

Rationale: The adult cardiac extracellular matrix (ECM) is largely comprised of type I collagen. In addition to serving as the primary structural support component of the cardiac ECM, type I collagen also provides an organizational platform for other ECM proteins, matricellular proteins, and signaling components that impact cellular stress sensing in vivo. Objective: Here we investigated how the content and integrity of type I collagen affect cardiac structure function and response to injury. Methods and Results: We generated and characterized Col1a2−/− mice using standard gene targeting. Col1a2−/− mice were viable, although by young adulthood their hearts showed alterations in ECM mechanical properties, as well as an unanticipated activation of cardiac fibroblasts and induction of a progressive fibrotic response. This included augmented TGFβ activity, increases in fibroblast number, and progressive cardiac hypertrophy, with reduced functional performance by 9 months of age. Col1a2-loxP-targeted mice were also generated and crossed with the tamoxifen-inducible Postn-MerCreMer mice to delete the Col1a2 gene in myofibroblasts with pressure overload injury. Interestingly, while germline Col1a2−/− mice showed gradual pathologic hypertrophy and fibrosis with aging, the acute deletion of Col1a2 from activated adult myofibroblasts showed a loss of total collagen deposition with acute cardiac injury and an acute reduction in pressure overload-induce cardiac hypertrophy. However, this reduction in hypertrophy due to myofibroblast-specific Col1a2 deletion was lost after 2 and 6 weeks of pressure overload, as fibrotic deposition accumulated. Conclusions: Defective type I collagen in the heart alters the structural integrity of the ECM and leads to cardiomyopathy in adulthood, with fibroblast expansion, activation, and alternate fibrotic ECM deposition. However, acute inhibition of type I collagen production can have an anti-fibrotic and anti-hypertrophic effect. [ABSTRACT FROM AUTHOR]

Introduction: Despite the use of highly specialized irradiation techniques in the treatment of head and neck tumors, it is still impossible to selectively destroy cancer cells without damaging normal structures, including connective tissue cells. Aim: The aim of the study was to analyze the concentration of degradation markers such as collagen type I (carboxyterminal telopeptide of type I collagen; ICTP) and elastin (elastin-derived peptides; EDPs) as well as selected metalloproteinases (MMP-1, MMP-2, MMP-9) in patients with head and neck malignancies undergoing radiotherapy. Material and methods: The test group consisted of 56 men, who underwent radical or palliative radiotherapy. The concentrations of ICTP, EDPs, MMP-1, MMP-2, MMP-9 were determined in three blood samples collected from patients prior to radiotherapy, immediately after its completion and 3 months after the therapy. Results: Both radical and palliative radiotherapy contribute to a significant increase in the concentration of EDPs. At the time of healing of post-irradiation lesions, the level of EDPs was reduced in both groups. The ICTP concentration was not affected by radiotherapy. No significant differences were observed in the concentration of MMP-1 and MMP-2 before and after radiotherapy. Radical radiotherapy caused a statistically significant late reduction in the concentration of MMP-9. The lowest concentrations of MMP-1, MMP-2, MMP-9 in the serum of patients qualified for palliative radiotherapy were recorded in a samples collected three months post-irradiation. Conclusions: The degradation markers of key extracellular matrix structural proteins may be helpful tools in the objective assessment of radiation-induced injuries to the connective tissue. [ABSTRACT FROM AUTHOR]

