Type V Collagen in Health, Disease, and Fibrosis

The Association of a Single Nucleotide Variant in COL5A1 to Early Onset Keratoconus and Pectus Excavatum-Convergence of Extracellular Matrix Pathologies

Keratoconus is a bilateral ocular condition characterized by irregularities and the thinning of the cornea. Decreased central corneal thickness is a hallmark of the condition, and numerous genes have played a role in altering corneal thickness and the subsequent development of keratoconus. Variants in the structural and regulatory genes of the extracellular matrix have been highly associated with keratoconus, as well as with pectus excavatum, a chest wall deformity commonly seen in connective tissue disorders. This report describes a patient with a c.1720-11T>A intronic variant in the collagen-encoding gene, COL5A1, who was diagnosed with early-onset keratoconus and demonstrated a significant pectus excavatum. This report associates a COL5A1 variant with these seemingly unrelated phenotypic associations, further advancing the literature on the topic.

Investigating the paracrine and juxtacrine abilities of adipose-derived stromal cells in angiogenesis triple cell co-cultures

The pro-angiogenic abilities of adipose-derived stromal cells (ASCs) make them attractive candidates for cellular therapy, especially for ischemic disease indications. However, details regarding the underlying mechanisms remain elusive. Therefore, this study aimed to investigate paracrine and juxtacrine abilities of ASCs in angiogenesis triple cell co-cultures by detailed image analysis of the vascular-like structures. Fibroblast-endothelial cell co-cultures were established, and ASCs were added directly or indirectly through inserts. The cultures were treated with antibodies or subjected to analyses using ELISA and RT2 PCR Arrays. The model consistently generated vascular-like structures. ASCs increased the total branch lengths equally well in paracrine and juxtacrine conditions, by increasing the number of branches and average branch lengths (ABL). In contrast, addition of VEGF to the model increased the number of branches, but not the ABL. Still, ASCs increased the VEGF levels in supernatants of paracrine and juxtacrine co-cultures, and anti-VEGF treatment decreased the sprouting. ASCs themselves up-regulated collagen type V in response to paracrine signals from the co-cultures. The results suggest that ASCs initiate sprouting through secretion of several paracrine factors, among which VEGF is identified, but VEGF alone does not recapitulate the paracrine actions of ASCs. By employing neutralizing antibodies and dismantling common model outputs using image analysis, the triple cell co-culture is an attractive tool for discovery of the paracrine factors in ASCs' secretome which act in concert with VEGF to improve angiogenesis.

Functional and Structural Properties of Type V Collagen from the Skin of the Shortbill Spearfish (Tetrapturus angustirostris)

Type V collagen is considered to be a crucial minor collagen in fish skin with unique physiological functions. In this research, the cDNAs of three procollagens (Tacol5a1, Tacol5a2, and Tacol5a3) in type V collagen were cloned from the skin of shortbill spearfish (Tetrapturus angustirostris). The open reading frames (ORFs) of Tacol5a1, Tacol5a2, and Tacol5a3 contained 5991, 4485, and 5607 bps, respectively, encoding 1997, 1495, and 1869 amino acid residues. Each of the deduced amino acid sequences of procollagens contained a signal peptide and a fibrillar collagen C-terminal domain (COLFI). A conserved thrombospondin-like N-terminal domain (TSPN) was found at the N-terminus of Tacol5a1 and 5a3 procollagens, whereas a von Willebrand factor (VWC) was found at the N-terminus of Tacol5a2 procollagen. Tacol5a1, Tacol5a2, and Tacol5a3 had their theoretical isoelectric points of 5.06, 6.75, and 5.76, respectively, and predicted molecular weights of 198,435.60, 145,058.48, and 189,171.18, respectively. The phylogenetic tree analysis revealed that Tacol5a1 of shortbill spearfish clustered with that of yellow perch (Perca flavescens) instead of broadbill swordfish (Xiphias gladius). In addition, type V collagen was extracted from the shortbill spearfish skin. The in silico method demonstrated that shortbill spearfish type V collagen has a high potential for angiotensin-converting enzyme (ACE) inhibition activity (79.50%), dipeptidyl peptidase IV inhibition (74.91%) activity, and antithrombotic activity (46.83%). The structural clarification and possible functional investigation in this study provide the foundation for the applications of exogenous type V collagen derived from fish sources.

Total flavone of Abelmoschus manihot regulates autophagy through the AMPK/mTOR signaling pathway to treat intestinal fibrosis in Crohn's disease

BACKGROUND AND AIM

Drug therapy is the treatment of choice for Crohn's disease because it effectively controls or prevents intestinal inflammation. The purpose was to research the molecular mechanism of the total flavones of Abelmoschus manihot (TFA) on intestinal fibrosis in Crohn's disease.

METHODS

A 2,4,6-Trinitrobenzenesulfonic acid (TNBS)-induced colitis model and IGF-1-treated intestinal fibroblasts were established. Then, TFA, 3-MA, and compound C were used treatments. Hematoxylin and eosin, Masson, and Picrosirius red staining were performed to observe the colon tissue. Immunohistochemical staining was used to detect α-SMA expression. Flow cytometry, CCK8, wound healing, and Transwell assays were conducted to determine apoptosis, proliferation, invasion, and migration. Col1a1 and Col3a1 levels were detected using quantitative polymerase chain reaction. Proteins related to autophagy and apoptosis were detected using western blotting.

RESULTS

TFA treated intestinal fibrosis in chronic Crohn's disease. Colon length was the shortest in the ethanol + TNBS group, and TFA treatment significantly improved the situation. Intestinal fibrosis and the percentage of collagen area decreased after TFA treatment. TFA reduced fibrosis by enhancing autophagy stimulation, whereas an autophagy inhibitor reversed the TFA effect. TFA also inhibited migration, proliferation, and collagen synthesis in intestinal fibroblasts. Moreover, it enhanced autophagy and apoptosis of intestinal fibroblasts. TFA upregulated p-AMPK expression and decreases p-mTOR levels. Compound C partially rescued the effect of TFA, indicating that TFA affected intestinal fibroblasts via the AMPK/mTOR pathway in vitro and in vivo. TFA also downregulated Col1a1 and Col3a1 expression.

CONCLUSION

TFA regulates autophagy through AMPK/mTOR signaling pathway to treat intestinal fibrosis, which may provide a new therapy for Crohn's disease treatment.

Comparative Gene-Expression Analysis of the Ligamentum Flavum of Patients with Lumbar Spinal Canal Stenosis: Comparison between the Dural and Dorsal Sides of the Thickened Ligamentum Flavum

Thickening of the ligamentum flavum is the main factor in the development of lumbar spinal canal stenosis (LSCS). Although previous studies have reported factors related to ligamentum flavum thickening, its etiology has not been clarified. Furthermore, it is often difficult to set proper controls to investigate the pathologies of thickening due to differences in patient characteristics, such as age, sex, obesity, and comorbidities. This study aimed to elucidate the pathologies of ligamentum flavum thickening by comparing the dural and dorsal sides of the thickened ligamentum flavum in patients with LSCS. Ligamentum flavum samples were collected from 19 patients with LSCS. The samples were divided into the dural and dorsal sides. The dural side was used as a control to assess the pathologies occurring on the dorsal side. Elastic Masson staining was used to assess the elastic fibres. Gene expression levels were comprehensively assessed using quantitative reverse transcription polymerase chain reaction and DNA microarray analyses. Gene ontology analysis was used to identify biological processes associated with differentially expressed genes. The elastic fibres were significantly decreased on the dorsal side of the thickened ligamentum flavum. Genes related to fibrosis, inflammation, tissue repair, remodeling, and chondrometaplasia, such as COL1A2, COL3A1, COL5A1, TGFB1, VEGFA, TNFA, MMP2, COL10A1, and ADAMTS4, were highly expressed on the dorsal side of the thickened ligamentum flavum. The biological processes occurring on the dorsal side of the thickened ligamentum flavum were extracellular matrix organization, cell adhesion, extracellular matrix disassembly, and proteolysis.These are considered important pathologies of ligamentum flavum thickening.

An engineered in vitro model of the human myotendinous junction

The myotendinous junction (MTJ) is a vulnerable region at the interface of skeletal muscle and tendon that forms an integrated mechanical unit. This study presents a technique for the spatially restrictive co-culture of human embryonic stem cell (hESC)-derived skeletal myocytes and primary tenocytes for two-dimensional modeling of the MTJ. Micropatterned lanes of extracellular matrix and a 2-well culture chamber define the initial regions of occupation. On day 1, both lines occupy less than 20 % of the initially vacant interstitial zone, referred to henceforth as the junction. Myocyte-tenocyte interdigitations are observed by day 7. Immunocytochemistry reveals enhanced organization and alignment of patterned myocyte and tenocyte features, as well as differential expression of multiple MTJ markers. On day 24, electrically stimulated junction myocytes demonstrate negative contractile strains, while positive tensile strains are exhibited by mechanically passive tenocytes at the junction. Unpatterned tenocytes distal to the junction experience significantly decreased strains in comparison to cells at the interface. Unpatterned myocytes have impaired organization and uncoordinated contractile behavior. These findings suggest that this platform is capable of inducing myocyte-tenocyte junction formation and mechanical coupling similar to the native MTJ, showing transduction of force across the cell-cell interface. STATEMENT OF SIGNIFICANCE: The myotendinous junction (MTJ) is an integrated structure that transduces force across the muscle-tendon boundary, making the region vulnerable to strain injury. Despite the clinical relevance, previous in vitro models of the MTJ lack the structure and mechanical accuracy of the native tissue and have difficulty transmitting force across the cell-cell interface. This study demonstrates an in vitro model of the MTJ, using spatially restrictive cues to inform human myocyte-tenocyte interactions and architecture. The model expressed MTJ markers and developed anisotropic myocyte-tenocyte integrations that resemble the native tissue and allow for force transduction from contracting myocytes to passive tenocyte regions. As such, this study presents a system capable of investigating development, injury, and pathology in the human MTJ.

