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| MFAP-4 directly interacts with fibrillin-1 to form microfibrils. (a) Concentrated supernatants from NHDFs cultured for 8 days were immunoprecipitated with an anti-MFAP-4 antibody or normal rabbit IgG. Immunoprecipitants were analyzed by Western blotting with an antifibrillin-1 antibody. (b) NHDFs were transfected with siRNAs for non-specific sequences (Control) or MFAP-4 twice during the culture for 8 days, followed by immunofluorescence staining with an anti-human MFAP-4 antibody (green) and an anti-human fibrillin-1 antibody (red). Nuclear staining (DAPI) and merged images are also shown. Scale bars 5 50 mm.
Source publication
UVB-induced cutaneous photodamage/photoaging is characterized by qualitative and quantitative deterioration in dermal extracellular matrix (ECM) components such as collagen and elastic fibers. Disappearance of microfibrillar-associated protein 4 (MFAP-4), a possible limiting factor for cutaneous elasticity, was documented in photoaged dermis, but i...
Contexts in source publication
Context 1
... to elucidate which cellular components interact directly or indirectly with MFAP-4, concentrated supernatants from NHDFs were immunoprecipitated with an anti-MFAP-4 antibody, followed by Western blotting analysis with anti-fibrillin-1 or anti- tropoelastin antibodies. Corresponding signals were detected using an antibody specific for fibrillin-1 (Fig. 6a), whereas no signal was observed when an anti-tropoelastin antibody was used (data not shown). Furthermore, the colocalisation of MFAP-4 with fibrillin-1 was confirmed in NHDFs transfected with a non-specific siRNA by immunocytochemical analysis (Fig. 6b). Intriguingly, decreased sig- nal of fibrillin-1 was observed in NHDFs transfected ...
Context 2
... antibodies. Corresponding signals were detected using an antibody specific for fibrillin-1 (Fig. 6a), whereas no signal was observed when an anti-tropoelastin antibody was used (data not shown). Furthermore, the colocalisation of MFAP-4 with fibrillin-1 was confirmed in NHDFs transfected with a non-specific siRNA by immunocytochemical analysis (Fig. 6b). Intriguingly, decreased sig- nal of fibrillin-1 was observed in NHDFs transfected with an MFAP- 4-specific siRNA synchronized with the depletion of MFAP-4, suggesting that MFAP-4 is in charge of the direct interaction with fibrillin-1 for the promotion of microfibril ...
Citations
... One of the involved genes was MFAP4 (Microfibril Associated Protein 4), which plays an essential role in photoprotection of the skin. Its downregulation observed in conjunctival EMZL may increase the susceptibility of the conjunctiva to ultraviolet light [42]. These findings reveal the biological processes and key genes which are modulated in conjunctival EMZL. ...
This study characterizes the transcriptional profile and the cellular tumor microenvironment of conjunctival extranodal marginal zone lymphoma (EMZL) and identifies prognostically relevant biomarkers. Ten formalin-fixed and paraffin-embedded conjunctival EMZL and eight healthy conjunctival specimens were analyzed by Massive Analysis of cDNA Ends (MACE) RNA sequencing. The 3417 upregulated genes in conjunctival EMZL were involved in processes such as B cell proliferation and Rac protein signaling, whereas the 1188 downregulated genes contributed most significantly to oxidative phosphorylation and UV protection. The tumor microenvironment, as determined by deconvolution analysis, was mainly composed of multiple B cell subtypes which reflects the tumor’s B cell lineage. However, several T cell types, including T helper 2 cells and regulatory T cells, as well as innate immune cell types, such as anti-inflammatory macrophages and plasmacytoid dendritic cells, were also strongly enriched in conjunctival EMZL. A 13-biomarker prognostic panel, including S100A8 and S100A9, classified ocular and extraocular tumor recurrence, exceeded prognostic accuracy of Ann Arbor and American Joint Committee on Cancer (AJCC) staging, and demonstrated prognostic value for patient survival in 21 different cancer types in a database of 12,332 tumor patients. These findings may lead to new options of targeted therapy and may improve prognostic prediction for conjunctival EMZL.
