From Structure to Phenotype: Impact of Collagen Alterations on Human Health

Promoting collagen synthesis: a viable strategy to combat skin ageing

Skin ageing is a complex physiological process primarily characterised by the deepening of wrinkles and the sagging of the skin. Collagen is essential for maintaining skin elasticity and firmness. As skin ages, it experiences structural and functional changes in collagen, including a decrease in collagen synthesis and an increase in collagen hydrolysis. Thus, promoting collagen synthesis represents a practical strategy for mitigating skin ageing. This review systematically described the functions, classifications and biosynthesis process of collagen, as well as its role in skin ageing. Additionally, the major signalling pathways and targets associated with collagen synthesis were also discussed. More importantly, the review provided a detailed summary of natural products with collagen synthesis-promoting effects and highlighted small molecule compounds with potential anti-ageing activity, especially PPARδ agonists. The relevant content offers potential targets and lead compounds for the development of anti-skin ageing therapies.

Determination via an Integration Strategy of the Potential Dermal ECM Reconstruction Mechanism by Which the WAW Formula Alleviates Skin Aging

BACKGROUND

Traditional Chinese medicine (TCM) treats skin conditions and delays aging using specific formulas. TCM links skin health to internal organ functions: kidney qi deficiency accelerates aging, whereas spleen deficiency leads to dry, loose skin from insufficient qi and blood. The renowned spleen-tonifying and kidney-nourishing formula "Wan An Wan" moisturizes the skin, but its antiageing mechanism remains unclear.

AIMS

The aim of this study was to investigate the development strategy and comprehensive methodological framework for incorporating TCM into cosmetics and to assess the mechanism of action and application potential of the WAW formula in mitigating skin aging.

RESULTS

In vitro experiments revealed that after optimizing the extraction of the active ingredients of the tailored WAW formula, it effectively inhibited NO production and tyrosinase activity and increased filaggrin, AQP, and HAS2 mRNA expression. Moreover, the active ingredients, including morroniside, were also analyzed separately. Mechanistic studies revealed that the tailored WAW formula upregulated the expression of the TGF-β1 gene associated with ECM production and downregulated the expression of the MMP-2/MMP-9 genes associated with ECM degradation, regulating cell behaviors such as migration, adhesion, and proliferation and thereby maintaining the healthy state of the skin.

CONCLUSIONS

In this study, an overall strategy for applying TCM for the development of skin care solutions was established, the potential value of WAW in modern dermatologic applications was revealed, innovative raw materials with comprehensive effects were developed, and new ideas for the fields of cosmetics and dermatology were provided.

Amniotic fluid-derived mesenchymal stem cells as a therapeutic tool against cytokine storm: a comparison with umbilical cord counterparts

BACKGROUND

Several immunosuppressive therapies have been proposed as key treatment options for critically ill patients since the first appearance of severe acute respiratory syndrome coronavirus 2. Mesenchymal stem cells (MSCs) from different sources have been considered for their potential to attenuate the cytokine storm associated to COVID-19 and the consequent multi-organ failure, providing evidence for safe and efficacious treatments. Among them, administration of umbilical cord-derived MSCs (UC-MSCs) has demonstrated a significant increase in survival rates, largely due to their potent immunosuppressive properties.

METHODS

We applied next-generation sequencing (NGS) analysis to compare the transcriptomic profiles of MSCs isolated from two gestational sources: amniotic fluid (AF) obtained during prenatal diagnosis and their clinically relevant umbilical cord counterparts, for which datasets were publicly available. A full meta-analysis was performed to identify suitable GEO and NGS datasets for comparison between AF- and UC-MSC samples.

RESULTS

Transcriptome analysis revelaed significant differences between groups, despite both cell lines being strongly involved in the tissue development, crucial to achieve the complex task of wound healing. Significantly enriched hallmark genes suggest AF-MSC superior immunomodulatory features against signaling pathways actively involved in the cytokine storm (i.e., IL-2/STAT, TNF-a/NFkB, IL-2/STAT5, PI3K/AKT/mTOR).

CONCLUSIONS

The data presented here suggest that AF-MSCs hold significant promise for treating not only COVID-19-associated cytokine storms but also a variety of other inflammatory syndromes (i.e., those induced by bacterial infections, autoimmune disorders, and therapeutic interventions). Realizing the full potential of AF-MSCs as a comprehensive therapeutic approach in inflammatory disease management will require more extensive clinical trials and in-depth mechanistic studies.

Healthy Aging Metabolomic and Proteomic Signatures Across Multiple Physiological Compartments

The study of biomarkers in biofluids and tissues expanded our understanding of the biological processes that drive physiological and functional manifestations of aging. However, most of these studies were limited to examining one biological compartment, an approach that fails to recognize that aging pervasively affects the whole body. The simultaneous modeling of hundreds of metabolites and proteins across multiple compartments may provide a more detailed picture of healthy aging and point to differences between chronological and biological aging. Herein, we report proteomic analyses of plasma and urine collected in healthy men and women, age 22-92 years. Using these data, we developed a series of metabolomic and proteomic predictors of chronological age for plasma, urine, and skeletal muscle. We then defined a biological aging score, which measures the departure between an individual's predicted age and the expected predicted age for that individual based on the full cohort. We show that these predictors are significantly and independently related to clinical phenotypes important for aging, such as inflammation, iron deficiency anemia, muscle mass, and renal and hepatic functions. Despite a different set of selected biomarkers in each compartment, the different scores reflect a similar degree of deviation from healthy aging in single individuals, thus allowing identification of subjects with significant accelerated or decelerated biological aging.

Impact of High Glucose on Bone Collagenous Matrix Composition, Structure, and Organization: An Integrative Analysis Using an Ex Vivo Model

Diabetes mellitus is a widespread metabolic disorder linked to numerous systemic complications, including adverse effects on skeletal health, such as increased bone fragility and fracture risk. Emerging evidence suggests that high glucose may disrupt the extracellular matrix (ECM) of bone, potentially altering its composition and organization. Collagen, the primary organic component of the ECM, is critical for maintaining structural integrity and biomechanical properties. However, definitive evidence and a comprehensive understanding of the molecular mechanisms through which high glucose impacts the ECM and collagen remain elusive. This study employed an ex vivo embryonic chicken femur model to investigate the effects of high glucose on the collagenous matrix. A comprehensive approach integrating histological evaluation, histomorphometry, ATR-FTIR spectroscopy, and proteomics was adopted to unravel structural, biochemical, and molecular changes in the ECM. Histomorphometric analysis revealed disrupted collagen fibril architecture, characterized by altered fibril diameter, alignment, and spatial organization. ATR-FTIR spectroscopy highlighted biochemical modifications, including non-enzymatic glycation that impaired collagen crosslinking and reduced matrix integrity. Proteomic profiling unveiled significant alterations in ECM composition and function, including downregulation of key collagen crosslinking enzymes and upregulation of inflammatory and coagulation pathways. High glucose profoundly disrupts the collagenous matrix of bone, weakening its structural integrity and organization. These findings emphasize the critical impact of high glucose environments on extracellular matrix composition and bone quality, offering insights into the mechanisms behind diabetic bone fragility and guiding future research toward targeted therapeutic strategies.

Evaluating the Effects of Laser Treatments on Visible Changes in the Photoaging Process of the Skin Using Specialized Measuring Devices

Background/Objectives: The skin is the largest organ of the human body and is exposed to the aging process (not only chronological aging, but also photoaging). One of the methods used to correct visible skin changes due to photoaging is lasers. The aim of this study was to objectively evaluate the effect of Q-switched laser treatments on visible changes in the photoaging process among women using specialized measuring devices-ultrasound and Courage & Khazaka. Methods: The study included 36 women with visible signs of photoaged skin. The women were given a series of three treatments with a Fotona QX MAX fractional head laser. Both before and after the treatment, the women were examined for selected skin parameters with the help of specialized measuring devices such as Courage & Khazaka and skin ultrasound. Skin firmness and elasticity, the degree of hydration, TEWL and HL TOTAL levels, and MEP and HEP skin echogenicity were taken into account. The obtained results were tabulated and statistically analyzed. Results: Statistically significant differences were noted for parameters representing skin elasticity R2 [p = 0.0210] and R7 [p = 0.0302], TEWL [p = 0.0152] and HL TOTAL [p = 0.0367] on the forehead, and HL TOTAL [p = 0.0450] on the cheek. In addition, statistically significant differences were observed in the MEP/TP parameter on the forehead and cheek [p = 0.0236, 0.0475, respectively] and HEP/TP in the forehead area [p = 0.0367]. Conclusions: Q-switched laser treatments have a positive effect on the condition of women's skin. Therapy with this laser reduces the visible changes in the photoaging process in the face.

