Tenascins: regulation and putative functions during pathological stress

Dermatofibrosarcoma protuberans with PDGFD rearrangements: a case series featuring a novel EMILIN1::PDGFD fusion and comprehensive literature review

Dermatofibrosarcoma protuberans (DFSP) is a locally infiltrative mesenchymal neoplasm usually characterized by a COL1A1::PDGFB fusion. A minority of DFSPs have recently been shown to harbor alternative fusions, involving the PDGFD gene. The aim of this case series and literature review is to highlight the clinicopathologic and molecular features of PDGFD-rearranged DFSPs. Eighteen patients (twelve females and six males) with PDGFD-rearranged DFSPs were collected from the authors' institutional archives. Eight (44%) cases harbored a COL6A3::PDGFD fusion, five (28%) an EMILIN2::PDGFD fusion, and two (11%) an EMILIN1::PDGFD fusion. In three (17%) cases, the fusion partner was unknown. A literature review revealed 29 additional cases. Cumulatively, four alternative fusion genes have been detected: COL6A3::PDGFD (24/47, 51%), EMILIN2::PDGFD (12/47, 26%), EMILIN1::PDGFD (2/47, 4%), and TNC::PDGFD (1/47, 2%). In eight (17%) cases, the fusion partner was unknown. Most (20/24, 83%) COL6A3::PDGFD-fused DFSPs occurred in females with only four (17%) cases described in males. Additionally, half of them (12/24, 50%) developed in the breast/chest wall. EMILIN2::PDGFD-fused DFSPs often occurred in males, were located in the extremities (9/12, 75%), exhibited fibrosarcomatous transformation (9/12, 75%), were confined exclusively or primarily to the subcutis (10/12, 83%), and had a well-circumscribed contour (10/12, 83%). Specific molecular alterations in DFSPs correlate with certain clinicopathologic features. Notably, EMILIN2::PDGFD-fused DFSPs have a slight predilection for males, develop almost exclusively in the subcutis, tend to be well-circumscribed, and often exhibit fibrosarcomatous transformation, while COL6A3::PDGFD-fused DFSPs might have a predilection for the breast/chest wall of female patients. To the best of our knowledge, this is the first report of EMILIN1::PDGFD-fused DFSP.

Structural extracellular matrix-mediated molecular signaling in wound repair and tissue regeneration

The extracellular matrix (ECM) is a complex, non-cellular network of molecules that offers structural support for cells and tissues. The ECM is composed of various structural components, including collagen, fibronectin, laminin, perlecan, nidogen, tenascin, and fibulin, which are capable of binding to each other and to cell-to-adhesion receptors, endowing the ECM with unique physical and biochemical properties that are essential for its function in maintaining health and managing disease. Over the past three decades, extensive research has shown that the core of the ECM can significantly impact cellular events at the molecular level. Structural modifications have also been strongly associated with tissue repair. Through interactions with cells, matrix proteins regulate critical processes such as cell proliferation and differentiation, migration, and apoptosis, essential for maintaining tissue homeostasis, formation, and regeneration. This review emphasizes the interlocking networks of ECM macromolecules and their primary roles in tissue regeneration and wound repair. Through studying ECM dynamics, researchers have discovered molecular signaling pathways that demonstrate how the ECM influences protein patterns and open up more possibilities for developing therapeutics that target the ECM to enhance wound repair and tissue regeneration.

Independent elevation of plasma fibulin-5 proceeding chronic hydrocephalus development after aneurysmal subarachnoid hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) causes chronic hydrocephalus (CH) due to disturbance in the reabsorption of cerebrospinal fluid following subarachnoidal fibrosis via inflammatory reactions or blood clotting products. Fibulin-5 (FBLN5) is one of matricellular proteins associated with fibrosis processes.

OBJECTIVE

The aim of this study was to assess whether FBLN5 elevation is related to CH after aSAH.

METHODS

This study prospectively enrolled consecutive aSAH patients at 9 institutions in Japan from 2013 to 2016. Plasma FBLN5 levels at days 1-3, 4-6, 7-9, and 10-12 were measured. Relationships between plasma FBLN5 levels and incidence of CH were analyzed. Multivariate logistic regression analyses were performed on clinical variables with a p value of < 0.05 on univariate analyses and plasma FBLN5 levels with the highest area under the receiver-operating characteristic (ROC) curve.

RESULTS

A total of 229 aSAH patients were analyzed, and CH occurred in 67 patients. FBLN5 levels at days 4-6 from aSAH onset elevated in patients resulting in subsequent CH occurrence. The ROC curve analyses revealed that the area under the curve (AUC) at days 4-6 post-aSAH was the highest (AUC, 0.592; 95 % confidence interval, 0.514-0.671) among the four time points. Multivariate logistic regression analyses using clinical variables related to CH on univariate analyses and plasma FBLN5 levels at days 4-6 post-aSAH revealed that FBLN5 levels at days 4-6 post-aSAH ≥ 366.4 ng/mL (adjusted odds ratio, 3.14) were an independent determinant of subsequent CH development.

CONCLUSION

The elevation of plasma FBLN5 levels in a subacute phase of aSAH may contribute to the development of CH. FBLN5 may be a molecular target to develop a new therapy against post-aSAH CH.

Transcription factor Twist1 drives fibroblast activation to promote kidney fibrosis via signaling proteins Prrx1/TNC

The transcription factor Twist1 plays a vital role in normal development in many tissue systems and continues to be important throughout life. However, inappropriate Twist1 activity has been associated with kidney injury and fibrosis, though the underlying mechanisms involved remain incomplete. Here, we explored the role of Twist1 in regulating fibroblast behaviors and the development kidney fibrosis. Initially Twist1 protein and activity was found to be markedly increased within interstitial myofibroblasts in fibrotic kidneys in both humans and rodents. Treatment of rat kidney interstitial fibroblasts with transforming growth factor-β1 (a profibrotic factor) also induced Twist1 expression in vitro. Gain- and loss-of-function experiments supported that Twist1 signaling was responsible for transforming growth factor-β1-induced fibroblast activation and fetal bovine serum-induced fibroblast proliferation. Mechanistically, Twist1 protein promoted kidney fibroblast activation by driving the expression of downstream signaling proteins, Prrx1 and Tnc. Twist1 directly enhanced binding to the promoter of Prrx1 but not TNC, whereas the promoter of TNC was directly bound by Prrx1. Finally, mice with fibroblast-specific deletion of Twist1 exhibited less Prrx1 and TNC protein abundance, interstitial extracellular matrix deposition and kidney inflammation in both the unilateral ureteral obstruction and ischemic-reperfusion injury-induced-kidney fibrotic models. Inhibition of Twist1 signaling with Harmine, a β-carboline alkaloid, improved extracellular matrix deposition in both injury models. Thus, our results suggest that Twist1 signaling promotes the activation and proliferation of kidney fibroblasts, contributing to the development of interstitial fibrosis, offering a potential therapeutic target for chronic kidney disease.

Expanded gene and taxon sampling of diplomonads shows multiple switches to parasitic and free-living lifestyle

BACKGROUND

Diplomonads are anaerobic flagellates classified within Metamonada. They contain both host-associated commensals and parasites that reside in the intestinal tracts of animals, including humans (e.g., Giardia intestinalis), as well as free-living representatives that inhabit freshwater and marine anoxic sediments (e.g., Hexamita inflata). The evolutionary trajectories within this group are particularly unusual as the free-living taxa appear to be nested within a clade of host-associated species, suggesting a reversal from host-dependence to a secondarily free-living lifestyle. This is thought to be an exceedingly rare event as parasites often lose genes for metabolic pathways that are essential to a free-living life strategy, as they become increasingly reliant on their host for nutrients and metabolites. To revert to a free-living lifestyle would require the reconstruction of numerous metabolic pathways. All previous studies of diplomonad evolution suffered from either low taxon sampling, low gene sampling, or both, especially among free-living diplomonads, which has weakened the phylogenetic resolution and hindered evolutionary insights into this fascinating transition.

RESULTS

We sequenced transcriptomes from 1 host-associated and 13 free-living diplomonad isolates; expanding the genome scale data sampling for diplomonads by roughly threefold. Phylogenomic analyses clearly show that free-living diplomonads form several branches nested within endobiotic species. Moreover, the phylogenetic distribution of genes related to an endobiotic lifestyle suggest their acquisition at the root of diplomonads, while traces of these genes have been identified in free-living diplomonads as well. Based on these results, we propose an evolutionary scenario of ancestral and derived lifestyle transitions across diplomonads.

CONCLUSIONS

Free-living taxa form several clades nested within endobiotic taxa in our phylogenomic analyses, implying multiple transitions between free-living and endobiotic lifestyles. The evolutionary history of numerous virulence factors corroborates the inference of an endobiotic ancestry of diplomonads, suggesting that there have been several reversals to a free-living lifestyle. Regaining host independence may have been facilitated by a subset of laterally transferred genes. We conclude that the extant diversity of diplomonads has evolved from a non-specialized endobiont, with some taxa becoming highly specialized parasites, others becoming free-living, and some becoming capable of both free-living and endobiotic lifestyles.