... At day 15, COL6A5 and MFAP4 were downregulated, and PCNA was upregulated in FA-treated skin compared to control skin. MFAP4 plays roles in microfibrillar assembly and maturation of elastic fibers, and its reduction in photoaged skin has been shown to contribute to ECM degradation and reduced elasticity [22]. Upregulation of PCNA, on the other hand, suggests that epithelial cells are actively proliferating to recover the atrophied skin. ...
... Collagen-associated proteins, namely SPARC and P3H3, were also downregulated at this point. COL6A5 and MFAP5, whose reduction in photoaged skin triggers ECM degradation [22], were downregulated 15 days after finishing 12 days of FA treatment. At day 30, COL6A5 expression was no longer affected but COL6A1 and COL6A2 expressions were downregulated in the FA-treated skin (Figure 4). ...
While topical corticosteroid (TCS) treatment is widely used for many skin diseases, it can trigger adverse side effects, and some of such effects can last for a long time after stopping the treatment. However, molecular changes induced by TCS treatment remain largely unexplored, although transient changes in histology and some major ECM components have been documented. Here, we investigated transcriptomic and proteomic changes induced by fluocinolone acetonide (FA) treatment in the mouse skin by conducting RNA-Seq and quantitative proteomics. Chronic FA treatment affected the expression of 4229 genes, where downregulated genes were involved in cell-cycle progression and ECM organization, and upregulated genes were involved in lipid metabolism. The effects of FA on transcriptome and histology of the skin largely returned to normal by two weeks after the treatment. Only a fraction of transcriptomic changes were reflected by proteomic changes, and the expression of 46 proteins was affected one day after chronic FA treatment. A comparable number of proteins were differentially expressed between control and FA-treated skin samples even at 15 and 30 days after stopping chronic FA treatment. Interestingly, proteins affected during and after chronic FA treatment were largely different. Our results provide fundamental information of molecular changes induced by FA treatment in the skin.
... The elastin-forming CAF subtype was highly correlated with the resolution phase of healing, and one of the top markers of this subtype was MFAP4, a key component of elastic fiber formation [69]. MFAP4 is downregulated during intrinsic skin aging along with other elastic fiber components [39], and it has a photo-protective role [70]. Previous bioinformatics data predicted better survival of breast cancer patients with high MFAP4 expression [71], and our data suggest that MFAP4-expressing late wound-associated CAFs may be involved in controlling tumorigenesis by influencing its ECM microenvironment. ...
Healing wounds and cancers present remarkable cellular and molecular parallels, but the specific roles of the healing phases are largely unknown. We developed a bioinformatics pipeline to identify genes and pathways that define distinct phases across the time course of healing. Their comparison to cancer transcriptomes revealed that a resolution-phase wound signature is associated with increased severity in skin cancer and enriches for extracellular matrix-related pathways. Comparisons of transcriptomes of early- and late-phase wound fibroblasts vs skin cancer-associated fibroblasts (CAFs) identified an "early-wound" CAF subtype, which localizes to the inner tumor stroma and expresses collagen-related genes that are controlled by the RUNX2 transcription factor. A "late-wound" CAF subtype localizes to the outer tumor stroma and expresses elastin-related genes. Matrix imaging of primary melanoma tissue microarrays validated these matrix signatures and identified collagen- vs elastin-rich niches within the tumor microenvironment, whose spatial organization predicts survival and recurrence. These results identify wound-regulated genes and matrix patterns with prognostic potential in skin cancer.
... ECM network assembly is a complex process that involves various ECM-associated proteins. These ECM-associated proteins affect important aspects of ECM biodynamics, such as elasticity [38], growth factor secretion, and ECM reservoir function [39][40][41]. Matrisomic profiling revealed a significant increase in S100A9, a matrisome-associated secreted factor, between BmpR1a △FoxL1+ mice and controls (logFC = 13.48; ...
... Microfibrillar-associated protein 4 (MFAP4) is also an important factor influencing ECM remodeling and fibrosis, as highlighted in this study. MFAP4 is a microfibril-associated glycoprotein known to bind elastin and collagen, providing proper elastic organization to fibers [38,59]. In the skin, it has been shown that the reduction of MFAP4 is a limiting factor in tissue elasticity [38]. ...