Gums as Macromolecular Crowding Agents in Human Skin Fibroblast Cultures

Even though tissue-engineered medicines are under intense academic, clinical, and commercial investigation, only a handful of products have been commercialised, primarily due to the costs associated with their prolonged manufacturing. While macromolecular crowding has been shown to enhance and accelerate extracellular matrix deposition in eukaryotic cell culture, possibly offering a solution in this procrastinating tissue-engineered medicine development, there is still no widely accepted macromolecular crowding agent. With these in mind, we herein assessed the potential of gum Arabic, gum gellan, gum karaya, and gum xanthan as macromolecular crowding agents in WS1 skin fibroblast cultures (no macromolecular crowding and carrageenan were used as a control). Dynamic light scattering analysis revealed that all macromolecules had negative charge and were polydispersed. None of the macromolecules affected basic cellular function. At day 7 (the longest time point assessed), gel electrophoresis analysis revealed that all macromolecules significantly increased collagen type I deposition in comparison to the non-macromolecular crowding group. Also at day 7, immunofluorescence analysis revealed that carrageenan; the 50 µg/mL, 75 µg/mL, and 100 µg/mL gum gellan; and the 500 µg/mL and 1000 µg/mL gum xanthan significantly increased both collagen type I and collagen type III deposition and only carrageenan significantly increased collagen type V deposition, all in comparison to the non-macromolecular crowding group at the respective time point. This preliminary study demonstrates the potential of gums as macromolecular crowding agents, but more detailed biological studies are needed to fully exploit their potential in the development of tissue-engineered medicines.

Atrial fibrillation in human patients is associated with increased collagen type V and TGFbeta1

Background and aim

Atrial fibrosis is an important factor in initiating and maintaining atrial fibrillation (AF). Collagen V belongs to fibrillar collagens. There are, however no data on collagen V in AF. The aim of this work was to study the quantity of collagen V and its relationship with the number of fibroblasts and TGF- b 1 expression in patients in sinus rhythm (SR) and in patients with atrial fibrillation (AF).

Methods

We used quantitative immuhistochemistry to study collagen V in right and left atrial biopsies obtained from 35 patients in SR, 35 patients with paroxysmal AF (pAF) and 27 patients with chronic, long-standing persistent AF (cAF). In addition, we have quantified the number of vimentin-positive fibroblasts and expression levels of TGF-β1.

Results

Compared to patients in SR, collagen V was increased 1.8- and 3.1-fold in patients with pAF and cAF, respectively. In comparison with SR patients, the number of vimentin-positive cells increased significantly 1.46- and 1.8-fold in pAF and cAF patients, respectively.Compared to SR patients, expression levels of TGF-ß1, expressed as fluorescence units per tissue area, was significantly increased by 77 % and 300 % in patients with pAF and cAF, respectively. Similar to intensity measurements, the number of TGFß1-positive cells per 1 mm2 atrial tissue increased significantly from 35.5 ± 5.5 cells in SR patients to 61.9 ± 12.4 cells in pAF and 131.5 ± 23.5 cells in cAF. In both types of measurements, there was a statistically significant difference between pAF and cAF groups.

Conclusions

This is the first study to show that AF is associated with increased expression levels of collagen V and TGF-ß1indicating its role in the pathogenesis of atrial fibrosis. In addition, increases in collagen V correlate with increased number of fibroblasts and TGF-β1 and are more pronounced in cAF patients than those in pAF patients.

ETS1, a target gene of the EWSR1::FLI1 fusion oncoprotein, regulates the expression of the focal adhesion protein TENSIN3

The mechanistic basis for the metastasis of Ewing sarcomas remains poorly understood, as these tumors harbor few mutations beyond the chromosomal translocation that initiates the disease. Instead, the epigenome of Ewing sarcoma (EWS) cells reflects the regulatory state of genes associated with the DNA binding activity of the fusion oncoproteins EWSR1::FLI1 or EWSR1::ERG. In this study, we examined the EWSR1::FLI1/ERG's repression of transcription factor genes, concentrating on those that exhibit a broader range of expression in tumors than in EWS cell lines. Focusing on one of these target genes, ETS1, we detected EWSR1::FLI1 binding and an H3K27me3 repressive mark at this locus. Depletion of EWSR1::FLI1 results in ETS1's binding of promoter regions, substantially altering the transcriptome of EWS cells, including the upregulation of the gene encoding TENSIN3 (TNS3), a focal adhesion protein. EWS cell lines expressing ETS1 (CRISPRa) exhibited increased TNS3 expression and enhanced movement compared to control cells. The cytoskeleton of control cells and ETS1-activated EWS cell lines also differed. Specifically, control cells exhibited a distributed vinculin signal and a network-like organization of F-actin. In contrast, ETS1-activated EWS cells showed an accumulation of vinculin and F-actin towards the plasma membrane. Interestingly, the phenotype of ETS1-activated EWS cell lines depleted of TNS3 resembled the phenotype of the control cells. Critically, these findings have clinical relevance as TNS3 expression in EWS tumors positively correlates with that of ETS1.

A genomic perspective of the aging human and mouse lung with a focus on immune response and cellular senescence

BACKGROUND

The aging lung is a complex process and influenced by various stressors, especially airborne pathogens and xenobiotics. Additionally, a lifetime exposure to antigens results in structural and functional changes of the lung; yet an understanding of the cell type specific responses remains elusive. To gain insight into age-related changes in lung function and inflammaging, we evaluated 89 mouse and 414 individual human lung genomic data sets with a focus on genes mechanistically linked to extracellular matrix (ECM), cellular senescence, immune response and pulmonary surfactant, and we interrogated single cell RNAseq data to fingerprint cell type specific changes.

RESULTS

We identified 117 and 68 mouse and human genes linked to ECM remodeling which accounted for 46% and 27%, respectively of all ECM coding genes. Furthermore, we identified 73 and 31 mouse and human genes linked to cellular senescence, and the majority code for the senescence associated secretory phenotype. These cytokines, chemokines and growth factors are primarily secreted by macrophages and fibroblasts. Single-cell RNAseq data confirmed age-related induced expression of marker genes of macrophages, neutrophil, eosinophil, dendritic, NK-, CD4+, CD8+-T and B cells in the lung of aged mice. This included the highly significant regulation of 20 genes coding for the CD3-T-cell receptor complex. Conversely, for the human lung we primarily observed macrophage and CD4+ and CD8+ marker genes as changed with age. Additionally, we noted an age-related induced expression of marker genes for mouse basal, ciliated, club and goblet cells, while for the human lung, fibroblasts and myofibroblasts marker genes increased with age. Therefore, we infer a change in cellular activity of these cell types with age. Furthermore, we identified predominantly repressed expression of surfactant coding genes, especially the surfactant transporter Abca3, thus highlighting remodeling of surfactant lipids with implications for the production of inflammatory lipids and immune response.

CONCLUSION

We report the genomic landscape of the aging lung and provide a rationale for its growing stiffness and age-related inflammation. By comparing the mouse and human pulmonary genome, we identified important differences between the two species and highlight the complex interplay of inflammaging, senescence and the link to ECM remodeling in healthy but aged individuals.

Histological assessment of nanostructured fibrin-agarose skin substitutes grafted in burnt patients. A time-course study

A previously developed fibrin-agarose skin model-UGRSKIN-showed promising clinical results in severely burnt patients. To determine the histological parameters associated to the biocompatibility and therapeutic effects of this model, we carried out a comprehensive structural and ultrastructural study of UGRSKIN grafted in severely burnt patients after 3 months of follow-up. The grafted epidermis was analogue to native human skin from day 30th onward, revealing well-structured strata with well-differentiated keratinocytes expressing CK5, CK8, CK10, claudin, plakoglobin, filaggrin, and involucrin in a similar way to controls, suggesting that the epidermis was able to mature and differentiate very early. Melanocytes and Langerhans cells were found from day 30th onward, together with a basement membrane, abundant hemidesmosomes and lack of rete ridges. At the dermal layer, we found an interface between the grafted skin and the host tissue at day 30th, which tended to disappear with time. The grafted superficial dermis showed a progressive increase in properly-oriented collagen fibers, elastic fibers and proteoglycans, including decorin, similarly to control dermis at day 60-90th of in vivo follow-up. Blood vessels determined by CD31 and SMA expression were more abundant in grafted skin than controls, whereas lymphatic vessels were more abundant at day 90th. These results contribute to shed light on the histological parameters associated to biocompatibility and therapeutic effect of the UGRSKIN model grafted in patients and demonstrate that the bioengineered skin grafted in patients is able to mature and differentiate very early at the epithelial level and after 60-90 days at the dermal level.