In vitro differentiation of mouse pluripotent stem cells into corticosteroid-producing adrenocortical cells

Directed differentiation of pluripotent stem cells into specialized cell types represents an invaluable tool for a wide range of applications. Here, we have exploited single-cell transcriptomic data to develop a stepwise in vitro differentiation system from mouse embryonic stem cells into adrenocortical cells. We show that during development, the adrenal primordium is embedded in an extracellular matrix containing tenascin and fibronectin. Culturing cells on fibronectin during differentiation increased the expression of the steroidogenic marker NR5A1. Furthermore, 3D cultures in the presence of protein kinase A (PKA)-pathway activators led to the formation of aggregates composed of different cell types expressing adrenal progenitor or steroidogenic markers, including the adrenocortical-specific enzyme CYP21A1. Importantly, in-vitro-differentiated cells responded to adrenocorticotropic hormone (ACTH) and angiotensin II with the production of glucocorticoids and mineralocorticoids, respectively, thus confirming the specificity of differentiation toward the adrenal lineage.

Creating 3D constructs with cranial neural crest-derived cell lines using a bio-3D printer

OBJECTIVES

The development of bio-three-dimensional (bio-3D) printers has led to significant advances in regenerative medicine. Three-dimensional constructs, including spheroids, are maintained by extracellular matrix proteins secreted by cells so that the cells can be cultured in conditions closer to the physiological environment. This study aimed to create a useful 3D construct as a model of the dentin-pulp complex.

METHODS

We examined the expression patterns of extracellular matrix proteins and cell proliferation areas in a 3D construct created using O9-1 cells derived from cranial neural crest cells of mice. The 3D construct was created by sticking the spheroid cultures onto a needle array using a bio-3D printer.

RESULTS

Cell proliferation areas along with characteristic expression of tenascin C and DMP1 were evaluated. The expression of tenascin C and DMP1 was significantly enhanced in the spheroids compared to that in two-dimensional cultures. Moreover, cell proliferation regions and tenascin C expression were confirmed in the outer layer of spheroids in the embryonic stem cell medium, with insignificant DMP1 expression being observed. Interestingly, in a 3D construct cultured in calcification-induction medium, DMP1 expression was promoted, and DMP1-positive cells existed in the outermost layer without overlapping with tenascin C expression.

CONCLUSIONS

The extracellular matrix proteins, tenascin C and DMP1, were expressed in a polarized manner in spheroids and 3D constructs, similar to the findings in the dental papilla. Therefore, these 3D constructs show potential as artificial models for studying odontogenesis.

Extracellular Matrix Remodeling in Atopic Dermatitis Harnesses the Onset of an Asthmatic Phenotype and Is a Potential Contributor to the Atopic March

The development of atopic dermatitis in infancy, and subsequent allergies, such as asthma in later childhood, is known as the atopic march. The mechanism is largely unknown, however the course of disease indicates an inter-epithelial crosstalk, through the onset of inflammation in the skin and progression to other mucosal epithelia. In this study, we investigated if and how skin-lung epithelial crosstalk contributes to the development of the atopic march. First, we emulated inter-epithelial crosstalk through indirect coculture of bioengineered atopic-like skin disease models and three-dimensional bronchial epithelial models triggering an asthma-like phenotype in the latter. A subsequent secretome analysis identified thrombospondin-1, CD44, complement factor C3, fibronectin, and syndecan-4 as potentially relevant skin-derived mediators. Because these mediators are extracellular matrix-related proteins, we then studied the involvement of the extracellular matrix, unveiling distinct proteomic, transcriptomic, and ultrastructural differences in atopic samples. The latter indicated extracellular matrix remodeling triggering the release of the above-mentioned mediators. In vivo mouse data showed that exposure to these mediators dysregulated activated circadian clock genes which are increasingly discussed in the context of atopic diseases and asthma development. Our data point toward the existence of a skin-lung axis that could contribute to the atopic march driven by skin extracellular matrix remodeling.

The role of fibrosis in cardiomyopathies: An opportunity to develop novel biomarkers of disease activity

Cardiomyopathies encompass a spectrum of heart disorders with diverse causes and presentations. Fibrosis stands out as a shared hallmark among various cardiomyopathies, reflecting a common thread in their pathogenesis. This prevalent fibrotic response is intricately linked to the consequences of dysregulated extracellular matrix (ECM) remodeling, emphasizing its significance in the development and progression the disease. This review explores the ECM involvement in various cardiomyopathies and its impact on myocardial stiffness and fibrosis. Additionally, we discuss the potential of ECM fragments as early diagnosis, prognosis, and risk stratification. Biomarkers deriving from turnover of collagens and other ECM proteins hold promise in clinical applications. We outline current clinical management, future directions, and the potential for personalized ECM-targeted therapies with specific focus on microRNAs. In summary, this review examines the role of the fibrosis in cardiomyopathies, highlighting the potential of ECM-derived biomarkers in improving disease management with implications for precision medicine.

Tenascin-C as a potential biomarker and therapeutic target for esophageal squamous cell carcinoma

PURPOSE

To establish a prognostic model of esophageal squamous cell carcinoma (ESCC) patients based on tenascin-C (TNC) expression level and clinicopathological characteristics, and to explore the therapeutic potential of TNC inhibition.

METHODS

The expression of TNC was detected using immunohistochemistry (IHC) in 326 ESCC specimens and 50 normal esophageal tissues. Prognostic factors were determined by Cox regression analyses and were incorporated to establish the nomogram. The effects of TNC knockdown on ESCC cells were assessed in vitro and in vivo. Transcriptome sequencing (RNA-seq) and gene set enrichment analysis (GSEA) were performed to reveal signaling pathways regulated by TNC knockdown. The therapeutic significance of TNC knockdown combined with small-molecule inhibitors on cell proliferation was examined.

RESULTS

TNC protein was highly expressed in 48.77 % of ESCC tissues compared to only 2 % in normal esophageal epithelia (p < 0.001). The established nomogram model, based on TNC expression, pT stage, and lymph node metastasis, showed good performance on prognosis evaluation. More importantly, the reduction of TNC expression inhibited tumor cell proliferation and xenograft growth, and mainly down-regulated signaling pathways involved in tumor growth, hypoxia signaling transduction, metabolism, infection, etc. Knockdown of TNC enhanced the inhibitory effect of inhibitors targeting ErbB, PI3K-Akt, Ras and MAPK signaling pathways.

CONCLUSION

The established nomogram may be a promising model for survival prediction in ESCC. Reducing TNC expression enhanced the sensitivity of ESCC cells to inhibitors of Epidermal Growth Factor Receptor (EGFR) and downstream signaling pathways, providing a novel combination therapy strategy.

Proteomic profiling of ovarian clear cell carcinomas identifies prognostic biomarkers for chemotherapy

Clear cell ovarian carcinoma (CCOC) is a relatively rare subtype of ovarian cancer (OC) with high degree of resistance to standard chemotherapy. Little is known about the underlying molecular mechanisms, and it remains a challenge to predict its prognosis after chemotherapy. Here, we first analyzed the proteome of 35 formalin-fixed paraffin-embedded (FFPE) CCOC tissue specimens from a cohort of 32 patients with CCOC (H1 cohort) and characterized 8697 proteins using data-independent acquisition mass spectrometry (DIA-MS). We then performed proteomic analysis of 28 fresh frozen (FF) CCOC tissue specimens from an independent cohort of 24 patients with CCOC (H2 cohort), leading to the identification of 9409 proteins with DIA-MS. After bioinformatics analysis, we narrowed our focus to 15 proteins significantly correlated with the recurrence free survival (RFS) in both cohorts. These proteins are mainly involved in DNA damage response, extracellular matrix (ECM), and mitochondrial metabolism. Parallel reaction monitoring (PRM)-MS was adopted to validate the prognostic potential of the 15 proteins in the H1 cohort and an independent confirmation cohort (H3 cohort). Interferon-inducible transmembrane protein 1 (IFITM1) was observed as a robust prognostic marker for CCOC in both PRM data and immunohistochemistry (IHC) data. Taken together, this study presents a CCOC proteomic data resource and a single promising protein, IFITM1, which could potentially predict the recurrence and survival of CCOC.

An investigation of the relationship between Behçet's disease and tenascin-C

Objectives

The study aimed to investigate serum tenascin-C levels and its relationship with pathogenesis of Behçet's disease (BD) with inflammatory processes.

Patients and methods

This prospective and analytical study included 34 BD patients (19 males, 15 females; mean age: 31.5±8.2 years; range, 18 to 48 years) who met the 2014 International Criteria for Behçet's Disease and had no comorbidities and 37 healthy volunteers (21 females, 16 males; mean age: 29.6±5.3 years; range, 21 to 45 years). Sex, age, age at diagnosis, clinical and laboratory data, medication use, and smoking history of the participants were recorded. Serum tenascin-C levels were measured using a commercially available tenascin-C enzyme-linked immunosorbent assay kit.