... MFAP4 is a microfibril-associated glycoprotein known to bind elastin and collagen, providing proper elastic organization to fibers [38,59]. In the skin, it has been shown that the reduction of MFAP4 is a limiting factor in tissue elasticity [38]. Thus, the improper unfolding/ remodeling process and changes observed in ECM components such as MFAP4 could undoubtedly be key players in the disease sequence, leading to tissue fibrosis that was seen in the BmpR1a △FoxL1+ mouse model [7]. ...
Recent studies have identified FoxL1⁺-telocytes (TCFoxL1+) as key players in gut epithelial-mesenchymal interactions which can determine the colonic microenvironment. Bone morphogenetic protein signaling disruption in TCFoxL1+ alters the physical and cellular microenvironment and leads to colon pathophysiology. This suggests a role for TCFoxL1+ in stromagenesis, but it is hard to identify the specific contribution of TCFoxL1+ when analyzing whole tissue profiling studies. We performed ex vivo deconstruction of control and BmpR1a△FoxL1+ colon samples, isolated the mesenchyme-enriched fractions, and determined the protein composition of the in vivo extracellular matrix (ECM) to analyze microenvironment variation. Matrisomic analysis of mesenchyme fractions revealed modulations in ECM proteins with functions associated with innate immunity, epithelial wound healing, and the collagen network. These results show that TCFoxL1+ is critical in orchestrating the biodynamics of the colon ECM. TCFoxL1+ disfunction reprograms the gut's microenvironment and drives the intestinal epithelium toward colonic pathologies.
Significance
In this study, the method that was elected to isolate ECM proteins might not encompass the full extent of ECM proteins in a tissue, due to the protocol chosen, as this protocol by Naba et al., targets more the insoluble part of the matrisome and eliminates the more soluble components in the first steps. However, this ECM-enrichment strategy represents an improvement and interesting avenue to study ECM proteins in the colon compared to total tissue analysis with a background of abundant cellular protein. Thus, the matrisomic approach presented in this study, and its target validation delivered a broader evaluation of the matrix remodeling occurring in the colonic sub-epithelial mesenchyme of the BmpR1a△FoxL1+ mouse model.
... Using immunogold-labeled electron microscopy, it was demonstrated that MFAP4 localizes to the interface between the microfibrils and the elastin core of elastic fibers but not microfibrils away from the elastin core [54,55]. In the skin, MFAP4 colocalized with elastic fibers in the dermis but not the epidermis, and MFAP4 synthesis was demonstrated in dermal fibroblasts in vivo and keratinocytes in vitro [56,57]. In the lung, MFAP4 immunoreactivity was shown in the interalveolar septae and pulmonary arterioles. ...
... Indeed, both endogenous and exogenous MFAP4 promotes association between tropoelastin and fibrillin-1 in human dermal fibroblasts. MFAP4 was also shown to accelerate microfibril assembly through direct interactions with fibrillin-1 [57]. MFAP4 interaction with fibrillin-1 was later confirmed in murine skin in vivo by colocalization [66]. ...
... In line with that, MFAP4 expression was significantly decreased both in extrinsically photoaged and intrinsically aged human skin in a human skin xenograft mouse model. Furthermore, it was demonstrated that MFAP4 suppresses MMP-1 and MMP-12 activity in vitro and in vivo, protecting against elastin and collagen fiber degradation [57]. These observations support an important role for MFAP4 in elastic fiber formation and stability in the skin ( Figure 2). ...
Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix (ECM) protein belonging to the fibrinogen-related domain superfamily. MFAP4 is highly expressed in elastin-rich tissues such as lung, blood vessels and skin. MFAP4 is involved in organization of the ECM, regulating proper elastic fiber assembly. On the other hand, during pathology MFAP4 actively contributes to disease development and progression due to its interactions with RGD-dependent integrin receptors. Both tissue expression and circulating MFAP4 levels are associated with various disorders, including liver fibrosis and cancer. In other experimental models, such as teleost fish, MFAP4 appears to participate in host defense as a macrophage-specific innate immune molecule. The aim of this review is to summarize the accumulating evidence that indicates the importance of MFAP4 in homeostasis as well as pathological conditions, discuss its known biological functions with special focus on elastic fiber assembly, integrin signaling and cancer, as well as describe the reported functions of non-mammalian MFAP4 in fish. Overall, our work provides a comprehensive overview on the role of MFAP4 in health and disease.