M1/M2 Macrophage Skewing is Related to Reduction in Types I, V, and VI Collagens with Aging in Sun-Exposed Human Skin

Sun-exposed, aged human skin is fragile because of collagen fragmentation and loss. We recently reported that the balance of M1 and M2 macrophages is associated with chronic inflammation and related inflammaging in sun-exposed human skin. In this study, we analyzed its role in the maintenance of collagen matrix formation by performing histological analyses of human facial skin. In addition, RNA sequencing, protein assays, and functional assays revealed the details of the mechanism. The number of M2 macrophages was positively correlated with the abundance of type I collagen, whereas the M1/M2 ratio was negatively correlated with the abundance of type V and VI collagen, which are the essential minor collagens required for collagen assembly in the skin; however, there was no correlation with type III collagen. Furthermore, M2 macrophages induced the expression of the proteins required for the assembly of collagen fibrils, suggesting that the M1/M2 balance controls not only the quantity but also the quality of the collagen matrix. Indeed, M1 macrophages induced abnormal collagen fibrils consisting of types I, V, and VI collagens. Our results demonstrate the relationship between the M1/M2 balance and the dysregulation of collagen homeostasis in photoaged skin and suggest the possible involvement of macrophages in skin photoaging.

Transcriptomic landscape of Atlantic salmon (Salmo salar L.) skin

In this study, we present the first spatial transcriptomic atlas of Atlantic salmon skin using the Visium Spatial Gene Expression protocol. We utilized frozen skin tissue from 4 distinct sites, namely the operculum, pectoral and caudal fins, and scaly skin at the flank of the fish close to the lateral line, obtained from 2 Atlantic salmon (150 g). High-quality frozen tissue sections were obtained by embedding tissue in optimal cutting temperature media prior to freezing and sectioning. Further, we generated libraries and spatial transcriptomic maps, achieving a minimum of 80 million reads per sample with mapping efficiencies ranging from 79.3 to 89.4%. Our analysis revealed the detection of over 80,000 transcripts and nearly 30,000 genes in each sample. Among the tissue types observed in the skin, the epithelial tissues exhibited the highest number of transcripts (unique molecular identifier counts), followed by muscle tissue, loose and fibrous connective tissue, and bone. Notably, the widest nodes in the transcriptome network were shared among the epithelial clusters, while dermal tissues showed less consistency, which is likely attributable to the presence of multiple cell types at different body locations. Additionally, we identified collagen type 1 as the most prominent gene family in the skin, while keratins were found to be abundant in the epithelial tissue. Furthermore, we successfully identified gene markers specific to epithelial tissue, bone, and mesenchyme. To validate their expression patterns, we conducted a meta-analysis of the microarray database, which confirmed high expression levels of these markers in mucosal organs, skin, gills, and the olfactory rosette.

Convergent alterations in the tumor microenvironment of MYC-driven human and murine prostate cancer

The tissue microenvironment in prostate cancer is profoundly altered. While such alterations have been implicated in driving prostate cancer initiation and progression to aggressive disease, how prostate cancer cells and their precursors mediate those changes is unclear, in part due to the inability to longitudinally study the disease evolution in human tissues. To overcome this limitation, we performed extensive single-cell RNA-sequencing (scRNA-seq) and rigorous molecular pathology of the comparative biology between human prostate cancer and key time points in the disease evolution of a genetically engineered mouse model (GEMM) of prostate cancer. Our studies of human tissues, with validation in a large external data set, revealed that cancer cell-intrinsic activation of MYC signaling was the top up-regulated pathway in human cancers, representing a common denominator across the well-known molecular and pathological heterogeneity of human prostate cancer. Likewise, numerous non-malignant cell states in the tumor microenvironment (TME), including non-cancerous epithelial, immune, and fibroblast cell compartments, were conserved across individuals, raising the possibility that these cell types may be a sequelae of the convergent MYC activation in the cancer cells. To test this hypothesis, we employed a GEMM of prostate epithelial cell-specific MYC activation in two mouse strains. Cell communication network and pathway analyses suggested that MYC oncogene-expressing neoplastic cells, directly and indirectly, reprogrammed the TME during carcinogenesis, leading to the emergence of cascading cell state alterations in neighboring epithelial, immune, and fibroblast cell types that paralleled key findings in human prostate cancer. Importantly, among these changes, the progression from a precursor-enriched to invasive-cancer-enriched state was accompanied by a cell-intrinsic switch from pro-immunogenic to immunosuppressive transcriptional programs with coinciding enrichment of immunosuppressive myeloid and Treg cells in the immune microenvironment. These findings implicate activation of MYC signaling in reshaping convergent aspects of the TME of prostate cancer as a common denominator across the otherwise well-documented molecular heterogeneity of human prostate cancer.

Identification and validation of targets of swertiamarin on idiopathic pulmonary fibrosis through bioinformatics and molecular docking-based approach

BACKGROUND

Swertiamarin is the main hepatoprotective component of Swertiapatens and has anti-inflammatory and antioxidation effects. Our previous study showed that it was a potent inhibitor of idiopathic pulmonary fibrosis (IPF) and can regulate the expressions of α-smooth muscle actin (α-SMA) and epithelial cadherin (E-cadherin), two markers of the TGF-β/Smad (transforming growth factor beta/suppressor of mothers against decapentaplegic family) signaling pathway. But its targets still need to be investigated. The main purpose of this study is to identify the targets of swertiamarin.

METHODS

GEO2R was used to analyze the differentially expressed genes (DEGs) of GSE10667, GSE110147, and GSE71351 datasets from the Gene Expression Omnibus (GEO) database. The DEGs were then enriched with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis for their biological functions and annotated terms. The protein-protein interaction (PPI) network was constructed to identify hub genes. The identified hub genes were predicted for their bindings to swertiamarin by molecular docking (MD) and validated by experiments.

RESULTS

76 upregulated and 27 downregulated DEGs were screened out. The DEGs were enriched in the biological function of cellular component (CC) and 7 cancer-related signaling pathways. Three hub genes, i.e., LOX (lysyl oxidase), COL5A2 (collagen type V alpha 2 chain), and CTGF (connective tissue growth factor) were selected, virtually tested for the interactions with swertiamarin by MD, and validated by in vitro experiments.

CONCLUSION

LOX, COL5A2, and CTGF were identified as the targets of swertiamarin on IPF.

Upregulated TIMP1 facilitates and coordinates myometrial contraction by decreasing collagens and cell adhesive capacity during human labor

Myometrial contraction is one of the key events involved in parturition. Increasing evidence suggests the importance of the extracellular matrix (ECM) in this process, in addition to the functional role of myometrial smooth muscle cells, and our previous study identified an upregulated tissue inhibitor of metalloproteinase 1 (TIMP1) in human laboring myometrium compared to nonlabor samples. This study aimed to further explore the potential role of TIMP1 in myometrial contraction. First, we confirmed increased myometrial TIMP1 levels in labor and during labor with cervical dilation using transcriptomic and proteomic analyses, followed by real-time PCR, western blotting, and immunohistochemistry. Then, a cell contraction assay was performed to verify the decreased contractility after TIMP1 knockdown in vitro. To further understand the underlying mechanism, we used RNA-sequencing analysis to reveal the upregulated genes after TIMP1 knockdown; these genes were enriched in collagen fibril organization, cell adhesion, and ECM organization. Subsequently, a human matrix metalloproteinase (MMP) array and collagen staining were performed to determine the TIMPs, MMPs and collagens in laboring and nonlabor myometrium. A real-time cell adhesion assay was used to detect cell adhesive capacity. The results showed upregulated MMP8 and MMP9, downregulated collagens, and attenuated cell adhesive capacity in laboring myometrium, while lower MMP levels and higher collagen levels and cell adhesive capacity were observed in nonlabor. Moreover, TIMP1 knockdown led to restoration of cell adhesive capacity. Together, these results indicate that upregulated TIMP1 during labor facilitates and coordinates myometrial contraction by decreasing collagen and cell adhesive capacity, which may provide effective strategies for the regulation of myometrial contraction.

Novel Correlation between TGF-β1/-β3 and Hormone Receptors in the Human Corneal Stroma

This study investigated the interplay between transforming growth factor beta (TGF-β1/T1 and TGF-β3/T3), and sex hormone receptors using our 3D in vitro cornea stroma model. Primary human corneal fibroblasts (HCFs) from healthy donors were plated in transwells at 106 cells/well and cultured for four weeks. HCFs were supplemented with stable vitamin C (VitC) and stimulated with T1 or T3. 3D construct proteins were analyzed for the androgen receptor (AR), progesterone receptor (PR), estrogen receptor alpha (ERα) and beta (ERβ), luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR), gonadotropin-releasing hormone receptor (GnRHR), KiSS1-derived peptide receptor (KiSS1R/GPR54), and follicle-stimulating hormone subunit beta (FSH-B). In female constructs, T1 significantly upregulated AR, PR, ERα, FSHR, GnRHR, and KiSS1R. In male constructs, T1 significantly downregulated FSHR and FSH-B and significantly upregulated ERα, ERβ, and GnRHR. T3 caused significant upregulation in expressions PR, ERα, ERβ, LHR, FSHR, and GNRHR in female constructs, and significant downregulation of AR, ERα, and FSHR in male constructs. Semi-quantitative Western blot findings present the interplay between sex hormone receptors and TGF-β isoforms in the corneal stroma, which is influenced by sex as a biological variable (SABV). Additional studies are warranted to fully delineate their interactions and signaling mechanisms.