Extraction and Purification of Biopolymers from Marine Origin Sources Envisaging Their Use for Biotechnological Applications

Biopolymers are a versatile and diverse class of materials that has won high interest due to their potential application in several sectors of the economy, such as cosmetics, medical materials/devices, and food additives. In the last years, the search for these compounds has explored a wider range of marine organisms that have proven to be a great alternative to mammal sources for these applications and benefit from their biological properties, such as low antigenicity, biocompatibility, and biodegradability, among others. Furthermore, to ensure the sustainable exploitation of natural marine resources and address the challenges of 3R's policies, there is a current necessity to valorize the residues and by-products obtained from food processing to benefit both economic and environmental interests. Many extraction methodologies have received significant attention for the obtention of diverse polysaccharides, proteins, and glycosaminoglycans to accomplish the increasing demands for these products. The present review gives emphasis to the ones that can be obtained from marine biological resources, as agar/agarose, alginate and sulfated polysaccharides from seaweeds, chitin/chitosan from crustaceans from crustaceans, collagen, and some glycosaminoglycans such as chondroitin sulfate and hyaluronic acids from fish. It is offered, in a summarized and easy-to-interpret arrangement, the most well-established extraction and purification methodologies used for obtaining the referred marine biopolymers, their chemical structure, as well as the characterization tools that are required to validate the extracted material and respective features. As supplementary material, a practical guide with the step-by-step isolation protocol, together with the various materials, reagents, and equipment, needed for each extraction is also delivered is also delivered. Finally, some remarks are made on the needs still observed, despite all the past efforts, to improve the current extraction and purification procedures to achieve more efficient and green methodologies with higher yields, less time-consuming, and decreased batch-to-batch variability.

A loss of primary cilia by a reduction in mTOR signaling correlates with age-related deteriorations in condylar cartilage

Age-related deterioration of condylar cartilage is an etiological factor in temporomandibular joint-osteoarthritis (TMJ-OA). However, its underlying mechanism remains unknown. Therefore, we examined age-related changes and the relationship between mTOR signaling and primary cilia in condylar cartilage to determine the intrinsic mechanisms of age-related TMJ-OA. Age-related morphological changes were analyzed using micro-computed tomography and safranin O-stained histological samples of the mandibular condyle of C57BL/6J mice (up to 78 weeks old). Immunohistochemistry was used to assess the activity of mTOR signaling, primary cilia frequency, and Golgi size of condylar chondrocytes. Four-week-old mice receiving an 11-week series of intraperitoneal injections of rapamycin, a potent mTOR signaling inhibitor, were used for the histological evaluation of the condylar cartilage. The condylar cartilage demonstrated an age-related reduction in cartilage area, including chondrocyte size, cell density, and cell size distribution. The Golgi size, primary cilia frequency, and mTOR signaling also decreased with age. Rapamycin injections resulted in both diminished cartilage area and cell size, resembling the phenotypes observed in aged mice. Rapamycin-injected mice also exhibited a smaller Golgi size and lower primary cilia frequency in condylar cartilage. We demonstrated that a loss of primary cilia due to a decline in mTOR signaling was correlated with age-related deteriorations in condylar cartilage. Our findings provide new insights into the tissue homeostasis of condylar cartilage, contributing to understanding the etiology of age-related TMJ-OA.

Loss of MMP9 disturbs cranial suture fusion via suppressing cell proliferation, chondrogenesis and osteogenesis in mice

Cranial sutures function as growth centers for calvarial bones. Abnormal suture closure will cause permanent cranium deformities. MMP9 is a member of the gelatinases that degrades components of the extracellular matrix. MMP9 has been reported to regulate bone development and remodeling. However, the function of MMP9 in cranial suture development is still unknown. Here, we identified that the expression of Mmp9 was specifically elevated during fusion of posterior frontal (PF) suture compared with other patent sutures in mice. Interestingly, inhibition of MMP9 ex vivo or knockout of Mmp9 in mice (Mmp9-/-) disturbed the fusion of PF suture. Histological analysis showed that knockout of Mmp9 resulted in wider distance between osteogenic fronts, suppressed cell condensation and endocranial bone formation in PF suture. Proliferation, chondrogenesis and osteogenesis of suture cells were decreased in Mmp9-/- mice, leading to the PF suture defects. Moreover, transcriptome analysis of PF suture revealed upregulated ribosome biogenesis and downregulated IGF signaling associated with abnormal closure of PF suture in Mmp9-/- mice. Inhibition of the ribosome biogenesis partially rescued PF suture defects caused by Mmp9 knockout. Altogether, these results indicate that MMP9 is critical for the fusion of cranial sutures, thus suggesting MMP9 as a potential therapeutic target for cranial suture diseases.

Agmatine alleviates diabetic-induced hyposalivation in rats: A histological and biochemical study

Diabetic patients commonly experience hyposalivation, which can cause challenges with eating, swallowing, dry mouth, and speaking. It also raises the likelihood of developing periodontal disease. This study aimed to evaluate if agmatine could improve the rate of salivation in rats with hyposalivation induced by streptozotocin (STZ). Five groups of Wistar rats were utilized with 10 animals in each group. They were classified as follows; Negative control group (G1), agmatine (G2) group, and Nicotinamide (NA)-STZ (G3) group; received a single intraperitoneal dose of 65 mg/kg of STZ after NA injection. NA was administered to protect residual β cells and enhance their insulin secretion; NA-STZ + Metformin (G4) Metformin-treated diabetic group; at day 10 diabetic rats received 50mg/kg orally for 28 days, and NA-STZ + Agmatine (G5) at day 10 diabetic rats received a daily intraperitoneal dose of 300 mg/kg Agmatine for 28 days. The salivary flow rate was assessed weekly. Then, the animals were euthanized, both parotid (PG) and submandibular (SMG) salivary glands were dissected, and the following parameters were assessed; salivary glands' histopathology, aquaporin 5 (AQP5), caspase-3, E-cadherin expressions, inflammatory markers and finally, salivary glands' oxidative stress status. Agmatine has alleviated the salivary glands' dysfunction in STZ-induced diabetic rats. It normalized diabetes mellitus-associated salivary glands' abnormalities including histopathological abnormalities, decreased AQP5 and E-cadherin expressions, increased caspase-3 expression, and oxidative stress and inflammatory parameters. Agmatine alleviates diabetes mellitus-associated hyposalivation. It can promote PGs and SMGs function through its histological and AQP5 expression improvements.

Identification of Potential Biomarkers in Papillary Thyroid Carcinoma Based on Proteomics

Background

To identify biomarkers of papillary thyroid carcinoma (PTC) and explore the possible pathogenic mechanism.

Methods

This study included five patients with PTC. Protein expression of cancer tissues and adjacent normal thyroid tissues from each patient were analyzed by TMT proteomics technology. Differentially expressed proteins were identified, and functional annotation of differentially expressed proteins was performed by bioinformatics and pathway enrichment analysis.

Results

A total of 639 differentially expressed proteins were identified, including 278 upregulated and 361 downregulated proteins. Six upregulated proteins were identified as potential specific markers of PTC.

Conclusion

Differentially expressed proteins may represent new molecular markers of PTC. These differentially expressed proteins and the related pathways may provide new insights into the pathogenic mechanisms of PTC.