BACKGROUND: The treatment of skin scars is a long-term focus and difficulty for plastic surgery and burn. Ultrasound has become a hot spot and trend in its scientific research due to its advantages of small trauma, fast recovery and low risk of scar treatment. OBJECTIVE: To explore the therapeutic effect of different intensities of ultrasound on abdominal skin scar in rabbits and its mechanism of action. METHODS: Sixteen 3-month-old New Zealand rabbits were selected and divided into four groups with four rabbits in each group, male and female, according to stratified random sampling method. After 21 days, sham ultrasound intervention was performed on abdominal scars in the sham ultrasound group, and 0.3, 0.5, and 0.8 W/cm2 ultrasound interventions were given to abdominal scars in the low-, medium- and high-intensity ultrasound groups, respectively, for 7 day each, for a total of two sessions with an interval of 2 days. The length and thickness of scars were measured before and after treatment. The area density of type I and III collagen in scar tissue after intervention was observed by Sirius red staining. The expression of serum N-terminal peptide of type III procollagen (PIIINP) was detected by ELISA before and after the intervention. RESULTS AND CONCLUSION: A total of 70 skin scars formed in 96 wound incisions, and the success rate of modeling was about 72.9%. After the intervention, the scar length in the low- and medium-intensity groups was significantly lower than that in the sham ultrasound group and the high-intensity group (P < 0.05). After the intervention, the scar thickness in the low-, medium- and high-intensity groups was significantly lower than that in the sham ultrasound group (P < 0.05). The scar thickness in the low-intensity group was significantly lower than that in the medium- and high-intensity groups (P < 0.05). After the intervention, the percentage of type I and III collagen in the low-intensity group was significantly higher than that in the high-intensity group (P < 0.05); the percentage of type I and III collagen in the high-intensity group was significantly lower than that in the sham ultrasound group (P < 0.05). After the intervention, the density ratio of type I/III collagen in the low-intensity group was significantly lower than that in the high-intensity group (P < 0.05). The difference of serum PIIINP expression before the intervention and after the first session was significantly lower in the low-, medium-, and high-intensity groups than the sham ultrasound group (P < 0.05), while the difference in the low-intensity group was lower than that in the medium- and high-intensity groups but with no statistical significance (P > 0.05). There was no significant difference between the two groups in the expression of serum PIIINP at the end of the first session and the end of the second session (P > 0.05). To conclude, low-intensity ultrasonic intervention has a better comprehensive effect on the treatment of hypertrophic scar. The mechanism of ultrasonic treatment may be to optimize the compliance of hypertrophic scar tissue through the mechanical, and physicochemica action on the arrangement of type I and III collagen fiber bundles in hypertrophic scar tissue, which still needs further research and confirmation. [ABSTRACT FROM AUTHOR]

Studies indicate that blue light (BL) irradiation can damage human skins, but the impact of BL irradiation on skin aging is unknown. This study aimed to give an insight to phenotypic characteristics and molecular mechanism of blue light-induced skin aging, and thus provide a theoretical basis for the precise protection of photodermatosis. The effect of BL on skin photoaging in mice was evaluated by non-invasive measurement equipment and histopathology analysis. The effect of BL irradiation on the proliferation of HFF-1 cells was detected by the Real-Time Cell Analyzer. The expression and protein levels of genes associated with skin aging were examined. Our studies indicated photoaging caused by BL irradiation, including collagen disorder and increased MMP1. BL irradiation also inhibited cell proliferation and collagen expression in human skin fibroblasts by inhibiting TGF-β signaling pathway, based on in vitro experiments. Importantly, BL irradiation promoted the degradation of collagen by increasing MMP1 activated by the JNK/c-Jun and EGFR pathways. Moreover, ROS levels were significantly increased after BL irradiation in human skin fibroblasts. Yet, the transcriptional change in human skin fibroblasts caused by BL irradiation was unable to be completely restored by ROS scavenger. BL irradiation down-regulated expression of type I collagen genes and up-regulated MMP1 expression to inhibit the proliferation of human skin fibroblasts. Multiple key pathways including TGF-β, JNK, and EGFR signaling were involved in BL-induced skin aging. Our results provide theoretical bases for the protection of photoaging caused by BL irradiation. • Blue light (BL) can induce skin photoaging phenotype in mice model. • BL irradiations can down-regulate type I collagen synthesis by inhibiting the TGF-β signaling pathway. • BL irradiations can degradant skin collagen by increasing MMP1 activated by the JNK/c-Jun and EGFR/p70S6K pathways. [ABSTRACT FROM AUTHOR]