Transcriptome profiling analysis of uterus during chicken laying periods

The avian eggshell is formed in the uterus. Changes in uterine function may have a significant effect on eggshell quality. To identify the vital genes impacting uterine functional maintenance in the chicken, uteri in three different periods (22W, 31W, 51W) were selected for RNA sequencing and bioinformatics analysis. In our study, 520, 706 and 736 differentially expressed genes (DEGs) were respectively detected in the W31 vs W22 group, W51 vs W31 group and W51 vs W22 group. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated DEGs were enriched in the extracellular matrix, extracellular region part, extracellular region, extracellular matrix structural constituent, ECM receptor interaction, collagen-containing extracellular matrix and collagen trimer in the uterus (P < 0.05). Protein-protein interaction analysis revealed that FN1, LOX, THBS2, COL1A1, COL1A2, COL5A1, COL5A2, POSTN, MMP13, VANGL2, RAD54B, SPP1, SDC1, BTC, ANGPTL3 might be key candidate genes for uterine functional maintenance in chicken. This study discovered dominant genes and pathways which enhanced our knowledge of chicken uterine functional maintenance.

Cartilage-Related Collagens in Osteoarthritis and Rheumatoid Arthritis: From Pathogenesis to Therapeutics

Collagens serve essential mechanical functions throughout the body, particularly in the connective tissues. In articular cartilage, collagens provide most of the biomechanical properties of the extracellular matrix essential for its function. Collagen plays a very important role in maintaining the mechanical properties of articular cartilage and the stability of the ECM. Noteworthily, many pathogenic factors in the course of osteoarthritis and rheumatoid arthritis, such as mechanical injury, inflammation, and senescence, are involved in the irreversible degradation of collagen, leading to the progressive destruction of cartilage. The degradation of collagen can generate new biochemical markers with the ability to monitor disease progression and facilitate drug development. In addition, collagen can also be used as a biomaterial with excellent properties such as low immunogenicity, biodegradability, biocompatibility, and hydrophilicity. This review not only provides a systematic description of collagen and analyzes the structural characteristics of articular cartilage and the mechanisms of cartilage damage in disease states but also provides a detailed characterization of the biomarkers of collagen production and the role of collagen in cartilage repair, providing ideas and techniques for clinical diagnosis and treatment.

Collagens Regulating Adipose Tissue Formation and Functions

The globally increasing prevalence of obesity is associated with the development of metabolic diseases such as type 2 diabetes, dyslipidemia, and fatty liver. Excess adipose tissue (AT) often leads to its malfunction and to a systemic metabolic dysfunction because, in addition to storing lipids, AT is an active endocrine system. Adipocytes are embedded in a unique extracellular matrix (ECM), which provides structural support to the cells as well as participating in the regulation of their functions, such as proliferation and differentiation. Adipocytes have a thin pericellular layer of a specialized ECM, referred to as the basement membrane (BM), which is an important functional unit that lies between cells and tissue stroma. Collagens form a major group of proteins in the ECM, and some of them, especially the BM-associated collagens, support AT functions and participate in the regulation of adipocyte differentiation. In pathological conditions such as obesity, AT often proceeds to fibrosis, characterized by the accumulation of large collagen bundles, which disturbs the natural functions of the AT. In this review, we summarize the current knowledge on the vertebrate collagens that are important for AT development and function and include basic information on some other important ECM components, principally fibronectin, of the AT. We also briefly discuss the function of AT collagens in certain metabolic diseases in which they have been shown to play central roles.

Proteomic characterization of aqueous humor in corneal endothelial decompensation after penetrating keratoplasty

Corneal endothelial decompensation (CED) is the major cause of the long-term graft failure, but the underlying mechanisms remain unclear. The purpose of this study was to characterize the proteomic profile in CED aqueous humor (AH) after penetrating keratoplasty (PKP). We collected AH samples (n = 6/group) from CED patients underwent PKP and cataract patients, respectively. The label-free quantitative proteomic analysis was performed to identify the differentially-expressed proteins (DEPs). The biological functions of DEPs were evaluated using Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genome (KEGG) analysis. The protein-protein interaction (PPI) network construction was employed to distinguish the hub proteins of DEPs, and the selected proteins were validated by parallel reaction monitoring (PRM). The human peripheral blood mononuclear cells (PBMCs) were adopted to investigate the effect of biglycan (BGN) on inflammatory response, and the subsequent outcomes of inflammation on human corneal endothelial cells (HCECs). A total of 174 DEPs were identified in CED AH of patients underwent PKP, including 102 up-regulated proteins and 72 down-regulated proteins. Bioinformatics analysis revealed the significant enrichment of cytokine-mediated signaling pathway and extracellular matrix (ECM) organization in the up-regulated proteins, as well as the alterations of cellular components, including the increase of collagen and complement component C1 complex, and reduction in extracellular exosomes. A hub protein cluster of 15 proteins was determined by Molecular Complex Detection (MCODE), including FN1, BGN, COMP, COL11A1, COLA3A1, and COL1A1. Moreover, BGN promoted pro-inflammatory cytokine (such as TNF-α, IL-1β and IL-6) production in PBMCs through NF-κB signaling pathway, which subsequently resulted in HCECs death. These findings provided a systemic protein profile of AH in CED patients after corneal transplantation, with the alterations implicated in cytokine-mediated signaling, ECM, complement system, and exsomes. The identified proteins and signaling pathways probably paved the novel insight into understanding the pathogenesis of the disease.

High serum levels of the C-propetide of type V collagen (PRO-C5) are prognostic for short overall survival in patients with pancreatic ductal adenocarcinoma

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is characterized by a pronounced fibrotic tumor microenvironment, which impairs treatment response. Type I and V collagens are responsible for the densely packed fibrils in the tumor fibrosis environment. While the role of the major type I collagen in cancer is well described, less is known about the minor type V collagen. Quantifying collagen propeptides in serum has been shown to have prognostic and predictive value. In this study, we evaluated the clinical utility of measuring the propeptide of type V collagen (PRO-C5) in serum from a discovery cohort and a validation cohort of patients with PDAC as well as in non-pancreatic solid tumor types to explore the relevance of the PRO-C5 biomarker in cancer.

Methods: Serum PRO-C5 was measured in three cohorts: a discovery cohort (19 healthy controls, 12 patients with chronic pancreatitis and 33 patients with PDAC (stage I-IV)), a validation cohort (800 patients with PDAC (stage I-IV)), and a non-pancreatic solid tumor type cohort of 33 healthy controls and 200 patients with 10 different non-pancreatic solid tumor types. The levels of serum PRO-C5 in patients with cancer were compared to levels in healthy controls. The association between PRO-C5 levels and overall survival (OS) was evaluated in patients with PDAC after adjusting for established prognostic factors.

Results: PRO-C5 was significantly increased in serum from patients with PDAC compared to healthy controls (p &lt; 0.001). High PRO-C5 levels were significantly associated with short OS in both the discovery- and the validation cohort, especially in early stages of PDAC (validation cohort stage II, HR = 2.0, 95%CI1.2-3.4). The association was independent of other prognostic parameters including stage, performance status and CA19-9. Furthermore, serum levels of PRO-C5 were significantly increased in serum from patients with other non-pancreatic solid tumor types compared to healthy controls.

Conclusion: High levels of serum PRO-C5 is prognostic for short OS in patients with PDAC and may provide clinical value in many other tumor types beyond PDAC. This underlines the importance of type V collagen in tumor fibrosis. PRO-C5 could have the potential to be used in several aspects within drug discovery, patient stratification and drug efficacy.

Collagen type V alpha 2 promotes the development of gastric cancer via M2 macrophage polarization

Gastric cancer is a type of digestive tract cancer with a high morbidity and mortality, which leads to a major health burden worldwide. More research into the functions of the immune system will improve therapy and survival in gastric cancer patients. We attempted to identify potential biomarkers or targets in gastric cancer via bioinformatical analysis approaches. Three gene expression profile datasets (GSE79973, GSE103236, and GSE118916) of gastric tissue samples were obtained from the Gene Expression Omnibus database. There were 65 overlapping differentially expressed genes (DEGs) identified from three microarrays. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway were carried out for the key functions and pathways enriched in the DEGs. Then, ten hub genes were identified by protein-protein interaction network. In addition, we observed that collagen type V alpha 2 (COL5A2) was linked to gastric cancer prognosis as well as M2 macrophage infiltration. Furthermore, COL5A2 enhanced gastric cancer cell proliferation through the PI3K-AKT signaling pathway and polarized M2 macrophage cells. Therefore, in this study, we found that COL5A2 was associated with the development of gastric cancer which might function as a potential therapeutic target for the disease.

The anti-asthmatic potential of Rho-kinase inhibitor hydroxyfasudil in the model of experimentally induced allergic airway inflammation

OBJECTIVE

This experimental study evaluated the anti-asthmatic potential of the Rho-kinase inhibitor hydroxyfasudil in the settings of allergen-induced allergen-induced experimental asthma.

METHODS

Chronic allergic airway inflammation was caused by 28 days-sensitisation of guinea pigs with ovalbumin (OVA). Hydroxyfasudil was administered intraperitoneally in two doses for the last two weeks (1 mg/kg b.w.; 10 mg/kg b.w.). The degree of allergic inflammation was determined based on concentrations of inflammatory Th2 cytokines (IL-4, IL-13), Th1 cytokines (TNF-α and IFN-γ) in the lung homogenate and leukocyte count in the bronchoalveolar lavage fluid (BALF). The markers of remodelling and fibrosis, the growth factors (TGF-β1, EGF), EGF receptor, collagen type III and V were estimated in lung homogenate. The changes in specific airway resistance (sRaw) were used as an in vivo bronchial hyperreactivity parameter.