Results

There was no significant difference between the groups in terms of age (p=0.262) and sex (p=0.287). Serum tenascin-C levels were significantly lower in the BD group (10,824±7,612 pg/mL) compared to the control group (27,574±14,533 pg/mL, p<0.001). In the receiver operating characteristic analysis performed for the diagnostic value of tenascin-C level in BD, the sensitivity was determined as 79.4% and the specificity as 82.5% (p<0.001). No statistically significant difference was observed in tenascin-C levels in correlation with clinical characteristics, laboratory values, medication use, and smoking in the BD group.

Conclusion

In contrast to other chronic inflammatory diseases, lower levels of tenascin-C were observed in patients with BD than in the healthy individuals, which can be attributed to the absence of prolonged chronic inflammatory course in BD. The fact that tenascin-C levels are high in other rheumatic inflammatory diseases but low in BD may be useful in the differential diagnosis of BD.

Comprehensive Matrisome Profiling of Human Adipose Tissue for Soft Tissue Reconstruction

For effective translation of research from tissue engineering and regenerative medicine domains, the cell-instructive extracellular matrix (ECM) of specific tissues must be accurately realized. As adipose tissue is gaining traction as a biomaterial for soft tissue reconstruction, with highly variable clinical outcomes obtained, a quantitative investigation of the adipose tissue matrisome is overdue. In this study, the human adipose tissue matrisome is profiled using quantitative sequential windowed acquisition of all theoretical fragment ion spectra - mass spectrometry (SWATH-MS) proteomics across a cohort of 13 fat-grafting patients, to provide characterization of ECM proteins within the tissue, and to understand human population variation. There are considerable differences in the expression of matrisome proteins across the patient cohort, with age and lipoaspirate collection technique contributing to the greatest variation across the core matrisome. A high abundance of basement membrane proteins (collagen IV and heparan sulfate proteoglycan) is detected, as well as fibrillar collagens I and II, reflecting the hierarchical structure of the tissue. This study provides a comprehensive proteomic evaluation of the adipose tissue matrisome and contributes to an enhanced understanding of the influence of the matrisome in adipose-related pathologies by providing a healthy reference cohort and details an experimental pipeline that can be further exploited for future biomaterial development.

Role of tenascin C in lesion formation in early peritoneal endometriosis

OBJECTIVE

To identify cytokines or extracellular matrix components that contribute to adhesion to, and invasion of, the peritoneum, proximal to lesions in the early phase of endometriosis.

DESIGN

Laboratory-based study.

SETTING

University Hospital and Laboratory of Animal Science.

PATIENTS AND ANIMALS

Five women with ovarian endometrioma, 138 wild-type (WT) C57BL/6N mice, and 48 Tenascin C (Tnc) knockout (TncKO) mice.

INTERVENTIONS

To establish a murine endometriosis model, 20 pieces of minced uterine tissue fragments from each horn were administered intraperitoneally to syngeneic mice. Three days later, endometriotic lesions and peritoneal tissues were collected. Separately, we transfected human peritoneal mesothelial cells (HMrSV5) or human endometrial stromal cells (hESCs) with Tnc small interfering ribonucleic acid.

MAIN OUTCOME MEASURES

We employed a polymerase chain reaction array to profile gene expression in the murine peritoneum, in both peritoneum distal to lesions and peritoneum surrounding lesions (PSL). The expression of upregulated genes in the PSL was verified in the peritoneal samples by real-time reverse transcription-polymerase chain reaction. TncKO mice were used to investigate the role of Tnc in the development of endometriosis. We evaluated the proliferative activity or inflammatory state of lesions by Ki67 or CD3 immunostaining. Intraperitoneal distribution of macrophages was assessed by fluorescence-activated cell sorting. Using Tnc small interfering ribonucleic acid, we examined the invasive capacity of hESCs in a coculture system with HMrSV5.

RESULTS

Tnc gene expression was significantly higher in PSL than in peritoneum distal to lesions. The weight and number of TncKO lesions in TncKO hosts were lower than those of WT lesions in WT hosts. In contrast, the weight and number of nonattached TncKO lesions in TncKO hosts were higher than those of nonattached WT lesions in WT hosts. We observed decreased Ki67-positive cells or H-scores for CD3, a lower proportion of M1 macrophages, and a higher proportion of M2 macrophages in TncKO lesions in TncKO recipients. Silencing of Tnc expression in hESCs and HMrSV5 diminished the invasivity of hESCs.

CONCLUSION

Tnc may be a crucial factor in the development of early peritoneal endometriosis.

Different PfEMP1-expressing Plasmodium falciparum variants induce divergent endothelial transcriptional responses during co-culture

The human malaria parasite Plasmodium falciparum is responsible for the majority of mortality and morbidity caused by malaria infection and differs from other human malaria species in the degree of accumulation of parasite-infected red blood cells in the microvasculature, known as cytoadherence or sequestration. In P. falciparum, cytoadherence is mediated by a protein called PfEMP1 which, due to its exposure to the host immune system, undergoes antigenic variation resulting in the expression of different PfEMP1 variants on the infected erythrocyte membrane. These PfEMP1s contain various combinations of adhesive domains, which allow for the differential engagement of a repertoire of endothelial receptors on the host microvasculature, with specific receptor usage associated with severe disease. We used a co-culture model of cytoadherence incubating human brain microvascular endothelial cells with erythrocytes infected with two parasite lines expressing different PfEMP1s that demonstrate different binding profiles to vascular endothelium. We determined the transcriptional profile of human brain microvascular endothelial cells (HBMEC) following different incubation periods with infected erythrocytes, identifying different transcriptional profiles of pathways previously found to be involved in the pathology of severe malaria, such as inflammation, apoptosis and barrier integrity, induced by the two PfEMP1 variants.

Tenascins and osteopontin in biological response in cornea

The structural composition, integrity and regular curvature of the cornea contribute to the maintenance of its transparency and vision. Disruption of its integrity caused by injury results in scarring, inflammation and neovascularization followed by losses in transparency. These sight compromising effects is caused by dysfunctional corneal resident cell responses induced by the wound healing process. Upregulation of growth factors/cytokines and neuropeptides affect development of aberrant behavior. These factors trigger keratocytes to first transform into activated fibroblasts and then to myofibroblasts. Myofibroblasts express extracellular matrix components for tissue repair and contract the tissue to facilitate wound closure. Proper remodeling following primary repair is critical for restoration of transparency and visual function. Extracellular matrix components contributing to the healing process are divided into two groups; a group of classical tissue structural components and matrix macromolecules that modulate cell behaviors/activities besides being integrated into the matrix structure. The latter components are designated as matricellular proteins. Their functionality is elicited through mechanisms which modulate the scaffold integrity, cell behaviors, activation/inactivation of either growth factors or cytoplasmic signaling regulation. We discuss here the functional roles of matricellular proteins in mediating injury-induced corneal tissue repair. The roles are described of major matricellular proteins, which include tenascin C, tenascin X and osteopontin. Focus is directed towards dealing with their roles in modulating individual activities of wound healing-related growth factors, e. g., transforming growth factor β (TGF β). Modulation of matricellular protein functions could encompass a potential novel strategy to improve the outcome of injury-induced corneal wound healing.

Strategic outline of interventions targeting extracellular matrix for promoting healthy longevity

The extracellular matrix (ECM), composed of interlinked proteins outside of cells, is an important component of the human body that helps maintain tissue architecture and cellular homeostasis. As people age, the ECM undergoes changes that can lead to age-related morbidity and mortality. Despite its importance, ECM aging remains understudied in the field of geroscience. In this review, we discuss the core concepts of ECM integrity, outline the age-related challenges and subsequent pathologies and diseases, summarize diagnostic methods detecting a faulty ECM, and provide strategies targeting ECM homeostasis. To conceptualize this, we built a technology research tree to hierarchically visualize possible research sequences for studying ECM aging. This strategic framework will hopefully facilitate the development of future research on interventions to restore ECM integrity, which could potentially lead to the development of new drugs or therapeutic interventions promoting health during aging.

Interactions between astrocytes and extracellular matrix structures contribute to neuroinflammation-associated epilepsy pathology

Often considered the "housekeeping" cells of the brain, astrocytes have of late been rising to the forefront of neurodegenerative disorder research. Identified as crucial components of a healthy brain, it is undeniable that when astrocytes are dysfunctional, the entire brain is thrown into disarray. We offer epilepsy as a well-studied neurological disorder in which there is clear evidence of astrocyte contribution to diseases as evidenced across several different disease models, including mouse models of hippocampal sclerosis, trauma associated epilepsy, glioma-associated epilepsy, and beta-1 integrin knockout astrogliosis. In this review we suggest that astrocyte-driven neuroinflammation, which plays a large role in the pathology of epilepsy, is at least partially modulated by interactions with perineuronal nets (PNNs), highly structured formations of the extracellular matrix (ECM). These matrix structures affect synaptic placement, but also intrinsic neuronal properties such as membrane capacitance, as well as ion buffering in their immediate milieu all of which alters neuronal excitability. We propose that the interactions between PNNs and astrocytes contribute to the disease progression of epilepsy vis a vis neuroinflammation. Further investigation and alteration of these interactions to reduce the resultant neuroinflammation may serve as a potential therapeutic target that provides an alternative to the standard anti-seizure medications from which patients are so frequently unable to benefit.