The matricellular secreted protein acidic and rich in cysteine (SPARC; also known as osteonectin), is involved in the regulation of extracellular matrix (ECM) synthesis, cell-ECM interactions, and bone mineralization. We found decreased SPARC expression in aged skin. Incubating foreskin fibroblasts with recombinant human SPARC led to increased type I collagen production and decreased matrix metalloproteinase-1 (MMP-1) secretion at the protein and mRNA levels. In a three-dimensional culture of foreskin fibroblasts mimicking the dermis, SPARC significantly increased the synthesis of type I collagen and decreased its degradation. In addition, SPARC also induced receptor-regulated SMAD (R-SMAD) phosphorylation. An inhibitor of transforming growth factor-beta (TGF-β) receptor type 1 reversed the SPARC-induced increase in type I collagen and decrease in MMP-1, and decreased SPARC-induced R-SMAD phosphorylation. Transcriptome analysis revealed that SPARC modulated expression of genes involved in ECM synthesis and regulation in fibroblasts. RT-qPCR confirmed that a subset of differentially expressed genes is induced by SPARC. These results indicated that SPARC enhanced ECM integrity by activating the TGF-β signaling pathway in fibroblasts. We inferred that the decline in SPARC expression in aged skin contributes to process of skin aging by negatively affecting ECM integrity in fibroblasts. [ABSTRACT FROM AUTHOR]

The world of science, particularly in oncology, continually strives to detect cancer or its recurrence at the earliest possible stage of the disease. Consequently, imaging techniques are constantly being refined, while molecular biology is concurrently advancing to understand the mechanisms and pathomechanisms at the cellular level. Immunodiagnostics, which quantitatively determine circulating tumour markers, are also subject to development. Researchers are also attempting to identify markers that enable a fast and accurate diagnosis of diseases with inflammatory, autoimmune, or genetic backgrounds. In this study, we addressed the construction and formation of TNFα, collagen I and II, as well as extracellular matrix metalloproteinases. These molecules also have a significant impact on various processes in the body, including inflammatory and cancer processes. Understanding them in detail allows for a better comprehension of the mechanisms and pathomechanisms of certain diseases. This publication explores their utility in diagnosis and potential treatment approaches for some illnesses. A literature review indicates a consistent increase in interest in these molecules, particularly in certain gastrointestinal, gastric, connective tissue disorders, and central nervous system cancers. [ABSTRACT FROM AUTHOR]

Type I collagen physiological scaffold for tissue regeneration is considered one of the widely used biomaterials for tissue engineering and medical applications. It is hierarchically organized: five laterally staggered molecules are packed within fibrils, arranged into fascicles and bundles. The structural organization is correlated to the direction and intensity of the forces which can be loaded onto the tissue. For a tissue-specific regeneration, the required macro- and microstructure of a suitable biomaterial has been largely investigated. Conversely, the function of multiscale structural integrity has been much less explored but is crucial for scaffold design and application. In this work, collagen was extracted from different animal sources with protocols that alter its structure. Collagen of tendon shreds excised from cattle, horse, sheep and pig was structurally investigated by wide- and small-angle X-ray scattering techniques, at both molecular and supramolecular scales, and thermo-mechanically with thermal and load-bearing tests. Tendons were selected because of their resistance to chemical degradation and mechanical stresses. The multiscale structural integrity of tendons' collagen was studied in relation to the animal source, anatomic location and source for collagen extraction. [ABSTRACT FROM AUTHOR]