Ethyl butyrate inhibits caudal fin regeneration in adult zebrafish by disrupting extracellular matrix remodeling

Wound healing and tissue regeneration are influenced by a variety of factors. Adverse lifestyle habits, such as excessive alcohol consumption, delay wound healing and increase the risk of secondary infections. Ethyl butyrate is a common food additive widely used to enhance the aroma of alcoholic beverages. This additive is generally considered harmless to human health in both industrial and domestic settings. However, the ecotoxicity and its effects on wound healing have not been elucidated. In this study, we used zebrafish as the experimental animal, and the caudal fins were amputated to explore the effects of ethyl butyrate on wound healing and tissue regeneration. The effect of ethyl butyrate on blastema and bone regeneration and its impact on the transcriptional levels of regeneration-related genes and inflammation-related genes were evaluated. RNA-seq was conducted to determine the differentially expressed genes (DEGs) between the treatment and the control groups. KEGG and GO analysis was conducted to explore the functions of DEGs. Significantly enriched GO terms and KEGG pathways were identified to explore the molecular mechanism underlying the inhibition of zebrafish caudal fin regeneration by ethyl butyrate. The results demonstrated that ethyl butyrate significantly inhibited the regeneration of zebrafish caudal fins, including blastema and bone regeneration. Ethyl butyrate exposure significantly downregulated the expression of genes associated with bone and blastema regeneration and inflammation response. KEGG and GO functional analyses revealed that the DEGs were associated with significant enrichment of extracellular matrix-receptor interactions. Ethyl butyrate treatment downregulated the expression of most extracellular matrix-related genes. These findings indicate that ethyl butyrate potentially modulates pathways associated with the structure, adhesion, modification, and degradation of the extracellular matrix, thereby disrupting extracellular matrix remodeling, inhibiting wound inflammation, impairing blastema and bone regeneration and ultimately hindering caudal fin regeneration. In summary, the findings demonstrate that ethyl butyrate disrupts extracellular matrix remodeling and inhibits the regeneration of zebrafish caudal fins. These results provide valuable insights into the rational use of ethyl butyrate and further investigation of wound healing mechanisms.

Comparison of primordial germ cell differences at different developmental time points in chickens

OBJECTIVE

Recently, the application in the field of germplasm resource conservation has become an important application of primordial germ cells (PGCs). However, due to the lack of deep understanding of the biological characteristics of PGCs at different time points, there is no systematic scheme for the selection of PGCs at which time points in practical application, which affects the practical application effect of PGCs. This study aims to clarify the differences in PGCs during development.

METHODS

Here, migration experiment, EdU proliferation assay and cell apoptosis assay were conducted to compare the differences in the migration ability, the proliferation ability and the recovery efficiency among female and male PGCs at E3.5, E4.5, and E5.5, which were explained by the following transcriptome sequencing analysis.

RESULTS

We found that there were larger differences between female and male PGCs at different embryonic ages, while smaller differences between female and male PGCs at the same embryonic age. Further comparison showed that the cell migration ability of female and male PGCs decreased gradually during development, so female and male PGCs at E3.5 are more suitable for in vitro allotransplantation. At the same time, the proliferation ability of PGCs gradually decreased during development, and cell adhesion and extracellular matrix communication were weakened, indicating that female and male PGCs of E3.5 are more suitable for in vitro long-term culture cell line establishment. Interestingly, female and male PGCs at E5.5 showed strong DNA damage repair ability, thus more suitable for in vitro long-term cryopreservation.

CONCLUSION

This study provides a theoretical basis for systematically selecting PGCs at suitable developmental time points as cell materials for efficient utilization by analyzing the characteristics of female and male PGCs at different developmental time points based on transcriptome.

Trabecular meshwork cell differentiation in response to collagen and TGFβ-2 spatial interactions

Primary open-angle glaucoma (POAG) is currently the most prevalent cause of irreversible blindness globally. To date, few in vitro models that can faithfully recapitulate the complex architecture of the trabecular meshwork (TM) and the specialised trabecular meshwork cell (TMC) characteristics that are local to the structurally opposing regions. This study aimed to investigate the parameters that govern TMC phenotype by adapting the extracellular matrix structure to mimic the juxtacanalicular tissue (JCT) region of the TM. Initially, TMC phenotypic characteristics were investigated within type I collagen matrices of controlled fiber density and anisotropy, generated through confined plastic compression (PC). Notably, PC-collagen presented biophysical cues that induced JCT cellular characteristics (elastin, α-β-Crystallin protein expression, cytoskeletal remodelling, increased mesenchymal markers and JCT-specific genetic markers). In parallel, a pathological mesenchymal phenotype associated with POAG was induced through localised transforming growth factor -beta 2 (TGFβ-2) exposure. This resulted in a profile of alternative mesenchymal states (fibroblast/smooth muscle or myofibroblast) displayed by the TMC in vitro. Overall, the study provides an advanced insight into the biophysical cues that modulate TMC fate, inducing a JCT-specific phenotype and transient mesenchymal characteristics that reflect healthy and pathological scenarios. STATEMENT OF SIGNIFICANCE: Glaucoma is a leading cause of blindness, with a lack of long-term efficacy within current drug candidates. Reliable trabecular meshwork (TM) in vitro models will be critical for enhancing the fields understanding of healthy and disease states for pre-clinical testing. Trabecular meshwork cells (TMCs) display heterogeneity throughout the hierarchical TM, however our understanding into recapitulating these phenotypes in vitro, remains elusive. This study hypothesizes the importance of specific matrix/growth factor spatial stimuli in governing TMCs phenotype. By emulating certain biophysical/biochemical in vivo parameters, we introduce an advanced profile of distinct TMC phenotypic states, reflecting healthy and disease scenarios. A notion that has not be stated prior and a fundamental consideration for future 3D TM in vitro modelling.

Multi-organ transcriptome atlas of a mouse model of relative energy deficiency in sport

Insufficient energy intake to meet energy expenditure demands of physical activity can result in systemic neuroendocrine and metabolic abnormalities in activity-dependent anorexia and relative energy deficiency in sport (REDs). REDs affects >40% of athletes, yet the lack of underlying molecular changes has been a hurdle to have a better understanding of REDs and its treatment. To assess the molecular changes in response to energy deficiency, we implemented the "exercise-for-food" paradigm, in which food reward size is determined by wheel-running activity. By using this paradigm, we replicated several aspects of REDs in female and male mice with high physical activity and gradually reduced food intake, which results in weight loss, compromised bone health, organ-specific mass changes, and altered rest-activity patterns. By integrating transcriptomics of 19 different organs, we provide a comprehensive dataset that will guide future understanding of REDs and may provide important implications for metabolic health and (athletic) performance.

Restoration of the Ultrastructural Integrity of the Dermal Collagen Network by 12-Week Ingestion of Special Collagen Peptides

INTRODUCTION

This pilot study investigated the effects of a 12-week administration of a nutritional supplement containing special collagen peptides on the structural and molecular properties of the collagen fiber network in the human skin. For the assessments, the suction blister method and electron microscopical comparisons were used.

METHODS

Three suction blisters were generated on the inner forearm of each test subject before and after the 12-week administration of the nutritional supplement. High-resolution scanning electron microscopy (SEM) was employed to meticulously investigate the structural characteristics of the skin's collagen network, including the length and diameter of collagen fibers within the suction blister roof. Furthermore, the analysis included immunohistochemistry and fluorescence light microscopy to study hyaluronic acid within the extracellular matrix. Additional assessments encompassed changes in various epidermal parameters. Nine female participants within the age range of 43.7-61.8 years (mean: 52.5 ± 5.9 years) completed the study in accordance with the study protocol.

RESULTS

Compared with baseline, the 12-week supplementation regimen led to a statistically significant average increase in the collagen fiber network size of 34.56% (p < 0.0001). Additionally, collagen fiber cross-linking and fiber length were substantially increased. The ingestion of the supplement also resulted in an 18.08% elevation in epidermal hyaluronic acid concentration (p < 0.0001). No adverse events were recorded during the study.

CONCLUSION

Using an innovative approach, this study demonstrated the ability of a targeted nutritional supplement to effectively restore the ultrastructural integrity of the dermal collagen network, which is typically disrupted by the natural aging process of the skin. These findings not only corroborate existing data regarding the positive effects of oral collagen peptides on skin structure and function but also contribute to our understanding of ultrastructural morphological aspects of changes in the skin's collagen network. Supplementation can induce regeneration of the collagen fiber network in the human skin.

TRIAL REGISTRATION NUMBER

German Clinical Trials Register, DRKS-ID DRKS00034161- Date of registration: 06.05.2024, retrospectively registered.

Constructing networks for comparison of collagen types

Collagens are structural proteins that are predominantly found in the extracellular matrix of multicellular animals, where they are mainly responsible for the stability and structural integrity of various tissues. All collagens contain polypeptide strands (α-chains). There are several types of collagens, some of which differ significantly in form, function, and tissue specificity. Because of their importance in clinical research, they are grouped into subdivisions, the so-called collagen families, and their sequences are often analysed. However, problems arise with highly homologous sequence segments. To increase the accuracy of collagen classification and prediction of their functions, the structure of these collagens and their expression in different tissues could result in a better focus on sequence segments of interest. Here, we analyse collagen families with different levels of conservation. As a result, clusters with high interconnectivity can be found, such as the fibrillar collagens, the COL4 network-forming collagens, and the COL9 FACITs. Furthermore, a large cluster between network-forming, FACIT, and COL28a1 α-chains is formed with COL6a3 as a major hub node. The formation of clusters also signifies, why it is important to always analyse the α-chains and why structural changes can have a wide range of effects on the body.