Matricellular proteins in atherosclerosis development

The extracellular matrix (ECM) is an intricate network composed of various multi-domain macromolecules like collagen, proteoglycans, and fibronectin, etc., that form a structurally stable composite, contributing to the mechanical properties of tissue. However, matricellular proteins are non-structural, secretory extracellular matrix proteins, which modulate various cellular functions via interacting with cell surface receptors, proteases, hormones, and cell-matrix. They play essential roles in maintaining tissue homeostasis by regulating cell differentiation, proliferation, adhesion, migration, and several signal transduction pathways. Matricellular proteins display a broad functionality regulated by their multiple structural domains and their ability to interact with different extracellular substrates and/or cell surface receptors. The expression of these proteins is low in adults, however, gets upregulated following injuries, inflammation, and during tumor growth. The marked elevation in the expression of these proteins during atherosclerosis suggests a positive association between their expression and atherosclerotic lesion formation. The role of matricellular proteins in atherosclerosis development has remained an area of research interest in the last two decades and studies revealed these proteins as important players in governing vascular function, remodeling, and plaque formation. Despite extensive research, many aspects of the matrix protein biology in atherosclerosis are still unknown and future studies are required to investigate whether targeting pathways stimulated by these proteins represent viable therapeutic approaches for patients with atherosclerotic vascular diseases. This review summarizes the characteristics of distinct matricellular proteins, discusses the available literature on the involvement of matrix proteins in the pathogenesis of atherosclerosis and suggests new avenues for future research.

Clinical Significance of Plasma Tenascin-C Levels in Recipients With Prolonged Jaundice After Living Donor Liver Transplantation

BACKGROUND

Focusing on tenascin-C (TNC), whose expression is enhanced during the tissue remodeling process, the present study aimed to clarify whether plasma TNC levels after living donor liver transplantation (LDLT) could be a predictor of irreversible liver damage in the recipients with prolonged jaundice (PJ).

METHODS

Among 123 adult recipients who underwent LDLT between March 2002 and December 2016, the subjects were 79 recipients in whom we could measure plasma TNC levels preoperatively (pre-) and on postoperative days 1 to 14 (POD1 to POD14). Prolonged jaundice was defined as serum total bilirubin level >10 mg/dL on POD14, and 79 recipients were divided into 2 groups: 56 in the non-PJ (NJ) group and 23 in the PJ group.

RESULTS

The PJ group had significantly increased pre-TNC; smaller grafts; decreased platelet counts POD14; increased TB-POD1, -POD7, and -POD14; increased prothrombin time-international normalized ratio on POD7 and POD14; and higher 90-day mortality than the NJ group. As for the risk factors for 90-day mortality, multivariate analysis identified TNC-POD14 as a single significant independent prognostic factor (P = .015). The best cut-off value of TNC-POD14 for 90-day survival was determined to be 193.7 ng/mL. In the PJ group, the patients with low TNC-POD14 (<193.7 ng/mL) had satisfactory survival, with 100.0 % at 90 days, while the patients with high TNC-POD14 (≥193.7 ng/mL) had significantly poor survival, with 38.5 % at 90 days (P = .004).

CONCLUSIONS

In PJ after LDLT, plasma TNC-POD14 is very useful for diagnosing postoperative irreversible liver damage early.

Epitenon-derived cells comprise a distinct progenitor population that contributes to both tendon fibrosis and regeneration following acute injury

Flexor tendon injuries are common and heal poorly owing to both the deposition of function- limiting peritendinous scar tissue and insufficient healing of the tendon itself. Therapeutic options are limited due to a lack of understanding of the cell populations that contribute to these processes. Here, we identified a bi-fated progenitor cell population that originates from the epitenon and goes on to contribute to both peritendinous fibrosis and regenerative tendon healing following acute tendon injury. Using a combination of genetic lineage tracing and single cell RNA-sequencing (scRNA-seq), we profiled the behavior and contributions of each cell fate to the healing process in a spatio-temporal manner. Branched pseudotime trajectory analysis identified distinct transcription factors responsible for regulation of each fate. Finally, integrated scRNA-seq analysis of mouse healing with human peritendinous scar tissue revealed remarkable transcriptional similarity between mouse epitenon- derived cells and fibroblasts present in human peritendinous scar tissue, which was further validated by immunofluorescent staining for conserved markers. Combined, these results clearly identify the epitenon as the cellular origin of an important progenitor cell population that could be leveraged to improve tendon healing.

Characterisation of collagen type I matrices for pathophysiologically relevant spatial cancer cell cultures

Specific cues provided to cells by the extracellular matrix (ECM) are determined by its composition. Except of collagens other naturally occurring ECM components should be considered in designing 3D models of diseases. We used spectrophotometric and rheological measurements and confocal imaging to characterise collagen matrices of human origin that can be modified by clinically relevant ECM components. pH of the neutralising solution, but not incubation of solidified collagen matrices in serum-free culture medium with pH 5.0-9.0 affected distribution of collagen fibres. Admixture of fibronectin or tenascin-C influenced assembly kinetics and resulted in slight increase in the Young's moduli of the matrices, indicating their incorporation into the collagen matrices. Co-localization of fibronectin with collagen fibres was confirmed by fluorescence imaging. Various cell types relevant for tumour tissue were able to proliferate within the matrices suggesting that they can be used to study role of ECM components in cancer in spatial models.

Pathways Activated by Infected and Bystander Chondrocytes in Response to Ross River Virus Infection

Old world alphaviruses, such as Ross River virus (RRV), cause debilitating arthralgia during acute and chronic stages of the disease. RRV-induced cartilage degradation has been implicated as a cause of joint pain felt by RRV patients. Chondrocytes are a major cell type of cartilage and are involved in the production and maintenance of the cartilage matrix. It is thought that these cells may play a vital role in RRV disease pathogenesis. In this study, we used RNA-sequencing (RNA-Seq) to examine the transcriptomes of RRV-infected and bystander chondrocytes in the same environment. RRV containing green fluorescent protein (GFP) allowed for the separation of RRV-infected (GFP+) and bystander uninfected cells (GFP-). We found that whereas GFP+ and GFP- populations commonly presented similar gene expression profiles during infection, there were also unique signatures. For example, RIMS2 and FOXJ1 were unique to GFP+ cells, whilst Aim2 and CCL8 were only found in bystander chondrocytes. This indicates that careful selection of potential therapeutic targets is important to minimise adverse effects to the neighbouring uninfected cell populations. Our study serves as a resource to provide more information about the pathways and responses elicited by RRV in cells which are both infected and stimulated because of neighbouring infected cells.

Matrix protein Tenascin-C promotes kidney fibrosis via STAT3 activation in response to tubular injury

Accumulating evidence indicates that the extracellular matrix (ECM) is not only a consequence of fibrosis, but also contributes to the progression of fibrosis, by creating a profibrotic microenvironment. Tenascin-C (TNC) is an ECM glycoprotein that contains multiple functional domains. We showed that following kidney injury, TNC was markedly induced in fibrotic areas in the kidney from both mouse models and humans with kidney diseases. Genetically deletion of TNC in mice significantly attenuated unilateral ureteral obstruction-induced kidney fibrosis. Further studies showed that TNC promoted the proliferation of kidney interstitial cells via STAT3 activation. TNC-expressing cells in fibrotic kidney were activated fibroblast 2 (Act.Fib2) subpopulation, according to a previously generated single nucleus RNA-seq dataset profiling kidney of mouse UUO model at day 14. To identify and characterize TNC-expressing cells, we generated a TNC-promoter-driven CreER2-IRES-eGFP knock-in mouse line and found that the TNC reporter eGFP was markedly induced in cells around injured tubules that had lost epithelial markers, suggesting TNC was induced in response to epithelium injury. Most of the eGFP-positive cells were both NG2 and PDGFRβ positive. These cells did not carry markers of progenitor cells or macrophages. In conclusion, this study provides strong evidence that matrix protein TNC contributes to kidney fibrosis. TNC pathway may serve as a potential therapeutic target for interstitial fibrosis and the progression of chronic kidney disease.

Dual Role of Fibroblasts Educated by Tumour in Cancer Behavior and Therapeutic Perspectives

Tumours are complex systems with dynamic interactions between tumour cells, non-tumour cells, and extracellular components that comprise the tumour microenvironment (TME). The majority of TME's cells are cancer-associated fibroblasts (CAFs), which are crucial in extracellular matrix (ECM) construction, tumour metabolism, immunology, adaptive chemoresistance, and tumour cell motility. CAF subtypes have been identified based on the expression of protein markers. CAFs may act as promoters or suppressors in tumour cells depending on a variety of factors, including cancer stage. Indeed, CAFs have been shown to promote tumour growth, survival and spread, and secretome changes, but they can also slow tumourigenesis at an early stage through mechanisms that are still poorly understood. Stromal-cancer interactions are governed by a variety of soluble factors that determine the outcome of the tumourigenic process. Cancer cells release factors that enhance the ability of fibroblasts to secrete multiple tumour-promoting chemokines, acting on malignant cells to promote proliferation, migration, and invasion. This crosstalk between CAFs and tumour cells has given new prominence to the stromal cells, from being considered as mere physical support to becoming key players in the tumour process. Here, we focus on the concept of cancer as a non-healing wound and the relevance of chronic inflammation to tumour initiation. In addition, we review CAFs heterogeneous origins and markers together with the potential therapeutic implications of CAFs "re-education" and/or targeting tumour progression inhibition.