Type I collagen and chitosan are two of the main biological macromolecules used to design scaffolds for tissue engineering. The former has the benefits of being biocompatible and provides biochemical cues for cell adhesion, proliferation and differentiation. However, collagen hydrogels usually exhibit poor mechanical properties and are difficult to functionalize. Chitosan is also often biocompatible, but is much more versatile in terms of structure and chemistry. Although it does have important biological properties, it is not a good substrate for mammalian cells. Combining of these two biomacromolecules is therefore a strategy of choice for the preparation of interesting biomaterials. The aim of this review is to describe the different protocols available to prepare Type I collagen–chitosan hydrogels for the purpose of presenting their physical and chemical properties and highlighting the benefits of mixed hydrogels over single-macromolecule ones. A critical discussion of the literature is provided to point out the poor understanding of chitosan–type I collagen interactions, in particular due to the lack of systematic studies addressing the effect of chitosan characteristics. [ABSTRACT FROM AUTHOR]

We investigated how the extracellular matrix (ECM) affects LoVo colorectal cancer cells behavior during a spatiotemporal invasion. Epithelial-to-mesenchymal transition (EMT) markers, matrix-degrading enzymes, and morphological phenotypes expressed by LoVo-S (doxorubicin-sensitive) and higher aggressive LoVo-R (doxorubicin-resistant) were evaluated in cells cultured for 3 and 24 h on Millipore filters covered by Matrigel, mimicking the basement membrane, or type I Collagen reproducing a desmoplastic lamina propria. EMT and invasiveness were investigated with RT-qPCR, Western blot, and scanning electron microscopy. As time went by, most gene expressions decreased, but in type I Collagen samples, a strong reduction and high increase in MMP-2 expression in LoVo-S and -R cells occurred, respectively. These data were confirmed by the development of an epithelial morphological phenotype in LoVo-S and invading phenotypes with invadopodia in LoVo-R cells as well as by protein-level analysis. We suggest that the duration of culturing and type of substrate influence the morphological phenotype and aggressiveness of both these cell types differently. In particular, the type I collagen meshwork, consisting of large fibrils confining inter fibrillar micropores, affects the two cell types differently. It attenuates drug-sensitive LoVo-S cell aggressiveness but improves a proteolytic invasion in drug-resistant LoVo-R cells as time goes by. Experimental studies on CRC cells should examine the peri-tumoral ECM components, as well as the dynamic physical conditions of TME, which affect the behavior and aggressiveness of both drug-sensitive and drug-resistant LoVo cells differently. [ABSTRACT FROM AUTHOR]

Bone biomineralization is a complex process in which type I collagen and associated non-collagenous proteins (NCPs), including glycoproteins and proteoglycans, interact closely with inorganic calcium and phosphate ions to control the precipitation of nanosized, non-stoichiometric hydroxyapatite (HAP, idealized stoichiometry Ca10(PO4)6(OH)2) within the organic matrix of a tissue. The ability of certain vertebrate tissues to mineralize is critically related to several aspects of their function. The goal of this study was to identify specific NCPs in mineralizing and non-mineralizing tissues of two animal models, rat and turkey, and to determine whether some NCPs are unique to each type of tissue. The tissues investigated were rat femur (mineralizing) and tail tendon (non-mineralizing) and turkey leg tendon (having both mineralizing and non-mineralizing regions in the same individual specimen). An experimental approach ex vivo was designed for this investigation by combining sequential protein extraction with comprehensive protein mapping using proteomics and Western blotting. The extraction method enabled separation of various NCPs based on their association with either the extracellular organic collagenous matrix phases or the inorganic mineral phases of the tissues. The proteomics work generated a complete picture of NCPs in different tissues and animal species. Subsequently, Western blotting provided validation for some of the proteomics findings. The survey then yielded generalized results relevant to various protein families, rather than only individual NCPs. This study focused primarily on the NCPs belonging to the small leucine-rich proteoglycan (SLRP) family and the small integrin-binding ligand N-linked glycoproteins (SIBLINGs). SLRPs were found to be associated only with the collagenous matrix, a result suggesting that they are mainly involved in structural matrix organization and not in mineralization. SIBLINGs as well as matrix Gla (γ-carboxyglutamate) protein were strictly localized within the inorganic mineral phase of mineralizing tissues, a finding suggesting that their roles are limited to mineralization. The results from this study indicated that osteocalcin was closely involved in mineralization but did not preclude possible additional roles as a hormone. This report provides for the first time a spatial survey and comparison of NCPs from mineralizing and non-mineralizing tissues ex vivo and defines the proteome of turkey leg tendons as a model for vertebrate mineralization.