RESULTS

Hydroxyfasudil administration at both doses significantly reduced sRaw after a week of therapy. We observed a decline of IL-13, TNF-α and IFN-γ in lung homogenate and a lower presence of lymphocytes in BALF after 14 days of hydroxyfasudil administration at both tested doses. Hydroxyfasudil 14 days-treatment at both doses effectively reduced the concentrations of TGF-β1, EGF receptors, collagen type III and V in BALF and modulated EGF levels.

CONCLUSIONS

These findings indicate that RhoA/Rho-kinase is involved in the pathophysiology of allergic airway inflammation and suggest that Rho-kinase inhibitor hydroxyfasudil has therapeutic potential for asthma management.

Identification of the collagen family as prognostic biomarkers in papillary thyroid carcinoma

OBJECTIVE

The aim of this study was to construct a collagen-related prognostic model for thyroid cancer and to investigate prognostic value of collagen family genes for thyroid cancer.

METHODS

A LASSO Cox regression model for thyroid cancer was developed based on the expression profiles of collagen-related genes. Kaplan-Meier survival analysis was performed for high and low risk groups. The ROC method was used to assess its predictive performance. Predictive independence was verified by multivariate Cox regression analysis. The relationship between this feature and immune cell infiltration was analyzed by tumor microenvironment. COL18A1 was validated by immunohistochemistry and RT-PCR in thyroid cancer tissues. The effect of COL18A1 on cell proliferation, migration and invasion ability of tumor cells were further valuated by CCK-8 assay and transwell assay. The effect of COL18A1 on the immune escape ability of tumor cells was further valuated by cytotoxicity assays.

RESULTS

A model including 4 collagen family genes was developed to predict thyroid cancer prognosis. Patients with high-risk score had a poorer prognosis than those with low-risk scores for 1-, 2-, 3-, and 5- year survival. The model independently predicted prognosis after adjusting for other prognostic factors. A nomogram combining risk score and age was constructed with high sensitivity and specificity. This feature was significantly associated with immune cell infiltration. COL18A1 was aberrantly over-expressed in thyroid cancer compared with control tissues and significantly increased proliferative capacity, migration capacity, invasion capacity, and immune escape ability of tumor cells.

CONCLUSION

Our findings establish a signature associated with collagen family genes that can be a promising tool to predict the prognosis of thyroid cancer. High COL18A1 expression significantly correlates with the poor prognosis of patients and enhances the immune escape ability of tumor cells.

β2-Microglobulin Elevates COL5A1 mRNA in the Subsynovial Connective Tissue of Patients Receiving Hemodialysis With Carpal Tunnel Syndrome

Background Although carpal tunnel syndrome (CTS) is frequently observed in patients undergoing long-term hemodialysis (HD), exactly how CTS arises is unknown. Here, we examined levels of COL5A1 in the subsynovial connective tissue (SSCT) of patients receiving HD and studied its potential regulation by β2-microglobulin (Β2-MG) in SSCT-derived cells (SSCTCs). Methods We extracted SSCT samples from 67 patients with CTS (49 non-HD and 18 HD) during carpal tunnel release. The samples were subjected to quantitative polymerase chain reaction (qPCR) to determine COL5A1 expression. Further, to examine the potential regulation of COL5A1 expression by Β2-MG, SSCTCs were stimulated in the absence (control) or presence of 10 µg/ml Β2-MG. Results The HD group showed significantly elevated COL5A1 levels compared to the non-HD group (P=0.027). Moreover, treating SSCTCs with Β2-MG for 24 h increased the mRNA expression of COL5A1 relative to control conditions (P=0.013). Conclusions Elevated COL5A1 expression may form part of the mechanism underlying the development of CTS, and Β2-MG may play a role in promoting COL5A1 expression in HD patients.

Dietary Moringa oleifera leaf powder improves jejunal permeability and digestive function by modulating the microbiota composition and mucosal immunity in heat stressed rabbits

Heat stress (HS) has detrimental effects on intestinal health by altering digestive and immune responses in animals. Dietary Moringa oleifera leaf powder (MOLP) has been implicated in ameliorating the impact of HS, but its effects in terms of intestinal function improvement under HS remain poorly characterized. Therefore, the current study investigated the impact of HS and MOLP supplementation on tight junction barriers, intestinal microbiota (jejunal digesta), and differentially expressed genes (DEGs) in jejunal mucosa of heat-stressed rabbits by using the next-generation sequencing techniques. A total of 21 male New Zealand White rabbits (32 weeks old mean body weight of 3318 ± 171 g) were divided into three groups (n = 7/group) as control (CON, 25 °C), heat stress (HS, 35 °C for 7 h daily), and HS with MOLP supplementation (HSM, 35 °C for 7 h daily) gavage at 200 mg/kg body weight per day for 4 weeks. The results indicated that MOLP supplementation increased mRNA expression of tight junction proteins and glutathione transferase activity, while the malonaldehyde concentration was decreased in the jejunal mucosa compared to HS group (P < 0.05). Furthermore, MOLP decreased the concentrations of lipopolysaccharide, pro-inflammatory cytokines, and myeloperoxidase compared with HS group (P < 0.05). Intestinal microbiota analysis revealed that at phyla level, the relative abundance of Bacteroidetes was higher in HSM group compared to CON and HS groups. MOLP supplementation also resulted in higher abundance of putatively health-associated genera such as Christensenellaceae R-7 gut group, Ruminococcaceae NK4A214 group, Ruminococcus 2, Lachnospiraceae NK4A136 group, and Lachnospiraceae unclassified along with higher butyrate levels in HSM group as compared to HS group. The analysis of DEGs revealed that MOLP reversed inflammatory response by downregulation of genes, such as TNFRSF13C, LBP, and COX2 in enriched KEGG pathway of NF-kβ pathway. MOLP supplementation also significantly upregulated the expression of genes in protein digestion and absorption pathway, including PRSS2, LOC100349163, CPA1, CPB1, SLC9A3, SLC1A1, and SLC7A9 in HSM group. Three genes of fibrillar collagens, i.e., COL3A1, COL5A3, and COL12A1 in protein digestion were also down-regulated in HSM group. In conclusion, MOLP supplementation could improve jejunal permeability and digestive function, positively modulate microbiota composition and mucosal immunity in heat-stressed rabbits.

Collagen V α1 Chain Decrease in Papillary Dermis from Early Systemic Sclerosis: A New Proposal in Cutaneous Fibrosis Molecular Structure

Cutaneous fibrosis is one of the main features of systemic sclerosis (SSc). Recent findings correlated abnormal collagen V (Col V) deposition in dermis with skin thickening and disease activity in SSc. Considering that Col V is an important regulator of collagen fibrillogenesis, understanding the role of Col V in the first two years of the skin fibrosis in SSc (early SSc) can help to determine new targets for future treatments. In this study, we analyzed the morphological, ultrastructural and molecular features of α1(V) and α2(V) chains and the expression of their coding genes COL5A1 and COL5A2 in collagen fibrillogenesis in early-SSc. Skin biopsies were obtained from seven consecutive treatment-naïve patients with SSc-related fibrosis and four healthy controls. Our data showed increased α1(V) and α2(V) chain expression in the reticular dermis of early-SSc patients; however, immunofluorescence and ultrastructural immunogold staining determined a significant decreased expression of the α1(V) chain along the dermoepidermal junction in the papillary dermis from early-SSc-patients in relation to the control (12.77 ± 1.34 vs. 66.84 ± 3.36; p < 0.0001). The immunoblot confirmed the decreased expression of the α1(V) chain by the cutaneous fibroblasts of early-SSc, despite the increased COL5A1 and COL5A2 gene expression. In contrast, the α2(V) chain was overexpressed in the small vessels (63.18 ± 3.56 vs. 12.16 ± 0.81; p < 0.0001) and capillaries (60.88 ± 5.82 vs. 15.11 ± 3.80; p < 0.0001) in the reticular dermis of early-SSc patients. Furthermore, COLVA2 siRNA in SSc cutaneous fibroblasts resulted in a decreased α1(V) chain expression. These results highlight an intense decrease in the α1(V) chain along the dermoepidermal junction, suggesting an altered molecular histoarchitecture in the SSc papillary dermis, with a possible decrease in the expression of the α1(V)3 homotrimeric isoform, which could interfere with the thickening and cutaneous fibrosis related to SSc.

Multiphoton microscopy assessment of the structure and variability changes of dermal connective tissue in vulvar lichen sclerosus: A pilot study

In this article, we offer a novel classification of progressive changes in the connective tissue of dermis in vulvar lichen sclerosus (VLS) relying on quantitative assessment of the second harmonic generation (SHG) signal received from formalin fixed and deparaffinized tissue sections. We formulate criteria for distinguishing four degrees of VLS development: Initial-Mild-Moderate-Severe. Five quantitative characteristics (length and thickness type I Collagen fibers, Mean SHG signal intensity, Skewness and Coherence SHG signal) are used to describe the sequential degradation of connective tissue (changes in the structure, orientation, shape and density of collagen fibers) up to the formation of specific homogeneous masses. Each of the degrees has a characteristic set of quantitatively expressed features. We focus on the identification and description of early, initial changes of the dermis as the least specific. The results obtained by us and the proposed classification of the degrees of the disease can be used to objectify the dynamics of tissue changes during treatment.