Vascular and lymphatic regulation of gastrointestinal function and disease risk

The vascular and lymphatic systems in the gut regulate lipid transport while restricting transfer of commensal gut microbiota and directing immune cell trafficking. Increased permeability of the endothelial systems in the intestine associates with passage of antigens and microbiota from the gut into the bloodstream leading to tissue inflammation, the release of pro-inflammatory mediators and ultimately to abnormalities of systemic metabolism. Recent studies show that lipid metabolism maintains homeostasis and function of intestinal blood and lymphatic endothelial cells, BECs and LECs, respectively. This review highlights recent progress in this area, and information related to the contribution of the lipid transporter CD36, abundant in BECs and LECs, to gastrointestinal barrier integrity, inflammation, and to gut regulation of whole body metabolism. The potential role of endothelial lipid delivery in epithelial tissue renewal after injury and consequently in the risk of gastric and intestinal diseases is also discussed.

Mass spectrometric analysis of chondroitin sulfate-linked peptides

Chondroitin sulfate proteoglycans (CSPGs) are extracellular matrix components composed of linear glycosaminoglycan (GAG) side chains attached to a core protein. CSPGs play a vital role in neurodevelopment, signal transduction, cellular proliferation and differentiation and tumor metastasis through interaction with growth factors and signaling proteins. These pleiotropic functions of proteoglycans are regulated spatiotemporally by the GAG chains attached to the core protein. There are over 70 chondroitin sulfate-linked proteoglycans reported in cells, cerebrospinal fluid and urine. A core glycan linker of 3-6 monosaccharides attached to specific serine residues can be extended by 20-200 disaccharide repeating units making intact CSPGs very large and impractical to analyze. The current paradigm of CSPG analysis involves digesting the GAG chains by chondroitinase enzymes and analyzing either the protein part, the disaccharide repeats, or both by mass spectrometry. This method, however, provides no information about the site of attachment or the composition of linker oligosaccharides and the degree of sulfation and/or phosphorylation. Further, the analysis by mass spectrometry and subsequent identification of novel CSPGs is hampered by technical challenges in their isolation, less optimal ionization and data analysis. Unknown identity of the linker oligosaccharide also makes it more difficult to identify the glycan composition using database searching approaches. Following chondroitinase digestion of long GAG chains linked to tryptic peptides, we identified intact GAG-linked peptides in clinically relevant samples including plasma, urine and dermal fibroblasts. These intact glycopeptides including their core linker glycans were identified by mass spectrometry using optimized stepped higher energy collision dissociation and electron-transfer/higher energy collision dissociation combined with hybrid database search/de novo glycan composition search. We identified 25 CSPGs including three novel CSPGs that have not been described earlier. Our findings demonstrate the utility of combining enrichment strategies and optimized high-resolution mass spectrometry analysis including alternative fragmentation methods for the characterization of CSPGs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42485-022-00092-3.

The role of Tenascin C in intracerebral hemorrhage-induced secondary brain injury in rats via induction of neuronal cell death and neuroinflammation

BACKGROUND

Spontaneous intracerebral hemorrhage (ICH) is a major cause of stroke that causes high rates of disability and mortality in adults. Tenascin C (TNC) protein, one of the matricellular proteins associated with platelet-derived growth factor receptor (PDGFR) activation, has been reported to induce neuronal apoptosis. However, the role and underlying mechanisms of TNC in ICH-induced secondary brain injury (SBI) have not yet been fully explained. The main purpose of this study was to explore the role of TNC and its potential mechanisms in ICH.

METHODS

An ICH model was established by injecting autologous blood into the right basal ganglia in male Sprague Dawley (SD) rats, and imatinib, an inhibitor of PDGFR, was used to inhibit the release of TNC.

RESULTS

We found that TNC protein was significantly increased in the brain tissues after ICH and expressed in both neurons and microglia. We also found that the TNC level was elevated in the cerebrospinal fluid (CSF) after ICH. Additionally, we observed that the infiltration of activated microglia and the release of TNFα and IL-1β induced by ICH were decreased after inhibition of the protein levels of TNC and cleaved-TNC by a chemical inhibitor (imatinib). Furthermore, imatinib improved neuronal cell death and neurobehavioral abnormalities induced by ICH.

CONCLUSION

In summary, our study revealed that TNC protein plays an important role in ICH-induced SBI, and inhibition of TNC could alleviate ICH-induced neuroinflammation, neuronal cell death, and neurobehaviour. Therefore, TNC may be a potential therapeutic target for ICH-induced SBI.

Immunotherapy and immunoengineering for breast cancer; a comprehensive insight into CAR-T cell therapy advancements, challenges and prospects

BACKGROUND

Breast cancer (BC) is a highly prevalent solid cancer with a high-rise infiltration of immune cells, turning it into a significant candidate for tumor-specific immunotherapies. Chimeric antigen receptor (CAR)-T cells are emerging as immunotherapeutic tools with genetically engineered receptors to efficiently recognize and attack tumor cells that express specific target antigens. Technological advancements in CAR design have provided five generations of CAR-T cells applicable to a wide range of cancer patients while boosting CAR-T cell therapy safety. However, CAR-T cell therapy is ineffective against breast cancer because of the loss of specified antigens, the immunosuppressive nature of the tumor and CAR-T cell-induced toxicities. Next-generation CAR-T cells actively pass through the tumor vascular barriers, persist for extended periods and disrupt the tumor microenvironment (TME) to block immune escape.

CONCLUSION

CAR-T cell therapy embodies advanced immunotherapy for BC, but further pre-clinical and clinical assessments are recommended to achieve maximized efficiency and safety.

The in vitro analysis of migration and polarity of blastema cells in the extracellular matrix derived from bovine mesenteric in the presence of fibronectin

Cell migration is an essential process in embryonic development, wound healing, and pathological conditions. Our knowledge of cell migration is often based on the two dimentional evaluation of cell movement, which usually differs from what occurred in vivo. In this study, we investigated cellular migration from blastema tissue toward bovine decellularized mesentery tissue. In this regard, fibronectin (FN) was assessed to confirm cell migration. Therefore, we established a cell migration model using blastema cells migration toward the extracellular matrix derived from bovine mesenteric tissue. A physiochemical decellularization method was utilized based on freeze-thaw cycles and agitation in sodium dodecyl sulfate and Triton X-100 to remove cells from the extracellular matrix (ECM) of bovine mesenteric tissue. These types of matrices were assembled by the rings of blastema tissues originated from the of New Zealand rabbits pinna and cultured in a medium containing FN in different days in vitro, and then they are histologically evaluated, and the expression of the Tenascin C gene is analyzed. By means of tissue staining and after confirmation of the cell removal from mesenteric tissue, polarity, and migration of blastema cells was observed in the interaction site with this matrix. Also, the expression of the Tenascin C gene was assessed on days 15 and 21 following the cell culture process. The results showed that the three dimentional model of cellular migration of blastema cells along with the ECM could be a suitable model for investigating cell behaviors, such as polarity and cell migration in vitro.

Carbon monoxide mechanism of protection against renal ischemia and reperfusion injury

Carbon monoxide is quickly moving past its historic label as a molecule once feared, to a therapeutic drug that modulates inflammation. The development of carbon monoxide releasing molecules and utilization of heme oxygenase-1 inducers have shown carbon monoxide to be a promising therapy in reducing renal ischemia and reperfusion injury and other inflammatory diseases. In this review, we will discuss the developments and application of carbon monoxide releasing molecules in renal ischemia and reperfusion injury, and transplantation. We will review the anti-inflammatory mechanisms of carbon monoxide in respect to mitigating apoptosis, suppressing dendritic cell maturation and signalling, inhibiting toll-like receptor activation, promoting anti-inflammatory responses, and the effects on renal vasculature.

Mechanotransduction in Skin Inflammation

In the process of mechanotransduction, the cells in the body perceive and interpret mechanical stimuli to maintain tissue homeostasis and respond to the environmental changes. Increasing evidence points towards dysregulated mechanotransduction as a pathologically relevant factor in human diseases, including inflammatory conditions. Skin is the organ that constantly undergoes considerable mechanical stresses, and the ability of mechanical factors to provoke inflammatory processes in the skin has long been known, with the Koebner phenomenon being an example. However, the molecular mechanisms and key factors linking mechanotransduction and cutaneous inflammation remain understudied. In this review, we outline the key players in the tissue's mechanical homeostasis, the available data, and the gaps in our current understanding of their aberrant regulation in chronic cutaneous inflammation. We mainly focus on psoriasis as one of the most studied skin inflammatory diseases; we also discuss mechanotransduction in the context of skin fibrosis as a result of chronic inflammation. Even though the role of mechanotransduction in inflammation of the simple epithelia of internal organs is being actively studied, we conclude that the mechanoregulation in the stratified epidermis of the skin requires more attention in future translational research.

Revisiting the Tenascins: Exploitable as Cancer Targets?