Apical cell expansion maintained by Dusky-like establishes a scaffold for corneal lens morphogenesis

The Drosophila corneal lens is entirely composed of chitin and other apical extracellular matrix components, and it is not known how it acquires the biconvex shape that enables it to focus light onto the retina. We show here that the zona pellucida domain-containing protein Dusky-like is essential for normal corneal lens morphogenesis. Dusky-like transiently localizes to the expanded apical surfaces of the corneal lens-secreting cells and prevents them from undergoing apical constriction and apicobasal contraction. Dusky-like also controls the arrangement of two other zona pellucida domain proteins, Dumpy and Piopio, external to the developing corneal lens. Loss of either dusky-like or dumpy delays chitin accumulation and disrupts the outer surface of the corneal lens. We find that artificially inducing apical constriction by activating myosin contraction is sufficient to similarly alter chitin deposition and corneal lens morphology. These results demonstrate the importance of cell shape in controlling the morphogenesis of overlying apical extracellular matrix structures such as the corneal lens.

The Mclust Analysis of Tumor Budding Unveils the Role of the Collagen Family in Cervical Cancer Progression

In RNA-seq data analysis, condensing the gene count matrix size is pivotal for downstream investigations, particularly pathway analysis. For this purpose, harnessing machine learning attracts increasing interest, while conventional methodologies depend on p-value comparisons. In this study, 20 tissue samples from real-world cervical cancers were subjected to sequencing, followed by the application of the Mclust algorithm to delineate an optimal cluster. By stratifying tumor budding into high and low groups and quantifying the epithelial-to-mesenchymal transition (EMT) score to scrutinize tumor budding, we discerned 24 EMT-related genes, with 5 showing strong associations with cervical cancer prognosis. Our observations elucidate a biological flow wherein EMT, Matrix Metallopep-tidase 2 (MMP2), and extracellular matrix (ECM) degradation are interconnected, ultimately leading to collagen type VI and exacerbating the prognosis of cervical cancer. The present study underscores an alternative method for selecting useful EMT-related genes by employing an appropriate clustering algorithm, thereby avoiding classical methods while unveiling novel insights into cervical cancer etiology and prognosis. Moreover, when comparing high and low tumor budding, collagen type VI emerges as a potential gene marker for the prognosis of cervical cancer.

The Role of Collagens in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease affecting both children and adults. The clinical picture of AD manifests in typical skin lesions, such as localized eczema and dry skin, with dominant, persistent itching that leads to sleep disturbances. The pathophysiology of AD has been extensively investigated with respect to epigenetic and genetic factors, skin barrier defects, as well as immunological and microbial disorders. However, to date, the involvement of extracellular matrix (ECM) elements has received limited attention. Collagen, a major component of the ECM, may serve as a therapeutic target for the future treatment of AD. This paper summarizes the role of collagens, which are the most abundant components of the extracellular matrix in AD.

miR-122-5p Promotes Cowshed Particulate Matter2.5-Induced Apoptosis in NR8383 by Targeting COL4A1

It is well known that Particulate Matter2.5 (PM2.5) has a major adverse effect on the organism. However, the health hazards of livestock farm PM2.5 to humans and animals are not yet known, and the role of miRNAs in the cellular damage induced by livestock farm PM2.5 is also unclear. Therefore, our study used cowshed PM2.5 to stimulate rat alveolar macrophage NR8383 to construct an in vitro injury model to investigate the effect of miR-122-5p on PM2.5-induced apoptosis in the NR8383. The level of apoptosis was quantified by flow cytometry and Hoechst 33342/PI double staining. Furthermore, the potential target gene Collagen type IV alpha (COL4A1) of miR-122-5p was identified through the use of bioinformatics methods. The results demonstrated a decline in cell viability and an increase in apoptosis with rising PM2.5 concentrations and exposure durations. The transfection of miR-122-5p mimics resulted in an upregulation of the pro-apoptotic protein Bcl-xL/Bcl-2 and activation of cleaved caspase-3 while inhibiting the anti-apoptotic protein B-cell lymphoma-2. The experimental data indicate that miR-122-5p is involved in the apoptotic process by targeting COL4A1. Furthermore, the overexpression of COL4A1 was observed to enhance the PM2.5-activated PI3K/AKT/NF-κB signaling pathway, which contributed to the inhibition of apoptosis. This finding offers a promising avenue for the development of therapeutic strategies aimed at mitigating cellular damage induced by PM2.5 exposure.

Unraveling the genetic collagen connection: clinical and therapeutic insights on genetic connective tissue disorders

Hereditary connective tissue disorders include more than 200 conditions affecting different organs and tissues, compromising the biological role of the extracellular matrix through interference in the synthesis, development, or secretion of collagen and/or its associated proteins. The clinical phenotype includes multiple signs and symptoms, usually nonspecific but of interest to rheumatologists because of musculoskeletal involvement. The patient´s journey to diagnosis is long, and physicians should include these disorders in their differential diagnoses of diseases with systemic involvement. In this review, insights for the diagnosis and treatment of osteogenesis imperfecta, hypermobility spectrum disorder/Ehlers-Danlos syndrome, Marfan, Loeys-Dietz, and Stickler syndromes are presented.

Collagen XIII Is the Key Molecule of Neurovascular Junctions in the Neuroendocrine System

INTRODUCTION

Axons of magnocellular neurosecretory cells project from the hypothalamus to the posterior lobe (PL) of the pituitary. In the PL, a wide perivascular space exists between the outer basement membrane (BM), where nerve axons terminate, and the inner BM lining the fenestrated capillaries. Hypothalamic axon terminals and outer BMs in the PL form neurovascular junctions. We previously had found that collagen XIII is strongly localized in the outer BMs. In this study, we investigated the role of collagen XIII in the PL of rat pituitaries.

METHODS

We first studied the expression of Col13a1, the gene encoding the α1 chains of collagen XIII, in rat pituitaries via quantitative real-time polymerase chain reaction and in situ hybridization. We observed the distribution of COL13A1 in the rat pituitary using immunohistochemistry and immunoelectron microscopy. We examined the expression of Col13a1 and the distribution of COL13A1 during the development of the pituitary. In addition, we examined the effects of water deprivation and arginine vasopressin (AVP) signaling on the expression of Col13a1 in the PL.

RESULTS

Col13a1 was expressed in NG2-positive pericytes, and COL13A1 signals were localized in the outer BM of the PL. The expression of Col13a1 was increased by water deprivation and was regulated via the AVP/AVPR1A/Gαq/11 cascade in pericytes of the PL.

CONCLUSION

These results suggest that pericytes surrounding fenestrated capillaries in the PL secrete COL13A1 and are involved in the construction of neurovascular junctions. COL13A1 is localized in the outer BM surrounding capillaries in the PL and may be involved in the connection between capillaries and axon terminals.

Craniofacial chondrogenesis in organoids from human stem cell-derived neural crest cells

Knowledge of cell signaling pathways that drive human neural crest differentiation into craniofacial chondrocytes is incomplete, yet essential for using stem cells to regenerate craniomaxillofacial structures. To accelerate translational progress, we developed a differentiation protocol that generated self-organizing craniofacial cartilage organoids from human embryonic stem cell-derived neural crest stem cells. Histological staining of cartilage organoids revealed tissue architecture and staining typical of elastic cartilage. Protein and post-translational modification (PTM) mass spectrometry and snRNA-seq data showed that chondrocyte organoids expressed robust levels of cartilage extracellular matrix (ECM) components: many collagens, aggrecan, perlecan, proteoglycans, and elastic fibers. We identified two populations of chondroprogenitor cells, mesenchyme cells and nascent chondrocytes, and the growth factors involved in paracrine signaling between them. We show that ECM components secreted by chondrocytes not only create a structurally resilient matrix that defines cartilage, but also play a pivotal autocrine cell signaling role in determining chondrocyte fate.