... In addition to the molecules reported above, fibrillin microfibrils interact with several other proteins, which play a role in elastic fibre formation. For example, latent transforming growth factor β-binding proteins support elastic fibre assembly and cell signalling [40]; microfibril-associated glycoproteins (MAGP-1 and 2) promote elastin deposition onto microfibrils and increase elastin assembly [41][42][43]; fibulins (FBL-4 and -5) facilitate elastin cross-linking by LOX/LOXL and deposition onto microfibrils [44]; a disintegrin and metalloprotease with thrombospondin type-1 repeats (ADAMTS) and ADAMTS-like proteins (ADAMTSL) are involved in microfibril assembly, adhesion and anchorage [45]; and elastinmicrofibril interface-located proteins (EMILINs) are necessary for microfibril deposition onto elastic fibres [46,47]. Therefore, the development of mature and functional elastic fibres is a finely temporally and spatially regulated process requiring dozens of different proteins (for more details see also reviews [12,48,49]). ...
Elastin represents the structural component of the extracellular matrix providing elastic recoil to tissues such as skin, blood vessels and lungs. Elastogenic cells secrete soluble tropoelastin monomers into the extracellular space where these monomers associate with other matrix proteins (e.g., microfibrils and glycoproteins) and are crosslinked by lysyl oxidase to form insoluble fibres. Once elastic fibres are formed, they are very stable, highly resistant to degradation and have an almost negligible turnover. However, there are circumstances, mainly related to inflammatory conditions, where increased proteolytic degradation of elastic fibres may lead to consequences of major clinical relevance. In severely affected COVID-19 patients, for instance, the massive recruitment and activation of neutrophils is responsible for the profuse release of elastases and other proteolytic enzymes which cause the irreversible degradation of elastic fibres. Within the lungs, destruction of the elastic network may lead to the permanent impairment of pulmonary function, thus suggesting that elastases can be a promising target to preserve the elastic component in COVID-19 patients. Moreover, intrinsic and extrinsic factors additionally contributing to damaging the elastic component and to increasing the spread and severity of SARS-CoV-2 infection are reviewed.
... Inspired by this, by proteomic analysis, our previous preliminary findings showed that MFAP4, an extracellular matrix protein, was notably upregulated in OSF tissues [5]. MFAP4 is a ubiquitous protein that plays an increasingly noteworthy part in elastin fiber formation and ECM remodeling processes during vascular injury and multitudinous fibrotic diseases, including myocardium, liver, joint and renal fibrosis [6][7][8][9][10][11][12]. In viral hepatitis and cirrhosis patients, transcription and protein levels experiment and histochemical analysis showed that MFAP4 levels increased significantly while progressing from non-fibrosis to severe stages [13,14]. ...
Background
Oral submucous fibrosis (OSF), distinguished by abnormal collagen deposition, is a potentially malignant disorder with 4.2% (95% CI 2.7–5.6%) of malignant transformation and rising global prevalence. However, the precise pathogenesis and effective treatment remain elusive and controversial despite the abundance of literature on this topic. Therefore, it is crucial to explore the clinicopathological characteristics and potential markers for the diagnosis and prognosis of OSF. The objective of this study was to evaluate the influence and correlation of Microfibrillar-associated protein 4 (MFAP4) and tropoelastin (TE) in the development of OSF patients.
Material and methods
Clinicopathological factors, hematoxylin–eosin (HE) and Masson trichome staining, immunohistochemical characteristics and the correlation between MFAP4 and TE were recorded and compared among different stages of OSF progression among cases (n = 60) and controls (n = 10). Student's t test, ANOVA analysis, and the chi-square test were performed to compare the categorical variables for clinicopathological characteristics and the expression level of MFAP4 and TE between the fibrotic and normal tissues. Correlation analysis of MFAP4 and TE was performed using Pearson's correlation test and linear regression.