Heat shock protein 47 (HSP47), also known as SERPINH1, functions as a collagen-specific molecular chaperone protein essential for the formation and stabilization of the collagen triple helix. Here, we delved into the regulatory pathways governed by HSP47, shedding light on collagen homeostasis. Our investigation revealed a significant reduction in HSP47 mRNA levels in the skin tissue of older mice as compared to their younger counterparts. The augmented expression of HSP47 employing lentivirus infection in fibroblasts resulted in an increased secretion of type I collagen. Intriguingly, the elevated expression of HSP47 in fibroblasts correlated with increased protein and mRNA levels of type I collagen. The exposure of fibroblasts to IRE1α RNase inhibitors resulted in the reduced manifestation of HSP47-induced type I collagen secretion and expression. Notably, HSP47-overexpressing fibroblasts exhibited increased XBP1 mRNA splicing. The overexpression of HSP47 or spliced XBP1 facilitated the nuclear translocation of β-catenin and transactivated a reporter harboring TCF binding sites on the promoter. Furthermore, the overexpression of HSP47 or spliced XBP1 or the augmentation of nuclear β-catenin through Wnt3a induced the expression of type I collagen. Our findings substantiate that HSP47 enhances type I collagen expression and secretion in fibroblasts by orchestrating a mechanism that involves an increase in nuclear β-catenin through IRE1α activation and XBP1 splicing. This study therefore presents potential avenues for an anti-skin-aging strategy targeting HSP47-mediated processes.

BACKGROUND: Collagen, which has good biocompatibility and degradability, is commonly used to promote wound healing, but it is not effective in preventing wound infection because of its non-antibacterial properties. OBJECTIVE: To prepare chitosan collagen sponge by freeze-drying method, which has good antibacterial and hemostatic effects. METHODS: Chitosan solution and sodium bicarbonate solution became gel at 37 ℃ . Chitosan/sodium bicarbonate/type I collagen composite sponge was prepared by freeze-drying method as the experimental group, and chitosan sponge and chitosan/sodium bicarbonate sponge were used as the control group. Scanning electron microscopy was used to observe the micro-morphology of the sponge and determine its pH value, porosity, water absorption, degradation rate and antimicrobial activity against Staphylococcus aureus and Escherichia coli. The cytotoxicity of the sponges was detected by CCK-8 assay and Live/Dead staining. The hemostatic effect of the sponges was detected by the rat model of amputation bleeding. The rat model of skin trauma was established. The tissue healing was observed by hematoxylin-eosin staining and Masson staining 7 days after sponge implantation. RESULTS AND CONCLUSION: (1) Compared with the other sponge groups, the chitosan/sodium bicarbonate/type I collagen composite sponge had larger porosity, rougher outer wall, stronger water absorption, greater porosity and water absorption multiple, and the porosity was greater than the other sponge groups (P < 0.01). The average water absorption multiple was greater than chitosan sponge (P < 0.000 1) and chitosan/sodium bicarbonate sponge (P < 0.05). (2) Anti-Escherichia coli test results showed that Escherichia coli resistance rate was chitosan sponge > chitosan/sodium bicarbonate sponge (P < 0.001) > chitosan/ sodium bicarbonate/type I collagen composite sponge (P < 0.000 1). (3) Anti-Staphylococcus aureus rate test results showed that anti-Staphylococcus aureus rate was chitosan sponge > chitosan/sodium bicarbonate sponge > chitosan/sodium bicarbonate/type I collagen composite sponge (P < 0.01). (4) Chitosan/ sodium bicarbonate/type I collagen composite sponge was non-cytotoxic and could promote the proliferation of mouse fibroblasts (L929), and the proproliferation effect was better than that of the blank group (P < 0.05), the chitosan sponge group (P < 0.000 1) and the chitosan/sodium bicarbonate sponge group (P < 0.05). (5) Chitosan/sodium bicarbonate/type I collagen composite sponge had a good hemostasis effect, which was better than the other three groups. (6) Chitosan/sodium bicarbonate/type I collagen composite sponge was implanted into the wound on the back of rats for one week without obvious inflammation in the surrounding skin, and the contents of capillary and collagen were significantly higher than those of chitosan sponge and chitosan/sodium bicarbonate sponge. The skin tissue recovered best. (7) It is concluded that chitosan/sodium bicarbonate/type I collagen composite sponge has excellent biocompatibility, antibacterial hemostasis and tissue healing properties. [ABSTRACT FROM AUTHOR]