Modulation of Stiffness-Dependent Macrophage Inflammatory Responses by Collagen Deposition

Macrophages are innate immune cells that interact with complex extracellular matrix environments, which have varied stiffness, composition, and structure, and such interactions can lead to the modulation of cellular activity. Collagen is often used in the culture of immune cells, but the effects of substrate functionalization conditions are not typically considered. Here, we show that the solvent system used to attach collagen onto a hydrogel surface affects its surface distribution and organization, and this can modulate the responses of macrophages subsequently cultured on these surfaces in terms of their inflammatory activation and expression of adhesion and mechanosensitive molecules. Collagen was solubilized in either acetic acid (Col-AA) or N-(2-hydroxyethyl)piperazine-N'-ethanesulfonic acid (HEPES) (Col-HEP) solutions and conjugated onto soft and stiff polyacrylamide (PA) hydrogel surfaces. Bone marrow-derived macrophages cultured under standard conditions (pH 7.4) on the Col-HEP-derived surfaces exhibited stiffness-dependent inflammatory activation; in contrast, the macrophages cultured on Col-AA-derived surfaces expressed high levels of inflammatory cytokines and genes, irrespective of the hydrogel stiffness. Among the collagen receptors that were examined, leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) was the most highly expressed, and knockdown of the Lair-1 gene enhanced the secretion of inflammatory cytokines. We found that the collagen distribution was more homogeneous on Col-AA surfaces but formed aggregates on Col-HEP surfaces. The macrophages cultured on Col-AA PA hydrogels were more evenly spread, expressed higher levels of vinculin, and exerted higher traction forces compared to those of cells on Col-HEP. These macrophages on Col-AA also had higher nuclear-to-cytoplasmic ratios of yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ), key molecules that control inflammation and sense substrate stiffness. Our results highlight that seemingly slight variations in substrate deposition for immunobiology studies can alter critical immune responses, and this is important to elucidate in the broader context of immunomodulatory biomaterial design.

Glycosylation Modulates the Structure and Functions of Collagen: A Review

Collagens are fundamental constituents of the extracellular matrix and are the most abundant proteins in mammals. Collagens belong to the family of fibrous or fiber-forming proteins that self-assemble into fibrils that define their mechanical properties and biological functions. Up to now, 28 members of the collagen superfamily have been recognized. Collagen biosynthesis occurs in the endoplasmic reticulum, where specific post-translational modification-glycosylation-is also carried out. The glycosylation of collagens is very specific and adds β-d-galactopyranose and β-d-Glcp-(1→2)-d-Galp disaccharide through β-O-linkage to hydroxylysine. Several glycosyltransferases, namely COLGALT1, COLGALT2, LH3, and PGGHG glucosidase, were associated the with glycosylation of collagens, and recently, the crystal structure of LH3 has been solved. Although not fully understood, it is clear that the glycosylation of collagens influences collagen secretion and the alignment of collagen fibrils. A growing body of evidence also associates the glycosylation of collagen with its functions and various human diseases. Recent progress in understanding collagen glycosylation allows for the exploitation of its therapeutic potential and the discovery of new agents. This review will discuss the relevant contributions to understanding the glycosylation of collagens. Then, glycosyltransferases involved in collagen glycosylation, their structure, and catalytic mechanism will be surveyed. Furthermore, the involvement of glycosylation in collagen functions and collagen glycosylation-related diseases will be discussed.

HTRA1-driven detachment of type I collagen from endoplasmic reticulum contributes to myocardial fibrosis in dilated cardiomyopathy

BACKGROUND

The aberrant secretion and excessive deposition of type I collagen (Col1) are important factors in the pathogenesis of myocardial fibrosis in dilated cardiomyopathy (DCM). However, the precise molecular mechanisms underlying the synthesis and secretion of Col1 remain unclear.

METHODS AND RESULTS

RNA-sequencing analysis revealed an increased HtrA serine peptidase 1 (HTRA1) expression in patients with DCM, which is strongly correlated with myocardial fibrosis. Consistent findings were observed in both human and mouse tissues by immunoblotting, quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunohistochemistry, and immunofluorescence analyses. Pearson's analysis showed a markedly positive correlation between HTRA1 level and myocardial fibrosis indicators, including extracellular volume fraction (ECV), native T1, and late gadolinium enhancement (LGE), in patients with DCM. In vitro experiments showed that the suppression of HTRA1 inhibited the conversion of cardiac fibroblasts into myofibroblasts and decreased Col1 secretion. Further investigations identified the role of HTRA1 in promoting the formation of endoplasmic reticulum (ER) exit sites, which facilitated the transportation of Col1 from the ER to the Golgi apparatus, thereby increasing its secretion. Conversely, HTRA1 knockdown impeded the retention of Col1 in the ER, triggering ER stress and subsequent induction of ER autophagy to degrade misfolded Col1 and maintain ER homeostasis. In vivo experiments using adeno-associated virus-serotype 9-shHTRA1-green fluorescent protein (AAV9-shHTRA1-GFP) showed that HTRA1 knockdown effectively suppressed myocardial fibrosis and improved left ventricular function in mice with DCM.

CONCLUSIONS

The findings of this study provide valuable insights regarding the treatment of DCM-associated myocardial fibrosis and highlight the therapeutic potential of targeting HTRA1-mediated collagen secretion.

Apical cell expansion maintained by Dusky-like establishes a scaffold for corneal lens morphogenesis

The biconvex shape of the Drosophila corneal lens, which enables it to focus light onto the retina, arises by organized assembly of chitin and other apical extracellular matrix components. We show here that the Zona Pellucida domain-containing protein Dusky-like is essential for normal corneal lens morphogenesis. Dusky-like transiently localizes to the expanded apical surfaces of the corneal lens-secreting cells, and in its absence, these cells undergo apical constriction and apicobasal contraction. Dusky-like also controls the arrangement of two other Zona Pellucida-domain proteins, Dumpy and Piopio, external to the developing corneal lens. Loss of either dusky-like or dumpy delays chitin accumulation and disrupts the outer surface of the corneal lens. Artificially inducing apical constriction with constitutively active Myosin light chain kinase is sufficient to similarly alter chitin deposition and corneal lens morphology. These results demonstrate the importance of cell shape for the morphogenesis of overlying apical extracellular matrix structures.

Exome sequencing-aided precise diagnosis of four families with type I Stickler syndrome

BACKGROUND

Stickler syndrome is a multisystemic disorder characterized by ophthalmological and non-ophthalmological abnormalities, frequently misdiagnosed due to high clinical heterogeneity. Stickler syndrome type I (STL1) is predominantly caused by mutations in the COL2A1 gene.

METHODS

Exome sequencing and co-segregation analysis were utilized to scrutinize 35 families with high myopia, and pathogenic mutations were identified. Mutant COL2A1 was overexpressed in cells for mechanistic study. A retrospective genotype-phenotype correlation analysis was further conducted.

RESULTS

Two novel pathogenic mutations (c.2895+1G>C and c.3505G>A (p.Val1169Ile)) and two reported mutations (c.1597C>T (p.Arg533*) and c.1693C>T (p.Arg565Cys)) in COL2A1 were identified causing STL1. These mutations are all in the G-X-Y triplet, and c.2895+1G>C contributed to aberrant RNA splicing. COL2A1 mutants tended to form large aggregates in the endoplasmic reticulum (ER) and elevated ER stress. Additionally, mutations c.550G>A (p.Ala184Thr) and c.2806G>A (p.Gly936Ser) in COL2A1 were found in high myopia families, but were likely benign, although c.2806G>A (p.Gly936Ser) is on G-X-Y triplet. Moreover, genotype-phenotype correlation analysis revealed that mutations in exon 2 mainly contribute to retinal detachment, whereas mutations in the collagen alpha-1 chain region of COL2A1 tend to cause non-ophthalmologic symptoms.

CONCLUSION

This study broadens the COL2A1 gene mutation spectrum, provides evidence for ER stress caused by pathogenic COL2A1 mutations and highlights the importance of non-ophthalmological examination in clinical diagnosis of high myopia.