Results
MFAP4 and TE proteins are upregulated and increased gradually in patients with varying stages of OSF, relative to the control group. Furthermore, statistical analyses revealed that the expression level of MFAP4 was positively associated with TE, with a Pearson correlation coefficient of 0.3781 ( p = 0.0048). Clinically, we found that OSF affected more males than females, with a ratio of 29:1. The age range was 16–60 years, and the mean age was 36.25 ± 10.25 years. In patients younger than 40 years, the positive expression rate of MFAP4 and TE was higher than in those over 40 years. All OSF cases had chewed areca nut, with 51.67% smoking tobacco.
Conclusions
Our study elucidates that the accumulation of MFAP4 and TE proteins may play a vital role in the occurrence and development of OSF and may be promising candidate moleculars for prevention, diagnosis, and treatment strategies for OSF in the future.
... MFAP4 engagement in MMP synthesis has previously been reported in human skin, where MFAP4 appeared to protect collagen integrity by reducing MMP-12 activity after UV light exposure (32). Moreover, MFAP4 is known to accelerate tropoelastin assembly into elastic fibers (13), and Mfap4-deficient mice develop a mild age-induced airspace enlargement linked to loss of alveolar surface (15), both indicating that MFAP4 contributes to ECM stability. ...
Objective: Abdominal aortic aneurysm (AAA) is a common age-related vascular disease characterized by progressive weakening and dilatation of the aortic wall. Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix (ECM) protein involved in the induction of vascular remodeling. This study aimed to investigate if MFAP4 facilitates the development of AAA and characterize the underlying MFAP4-mediated mechanisms.
Approach and Results: Double apolipoprotein E- and Mfap4 -deficient ( ApoE −/− Mfap4 −/− ) and control apolipoprotein E-deficient ( ApoE −/− ) mice were infused subcutaneously with angiotensin II (Ang II) for 28 days. Mfap4 expression was localized within the adventitial and medial layers and was upregulated after Ang II treatment. While Ang II-induced blood pressure increase was independent of Mfap4 genotype, ApoE −/− Mfap4 −/− mice exhibited significantly lower AAA incidence and reduced maximal aortic diameter compared to ApoE −/− littermates. The ApoE −/− Mfap4 −/− AAAs were further characterized by reduced macrophage infiltration, matrix metalloproteinase (MMP)-2 and MMP-9 activity, proliferative activity, collagen content, and elastic membrane disruption. MFAP4 deficiency also attenuated activation of integrin- and TGF-β-related signaling within the adventitial layer of AAA tissues. Finally, MFAP4 stimulation promoted human monocyte migration and significantly upregulated MMP-9 activity in macrophage-like THP-1 cells.
Conclusion: This study demonstrates that MFAP4 induces macrophage-rich inflammation, MMP activity, and maladaptive remodeling of the ECM within the vessel wall, leading to an acceleration of AAA development and progression. Collectively, our findings suggest that MFAP4 is an essential aggravator of AAA pathology that acts through regulation of monocyte influx and MMP production.
... Inspired by this, our previous preliminary findings have observed that MFAP4, an extracellular matrix protein, was notably upregulated in OSF tissues by proteomic analysis [5]. MFAP4 is a ubiquitous protein playing an increasingly noteworthy part in elastin fiber formation and ECM remodeling processes during vascular injury and multitudinous fibrotic diseases, including myocardium, liver, joint and renal fibrosis [6][7][8][9][10][11][12]. In viral hepatitis and cirrhosis patients, MFAP4 levels increased significantly from non-fibrosis stage to the severe stage via transcription and protein levels experiment and histochemical analysis [13,14]. ...
Background: Oral submucous fibrosis (OSF), distinguished by abnormal collagen deposition, is a precancerous disorder with 7%-30% of malignant transformation and rising global prevalence. However, the precise pathogenesis and effective treatment still remains elusive and controversial despite superfluity of literature. Therefore, it is extremely necessary and significant to explore the clinicopathological characteristics and potential markers for diagnosis and prognosis of OSF. Here, the objective of this research is to evaluate the influence and correlation of Microfibrillar-associated protein 4 [MFAP4] and tropoelastin [TE] on the development of OSF patients.
Material and Methods: Classic clinicopathological factors, HE and Masson trichome staining, immunohistochemical characteristics and the correlation (MFAP4 and TE) were recorded and compared among different stages of OSF cases (n = 60) and among those normal individuals (n = 10). Then, the comparison using Student's t test, ANOVA analysis, the chi-square test for categorical variables was conducted in clinicopathological characteristics and the expression level of MFAP4 and TE between the patients' and normal tissue. The correlation analysis of MFAP4 and TE were assessed via means of Pearson's correlation test and linear regression.