Similar collagen distribution in full-thickness skin grafts in intraperitoneal and onlay positions, an experimental mice-study

PURPOSE

Autologous full-thickness skin grafting (FTSG) has the potential to become an option in abdominal wall repair. An understanding of tissue remodelling in the extracellular matrix (ECM) is crucial as this interplay determines such parameters as tissue strength and flexibility. This cross-sectional preclinical laboratory study in mice provides information on the distribution of collagen types and matrix metalloproteinases (MMPs) in the ECM of FTSGs in the intraperitoneal and onlay positions compared with internal controls. The aim was to evaluate morphologic changes after tissue remodelling and repair in FTSGs applied in the two positions and to detect any adverse host response.

METHODS

ECM components were evaluated as follows: qualitative examination of collagen bundle thickness using Picrosirius Red staining (collagen types I, III and IV); and evaluation of collagen types IV and V, as well as MMPs 1, 8 and 9 using immunohistochemical staining. Full-thickness grafts transplanted between female twin mice were examined as this best mimics autologous transplantation.

RESULTS

At 8 weeks, FTSGs in the intraperitoneal position did not show any noticeable differences in morphologic appearance to those in the onlay position. Both intraperitoneal and onlay FTSGs showed increases in the amount of thick collagen bundles compared to internal controls. No correlation was seen between distribution of MMPs 1, 8 or 9 and distribution of collagen types I, III, IV or V.

CONCLUSION

This preclinical study shows that FTSGs in both intraperitoneal and onlay positions are possible application site options and, by extension, promising application site options for abdominal wall reinforcement in hernia surgery. Clinical studies in humans are required to confirm these findings.

Bioinformatics analysis on differentially expressed genes between colorectal adenoma and colorectal adenocarcinoma

BACKGROUND

Colorectal adenoma (CRA) is the main cause of the progression of Colorectal adenocarcinoma (COAD). Therefore, it is very important to accurately reveal its developmental mechanism.

METHODS

Differential expression genes (DEGs) in three microarray datasets were screened using GEO and GEO2R. R packages were used for gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) path enrichment analysis. Hub genes screened by STRING, Cytoscape and CytoHubba were used. R was used for DEGs of hub genes, and Gene Expression Profiling Interactive Analysis (GEPIA2) database was used for prognostic Analysis. R-packet were used to analyze tumor pathology, tumour, lymph-nodes, and metastases (TNM) staging, enrichment, immune invasion and prognosis.

RESULTS

Among the 66 genes, including 36 up-regulated and 30 down-regulated genes. Survival analysis showed that COL1A1, COL5A2, COL5A1 and secreted protein acidic and rich in cysteine (SPARC) were associated with disease-free survival in patients. The four genes were related to tumor pathological stage, TNM stage and immune invasion. COL1A1 and COL5A2 were highly expressed in chromatin modification and cellular senescence. Low expression of COL5A1 and SPARC was significantly enriched in neutrophil degranulation and Wp VegfavegFR2 signaling pathways.

CONCLUSIONS

Obviously, these four key genes can serve as important targets for early diagnosis, treatment, immunity and prognosis of CRA to COAD.

Investigation of the long-term healing response of the liver to boiling histotripsy treatment in vivo

Boiling histotripsy (BH) is a promising High-Intensity Focused Ultrasound technique that can be employed to mechanically fractionate solid tumours. Whilst studies have shown the feasibility of BH to destroy liver cancer, no study has reported on the healing process of BH-treated liver tissue. We therefore extensively investigated the evolution of the healing response of liver to BH in order to provide an insight into the healing mechanisms. In the present study, 14 Sprague Dawley rats underwent the BH treatment and were sacrificed on days 0, 3, 7, 14, and 28 for morphological, histological, serological and qPCR analyses. The area of the treated region was 1.44 cm² (1.2 cm × 1.2 cm). A well-defined BH lesion filled with coagulated blood formed on day 0. A week after the treatment, fibroblast activation was induced at the treatment site, leading to the formation of extracellular matrix structure (ECM). The ECM was then disrupted for 7 to 28 days. Regenerated normal hepatocytes and newly formed blood vessels were found within the BH region with the absence of hepatic fibrosis. No significant morphological, histological and genetic changes around the BH lesion occurred. These results suggest that BH could be a safe and promising therapeutic tool for treating solid tumours without inducing any significant adverse effect such as the formation of liver fibrosis.

Selection signature analyses and genome-wide association reveal genomic hotspot regions that reflect differences between breeds of horse with contrasting risk of degenerative suspensory ligament desmitis

Degenerative suspensory ligament desmitis is a progressive idiopathic condition that leads to scarring and rupture of suspensory ligament fibers in multiple limbs in horses. The prevalence of degenerative suspensory ligament desmitis is breed related. Risk is high in the Peruvian Horse, whereas pony and draft breeds have low breed risk. Degenerative suspensory ligament desmitis occurs in families of Peruvian Horses, but its genetic architecture has not been definitively determined. We investigated contrasts between breeds with differing risk of degenerative suspensory ligament desmitis and identified associated risk variants and candidate genes. We analyzed 670k single nucleotide polymorphisms from 10 breeds, each of which was assigned one of the four breed degenerative suspensory ligament desmitis risk categories: control (Belgian, Icelandic Horse, Shetland Pony, and Welsh Pony), low risk (Lusitano, Arabian), medium risk (Standardbred, Thoroughbred, Quarter Horse), and high risk (Peruvian Horse). Single nucleotide polymorphisms were used for genome-wide association and selection signature analysis using breed-assigned risk levels. We found that the Peruvian Horse is a population with low effective population size and our breed contrasts suggest that degenerative suspensory ligament desmitis is a polygenic disease. Variant frequency exhibited signatures of positive selection across degenerative suspensory ligament desmitis breed risk groups on chromosomes 7, 18, and 23. Our results suggest degenerative suspensory ligament desmitis breed risk is associated with disturbances to suspensory ligament homeostasis where matrix responses to mechanical loading are perturbed through disturbances to aging in tendon (PIN1), mechanotransduction (KANK1, KANK2, JUNB, SEMA7A), collagen synthesis (COL4A1, COL5A2, COL5A3, COL6A5), matrix responses to hypoxia (PRDX2), lipid metabolism (LDLR, VLDLR), and BMP signaling (GREM2). Our results do not suggest that suspensory ligament proteoglycan turnover is a primary factor in disease pathogenesis.

Transcriptomic Profile of Genes Regulating the Structural Organization of Porcine Atrial Cardiomyocytes during Primary In Vitro Culture

Numerous cardiovascular diseases (CVD) eventually lead to severe myocardial dysfunction, which is the most common cause of death worldwide. A better understanding of underlying molecular mechanisms of cardiovascular pathologies seems to be crucial to develop effective therapeutic options. Therefore, a worthwhile endeavor is a detailed molecular characterization of cells extracted from the myocardium. A transcriptomic profile of atrial cardiomyocytes during long-term primary cell culture revealed the expression patterns depending on the duration of the culture and the heart segment of origin (right atrial appendage and right atrium). Differentially expressed genes (DEGs) were classified as involved in ontological groups such as: “cellular component assembly”, “cellular component organization”, “cellular component biogenesis”, and “cytoskeleton organization”. Transcriptomic profiling allowed us to indicate the increased expression of COL5A2, COL8A1, and COL12A1, encoding different collagen subunits, pivotal in cardiac extracellular matrix (ECM) structure. Conversely, genes important for cellular architecture, such as ABLIM1, TMOD1, XIRP1, and PHACTR1, were downregulated during in vitro culture. The culture conditions may create a favorable environment for reconstruction of the ECM structures, whereas they may be suboptimal for expression of some pivotal transcripts responsible for the formation of intracellular structures.

RNA-sequencing of human aortic valves identifies that miR-629-3p and TAGLN miRNA-mRNA pair involving in calcified aortic valve disease

This study aimed to uncover the microRNA and messenger RNA (miRNA/mRNA) interactions in the pathophysiological process of calcified aortic valve disease (CAVD) of the human aortic valve. RNA sequencing of six selected samples (3 healthy control samples vs. 3 CAVD samples) was performed to obtain mRNA and miRNA sequences, and differential expression (DE) analysis of miRNA and mRNAs was performed. To build a CAVD-specific miRNA-mRNA interactome, the upregulated mRNAs and downregulated miRNAs were selected, followed by the establishment of inverse DE of mRNA-miRNA co-expression network based on Pearson's correlation coefficient using miRanda in the R language software. Subsequently, pathway enrichment analysis was performed to elucidate CAVD-related pathways that were likely mediated by miRNA regulatory mechanisms. In addition, miRNAs with an mRNA correlation greater than 0.9 in the co-expression network were selected for anti-calcification verification in a CAVD cellular model. We identified 216 mRNAs (99 downregulated and 117 upregulated) and 602 miRNAs (371 downregulated and 231 upregulated) that were differentially expressed between CAVD and healthy aortic valves. After applying Pearson's correlation toward miRNA-mRNA targets, a regulatory network of 67 miRNAs targeting 76 mRNAs was created. The subsequent pathway enrichment analysis of these targeted mRNAs elucidated that genes within the focal adhesion pathway are likely mediated by miRNA regulatory mechanisms. The selected hsa-miR-629-3p and TAGLN pair exhibited anti-calcification effects on osteogenic differentiation-induced human aortic valve interstitial cells (hVICs). On integrating the miRNA and mRNA sequencing data for healthy aortic valves and those with CAVD, the CAVD-associated miRNA-mRNA interactome and related pathways were elucidated. Additional cell function data demonstrated anti-calcification effects of the selected hsa-miR-629-3p targeting TAGLN, validating that it is a potential therapeutic target for inhibiting CAVD.