Simple Summary: The deposition of excessive collagen resulting in scarring is a detrimental outcome of the wound healing process in humans, ultimately impeding the successful restoration of skin function. Surprisingly, in Fraser's dolphins (Lagenodelphis hosei), collagens undergo a configuration change during wound healing and eventually recover to normal architecture. However, little research has been conducted on dolphins' collagen composition in the skin and the underlying mechanism during the wound healing process. Here, histochemical staining and immunostaining were performed on normal and wounded skin samples in different healing stages of Fraser's dolphins. The results demonstrate that collagens changed in composition during the wound-healing process. The mature healed wound implies the great ability to remove excessive collagen depositions in hypertrophic-like scars in Fraser's dolphins. A better understanding of collagen dynamics in Fraser's dolphins would provide more information and possibilities for solving aberrant scarring problems in humans. Fraser's dolphins (Lagenodelphis hosei) possess great healing abilities. Their skin composition can be restored after wounding, including collagen spacing, orientation, and bundle thickness. However, it remains unclear how collagens are involved in the wound-healing process and eventually regain normality in Fraser's dolphins. Learned from the other two scarless healing animals, changes in type III/I collagen composition are believed to modulate the wound healing process and influence the scarring or scarless fate determination in human fetal skin and spiny mouse skin. In the current study, Herovici's, trichrome, and immunofluorescence staining were used on normal and wounded skin samples in Fraser's dolphins. The results suggested that type I collagens were the main type of collagens in the normal skin of Fraser's dolphins, while type III collagens were barely seen. During the wound healing process, type III collagens showed at early wound healing stages, and type I collagen increased in the mature healed wound. In an early healed wound, collagens were organized in a parallel manner, showing a transient hypertrophic-like scar, and eventually restored to normal collagen configuration and adipocyte distribution in the mature healed wound. The remarkable ability to remove excessive collagens merits further investigation to provide new insights into clinical wound management. [ABSTRACT FROM AUTHOR]

Collagen, the most abundant organic compound of vertebrate organisms, is a supramolecular, protein-made polymer. Details of its post-translational maturation largely determine the mechanical properties of connective tissues. Its assembly requires massive, heterogeneous prolyl-4-hydroxylation (P4H), catalyzed by Prolyl-4-hydroxylases (P4HA1–3), providing thermostability to its elemental, triple helical building block. So far, there was no evidence of tissue-specific regulation of P4H, nor of a differential substrate repertoire of P4HAs. Here, the post-translational modifications of collagen extracted from bone, skin, and tendon were compared, revealing lower hydroxylation of most GEP/GDP triplets, together with fewer other residue positions along collagen a chains, in the tendon. This regulation is mostly conserved in two distant homeotherm species, mouse and chicken. The comparison of detailed P4H patterns in both species suggests a two-step mechanism of specificity. P4ha2 expression is low in tendon and its genetic invalidation in the ATDC5 cellular model of collagen assembly specifically mimics the tendon-related P4H profile. Therefore, P4HA2 has a better ability than other P4HAs to hydroxylate the corresponding residue positions. Its local expression participates in determining the P4H profile, a novel aspect of the tissue specificities of collagen assembly. [ABSTRACT FROM AUTHOR]