For their full manifestation, tumors require support from the surrounding tumor microenvironment (TME), which includes a specific extracellular matrix (ECM), vasculature, and a variety of non-malignant host cells. Together, these components form a tumor-permissive niche that significantly differs from physiological conditions. While the TME helps to promote tumor progression, its special composition also provides potential targets for anti-cancer therapy. Targeting tumor-specific ECM molecules and stromal cells or disrupting aberrant mesenchyme-cancer communications might normalize the TME and improve cancer treatment outcome. The tenascins are a family of large, multifunctional extracellular glycoproteins consisting of four members. Although each have been described to be expressed in the ECM surrounding cancer cells, tenascin-C and tenascin-W are currently the most promising candidates for exploitability and clinical use as they are highly expressed in various tumor stroma with relatively low abundance in healthy tissues. Here, we review what is known about expression of all four tenascin family members in tumors, followed by a more thorough discussion on tenascin-C and tenascin-W focusing on their oncogenic functions and their potential as diagnostic and/or targetable molecules for anti-cancer treatment purposes.

miR-218 affects the ECM composition and cell biomechanical properties of glioblastoma cells

Glioblastoma (GBM) is the most common malignant brain tumour. GBM cells have the ability to infiltrate into the surrounding brain tissue, which results in a significant decrease in the patient’s survival rate. Infiltration is a consequence of the low adhesion and high migration of the tumour cells, two features being associated with the highly remodelled extracellular matrix (ECM). In this study, we report that ECM composition is partially regulated at the post‐transcriptional level by miRNA. Particularly, we show that miR‐218, a well‐known miRNA suppressor, is involved in the direct regulation of ECM components, tenascin‐C (TN‐C) and syndecan‐2 (SDC‐2). We demonstrated that the overexpression of miR‐218 reduces the mRNA and protein expression levels of TN‐C and SDC‐2, and subsequently influences biomechanical properties of GBM cells. Atomic force microscopy (AFM) and real‐time migration analysis revealed that miR‐218 overexpression impairs the migration potential and enhances the adhesive properties of cells. AFM analysis followed by F‐actin staining demonstrated that the expression level of miR‐218 has an impact on cell stiffness and cytoskeletal reorganization. Global gene expression analysis showed deregulation of a number of genes involved in tumour cell motility and adhesion or ECM remodelling upon miR‐218 treatment, suggesting further indirect interactions between the cells and ECM. The results demonstrated a direct impact of miR‐218 reduction in GBM tumours on the qualitative ECM content, leading to changes in the rigidity of the ECM and GBM cells being conducive to increased invasiveness of GBM.

Lack of autoantibodies against collagen and related proteins in collagenous colitis

Introduction

Collagenous colitis (CC) is a common cause of chronic diarrhea and is characterized by a subepithelial thickened collagen layer in the colonic mucosa.

It shares many of the characteristics found in autoimmune diseases, but no autoantibodies have been identified. In CC, an imbalance in collagen turnover is evident. The purpose of the present study was to investigate whether any collagen-associated autoantibodies or other antibodies such as TPO and ASCA were present, and if levels of total IgE were increased.

Methods

Sera from women with active CC were analysed with ELISA for detection of autoantibodies against collagen type III and IV (Col III and IV), matrix metalloproteinase-9 (MMP-9), tissue inhibitors of metalloproteinase-1 (TIMP-1) and tenascin-C (TNC). Sera were also analysed for TPO, ASCA and total IgE. Healthy female blood donors served as controls. The cut-off value in the control group was defined as relative units > 97.5th percentile.

Results

Sixty-six women were included (mean age 60 years; range 31–74, mean disease duration 6 years; range 1–22). No autoantibody was significantly overexpressed in the CC population compared to controls. The mean disease duration was lower (p = 0.03) in the subjects who expressed collagen-associated autoantibodies (3.7 years; range 1–14), compared to those who did not (6.4 years; range 1–22). Treatment with budesonide was not associated with any of these autoantibodies.

Conclusion

No increased presence of the investigated antibodies could be found in the present study of CC. Neither could antibodies against ASCA or TPO, or elevated levels of IgE, be found. Consequently, no association was found between CC and these proteins, even though this may not be generalizable to other compounds in the collagen layer.

Assessment of circulating fibrotic proteins (periostin and tenascin -C) In Type 2 diabetes mellitus patients with and without retinopathy

PURPOSE

Diabetic retinopathy is a leading cause of vision impairment. Surging diabetic population and poor visual care raises the need for better diagnostic tools. Hence, it is worthwhile to look for biomarkers associated with the disease pathogenesis. Periostin and tenascin-C are matricellular proteins mediating fibrillogenesis in retinopathy. Their serum levels and association with the presence and severity of retinopathy in diabetics is of importance to be explored.

METHODS

The study involved two groups of type 2 diabetes patients, 38 controls without retinopathy and 38 cases with retinopathy. We obtained serum sample and performed biochemical autoanalysis for routine parameters. Special parameters periostin, tenascin-C, and C-peptide were estimated by ELISA.

RESULTS

Periostin and tenascin-C were significantly elevated in the retinopathy group. Periostin progressively increased among subgroups. C-peptide decreased significantly in retinopathy group and had a negative correlation with duration of DM, duration of retinopathy, HbA1c and tenascin-C. We observed a positive correlation for periostin and tenascin-C with duration of diabetes. The AUC for C-peptide was the highest (0.750) amongst our parameters. HOMA 2 (%B) index was significantly lower in retinopathy group.

CONCLUSIONS

Serum Levels of PO and TnC increased in retinopathy. As the disease advances, periostin level increases, indicating continuing fibrosis and fibrovascular membrane formation. Periostin and tenascin-C increase with duration of retinopathy whereas levels of C-peptide decrease. C-peptide has a better differentiating potential for DR from DM. Reduced insulin production as indicated by declined HOMA 2-%BETA in retinopathy favors hyperglycemia and chronic inflammatory state for the disease progression.

Controlled Oxygenated Rewarming Compensates for Cold Storage-induced Dysfunction in Kidney Grafts

BACKGROUND

Normothermic machine perfusion (NMP) provides a promising strategy for preservation and conditioning of marginal organ grafts. However, at present, high logistic effort limits normothermic renal perfusion to a short, postponed machine perfusion at site of the recipient transplant center. Thus, organ preservation during transportation still takes place under hypothermic conditions, leading to significantly reduced efficacy of NMP. Recently, it was shown that gentle and controlled warming up of cold stored kidneys compensates for hypothermic induced damage in comparison to end ischemic NMP. This study aims to compare controlled oxygenated rewarming (COR) with continuous upfront normothermic perfusion in a porcine model of transplantation.

METHODS

Following exposure to 30 min of warm ischemia, kidneys (n = 6/group) were removed and either cold stored for 8 h (cold storage [CS]), cold stored for 6 h with subsequent controlled rewarming up to 35 °C for 2 h (COR), or directly subjected to 8 h of continuous NMP. Kidney function was evaluated using a preclinical autotransplant model with follow-up for 7 d.

RESULTS

NMP and COR both improved renal function in comparison to CS and displayed similar serum creatinine and urea levels during follow-up. COR resulted in less tenascin C expression in the tissue compared with CS, indicating reduced proinflammatory upregulation in the graft by gentle rewarming.

CONCLUSIONS

COR seems to be a potential alternative in clinical application of NMP, thereby providing logistic ease and usability.

The neuropeptide Substance P facilitates the transition from an inflammatory to proliferation phase associated responses in dermal fibroblasts

The wound healing process is a product of three successive and overlapping phases of inflammation, proliferation and remodeling. Considerable efforts have been invested in deconstructing the intercellular crosstalk that orchestrates tissue repair and we investigated the role of neuropeptides released from peripheral neurons upon injury in mediating these interactions. Amongst the most abundant of these neuropeptides secreted by nerves in the skin, is Substance P (SP). Given the role of dermal fibroblasts in coordinating multiple processes in the wound healing program, the effect of SP on human dermal fibroblasts of different ages was evaluated. The use of a substrate that recapitulates the mechanical properties of the in vivo tissue revealed novel effects of SP on dermal fibroblasts, including a block in inflammatory cytokine expression. Moreover, SP can promote expression of some extracellular matrix components and generates signals that regulate angiogenesis. Interestingly, the response of fibroblasts to SP was reduced concomitant with donor age. Altogether, SP acts to inhibit the inflammatory responses and promote proliferation associated responses in an age-dependent manner in dermal fibroblasts, suggesting a role as a molecular switch between the inflammatory and proliferative phases of the wound healing response.

Tissue microenvironment dictates inflammation and disease activity in rheumatoid arthritis

The recent advance in treatments for rheumatoid arthritis (RA) has significantly improved the prognosis of RA patients. However, these novel therapies do not work well for all RA patients. The unmet need suggests that the current understanding about how inflammatory response arises and progresses in RA is limited. Recent accumulating evidence reveals an important role for the tissue microenvironment in the pathogenesis of RA. The synovium, the main tissue where the RA activity occurs, is composed by a unique extracellular matrix (ECM) and residing cells. The ECM molecules provide environmental signals that determine programmed site-specific cell behavior. Improved understanding of the tissue microenvironment, especially how the synovial architecture, ECM molecules, and site-specific cell behavior promote chronic inflammation and tissue destruction, will enhance deciphering the pathogenesis of RA. Moreover, in-depth analysis of tissue microenvironment will allow us to identify potential therapeutic targets. Research is now undertaken to explore potential candidates, both cellular and ECM molecules, to develop novel therapies. This article reviews recent advances in knowledge about how changes in cellular and ECM factors within the tissue microenvironment result in propagation of chronic inflammation in RA.

