TGF-β Activity Related to the Use of Collagen Membranes: In Vitro Bioassays

Quercetin Alleviates Cardiac Fibrosis via Regulating the SIRT3 Signaling Pathway

PURPOSE

Cardiovascular diseases, exacerbated by cardiac fibrosis, are the leading causes of mortality. We aimed to determine the role of quercetin (QU) in cardiac fibrosis and the underlying mechanism.

METHODS

In this study, 8-week-old mice were subjected to either transverse aortic constriction (TAC) or sham surgery, then they were administered QU or saline. Thereafter, cardiac function and cardiac hypertrophy were accessed. In vitro, cardiac fibroblasts (CFs) were treated with angiotensin II (Ang II) with or without QU. Western blot, qPCR, EdU incorporation assay, and immunofluorescence staining analysis were used to investigate the molecular and cellular features.

RESULTS

For the TAC mouse model, cardiac fibrosis was alleviated by QU. The study revealed that the trans-differentiation and proliferation of CFs promoted by Ang II would be reversed by QU in vitro. Mechanistically, QU exerted the anti-fibrotic effect by regulating the SIRT3/TGF-β/Smad3 signaling pathway.

CONCLUSION

Quercetin protects against cardiac fibrosis by mediating the SIRT3 signaling pathway.

Proteomic Analysis of Human Serum Proteins Adsorbed onto Collagen Barrier Membranes

Collagen barrier membranes are frequently used in guided tissue and bone regeneration. The aim of this study was to analyze the signature of human serum proteins adsorbed onto collagen membranes using a novel protein extraction method combined with mass spectrometry. Native porcine-derived collagen membranes (Geistlich Bio-Gide®, Wolhusen, Switzerland) were exposed to pooled human serum in vitro and, after thorough washing, subjected to protein extraction either in conjunction with protein enrichment or via a conventional surfactant-based method. The extracted proteins were analyzed via liquid chromatography with tandem mass spectrometry. Bioinformatic analysis of global profiling, gene ontology, and functional enrichment of the identified proteins was performed. Overall, a total of 326 adsorbed serum proteins were identified. The enrichment and conventional methods yielded similar numbers of total (315 vs. 309), exclusive (17 vs. 11), and major bone-related proteins (18 vs. 14). Most of the adsorbed proteins (n = 298) were common to both extraction groups and included several growth factors, extracellular matrix (ECM) proteins, cell adhesion molecules, and angiogenesis mediators involved in bone regeneration. Functional analyses revealed significant enrichment of ECM, exosomes, immune response, and cell growth components. Key proteins [transforming growth factor-beta 1 (TGFβ1), insulin-like growth factor binding proteins (IGFBP-5, -6, -7)] were exclusively detected with the enrichment-based method. In summary, native collagen membranes exhibited a high protein adsorption capacity in vitro. While both extraction methods were effective, the enrichment-based method showed distinct advantages in detecting specific bone-related proteins. Therefore, the use of multiple extraction methods is advisable in studies investigating protein adsorption on biomaterials.

Elevated BEAN1 expression correlates with poor prognosis, immune evasion, and chemotherapy resistance in rectal adenocarcinoma

BACKGROUND

The BEAN1 gene, primarily studied in neurodegenerative diseases, has been scarcely studied in the context of cancers. Our research examines BEAN1 expression specifically in rectal adenocarcinoma (READ) and its association with prognosis, immune evasion, and chemotherapy resistance.

METHODS

Data from TCGA and GEO were analyzed to assess BEAN1 levels across various cancer types, with particular emphasis on READ. Functional enrichment, immune infiltration, and treatment response analyses were conducted, followed by validation using patient tissue samples.

RESULTS

READ tissues exhibited a marked increase in BEAN1 expression compared to normal tissues. Elevated BEAN1 levels were associated with reduced overall survival and increased immune suppression, characterized by elevated M2 macrophage infiltration and reduced CD8+ T cell presence. BEAN1 expression was also linked to higher immune checkpoint genes expression and resistance to immune checkpoint inhibitors and 5-fluorouracil.

CONCLUSION

This research offers initial evidence that BEAN1 is linked to unfavorable prognosis, immune escape, and resistance to chemotherapy in READ. BEAN1 appears to be a promising new biomarker and potential therapeutic target, warranting further investigation into its potential clinical applications in improving treatment outcomes for READ patients.