Outbreaks of starfish (Asterias amurensis) pose a major threat to aquaculture and marine ecosystems in Qingdao, China, and no effective methods have been found to control them. A comprehensive study of collagen in starfish could be an alternative to high efficient utilization. Based on this, collagen was firstly extracted from Qingdao A. amurensis. Then, its protein pattern, amino acid composition, secondary structure, microstructure and thermal stability were investigated. The results showed that the A. amurensis collagen (AAC) is a type I collagen composed of α1, α2, and β chains. Glycine, hydroxyproline, and alanine were the major amino acids. The melting temperature was 57.7 °C. From FTIR, UV spectra and CD chromatography, the AAC had an intact triple helix and secondary structure, and microstructural analysis showed that the AAC had a loose, fibrous porous structure. Next, the osteogenic differentiation effect of AAC on Mouse bone marrow stem cells (BMSCs) was investigated, and the results showed that AAC induced osteogenic differentiation of cells by promoting the proliferation of BMSCs, enhancing alkaline phosphatase (ALP) activity, promoting cell mineralization nodules and upregulating the expression of mRNA of relevant osteogenic genes. These results suggest that AAC might have the potential application to bone health-related functional foods. [ABSTRACT FROM AUTHOR]

Osteogenesis imperfecta (OI) is a genetically and clinically heterogeneous disorder characterized by bone fragility and reduced bone mass generally caused by defects in type I collagen structure or defects in proteins interacting with collagen processing. We identified a homozygous missense mutation in SEC16B in a child with vertebral fractures, leg bowing, short stature, muscular hypotonia, and bone densitometric and histomorphometric features in keeping with OI with distinct ultrastructural features. In line with the putative function of SEC16B as a regulator of trafficking between the ER and the Golgi complex, we showed that patient fibroblasts accumulated type I procollagen in the ER and exhibited a general trafficking defect at the level of the ER. Consequently, patient fibroblasts exhibited ER stress, enhanced autophagosome formation, and higher levels of apoptosis. Transfection of wild‐type SEC16B into patient cells rescued the collagen trafficking. Mechanistically, we show that the defect is a consequence of reduced SEC16B expression, rather than due to alterations in protein function. These data suggest SEC16B as a recessive candidate gene for OI. Synopsis: The newly found mutant SEC16B causes type I collagen accumulation in the ER. This in turn leads to increased ER stress, autophagosome numbers and enhanced apoptosis. In addition, there is alteration of secreted COL1A1 in the SEC16B mutated cells. SEC16B homozygous mutation was identified in a boy with moderate osteogenesis imperfecta.The mutation reduces the expression of SEC16B mRNA.SEC16B mutant cells accumulate type I procollagen in the ER due to a secretory trafficking defect.SEC16B is a candidate gene for osteogenesis imperfecta.This study uncovers a new role for the SEC16B protein in the ER to Golgi Apparatus trafficking. [ABSTRACT FROM AUTHOR]

Type I collagen is the most common extracellular matrix protein in the human body that provides the basis of tissue structure and regulates cellular functions. In the process of vital activity, the components of the extracellular matrix, in particular collagen, are exposed to ultraviolet radiation. The purpose of this work was to study the effect of ultraviolet irradiation on the stability and structure of collagen fibrils. It has been shown that ultraviolet irradiation had a stabilizing effect on a collagen gel at a concentration of 0.5 mg/mL. The analysis of the diameters of collagen fibrils after ultraviolet irradiation by scanning electron microscopy revealed no change in their size. The area of spreading of cells cultured on collagen fibrils after ultraviolet irradiation was higher compared to the area of cells cultured on collagen fibrils without treatment. It was shown by IR-Fourier spectroscopy that ultraviolet irradiation caused a shift of the amide A band of collagen to a lower frequency region, which indicated a change in the structural order of collagen. [ABSTRACT FROM AUTHOR]