Identification of Interphotoreceptor retinoid-binding protein in the Schisis cavity fluid of a patient with congenital X-linked Retinoschisis

Background

This case report describes the surgical outcome in a patient with congenital X-linked retinoschisis (CXLRS) and the results of proteomic analysis of surgically extracted samples from both vitreous and intraschisis cavities by mass spectrometry.

Case presentation

A 3-month-old boy presented with extensive retinoschisis involving macula and retinal periphery in both eyes. Genetic analysis confirmed retinoschisin 1 mutation (c.554C > T), and an electroretinogram showed significant reduction of b-wave and decreased cone and rod responses, which led to a diagnosis of CXLRS. By performing pars plana vitrectomy, including inner wall retinectomy, clear visual axes with stable retinal conditions and functional vision in both eyes were obtained during the 4 years of follow-up. Proteomic analysis of surgically retrieved fluid from the intraschisis cavity revealed a higher expression of interphotoreceptor retinoid-binding protein (IRBP) than that from the vitreous humor. However, both samples showed equal levels of albumin, transferrin, and pigment epithelium-derived factor.

Conclusions

Cellular adhesive imperfection in CXLRS may cause IRBP diffusion from the interphotoreceptor matrix, resulting in the strong expression of IRBP in the intraschisis cavity. An impaired retinoid cycle caused by an absence of IRBP in the retina may potentially underlie the pathology of CXLRS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02234-5.

Tumor Microenvironment in Pancreatic Intraepithelial Neoplasia

Simple Summary

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive neoplasm with a poor survival rate. This is mainly due to late detection, which substantially limits therapy options. A better understanding of the early phases of pancreatic carcinogenesis is fundamental for improving patient prognosis in the future. In this article, we focused on the tumor microenvironment (TME), which provides the biological niche for the development of PDAC from its most common precursor lesions, PanIN (pancreatic intraepithelial neoplasias).

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive tumors with a poor prognosis. A characteristic of PDAC is the formation of an immunosuppressive tumor microenvironment (TME) that facilitates bypassing of the immune surveillance. The TME consists of a desmoplastic stroma, largely composed of cancer-associated fibroblasts (CAFs), immunosuppressive immune cells, immunoregulatory soluble factors, neural network cells, and endothelial cells with complex interactions. PDAC develops from various precursor lesions such as pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasms (IPMN), mucinous cystic neoplasms (MCN), and possibly, atypical flat lesions (AFL). In this review, we focus on the composition of the TME in PanINs to reveal detailed insights into the complex restructuring of the TME at early time points in PDAC progression and to explore ways of modifying the TME to slow or even halt tumor progression.

Basic Components of Connective Tissues and Extracellular Matrix: Fibronectin, Fibrinogen, Laminin, Elastin, Fibrillins, Fibulins, Matrilins, Tenascins and Thrombospondins

Collagens are the most abundant components of the extracellular matrix (ECM) and many types of soft tissues. Elastin is another major component of certain soft tissues, such as arterial walls and ligaments. It is an insoluble polymer of the monomeric soluble precursor tropoelastin, and the main component of elastic fibers in matrix tissue where it provides elastic recoil and resilience to a variety of connective tissues, e.g., aorta and ligaments. Elastic fibers regulate activity of transforming growth factors β (TGFβ) through their association with fibrillin microfibrils. Elastin also plays a role in cell adhesion, cell migration, and has the ability to participate in cell signaling. Mutations in the elastin gene lead to cutis laxa. Many other molecules, though lower in quantity, function as essential, structural and/or functional components of the extracellular matrix in soft tissues. Some of these are reviewed in this chapter. Besides their basic structure, biochemistry and physiology, their roles in disorders of soft tissues are discussed only briefly as most chapters in this volume deal with relevant individual compounds. Fibronectin with its multidomain structure plays a role of "master organizer" in matrix assembly as it forms a bridge between cell surface receptors, e.g., integrins, and compounds such collagen, proteoglycans and other focal adhesion molecules. It also plays an essential role in the assembly of fibrillin-1 into a structured network. Though the primary role of fibrinogen is in clot formation, after conversion to fibrin by thrombin it also binds to a variety of compounds, particularly to various growth factors, and as such, fibrinogen is a player in cardiovascular and extracellular matrix physiology. Laminins contribute to the structure of the ECM and modulate cellular functions such as adhesion, differentiation, migration, stability of phenotype, and resistance towards apoptosis. Fibrillins represent the predominant core of microfibrils in elastic as well as non-elastic extracellular matrixes, and interact closely with tropoelastin and integrins. Not only do microfibrils provide structural integrity of specific organ systems, but they also provide basis for elastogenesis in elastic tissues. Fibrillin is important for the assembly of elastin into elastic fibers. Mutations in the fibrillin-1 gene are closely associated with Marfan syndrome. Latent TGFβ binding proteins (LTBPs) are included here as their structure is similar to fibrillins. Several categories of ECM components described after fibrillins are sub-classified as matricellular proteins, i.e., they are secreted into ECM, but do not provide structure. Rather they interact with cell membrane receptors, collagens, proteases, hormones and growth factors, communicating and directing cell-ECM traffic. Fibulins are tightly connected with basement membranes, elastic fibers and other components of extracellular matrix and participate in formation of elastic fibers. Matrilins have been emerging as a new group of supporting actors, and their role in connective tissue physiology and pathophysiology has not been fully characterized. Tenascins are ECM polymorphic glycoproteins found in many connective tissues in the body. Their expression is regulated by mechanical stress both during development and in adulthood. Tenascins mediate both inflammatory and fibrotic processes to enable effective tissue repair and play roles in pathogenesis of Ehlers-Danlos, heart disease, and regeneration and recovery of musculo-tendinous tissue. One of the roles of thrombospondin 1 is activation of TGFβ. Increased expression of thrombospondin and TGFβ activity was observed in fibrotic skin disorders such as keloids and scleroderma. Cartilage oligomeric matrix protein (COMP) or thrombospondin-5 is primarily present in the cartilage. High levels of COMP are present in fibrotic scars and systemic sclerosis of the skin, and in tendon, especially with physical activity, loading and post-injury. It plays a role in vascular wall remodeling and has been found in atherosclerotic plaques as well.

Tenascin-C: Friend or Foe in Lung Aging?

Lung aging is characterized by lung function impairment, ECM remodeling and airspace enlargement. Tenascin-C (TNC) is a large extracellular matrix (ECM) protein with paracrine and autocrine regulatory functions on cell migration, proliferation and differentiation. This matricellular protein is highly expressed during organogenesis and morphogenetic events like injury repair, inflammation or cancer. We previously showed that TNC deficiency affected lung development and pulmonary function, but little is known about its role during pulmonary aging. In order to answer this question, we characterized lung structure and physiology in 18 months old TNC-deficient and wild-type (WT) mice. Mice were mechanically ventilated with a basal and high tidal volume (HTV) ventilation protocol for functional analyses. Additional animals were used for histological, stereological and molecular biological analyses. We observed that old TNC-deficient mice exhibited larger lung volume, parenchymal volume, total airspace volume and septal surface area than WT, but similar mean linear intercept. This was accompanied by an increase in proliferation, but not apoptosis or autophagy markers expression throughout the lung parenchyma. Senescent cells were observed in epithelial cells of the conducting airways and in alveolar macrophages, but equally in both genotypes. Total collagen content was doubled in TNC KO lungs. However, basal and HTV ventilation revealed similar respiratory physiological parameters in both genotypes. Smooth muscle actin (α-SMA) analysis showed a faint increase in α-SMA positive cells in TNC-deficient lungs, but a marked increase in non-proliferative α-SMA + desmin + cells. Major TNC-related molecular pathways were not up- or down-regulated in TNC-deficient lungs as compared to WT; only minor changes in TLR4 and TGFβR3 mRNA expression were observed. In conclusion, TNC-deficient lungs at 18 months of age showed exaggerated features of the normal structural lung aging described to occur in mice between 12 and 18 months of age. Correlated to the increased pulmonary function parameters previously observed in young adult TNC-deficient lungs and described to occur in normal lung aging between 3 and 6 months of age, TNC might be an advantage in lung aging.