Comparison of Biological Activities and Protective Effects on PAH-Induced Oxidative Damage of Different Coffee Cherry Pulp Extracts

Polycyclic aromatic hydrocarbons (PAHs) are the main toxic components of ambient air particulate matter (PM), causing oxidative damage to the skin and ultimately resulting in skin aging. This study was conducted to determine the anti-oxidant, anti-aging properties and protective effects of the extracts of coffee cherry pulp (Coffea arabica L.), which is a by-product of the coffee industry, against the oxidative damage induced by PAH exposure in human epidermal keratinocytes (HaCaT). Three different techniques were used to extract the coffee cherry pulp: maceration, Soxhlet and ultrasonication to obtain CCM, CCS and CCU extract, respectively, which were then compared to investigate the total phenolic content (TPC) and total flavonoid content (TFC). The chemical compositions were identified and quantified using high-performance liquid chromatography (HPLC). The results demonstrated that Soxhlet could extract the highest content of chlorogenic acid, caffeine and theophylline. CCS showed the significantly highest TPC (324.6 ± 1.2 mg GAE/g extract), TFC (296.8 ± 1.2 mg QE/g extract), anti-radical activity against DPPH free radicals (98.2 ± 0.8 µM Trolox/g extract) and lipid peroxidation inhibition (136.6 ± 6.2 µM Trolox/g extract). CCS also showed the strongest anti-aging effects based on collagenase, elastase, hyaluronidase and tyrosinase inhibitory enzymes. In addition, CCS can protect human keratinocyte cells from PAH toxicity by increasing the cellular anti-oxidant capacity. This study suggests that CCS has the potential to be used as a cosmetic material that helps alleviate skin damage caused by air pollution.

Proteomic interrogation of the meninges reveals the molecular identities of structural components and regional distinctions along the CNS axis

The meninges surround the brain and spinal cord, affording physical protection while also serving as a niche of neuroimmune activity. Though possessing stromal qualities, its complex cellular and extracellular makeup has yet to be elaborated, and it remains unclear whether the meninges vary along the neuroaxis. Hence, studies were carried-out to elucidate the protein composition and structural organization of brain and spinal cord meninges in normal, adult Biozzi ABH mice. First, shotgun, bottom-up proteomics was carried-out. Prominent proteins at both brain and spinal levels included Type II collagen and Type II keratins, representing extracellular matrix (ECM) and cytoskeletal categories, respectively. While the vast majority of total proteins detected was shared between both meningeal locales, more were uniquely detected in brain than in spine. This pattern was also seen when total proteins were subdivided by cellular compartment, except in the case of the ECM category where brain and spinal meninges each had near equal number of unique proteins, and Type V and type III collagen registered exclusively in the spine. Quantitative analysis revealed differential expression of several collagens and cytoskeletal proteins between brain and spinal meninges. High-resolution immunofluorescence and immunogold-scanning electronmicroscopy on sections from whole brain and spinal cord - still encased within bone -identified major proteins detected by proteomics, and highlighted their association with cellular and extracellular elements of variously shaped arachnoid trabeculae. Western blotting aligned with the proteomic and immunohistological analyses, reinforcing differential appearance of proteins in brain vs spinal meninges. Results could reflect regional distinctions in meninges that govern protective and/or neuroimmune functions.

Novel scaffold platforms for simultaneous induction osteogenesis and angiogenesis in bone tissue engineering: a cutting-edge approach

Despite the recent advances in the development of bone graft substitutes, treatment of critical size bone defects continues to be a significant challenge, especially in the elderly population. A current approach to overcome this challenge involves the creation of bone-mimicking scaffolds that can simultaneously promote osteogenesis and angiogenesis. In this context, incorporating multiple bioactive agents like growth factors, genes, and small molecules into these scaffolds has emerged as a promising strategy. To incorporate such agents, researchers have developed scaffolds incorporating nanoparticles, including nanoparticulate carriers, inorganic nanoparticles, and exosomes. Current paper provides a summary of the latest advancements in using various bioactive agents, drugs, and cells to synergistically promote osteogenesis and angiogenesis in bone-mimetic scaffolds. It also discusses scaffold design properties aimed at maximizing the synergistic effects of osteogenesis and angiogenesis, various innovative fabrication strategies, and ongoing clinical studies.

Advances of three-dimensional (3D) culture systems for in vitro spermatogenesis

The loss of germ cells and spermatogenic failure in non-obstructive azoospermia are believed to be the main causes of male infertility. Laboratory studies have used in vitro testicular models and different 3-dimensional (3D) culture systems for preservation, proliferation and differentiation of spermatogonial stem cells (SSCs) in recent decades. The establishment of testis-like structures would facilitate the study of drug and toxicity screening, pathological mechanisms and in vitro differentiation of SSCs which resulted in possible treatment of male infertility. The different culture systems using cellular aggregation with self-assembling capability, the use of different natural and synthetic biomaterials and various methods for scaffold fabrication provided a suitable 3D niche for testicular cells development. Recently, 3D culture models have noticeably used in research for their architectural and functional similarities to native microenvironment. In this review article, we briefly investigated the recent 3D culture systems that provided a suitable platform for male fertility preservation through organ culture of testis fragments, proliferation and differentiation of SSCs.

Organization of collagen fibers and tissue hardening: Markers of fibrotic scarring after spinal cord injury in mice revealed by multiphoton-atomic force microscopy imaging

Spinal cord injury is a dramatic disease leading to severe motor, sensitive and autonomic impairments. After injury the axonal regeneration is partly inhibited by the glial scar, acting as a physical and chemical barrier. The scarring process involves microglia, astrocytes and extracellular matrix components, such as collagen, constructing the fibrotic component of the scar. To investigate the role of collagen, we used a multimodal label-free imaging approach combining multiphoton and atomic force microscopy. The second harmonic generation signal exhibited by fibrillar collagen enabled to specifically monitor it as a biomarker of the lesion. An increase in collagen density and the formation of more tortuous fibers over time after injury are observed. Nano-mechanical investigations revealed a noticeable hardening of the injured area, correlated with collagen fibers' formation. These observations indicate the concomitance of important structural and mechanical modifications during the fibrotic scar evolution.

Tolerability and efficacy assessment of an oral collagen supplement for the improvement of biophysical and ultrasonographic parameters of skin in middle eastern consumers

BACKGROUND

Topical skin care products often do not reach the deeper layers of the skin, and oral hydrolyzed collagen is one of the newest and most popular systemic supplementations for skin rejuvenation. However, there are limited information in case of Middle Eastern consumers OBJECTIVE: The purpose of this study was to evaluate the tolerability and efficacy of an oral collagen supplement for improvement of skin elasticity, hydration, and roughness in Middle Eastern consumers.

METHODS AND MATERIALS

It was a 12-week, before-after clinical study, conducted on 20 participants (18 women and 2 men) aged 44.15 ± 5.36 years with skin type III-IV. Skin elasticity parameters (R0, R2, R5, and R7), skin hydration and friction, as well as the thickness and echo density of the dermis, were measured after six and 12 weeks daily intake of the study product, as well as 4 weeks after stopping its use (week 16). Participants' satisfaction was assessed on the basis of their answers to the standard questionnaire, and tolerability of the product was assessed by monitoring the adverse effects.

RESULTS

A significant improvement was detected in R2, R5, and skin friction at week 12 (p-values 0.041, 0.012 and <0.01, respectively). At week 16, the values remained at an increased level, which indicates the persistence of the results. The increase of dermis density in week 16 was also significant (p-value = 0.03). Moderate overall satisfaction was reported with the treatment, and a few gastrointestinal complications were reported.

CONCLUSION

The study demonstrated that oral collagen peptides could significantly improve the skin elasticity, roughness, and dermis echo density, and they also proved to be safe and well-tolerated.

Quantitative nanohistology of aging dermal collagen

The skin is the largest organ in the body and is essential for protecting us from environmental stressors such as UV radiation, pollution, and pathogens. As we age, our skin undergoes complex changes that can affect its function, appearance, and health. These changes result from intrinsic (chronological) and extrinsic (environmental) factors that can cause damage to the skin's cells and extracellular matrix. As higher-resolution microscopical techniques, such as Atomic Force Microscopy (AFM), are being deployed to support histology, it is possible to explore the biophysical properties of the dermal scaffold's constituents, such as the collagen network. In this study, we demonstrate the use of our AFM-based quantitative nanohistology, performed directly on unfixed cryosections of 30 donors (female, Caucasian), to differentiate between dermal collagen from different age groups and anatomical sites. The initial 420 (10 × 10 μm²) Atomic Force Microscopy images were segmented into 42,000 (1 × 1 μm²) images before being classified according to four pre-defined empirical collagen structural biomarkers to quantify the structural heterogeneity of the dermal collagen. These markers include interfibrillar gap formation, undefined collagen structure, and registered or unregistered dense collagen fibrillar network with evident D-banding. The structural analysis was also complemented by extensive nanoindentation (∼1,000 curves) performed on individual fibrils from each section, yielding 30,000 indentation curves for this study. Principal Component Analysis was used to reduce the complexity of high-dimensional datasets. The % prevalence of the empirical collagen structural biomarkers between the papillary and reticular dermis for each section proves determinant in differentiating between the donors as a function of their age or the anatomical site (cheek or breast). A case of abnormal biological aging validated our markers and nanohistology approach. This case also highlighted the difference between chronological and biological aging regarding dermal collagen phenotyping. However, quantifying the impact of chronic and pathological conditions on the structure and function of collagen at the sub-micron level remains challenging and lengthy. By employing tools such as the Atomic Force Microscope as presented here, it is possible to start evaluating the complexity of the dermal matrix at the nanoscale and start identifying relevant collagen morphology which could be used toward histopathology standards.