Multiscale Characterization of Type I Collagen Fibril Stress–Strain Behavior under Tensile Load: Analytical vs. MD Approaches

Type I collagen is one of the most important proteins in the human body because of its role in providing structural support to the extracellular matrix of the connective tissues. Understanding its mechanical properties was widely investigated using experimental testing as well as molecular and finite element simulations. In this work, we present a new approach for defining the properties of the type I collagen fibrils by analytically formulating its response when subjected to a tensile load and investigating the effects of enzymatic crosslinks on the behavioral response. We reveal some of the shortcomings of the molecular dynamics (MD) method and how they affect the obtained stress–strain behavior of the fibril, and we prove that not only does MD underestimate the Young’s modulus and the ultimate tensile strength of the collagen fibrils, but also fails to detect the mechanics of some stretching phases of the fibril. We prove that non-crosslinked fibrils have three tension phases: (i) an initial elastic deformation corresponding to the collagen molecule uncoiling, (ii) a linear regime related to the stretching of the backbone of the tropocollagen molecules, and (iii) a plastic regime dominated by molecular sliding. We also show that for crosslinked fibrils, the second regime can be subdivided into three sub-regimes, and we define the properties of each regime. We also prove, analytically, the alleged MD quadratic relation between the ultimate tensile strength of the fibril and the concentration of enzymatic crosslinks (β).

Mechanobiology in the Comorbidities of Ehlers Danlos Syndrome

Ehlers-Danlos Syndromes (EDSs) are a group of connective tissue disorders, characterized by skin stretchability, joint hypermobility and instability. Mechanically, various tissues from EDS patients exhibit lowered elastic modulus and lowered ultimate strength. This change in mechanics has been associated with EDS symptoms. However, recent evidence points toward a possibility that the comorbidities of EDS could be also associated with reduced tissue stiffness. In this review, we focus on mast cell activation syndrome and impaired wound healing, comorbidities associated with the classical type (cEDS) and the hypermobile type (hEDS), respectively, and discuss potential mechanobiological pathways involved in the comorbidities.

A review of hepatic fibrosis-associated histopathology in aged cadavers

This article reviews hepatic fibrosis-associated histopathology of aged cadavers (mean age 82 years). A study of 68 livers identified steatosis in 35.5%, central vein fibrosis in 49.2%, perisinusoidal fibrosis in 63.2%, portal tract fibrosis in 47.7%, septa formation in 44.1%, bridging fibrosis in 30.8%, and cirrhosis in 4.4% of the samples as well as one hepatocellular carcinoma and six metastatic tumors. Other studies have revealed that collagens I, III, IV, V, and VI and fibronectin constitute the matrices of fibrous central veins, perisinusoidal space, portal tracts, and septa. Elastin is rich in portal tracts and fibrous septa but absent from the perisinusoidal space. Hepatic stellate cells are ubiquitous in the liver parenchyma while myofibroblasts localize in fibrotic foci. Factor VIII-related antigen expression signals sinusoidal to systemic vascular endothelium transformation while collagen IV and laminin codistribution indicates formation of perisinusoidal membranes. Their coincidence reflects focalized capillarization of sinusoids in the aged liver. In response to fibrogenesis, hepatic progenitor cells residing in the canal of Hering in the periportal parenchyma undergo expansion and migration deep into the lobule. Concomitantly, intermediate hepatocyte-like cells increase in advanced fibrosis stages, which is possibly related to hepatic regeneration. Metabolic zonation of glutamine synthetase expands from the perivenous to non-perivenous parenchyma in fibrosis progression but its expression is lost in cirrhosis, while cytochrome P-4502E1 expression is maintained in centrilobular and midlobular zones in fibrosis progression and expressed in cirrhosis. Hence, cadaveric livers provide a platform for further investigation of hepatic histopathologies associated with the aging liver.

Inherited connective tissue diseases highlight macromolecular network interdependences in skin extracellular matrix: a histomorphometric study

Mutation of just a single extracellular matrix protein, a receptor or enzyme involved in connective tissue metabolism is sufficient to cause systemic pathologies and failure of tissues that are subjected to strong mechanical stresses. Skin histological and computerized image analyses can provide a good qualitative and quantitative indication of these inherited connective tissue diseases. In this study, skin biopsies from young (10 to 25 years) and middle-aged patients (26 to 50 years) suffering from Ehlers-Danlos syndromes (EDS), Marfan syndrome (MS) or pseudoxanthoma elasticum (PXE) were studied after specific staining of both the collagen and elastic networks. Findings from the histomorphometric analyses conducted on skin sections of the patients with EDS, MS and PXE were compared to skin sections of healthy subjects from the same age groups. Our results show that both the collagen and the elastic networks were affected in all the studied pathological cases, but that the adverse changes to the elastic network in older patients were distinct from the physiological changes observed during aging process for healthy subjects. This degenerative process may be explained by an added phenomenon involving a general connective tissue proteolysis.

Somatic mutations in collagens are associated with a distinct tumor environment and overall survival in gastric cancer

Background

Gastric cancer is a heterogeneous disease with poorly understood genetic and microenvironmental factors. Mutations in collagen genes are associated with genetic diseases that compromise tissue integrity, but their role in tumor progression has not been extensively reported. Aberrant collagen expression has been long associated with malignant tumor growth, invasion, chemoresistance, and patient outcomes. We hypothesized that somatic mutations in collagens could functionally alter the tumor extracellular matrix.

Methods

We used publicly available datasets including The Tumor Cancer Genome Atlas (TCGA) to interrogate somatic mutations in collagens in stomach adenocarcinomas. To demonstrate that collagens were significantly mutated above background mutation rates, we used a moderated Kolmogorov-Smirnov test along with combination analysis with a bootstrap approach to define the background accounting for mutation rates. Association between mutations and clinicopathological features was evaluated by Fisher or chi-squared tests. Association with overall survival was assessed by Kaplan-Meier and the Cox-Proportional Hazards Model. Gene Set Enrichment Analysis was used to interrogate pathways. Immunohistochemistry and in situ hybridization tested expression of COL7A1 in stomach tumors.

Results

In stomach adenocarcinomas, we identified individual collagen genes and sets of collagen genes harboring somatic mutations at a high frequency compared to background in both microsatellite stable, and microsatellite instable tumors in TCGA. Many of the missense mutations resemble the same types of loss of function mutations in collagenopathies that disrupt tissue formation and destabilize cells providing guidance to interpret the somatic mutations. We identified combinations of somatic mutations in collagens associated with overall survival, with a distinctive tumor microenvironment marked by lower matrisome expression and immune cell signatures. Truncation mutations were strongly associated with improved outcomes suggesting that loss of expression of secreted collagens impact tumor progression and treatment response. Germline collagenopathy variants guided interpretation of impactful somatic mutations on tumors.

Conclusions

These observations highlight that many collagens, expressed in non-physiologically relevant conditions in tumors, harbor impactful somatic mutations in tumors, suggesting new approaches for classification and therapy development in stomach cancer. In sum, these findings demonstrate how classification of tumors by collagen mutations identified strong links between specific genotypes and the tumor environment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09136-1.

Glucocorticoid-induced Fingerprints on Visceral Adipose Tissue Transcriptome and Epigenome

CONTEXT

Chronic glucocorticoid (GC) overexposure, resulting from endogenous Cushing's syndrome (CS) or exogenous GC therapy, causes several adverse outcomes, including persistent central fat accumulation associated with a low-grade inflammation. However, no previous multiomics studies in visceral adipose tissue (VAT) from patients exposed to high levels of unsuppressed GC during active CS or after remission are available yet.

OBJECTIVE

To determine the persistent VAT transcriptomic alterations and epigenetic fingerprints induced by chronic hypercortisolism.

METHODS

We employed a translational approach combining high-throughput data on endogenous CS patients and a reversible CS mouse model. We performed RNA sequencing and chromatin immunoprecipitation sequencing on histone modifications (H3K4me3, H3K27ac, and H3K27me3) to identify persistent transcriptional and epigenetic signatures in VAT produced during active CS and maintained after remission.

RESULTS

VAT dysfunction was associated with low-grade proinflammatory status, macrophage infiltration, and extracellular matrix remodeling. Most notably, chronic hypercortisolism caused a persistent circadian rhythm disruption in VAT through core clock genes modulation. Importantly, changes in the levels of 2 histone modifications associated to gene transcriptional activation (H3K4me3 and H3K27ac) correlated with the observed differences in gene expression during active CS and after CS remission.

CONCLUSION

We identified for the first time the persistent transcriptional and epigenetic signatures induced by hypercortisolism in VAT, providing a novel integrated view of molecular components driving the long-term VAT impairment associated with CS.