Results: MFAP4 and TE proteins are upregulated and even increasing gradually in varying grades of OSF patients relative to the normal cases. Furthermore, statistical analyses yielded that the expression level of MFAP4 was positively associated with TE, and the Pearson correlation coefficient was 0.3781 (p = 0.0048). Clinically, we found that OSF affected more male than female with a ratio of 29: 1. The age range was 16-60 years, and the mean age was 36.25 ± 10.25 years old. Moreover, the positive expression rate of MFAP4 and TE in patients less than 40 years old is higher than that of those over 40 years old. Meanwhile, all OSF cases had chewed areca nut, with 51.67% smoking tobacco.
Conclusions: Our study elucidates that the accumulation of MFAP4 and TE proteins may play a vitally important effect in the occurrence and development of OSF and has a hope to become a promising candidate molecular for prevention, diagnosis, and treatment strategies of OSF in the future.
... Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix protein, which binds to extracellular matrix (ECM) fibers like collagen, elastin and fibrillin. [1][2][3][4][5][6] MFAP4 is localized primarily to sites rich in elastic fibers comprising aorta, 4,7,8 skin, 5,6,9 and a range of internal organs including lung, intestine, kidney, spleen, liver, and heart. 1,3,10 Immunohistochemical staining reveals a major site of expression in blood vessels, where MFAP4 is synthesized by vascular smooth muscle cells. 1 Furthermore, MFAP4 synthesis is demonstrated in dermal fibroblasts 5 and hepatic stellate cells. ...
... Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix protein, which binds to extracellular matrix (ECM) fibers like collagen, elastin and fibrillin. [1][2][3][4][5][6] MFAP4 is localized primarily to sites rich in elastic fibers comprising aorta, 4,7,8 skin, 5,6,9 and a range of internal organs including lung, intestine, kidney, spleen, liver, and heart. 1,3,10 Immunohistochemical staining reveals a major site of expression in blood vessels, where MFAP4 is synthesized by vascular smooth muscle cells. 1 Furthermore, MFAP4 synthesis is demonstrated in dermal fibroblasts 5 and hepatic stellate cells. ...
... [1][2][3][4][5][6] MFAP4 is localized primarily to sites rich in elastic fibers comprising aorta, 4,7,8 skin, 5,6,9 and a range of internal organs including lung, intestine, kidney, spleen, liver, and heart. 1,3,10 Immunohistochemical staining reveals a major site of expression in blood vessels, where MFAP4 is synthesized by vascular smooth muscle cells. 1 Furthermore, MFAP4 synthesis is demonstrated in dermal fibroblasts 5 and hepatic stellate cells. 11,12 While embedded in the ECM, MFAP4 exposes a cell adhesion motif (RGD-sequence) enabling integrin ligation and focal adhesion for cellular activation. ...
Serum microfibrillar-associated protein 4 (sMFAP4) has been investigated as a biomarker for various diseases and is demonstrated to show significant gradual increase with severity of liver fibrosis. Ideal biomarkers used for disease diagnosis or prognosis should display deviating levels in affected individuals only and be robust to factors unrelated to the disease. Here we show the impact of normal physiological variation of sMFAP4 by characterizing the circadian variation, week-to-week variation, and physical exercise-induced levels. Serum samples from 3 groups of healthy volunteers were drawn: 7 times during a 24-hour period, 5 times during a 3-week period, and before and after a standardized physical exercise challenge. sMFAP4 was determined by AlphaLISA. Statistical analysis was performed using mixed effects modeling of repeated measurements. Circadian variation of sMFAP4 was demonstrated, with time of peak and nadir values depending on age and gender. For males, the peak values were observed during nighttime whereas for females, peak values were observed in the morning. Individual sMFAP4 levels remained stable over a period of 3 weeks and physical exercise inferred a mild negative influence. In conclusion, the circadian sMFAP4 variation was significant, and the levels could be influenced by physical activity. However, these variations were of limited magnitude relative to previously observed disease-induced levels in support of the biomarker potential of sMFAP4.