The Human Extracellular Matrix Diseasome Reveals Genotype-Phenotype Associations with Clinical Implications for Age-Related Diseases

The extracellular matrix (ECM) is earning an increasingly relevant role in many disease states and aging. The analysis of these disease states is possible with the GWAS and PheWAS methodologies, and through our analysis, we aimed to explore the relationships between polymorphisms in the compendium of ECM genes (i.e., matrisome genes) in various disease states. A significant contribution on the part of ECM polymorphisms is evident in various types of disease, particularly those in the core-matrisome genes. Our results confirm previous links to connective-tissue disorders but also unearth new and underexplored relationships with neurological, psychiatric, and age-related disease states. Through our analysis of the drug indications for gene-disease relationships, we identify numerous targets that may be repurposed for age-related pathologies. The identification of ECM polymorphisms and their contributions to disease will play an integral role in future therapeutic developments, drug repurposing, precision medicine, and personalized care.

The Associations of Single Nucleotide Polymorphisms of the COL3A1, COL6A5, and COL8A1 Genes with Atopic Dermatitis

The pathophysiology of atopic dermatitis (AD) is complex, multifactorial, and not fully understood. Genes encoding collagens, the most abundant proteins in the extracellular matrix (ECM), may play a potential role in the pathogenesis of AD. Our study aimed to estimate the associations between Col3A1/rs1800255, Col6A5 /29rs12488457, and Col8A1/rs13081855 polymorphisms and the occurrence, course, and features of AD in the Polish population. Blood samples were collected from 157 patients with AD and 111 healthy volunteers. The genotype distribution of the investigated collagens genes did not differ significantly between the AD and control subjects (p > 0.05). The AA genotype of Col3A1/rs1800255 was significantly associated with the occurrence of mild SCORAD (OR = 0.16; 95% Cl: 0.03-0.78; p = 0.02) and mild pruritus (OR = 18.5; 95% Cl: 3.48-98.40; p = 0.0006), while the GG genotype was significantly associated with severe SCORAD (OR = 6.6; 95% Cl: 1.23-32.35; p = 0.03). Regarding Col6A5/29rs12488457 polymorphism, the average SCORAD score was significantly lower in the group of patients with genotype AA than in patients with the AC genotype (39.8 vs. 53.4; p = 0.04). Nevertheless, both average SCORAD scores were high, and represent the moderate and severe grades of the diseases, respectively. The single nucleotide polymorphisms (SNPs) of COL3A1/ rs1800255 and Col6A5/29rs12488457 seem to be associated with AD courses and symptoms, suggesting new disease biomarkers. The modulation of collagens, the major component of the ECM, may serve as a therapeutic target of AD in the future.

Potential of Atlantic Codfish (Gadus morhua) Skin Collagen for Skincare Biomaterials

Collagen is the major structural protein in extracellular matrix present in connective tissues, including skin, being considered a promising material for skin regeneration. Marine organisms have been attracting interest amongst the industry as an alternative collagen source. In the present work, Atlantic codfish skin collagen was analyzed, to evaluate its potential for skincare. The collagen was extracted from two different skin batches (food industry by-product) using acetic acid (ASColl), confirming the method reproducibility since no significant yield differences were observed. The extracts characterization confirmed a profile compatible with type I collagen, without significant differences between batches or with bovine skin collagen (a reference material in biomedicine). Thermal analyses suggested ASColl's native structure loss at 25 °C, and an inferior thermal stability to bovine skin collagen. No cytotoxicity was found for ASColl up to 10 mg/mL in keratinocytes (HaCaT cells). ASColl was used to develop membranes, which revealed smooth surfaces without significative morphological or biodegradability differences between batches. Their water absorption capacity and water contact angle indicated a hydrophilic feature. The metabolic activity and proliferation of HaCaT were improved by the membranes. Hence, ASColl membranes exhibited attractive characteristics to be applied in the biomedical and cosmeceutical field envisaging skincare.

Identifying sex-specific injury predictors as a key factor in maintaining optimal physical activity levels

BACKGROUND

Optimal physical activity is known to reduce cardiovascular, respiratory and endocrine system diseases and, as a consequence, improve quality of life. An important risk factor for reinjuries during normal exercise is the initial connective tissue pathology. The variety of clinical dysplastic manifestations significantly complicate the timely diagnosis of this comorbidity.

AIM

To establish pathognomonic sex-specific dysplasia phenotypes that indicate a particular sensitivity to physical exertion.

METHODS

The study involved 117 participants with recurrent musculoskeletal injuries that occurred during normal exercise. There were 67 women (57.26%) and 50 men (42.74%), which made it possible to compare the presence of the identified signs between sexes. A validated questionnaire was used to screen their connective tissue status.

RESULTS

Ranking the most commonly revealed dysplasia signs depending on their clinical significance made it possible to establish pathognomonic sex-specific phenotypes that indicated a particular susceptibility to injuries. Individualized programs of optimal physical activity are necessary for men with chest deformities, flat-valgus feet, dolichostenomelia, arachnodactylia, hemorrhoids, abdominal muscle diastasis and recurrent hernias. In women, special sensitivity to physical exertion was associated with a combination of signs such as asthenic body, joint hypermobility, overly soft auricles, thin hyperelastic skin, atrophic striae, telangiectasias and varicose veins. Of particular importance were universal signs such as gothic palate, scoliosis, kyphosis, leg deformities, temporomandibular joint crunching, and moderate to high myopia.

CONCLUSION

Participants' connective tissue condition should be considered when designing optimal physical activity programs. Identifying the established sex-specific dysplasia phenotypes will allow timely optimization of training loads, thus reducing the risk of injury.

Biodegradable Materials for Tissue Engineering: Development, Classification and Current Applications

The goal of this review is to map the current state of biodegradable materials that are used in tissue engineering for a variety of applications. At the beginning, the paper briefly identifies typical clinical indications in orthopedics for the use of biodegradable implants. Subsequently, the most frequent groups of biodegradable materials are identified, classified, and analyzed. To this end, a bibliometric analysis was applied to evaluate the evolution of the scientific literature in selected topics of the subject. The special focus of this study is on polymeric biodegradable materials that have been widely used for tissue engineering and regenerative medicine. Moreover, to outline current research trends and future research directions in this area, selected smart biodegradable materials are characterized, categorized, and discussed. Finally, pertinent conclusions regarding the applicability of biodegradable materials are drawn and recommendations for future research are suggested to drive this line of research forward.

Designing Collagen-Binding Peptide with Enhanced Properties Using Hydropathic Free Energy Predictions

Collagen is fundamental to a vast diversity of health functions and potential therapeutics. Short peptides targeting collagen are attractive for designing modular systems for site-specific delivery of bioactive agents. Characterization of peptide-protein binding involves a larger number of potential interactions that require screening methods to target physiological conditions. We build a hydropathy-based free energy estimation tool which allows quick evaluation of peptides binding to collagen. Previous studies showed that pH plays a significant role in collagen structure and stability. Our design tool enables probing peptides for their collagen-binding property across multiple pH conditions. We explored binding features of currently known collagen-binding peptides, collagen type I alpha chain 2 sense peptide (TKKTLRT) and decorin LRR-10 (LRELHLNNN). Based on these analyzes, we engineered a collagen-binding peptide with enhanced properties across a large pH range in contrast to LRR-10 pH dependence. To validate our predictions, we used a quantum-dots-based binding assay to compare the coverage of the peptides on type I collagen. The predicted peptide resulted in improved collagen binding. Hydropathy of the peptide-protein pair is a promising approach to finding compatible pairings with minimal use of computational resources, and our method allows for quick evaluation of peptides for binding to other proteins. Overall, the free-energy-based tool provides an alternative computational screening approach that impacts protein interaction search methods.

