Downregulation of fibromodulin attenuates inflammatory signaling and atrial fibrosis in spontaneously hypertensive rats with atrial fibrillation via inhibiting TLR4/NLRP3 signaling pathway.

BACKGROUND: Myocardial fibrosis is an important factor in the induction and maintenance of atrial fibrillation (AF). Fibromodulin (FMOD) promotes fibrotic gene expression. However, its specific role in spontaneously hypertensive rats (SHR)-AF remains unclear. METHODS: We analyzed FMOD mRNA and protein expression in rat atrial tissues using RT-qPCR, Western blot analysis, and immunohistochemistry. Histopathological examination of atrial tissues was performed using hematoxylin and eosin (H&E), Masson's trichrome, and Picrosirius red staining. The levels of inflammatory and fibrosis-related proteins were measured using Western blot analysis. RESULTS: FMOD relative mRNA and protein expression levels were notably upregulated in atrial tissues of both AF groups (normal-AF and SHR-AF groups) than that in atrial tissues of the no-AF group (normal and SHR group). This effect was particularly pronounced in the SHR-AF group. Pathological changes revealed that the extracellular matrix, collagen, collagen fibers, and left atrial diameter were notably increased in the atrial tissues from the SHR-AF group compared to those in the atrial tissues from the SHR group, whereas the left ventricular fractional shortening and left ventricular ejection fraction were notably lower. Expression of TLR4, MyD88, NLRP3, TGF-ß1, collagen I, and collagen II mRNA were clearly higher in atrial tissues from the SHR-AF group than in those from the SHR group. Protein levels of TLR4, MyD88, NLRP3, Cleavage-Caspase-1, Cleavage-IL-1ß, TGF-ß1, p-Smad2, collagen I, and collagen II were clearly higher in atrial tissues from the SHR-AF group than in those from the SHR group. FMOD knockdown inhibited atrial fibrosis, collagen accumulation, and the TLR4/MyD88/NLRP3 signaling pathway. CONCLUSION: Downregulation of FMOD attenuated inflammatory signaling and atrial fibrosis in SHR-AF by inhibiting the TLR4/NLRP3 signaling pathway. Therefore, FMOD may be a promising therapeutic target in AF.

Fibromodulin Gene Variants (FMOD) as Potential Biomarkers for Prostate Cancer and Benign Prostatic Hyperplasia.

By the year 2050, the world's elderly population may increase exponentially, raising the rate of disease characteristic of this group, such as prostate cancer (PCa) and benign prostatic hyperplasia (BPH). Prostate disorders have a multifactorial etiology, especially age and genetic factors. Currently, PCa is the second most frequent neoplasm in the male population worldwide. The fibromodulin gene encodes a small leucine-rich proteoglycan (SLRP) which acts in the collagen fibrillogenesis pathway, cell adhesion, and modulation of TGF-ß signaling pathways, which has been recently associated with PCa. The present study sequenced the coding region of the FMOD in a sample of 44 PCa, 90 BPH, and 82 controls from a Brazilian population, and the results identified 6 variants: 2 missenses (p.(Tyr42Ser) and p.(Pro24Ala)); 3 synonymous (p.(His253=), p.(Asn353=), and p.(Glu79=)); and 1 intronic (c.980-114A>G). Of these, p.(Tyr42Ser), p.(Pro24Ala), and p.(Asn353=) are rare variants, and p.(Tyr42Ser) was predicted as potential pathogenic by the algorithms used here, in addition to not being observed in controls, suggesting that may be a potential biomarker for development of PCa and BPH. In conclusion, we identified for the first time, in Brazilian individuals with PCa and BPH, a potentially pathogenic variant in the analysis of FMOD gene. Further studies are needed to investigate the deleterious effect of this variant on the structure and/or function of the FMOD protein.

Coupled fibromodulin and SOX2 signaling as a critical regulator of metastatic outgrowth in melanoma.

We aimed to study mechanisms controlling metastatic outgrowth of melanoma into clinically relevant lesions, a critical process responsible for the majority of melanoma deaths. To this end, we developed novel in vivo models and identified molecular events that can be ascribed to their distinct phenotypes, indolent or highly metastatic. Induction of a proliferative state at distant sites was associated with high levels of the stem-like/progenitor marker, SOX2, and required the upregulation of FMOD, an extracellular matrix component, which modulates tumor-stroma interactions. Functional studies revealed a possible link between FMOD and SOX2; dual FMOD and SOX2 silencing nearly abolished brain metastasis and had a similar effect on distant metastasis to other sites. Our in vitro data suggests that FMOD and SOX2 cooperation plays an important role in tumor vasculogenic mimicry. Furthermore, we found that FMOD and SOX2 functional roles might converge at the activation of transcriptional co-factors YAP and TAZ, possibly via crosstalk with the tumor suppressor Hippo pathway. Finally, high expression of both genes in patient specimens predicted early development of brain metastasis. Thus, our study identifies FMOD and SOX2 cooperation as a novel regulatory mechanism that might be linked functionally to melanoma metastatic competence.