VDAC1 Silencing in Cancer Cells Leads to Metabolic Reprogramming That Modulates Tumor Microenvironment

Simple Summary

Tumors are comprised of proliferating cancer cells, and their microenvironment consists of the extracellular matrix, blood vessels, and a variety of tissue cells. The tumor microenvironment functions in cell growth, proliferation, migration, immunity, malignant transformation, and apoptosis. Understanding the molecular interactions between cancer cells and their microenvironment would facilitate the development of therapeutic strategies to disrupt these interactions and fight cancer. Here, we demonstrate that depleting the mitochondrial gatekeeper VDAC1 in human cancer cells in tumors led to metabolic reprogramming, inhibited tumor growth, and disrupted tumor–host interactions. A next-generation sequencing analysis of human lung cell-derived tumors expressing or depleted of VDAC1 allows distinguishing genes of human or murine origin, thus enabling the separation of the bidirectional cross-talk between malignant cells and the tumor microenvironment. A battery of human cancer cell and mouse genes associated with tumor microenvironment formation and remodeling were altered. The results point to VDAC1 as a novel target for both inhibiting tumor growth and modulating the tumor microenvironment, thus influencing cancer progression, migration, and invasion.

Abstract

The tumor microenvironment (TME) plays an important role in cell growth, proliferation, migration, immunity, malignant transformation, and apoptosis. Thus, better insight into tumor–host interactions is required. Most of these processes involve the metabolic reprogramming of cells. Here, we focused on this reprogramming in cancerous cells and its effect on the TME. A major limitation in the study of tumor–host interactions is the difficulty in separating cancerous from non-cancerous signaling pathways within a tumor. Our strategy involved specifically silencing the expression of VDAC1 in the mitochondria of human-derived A549 lung cancer xenografts in mice, but not in the mouse-derived cells of the TME. Next-generation sequencing (NGS) analysis allows distinguishing the human or mouse origin of genes, thus enabling the separation of the bidirectional cross-talk between the TME and malignant cells. We demonstrate that depleting VDAC1 in cancer cells led to metabolic reprogramming, tumor regression, and the disruption of tumor–host interactions. This was reflected in the altered expression of a battery of genes associated with TME, including those involved in extracellular matrix organization and structure, matrix-related peptidases, angiogenesis, intercellular interacting proteins, integrins, and growth factors associated with stromal activities. We show that metabolic rewiring upon mitochondrial VDAC1 silencing in cancer cells affected several components of the TME, such as structural protein matrix metalloproteinases and Lox, and elicited a stromal response resembling the reaction to a foreign body in wound healing. As tumor progression requires a cooperative interplay between the host and cancer cells, and the ECM is intensively remodeled during cancer progression, VDAC1 depletion induced metabolic reprogramming that targeted both tumor cells and resulted in the alteration of the whole spectrum of TME-related genes, affecting the reciprocal feedback between ECM molecules, host cells, and cancer cells. Thus, VDAC1 depletion using si-VDAC1 represents therapeutic potential, inhibiting cancer cell proliferation and also inducing the modulation of TME components, which influences cancer progression, migration, and invasion.

Cyclically stretched ACL fibroblasts emigrating from spheroids adapt their cytoskeleton and ligament-related expression profile

Mechanical stress of ligaments varies; hence, ligament fibroblasts must adapt their expression profile to novel mechanomilieus to ensure tissue resilience. Activation of the mechanoreceptors leads to a specific signal transduction, the so-called mechanotransduction. However, with regard to their natural three-dimensional (3D) microenvironment cell reaction to mechanical stimuli during emigrating from a 3D spheroid culture is still unclear. This study aims to provide a deeper understanding of the reaction profile of anterior cruciate ligament (ACL)-derived fibroblasts exposed to cyclic uniaxial strain in two-dimensional (2D) monolayer culture and during emigration from 3D spheroids with respect to cell survival, cell and cytoskeletal orientation, distribution, and expression profile. Monolayers and spheroids were cultured in crosslinked polydimethyl siloxane (PDMS) elastomeric chambers and uniaxially stretched (14% at 0.3 Hz) for 48 h. Cell vitality, their distribution, nuclear shape, stress fiber orientation, focal adhesions, proliferation, expression of ECM components such as sulfated glycosaminoglycans, collagen type I, decorin, tenascin C and cell-cell communication-related gap junctional connexin (CXN) 43, tendon-related markers Mohawk and tenomodulin (myodulin) were analyzed. In contrast to unstretched cells, stretched fibroblasts showed elongation of stress fibers, cell and cytoskeletal alignment perpendicular to strain direction, less rounded cell nuclei, increased numbers of focal adhesions, proliferation, amplified CXN43, and main ECM component expression in both cultures. The applied cyclic stretch protocol evoked an anabolic response and enhanced tendon-related marker expression in ACL-derived fibroblasts emigrating from 3D spheroids and seems also promising to support in future tissue formation in ACL scaffolds seeded in vitro with spheroids.

The Pathogenesis of Hydrocephalus Following Aneurysmal Subarachnoid Hemorrhage

Hydrocephalus is a common complication of aneurysmal subarachnoid hemorrhage (aSAH) and reportedly contributes to poor neurological outcomes. In this review, we summarize the molecular and cellular mechanisms involved in the pathogenesis of hydrocephalus following aSAH and summarize its treatment strategies. Various mechanisms have been implicated for the development of chronic hydrocephalus following aSAH, including alterations in cerebral spinal fluid (CSF) dynamics, obstruction of the arachnoid granulations by blood products, and adhesions within the ventricular system. Regarding molecular mechanisms that cause chronic hydrocephalus following aSAH, we carried out an extensive review of animal studies and clinical trials about the transforming growth factor-β/SMAD signaling pathway, upregulation of tenascin-C, inflammation-dependent hypersecretion of CSF, systemic inflammatory response syndrome, and immune dysregulation. To identify the ideal treatment strategy, we discuss the predictive factors of shunt-dependent hydrocephalus between surgical clipping and endovascular coiling groups. The efficacy and safety of other surgical interventions including the endoscopic removal of an intraventricular hemorrhage, placement of an external ventricular drain, the use of intraventricular or cisternal fibrinolysis, and an endoscopic third ventriculostomy on shunt dependency following aSAH were also assessed. However, the optimal treatment is still controversial, and it necessitates further investigations. A better understanding of the pathogenesis of acute and chronic hydrocephalus following aSAH would facilitate the development of treatments and improve the outcome.

The Extracellular Matrix Glycoprotein Tenascin C and Adult Neurogenesis

Tenascin C (TnC) is a glycoprotein highly expressed in the extracellular matrix (ECM) during development and in the adult central nervous system (CNS) in regions of active neurogenesis, where neuron development is a tightly regulated process orchestrated by extracellular matrix components. In addition, newborn cells also communicate with glial cells, astrocytes and microglia, indicating the importance of signal integration in adult neurogenesis. Although TnC has been recognized as an important molecule in the regulation of cell proliferation and migration, complete regulatory pathways still need to be elucidated. In this review we discuss the formation of new neurons in the adult hippocampus and the olfactory system with specific reference to TnC and its regulating functions in this process. Better understanding of the ECM signaling in the niche of the CNS will have significant implications for regenerative therapies.

Identification of key genes of papillary thyroid carcinoma by integrated bioinformatics analysis

BACKGROUND

Papillary thyroid carcinoma (PTC) is one of the fastest-growing malignant tumor types of thyroid cancer. Therefore, identifying the interaction of genes in PTC is crucial for elucidating its pathogenesis and finding more specific molecular biomarkers.

METHODS

Four pairs of PTC tissues and adjacent tissues were sequenced using RNA-Seq, and 3745 differentially expressed genes were screened (P<0.05, |logFC|>1). The enrichment analysis indicated that the vast majority of differentially expressed genes (DEGs) may play a positive role in the development of cancer. Then, the significant modules were analyzed using Cytoscape software in the protein-protein interaction network. Survival analysis, TNM analysis, and immune infiltration analysis of key genes were analyzed. And the expression of ADORA1, APOE, and LPAR5 genes were verified by qPCR in PTC compared with matching adjacent tissues.

RESULTS

Twenty-five genes were identified as hub genes with nodes greater than 10. The expression of 25 genes were verified by the GEPIA database, and the overall survival and disease-free survival analyses were conducted with Kaplan-Meier plotter. We found only three genes were confirmed with our validation and were statistically significant in PTC, namely ADORA1, APOE, and LPAR5. Further analysis found that the mRNA levels and methylation degree of these three genes were significantly correlated with the TNM staging of PTC. And these three genes were related to PTC immune infiltration. Verification of the expression of these three genes by RT-qPCR and Western blot further confirmed the reliability of our results.

CONCLUSION

Our study identified three genes that may play key regulatory roles in the development, metastasis, and immune infiltration of papillary thyroid carcinoma.

Targeting Strategies for Enhancing Paclitaxel Specificity in Chemotherapy

Paclitaxel (PTX) has been used for cancer treatment for decades and has become one of the most successful chemotherapeutics in the clinic and financially. However, serious problems with its use still exist, owing to its poor solubility and non-selective toxicity. With respect to these issues, recent advances have addressed the water solubility and tumor specificity related to PTX application. Many measures have been proposed to remedy these limitations by enhancing tumor recognition via ligand-receptor-mediated targeting as well as other associated strategies. In this review, we investigated various kinds of ligands that have emerged as PTX tumor-targeting tools. In particular, this article highlights small molecule-, protein-, and aptamer-functionalized conjugates and nanoparticles (NPs), providing a promising approach for PTX-based individualized treatment prospects.