An Update on the Clinical Efficacy and Safety of Collagen Injectables for Aesthetic and Regenerative Medicine Applications

Soft tissues diseases significantly affect patients quality of life and usually require targeted, costly and sometimes constant interventions. With the average lifetime increase, a proportional increase of age-related soft tissues diseases has been witnessed. Due to this, the last two decades have seen a tremendous demand for minimally invasive one-step resolutive procedures. Intensive scientific and industrial research has led to the recognition of injectable formulations as a new advantageous approach in the management of complex diseases that are challenging to treat with conventional strategies. Among them, collagen-based products are revealed to be one of the most promising among bioactive biomaterials-based formulations. Collagen is the most abundant structural protein of vertebrate connective tissues and, because of its structural and non-structural role, is one of the most widely used multifunctional biomaterials in the health-related sectors, including medical care and cosmetics. Indeed, collagen-based formulations are historically considered as the "gold standard" and from 1981 have been paving the way for the development of a new generation of fillers. A huge number of collagen-based injectable products have been approved worldwide for clinical use and have routinely been introduced in many clinical settings for both aesthetic and regenerative surgery. In this context, this review article aims to be an update on the clinical outcomes of approved collagen-based injectables for both aesthetic and regenerative medicine of the last 20 years with an in-depth focus on their safety and effectiveness for the treatment of diseases of the integumental, gastrointestinal, musculoskeletal, and urogenital apparatus.

A natural strategy for astaxanthin stabilization and color regulation: Interaction with proteins

The pigment astaxanthin, one of the carotenoids, is regarded as a functional factor with various biological activities, widely applied in feed, nutraceutical, and cosmetic industries. However, its low stability and poor water solubility limit its application. Examples in nature suggest that binding to proteins is a simple and effective method to improve the stability and bioavailability of astaxanthin. Proteins from algae, fish, and crustaceans have all been demonstrated to have astaxanthin-binding capacity. Inspired by nature, artificial astaxanthin-protein systems have been established in foods. Binding to proteins could bring aquatic species various colors, and changes in the conformation of astaxanthin after binding to proteins leads to color changes. The review innovatively summarizes multiple examples of proteins as means of protecting astaxanthin, giving a reference for exploring and analyzing pigment-protein interactions and providing a strategy for carotenoids stabilization and color regulation, which is beneficial to the broader and deeper applications of carotenoids.

Unique ligand and kinase-independent roles of the insulin receptor in regulation of cell cycle, senescence and apoptosis

Insulin acts through the insulin receptor (IR) tyrosine kinase to exert its classical metabolic and mitogenic actions. Here, using receptors with either short or long deletion of the β-subunit or mutation of the kinase active site (K1030R), we have uncovered a second, previously unrecognized IR signaling pathway that is intracellular domain-dependent, but ligand and tyrosine kinase-independent (LYK-I). These LYK-I actions of the IR are linked to changes in phosphorylation of a network of proteins involved in the regulation of extracellular matrix organization, cell cycle, ATM signaling and cellular senescence; and result in upregulation of expression of multiple extracellular matrix-related genes and proteins, down-regulation of immune/interferon-related genes and proteins, and increased sensitivity to apoptosis. Thus, in addition to classical ligand and tyrosine kinase-dependent (LYK-D) signaling, the IR regulates a second, ligand and tyrosine kinase-independent (LYK-I) pathway, which regulates the cellular machinery involved in senescence, matrix interaction and response to extrinsic challenges.

The Role of Selected Flavonoids from Bajakah Tampala (Spatholobus littoralis Hassk.) Stem on Cosmetic Properties: A Review

Cosmetics made from natural ingredients are increasingly popular because they contain bioactive compounds which can provide many health benefits, more environmentally friendly and sustainable. The health benefits obtained from natural-based ingredients include anti-aging, photoprotective, antioxidant, and anti-inflammatory. This article reviewed the potential of selected flavonoids from bajakah tampala (Spatholobus littoralis Hassk.) as the native plant in Indonesia. We present in silico, in vitro, in vivo, and clinical research data on the use of selected flavonoids that have been reported in other extracts.

Regulation of Collagen I and Collagen III in Tissue Injury and Regeneration

The structure of connective tissues including cartilage, tendons, and ligaments as well as many organs, like the skin, heart, liver, kidney, lungs, blood vessels, and bones, depend on collagen. The bulk of the network of structural proteins that make up the extracellular matrix of the heart is composed of collagen type I and type III, which provide structural support for the muscle cells and are crucial for cardiac function. The prognosis and progression of a disease or diseased state may be significantly impacted by the upregulation or downregulation of the collagen types, particularly Col I and Col III. For example, increasing Col I protein levels may impose increasing myocardial stiffness, impairing the diastolic and systolic function of the myocardium. Collagen I is a stiff fibrillar protein that gives tensile strength, whereas Col III produces an elastic network that stores kinetic energy as an elastic rebound. These two collagen proteins have distinct physical properties in nature. Therefore, the control of Col I and Col III as well as the potential relevance of the Col I/Col III ratio in many biological processes serve as the foundation for this comprehensive review article.

2-kDa hyaluronan ameliorates human facial wrinkles through increased dermal collagen density related to promotion of collagen remodeling

BACKGROUND/AIMS

Hyaluronan (HA) oligosaccharides are involved in several biological processes, primarily collagen remodeling and wound healing. Collagen remodeling is retarded in aging skin and causes wrinkles. The aim of this study was to evaluate the effect of 2-kDa HA oligosaccharides (HA2k) on wrinkles by permeation through the stratum corneum and promotion of collagen remodeling.

METHODS

A 3D skin model and excised human skin were used to evaluate the permeation of fluorescein-labeled HA2k. The effect of HA2k on collagen metabolism was evaluated by measuring the protein level of type 1 pro-collagen (COL1A1) and matrix metalloproteinase-1 (MMP-1) in the 3D skin model. 0.1% HA2k solution and vehicle control was applied to the human forearm for 8 weeks to evaluate dermal collagen density. To evaluate the effect of HA2k on depth of facial wrinkles, a randomized controlled trial was conducted with 0.1% HA2k lotion and vehicle lotion for 8 weeks.

RESULTS

HA2k was confirmed to permeate through the stratum corneum by fluorescent microscopy. Both COL1A1 and MMP-1 were upregulated by HA2k application in a 3D skin model culture. The collagen density was higher for the HA2k-treated forearm than for the vehicle control-treated forearm after 4 weeks. The maximum wrinkle depths in the nasolabial fold and crow's feet area were significantly shallower in the HA2k lotion group than in the control group.

CONCLUSION

HA2k permeated the stratum corneum, activated collagen synthesis and degradation simultaneously, and ameliorated wrinkles.

RNA-Seq reveals distinct transcriptomic differences in rotator cuff tendon based on tear etiology and patient sex

Rotator cuff tears are a common pathology in the shoulder and generally have two underlying etiologies: traumatic and degenerative. Little is known about the molecular underpinning of these etiologies. Here we queried transcript level differences in tear etiology stratified by sex in 31 patients with rotator cuff tears. Tendon tissues were isolated from females (N = 16) and males (N = 15) with traumatic (N = 16) or degenerative (N = 15) tears during arthroscopy. Differentially expressed transcripts were identified by RNA-seq and biological processes were probed computationally. Expression of some transcripts was validated by real-time quantitative polymerase chain reaction (qPCR). We identified 339 and 336 transcripts differentially expressed by tear etiology in females and males, respectively, at a fold-change greater than |2|. In females, GSTM1, MT1G, S1008A, ACSM3, DSC, FAM110C, and VNN2 were elevated in traumatic tears representing metabolic/catabolic processes, and immune response whereas CHAD, CLEC3A, IBSP, TNMD, APLNR, and CPA3 were elevated in degenerative tears representing tissue morphogenesis and developmental processes, angiogenesis, and extracellular matrix organization. In males, ELOA3B, CXCL8, ADM, TNS4, and SPOCK1 were elevated in traumatic tears representing localization of endoplasmic reticulum, chromosome organization, leukocyte/neutrophil degranulation, and protein transport whereas MYL2, TNNC1, MB, CPA3, APLNR, and CA3 were highly upregulated in degenerative tears representing muscle cell differentiation and development and angiogenesis. Numerous novel lncRNAs were identified to be differentially expressed by tear etiology in both sexes. Real-time qPCR confirmed RNA-seq data. This study improves our understanding of tendon biology based on underlying etiology (trauma or degeneration) in a sex-specific manner. These findings may help drive clinical decision-making in females and males with traumatic and degenerative shoulder injuries.