Effect of magnetic microbeads on sustained and targeted delivery of transforming growth factor-beta-1 for rotator cuff healing in a rat rotator cuff repair model

Structural failure is a well-established complication of rotator cuff repair procedures. To evaluate the effect of magnetic microbeads, designed for precise drug delivery via magnetic force, on sustained transforming growth factor-beta-1 (TGF-β1) release and rotator cuff healing in a rat rotator cuff repair model. TGF-β1 laden microbeads were prepared, and baseline in vitro experiments included the magnetization of the microbeads and TGF-β1 release tests. In an in vivo experiment using a rat rotator cuff repair model on both shoulders, 72 rats were randomly assigned to three groups (24 per group): group A, conventional repair; group B, repair with and simple TGF-β1 injection; and group C, repair with magnet insertion into the humeral head and TGF-β1 laden microbead injection. Delivery of TGF-β1 was evaluated at 1 and 7 days after the intervention using PCR, Western blot, and immunohistochemistry. At 6 weeks post-intervention, rotator cuff healing was assessed using biomechanical and histological analysis. The in vitro experiments confirmed the magnetization property of the microbeads and sustained delivery of TGF-β1 for up to 10 days. No difference in the TGF-β1 expression was found at day 1 in vivo. However, at day 7, group C exhibited a significantly elevated expression of TGF-β1 in both PCR and Western blot analyses compared to groups A and B (all P < 0.05). Immunohistochemical analysis revealed a higher expression of TGF-β1 at the repair site in group C on day 7. At 6 weeks, biomechanical analysis demonstrated a significantly higher ultimate failure load in group C than in groups A and B (P < 0.05) and greater stiffness than in group A (P = 0.045). In addition, histological analysis showed denser and more regular collagen fibers with complete continuity to the bone in group C than in groups A and B, a statistically significant difference according to the semi-quantitative scoring system (all P < 0.05). The use of the TGF-β1 laden magnetic microbeads demonstrated sustained delivery of TGF-β1 to the repair site, improving rotator cuff healing.

Systematic evaluation of three porcine-derived collagen membranes for guided bone regeneration

Guided bone regeneration is one of the most common surgical treatment modalities performed when an additional alveolar bone is required to stabilize dental implants in partially and fully edentulous patients. The addition of a barrier membrane prevents non-osteogenic tissue invasion into the bone cavity, which is key to the success of guided bone regeneration. Barrier membranes can be broadly classified as non-resorbable or resorbable. In contrast to non-resorbable membranes, resorbable barrier membranes do not require a second surgical procedure for membrane removal. Commercially available resorbable barrier membranes are either synthetically manufactured or derived from xenogeneic collagen. Although collagen barrier membranes have become increasingly popular amongst clinicians, largely due to their superior handling qualities compared to other commercially available barrier membranes, there have been no studies to date that have compared commercially available porcine-derived collagen membranes with respect to surface topography, collagen fibril structure, physical barrier property, and immunogenic composition. This study evaluated three commercially available non-crosslinked porcine-derived collagen membranes (Striate+^TM, Bio-Gide^® and Creos^TM Xenoprotect). Scanning electron microscopy revealed similar collagen fibril distribution on both the rough and smooth sides of the membranes as well as the similar diameters of collagen fibrils. However, D-periodicity of the fibrillar collagen is significantly different among the membranes, with Striate+^TM membrane having the closest D-periodicity to native collagen I. This suggests that there is less deformation of collagen during manufacturing process. All collagen membranes showed superior barrier property evidenced by blocking 0.2-16.4 μm beads passing through the membranes. To examine the immunogenic agents in these membranes, we examined the membranes for the presence of DNA and alpha-gal by immunohistochemistry. No alpha-gal or DNA was detected in any membranes. However, using a more sensitive detection method (real-time polymerase chain reaction), a relatively strong DNA signal was detected in Bio-Gide^® membrane, but not Striate+^TM and Creos^TM Xenoprotect membranes. Our study concluded that these membranes are similar but not identical, probably due to the different ages and sources of porcine tissues, as well as different manufacturing processes. We recommend further studies to understand the clinical implications of these findings.

Advances in Modification Methods Based on Biodegradable Membranes in Guided Bone/Tissue Regeneration: A Review

Guided tissue/bone regeneration (GTR/GBR) is commonly applied in dentistry to aid in the regeneration of bone/tissue at a defective location, where the assistive material eventually degrades to be substituted with newly produced tissue. Membranes separate the rapidly propagating soft tissue from the slow-growing bone tissue for optimal tissue regeneration results. A broad membrane exposure area, biocompatibility, hardness, ductility, cell occlusion, membrane void ratio, tissue integration, and clinical manageability are essential functional properties of a GTR/GBR membrane, although no single modern membrane conforms to all of the necessary characteristics. This review considers ongoing bone/tissue regeneration engineering research and the GTR/GBR materials described in this review fulfill all of the basic ISO requirements for human use, as determined through risk analysis and rigorous testing. Novel modified materials are in the early stages of development and could be classified as synthetic polymer membranes, biological extraction synthetic polymer membranes, or metal membranes. Cell attachment, proliferation, and subsequent tissue development are influenced by the physical features of GTR/GBR membrane materials, including pore size, porosity, and mechanical strength. According to the latest advances, key attributes of nanofillers introduced into a polymer matrix include suitable surface area, better mechanical capacity, and stability, which enhances cell adhesion, proliferation, and differentiation. Therefore, it is essential to construct a bionic membrane that satisfies the requirements for the mechanical barrier, the degradation rate, osteogenesis, and clinical operability.