Gonosomal Mosaicism for a Novel COL5A1 Pathogenic Variant in Classic Ehlers-Danlos Syndrome

(1) Background: Classic Ehlers-Danlos syndrome (cEDS) is a heritable connective tissue disorder characterized by joint hypermobility and skin hyperextensibility with atrophic scarring. Many cEDS individuals carry variants in either the COL5A1 or COL5A2 genes. Mosaicism is relatively common in heritable connective tissue disorders but is rare in EDS. In cEDS, a single example of presumed gonosomal mosaicism for a COL5A1 variant has been published to date. (2) Methods: An 8-year-old girl with cEDS was analyzed by next-generation sequencing (NGS). Segregation was performed by Sanger sequencing in her unaffected parents. In the father, the mosaicism of the variant was further analyzed by targeted NGS and droplet digital PCR (ddPCR) in the blood and by Sanger sequencing in other tissues. (3) Results: The NGS analysis revealed the novel germline heterozygous COL5A1 c.1369G>T, p.(Glu457*) variant in the proband. Sanger chromatogram of the father's blood specimen suggested the presence of a low-level mosaicism for the COL5A1 variant, which was confirmed by NGS and estimated to be 4.8% by ddPCR. The mosaicism was also confirmed by Sanger sequencing in the father's saliva, hair bulbs and nails. (4) Conclusions: We described the second case of cEDS caused by paternal gonosomal mosaicism in COL5A1. Parental mosaicism could be an issue in cEDS and, therefore, considered for appropriate genetic counseling.

Molecular alterations due to Col5a1 haploinsufficiency in a mouse model of classic Ehlers-Danlos syndrome

Type V collagen is a regulatory fibrillar collagen essential for type I collagen fibril nucleation and organization and its deficiency leads to structurally abnormal extracellular matrix (ECM). Haploinsufficiency of the Col5a1 gene encoding α(1) chain of type V collagen is the primary cause of classic Ehlers-Danlos syndrome (EDS). The mechanisms by which this initial insult leads to the spectrum of clinical presentation are not fully understood. Using transcriptome analysis of skin and Achilles tendons from Col5a1 haploinsufficient (Col5a1+/-) mice, we recognized molecular alterations associated with the tissue phenotypes. We identified dysregulation of ECM components including thrombospondin-1, lysyl oxidase, and lumican in the skin of Col5a1+/- mice when compared with control. We also identified upregulation of transforming growth factor β1 (Tgf-β) in serum and increased expression of pSmad2 in skin from Col5a1+/- mice, suggesting Tgf-β dysregulation is a contributor to abnormal wound healing and atrophic scarring seen in classic EDS. Together, these findings support altered matrix to cell signaling as a component of the pathogenesis of the tissue phenotype in classic EDS and point out potential downstream signaling pathways that may be targeted for the treatment of this disease.

Chick Embryo Experimental Platform for Micrometastases Research in a 3D Tissue Engineering Model: Cancer Biology, Drug Development, and Nanotechnology Applications

Colonization of distant organs by tumor cells is a critical step of cancer progression. The initial avascular stage of this process (micrometastasis) remains almost inaccessible to study due to the lack of relevant experimental approaches. Herein, we introduce an in vitro/in vivo model of organ-specific micrometastases of triple-negative breast cancer (TNBC) that is fully implemented in a cost-efficient chick embryo (CE) experimental platform. The model was built as three-dimensional (3D) tissue engineering constructs (TECs) combining human MDA-MB-231 cells and decellularized CE organ-specific scaffolds. TNBC cells colonized CE organ-specific scaffolds in 2–3 weeks, forming tissue-like structures. The feasibility of this methodology for basic cancer research, drug development, and nanomedicine was demonstrated on a model of hepatic micrometastasis of TNBC. We revealed that MDA-MB-231 differentially colonize parenchymal and stromal compartments of the liver-specific extracellular matrix (LS-ECM) and become more resistant to the treatment with molecular doxorubicin (Dox) and Dox-loaded mesoporous silica nanoparticles than in monolayer cultures. When grafted on CE chorioallantoic membrane, LS-ECM-based TECs induced angiogenic switch. These findings may have important implications for the diagnosis and treatment of TNBC. The methodology established here is scalable and adaptable for pharmacological testing and cancer biology research of various metastatic and primary tumors.

Clinical and molecular characteristics of 168 probands and 65 relatives with a clinical presentation of classical Ehlers-Danlos syndrome

Classical Ehlers-Danlos syndrome (cEDS) is a heritable connective tissue disorder mainly caused by pathogenic variants in COL5A1 or COL5A2, encoding type V collagen. Its diagnosis, based on clinical criteria and molecular confirmation, can be challenging. We report the molecular and clinical characteristics of 168 probands (72 clinically evaluated at our center) and 65 relatives with a clinical presentation of cEDS. Type V collagen defects were found in 145 probands, 121 (83.5%) were located in COL5A1 and 24 (16.5%) in COL5A2. Although 85.6% of molecularly confirmed patients presented the two major clinical criteria (generalized joint hypermobility, hyperextensible skin with atrophic scarring), significant inter- and intrafamilial phenotypic variability was noted. COL5A2 variants often caused a more severe phenotype. Vascular complications were rare in individuals with type V collagen defects (1.4%). Among the 72 probands clinically evaluated in our center, the mutation detection rate was 82.0%. The majority (68.1%) harbored COL5A1/COL5A2 defects. Yet, 13.9% harbored a defect in another gene (COL1A1, PLOD1, TNXB, AEBP1) highlighting important clinical overlap and the need for molecular confirmation of the diagnosis as this has implications regarding follow-up and genetic counseling. Eighteen percent of the 72 probands remained molecularly unexplained and a COL5A1 variant of unknown significance was identified in 6.9%.

Proteomics analysis of hip articular cartilage identifies differentially expressed proteins associated with osteonecrosis of the femoral head

OBJECTIVE

The cartilage degeneration that accompanies subchondral bone necrosis plays an important role in the development of osteonecrosis of femoral head (ONFH). To better understand the molecular basis of cartilage degradation in ONFH, we compared the proteomic profiles of ONFH cartilage with that of fracture control.

DESIGN

Hip cartilage samples were collected from 16 ONFH patients and 16 matched controls with femoral neck fracture. Proteomics analysis was conducted using tandem mass tag-based quantitation technique. Gene ontology (GO) analysis, KEGG pathway and protein-protein interaction analysis were used to investigate the functions of the altered proteins and biological pathways. Differentially expressed proteins including alpha-2-HS-glycoprotein (AHSG) and Cytokine-like protein 1 (Cytl1) were validated by Western blot (WB) and immunohistochemistry (IHC).

RESULTS

303 differentially expressed proteins were identified in ONFH cartilage with 72 up-regulated and 231 down-regulated. Collagen turnover, glycosaminoglycan biosynthesis, metabolic pathways, and complement and coagulation cascades were significantly modified in ONFH cartilage. WB and IHC confirmed the increased expression of AHSG and decreased expression of Cytl1 in ONFH cartilage.

CONCLUSIONS

Our results reveal the implication of altered protein expression in the development of ONFH, and provide novel clues for pathogenesis studies of cartilage degradation in ONFH.

Understanding collagen interactions and their targeted regulation by novel drugs

Introduction: Among protein and fibers in the extracellular matrix (ECM), collagen is the most copious and widely employed in cosmetic, food, pharmaceutical, and biomedical industries due to its extensive biocompatible and versatile properties. In the last years, the knowledge about functions of collagens increased and expanded dramatically. Once considered only crucial for the ECM scaffolding and mechanotransduction, additional functional roles have now been ascribed to the collagen superfamily which are defined by other recently discovered domains, supramolecular assembly and receptors.Areas covered: Given the importance of each step in the collagen biosynthesis, folding and signaling, medicinal chemists have explored small molecules, peptides, and monoclonal antibodies to modulate enzymes, receptors and interactions with the physiological ligands of collagen. These compounds were also explored toward diseases and pathological conditions. The authors discuss this providing their expert perspectives on the subject area.Expert opinion: Understanding collagen protein properties and its interactome is beneficial for therapeutic drug design. Nevertheless, compounds targeting collagen-based interactome suffered from the presence of different isoforms for each target and the lack of specific 3D crystal structures able to guide properly drug design.

RUNX1/miR-582-5p Pathway Regulates the Tumor Progression in Clear Cell Renal Cell Carcinoma by Targeting COL5A1

Recent evidences indicated that miRNAs played core role in the progression of clear cell renal cell carcinoma (ccRCC). However, its molecular mechanism in ccRCC is still remained unclear. The study was designed to identify the role and regulatory mechanism of miR-582-5p in ccRCC. In this study, the low expression level of miR-582-5p were detected by qRT-PCR in ccRCC patient tumor samples and ccRCC cell lines, respectively. The expression level of miR-582-5p was associated with tumor stage and metastasis. In vivo and in vitro experiments found miR-582-5p inhibit tumor growth via suppressing COL5A1 expression. Additionally, RUNX1 was identified as the negative regulator of miR-582-5p through database prediction and chromatin immunoprecipitation. Finally, the negative relation of RUNX1 and miR-582-5p was verified through rescue experiment both in vitro and in vivo. In summary, miR-582-5p, which was regulated by RUNX1, inhibited tumor growth and invasion by targeting COL5A1, indicating that miR-582-5p may act as a biomarker and that the RUNX1/miR-582-5p/COL5A1 axis could be a potential therapeutic target for ccRCC.