Osteoconductive Properties of a Volume-Stable Collagen Matrix in Rat Calvaria Defects: A Pilot Study

Volume-stable collagen matrices (VSCM) are conductive for the connective tissue upon soft tissue augmentation. Considering that collagen has osteoconductive properties, we have investigated the possibility that the VSCM also consolidates with the newly formed bone. To this end, we covered nine rat calvaria circular defects with a VSCM. After four weeks, histology, histomorphometry, quantitative backscattered electron imaging, and microcomputed tomography were performed. We report that the overall pattern of mineralization inside the VSCM was heterogeneous. Histology revealed, apart from the characteristic woven bone formation, areas of round-shaped hypertrophic chondrocyte-like cells surrounded by a mineralized extracellular matrix. Quantitative backscattered electron imaging confirmed the heterogenous mineralization occurring within the VSCM. Histomorphometry found new bone to be 0.7 mm² (0.01 min; 2.4 max), similar to the chondrogenic mineralized extracellular matrix with 0.7 mm² (0.0 min; 4.2 max). Microcomputed tomography showed the overall mineralized tissue in the defect to be 1.6 mm³ (min 0.0; max 13.3). These findings suggest that in a rat cranial defect, VSCM has a limited and heterogeneous capacity to support intramembranous bone formation but may allow the formation of bone via the endochondral route.

Proteomic and genomic analysis of acid dentin lysate with focus on TGF-β signaling

Particulate autologous tooth roots are increasingly used for alveolar bone augmentation; however, the proteomic profile of acid dentin lysate and the respective cellular response have not been investigated. Here we show that TGF-β1 is among the 226 proteins of acid dentin lysate (ADL) prepared from porcine teeth. RNA sequencing identified 231 strongly regulated genes when gingival fibroblasts were exposed to ADL. Out of these genes, about one third required activation of the TGF-β receptor type I kinase including interleukin 11 (IL11) and NADPH oxidase 4 (NOX4). Reverse transcription-quantitative polymerase chain reaction and immunoassay confirmed the TGF-β-dependent expression of IL11 and NOX4. The activation of canonical TGF-β signaling by ADL was further confirmed by the phosphorylation of Smad3 and translocation of Smad2/3, using Western blot and immunofluorescence staining, respectively. Finally, we showed that TGF-β activity released from dentin by acid lysis adsorbs to titanium and collagen membranes. These findings suggest that dentin particles are a rich source of TGF-β causing a major response of gingival fibroblasts.

Proteomic Analysis of Porcine-Derived Collagen Membrane and Matrix

Collagen membranes and matrices being widely used in guided bone regeneration and soft tissue augmentation have characteristic properties based on their composition. The respective proteomic signatures have not been identified. Here, we performed a high-resolution shotgun proteomic analysis on two porcine collagen-based biomaterials designed for guided bone regeneration and soft tissue augmentation. Three lots each of a porcine-derived collagen membrane and a matrix derived from peritoneum and/or skin were digested and separated by nano-reverse-phase high-performance liquid chromatography. The peptides were subjected to mass spectrometric detection and analysis. A total of 37 proteins identified by two peptides were present in all collagen membranes and matrices, with 11 and 16 proteins being exclusively present in the membrane and matrix, respectively. The common extracellular matrix proteins include fibrillar collagens (COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL5A3, COL11A2), non-fibrillar collagens (COL4A2, COL6A1, COL6A2, COL6A3, COL7A1, COL16A1, COL22A1), and leucine-rich repeat proteoglycans (DCN, LUM, BGN, PRELP, OGN). The structural proteins vimentin, actin-based microfilaments (ACTB), annexins (ANXA1, ANXA5), tubulins (TUBA1B, TUBB), and histones (H2A, H2B, H4) were also identified. Examples of membrane-only proteins are COL12A1 and COL14A1, and, of matrix only proteins, elastin (ELN). The proteomic signature thus revealed the similarities between but also some individual proteins of collagen membrane and matrix.

Growth Factor Applied to Oral and Regenerative Surgery

The complex tissue engineering/regenerative medicine now represents a therapeutic reality applicable to various organic substrates, with the aim of repairing deficient tissues and restoring normal organ function. Among the possible specialized uses, in the dental field, the treatment of periodontal, pre- and peri-implant bone defects should be mentioned. Nowadays, in oral surgery, there are many surgical methods that can be used, despite that the literature still seems controversial regarding the actual advantages of their use. Surely, this work will bring to light the current clinical-surgical orientations and the different perspectives.