Interaction of Fibromodulin and Myostatin to Regulate Skeletal Muscle Aging: An Opposite Regulation in Muscle Aging, Diabetes, and Intracellular Lipid Accumulation.

The objective of this study was to investigate fibromodulin (FMOD) and myostatin (MSTN) gene expressions during skeletal muscle aging and to understand their involvements in this process. The expressions of genes related to muscle aging (Atrogin 1 and Glb1), diabetes (RAGE and CD163), and lipid accumulation (CD36 and PPARγ) and those of FMOD and MSTN were examined in CTX-injected, aged, MSTN-/-, and high-fat diet (HFD) mice and in C2C12 myoblasts treated with ceramide or grown under adipogenic conditions. Results from CTX-injected mice and gene knockdown experiments in C2C12 cells suggested the involvement of FMOD during muscle regeneration and myoblast proliferation and differentiation. Downregulation of the FMOD gene in MSTN-/- mice, and MSTN upregulation and FMOD downregulation in FMOD and MSTN knockdown C2C12 cells, respectively, during their differentiation, suggested FMOD negatively regulates MSTN gene expression, and MSTN positively regulates FMOD gene expression. The results of our in vivo and in vitro experiments indicate FMOD inhibits muscle aging by negatively regulating MSTN gene expression or by suppressing the action of MSTN protein, and that MSTN promotes muscle aging by positively regulating the expressions of Atrogin1, CD36, and PPARγ genes in muscle.

Characterisation of key proteoglycans in the cranial cruciate ligaments (CCLs) from two dog breeds with different predispositions to CCL disease and rupture.

Cranial cruciate ligament disease and rupture (CCLD/R) is one of the most common orthopaedic conditions in dogs, eventually leading to osteoarthritis of the stifle joint. Certain dog breeds such as the Staffordshire bull terrier have an increased risk of developing CCLD/R. Previous studies into CCLD/R have found that glycosaminoglycan levels were elevated in cranial cruciate ligament (CCL) tissue from high-risk breeds when compared to the CCL from a low-risk breed to CCLD/R. Our objective was to determine specific proteoglycans/glycosaminoglycans in the CCL and to see whether their content was altered in dog breeds with differing predispositions to CCLD/R. Disease-free CCLs from Staffordshire bull terriers (moderate/high-risk to CCLD/R) and Greyhounds (low-risk to CCLD/R) were collected and key proteoglycan/glycosaminoglycans were determined by semi-quantitative Western blotting, quantitative biochemistry, quantitative reverse transcription polymerase chain reaction, and immunohistochemistry. Gene expression of fibromodulin (P = 0.03), aggrecan (P = 0.0003), and chondroitin-6-sulphate stubs (P = 0.01) were significantly increased, and for fibromodulin this correlated with an increase in protein content in Staffordshire bull terriers compared to Greyhound CCLs (P = 0.02). Decorin (P = 0.03) and ADAMTS-4 (P = 0.04) gene expression were significantly increased in Greyhounds compared to Staffordshire bull terrier CCLs. The increase of specific proteoglycans and glycosaminoglycans within the Staffordshire bull terrier CCLs may indicate a response to higher compressive loads, potentially altering their risk to traumatic injury. The higher decorin content in the Greyhound CCLs is essential for maintaining collagen fibril strength, while the increase of ADAMTS-4 indicates a higher rate of turnover helping to regulate normal CCL homeostasis in Greyhounds.

Identification of Lumican and Fibromodulin as Hub Genes Associated with Accumulation of Extracellular Matrix in Diabetic Nephropathy.

INTRODUCTION: Diabetic nephropathy (DN) remains a major cause of end-stage renal disease. The development of novel biomarkers and early diagnosis of DN are of great clinical importance. The goal of this study was to identify hub genes with diagnostic potential for DN by weighted gene co-expression network analysis (WGCNA). METHODS: Gene Expression Omnibus database was searched for microarray data including distinct types of CKD. Gene co-expression network was constructed, and modules specific for DN were identified by WGCNA. Gene ontology (GO) analysis was performed, and the hub genes were screened out within the selected gene modules. In addition, cross-validation was performed in an independent dataset and in samples of renal biopsies with DN and other types of glomerular diseases. RESULTS: Dataset GSE99339 was selected, and a total of 179 microdissected glomeruli samples were analyzed, including DN, normal control, and 7 groups of other glomerular diseases. Twenty-three modules of the total 10,947 genes were grouped by WGCNA, and a module was specifically correlated with DN (r = 0.54, p = 9e-15). GO analysis showed that module genes were mainly enriched in the accumulation of extracellular matrix (ECM). LUM, ELN, FBLN1, MMP2, FBLN5, and FMOD were identified as hub genes. Cross verification showed LUM and FMOD were higher in the DN group and were negatively correlated with estimated glomerular filtration rate (eGFR). In renal biopsies, expression levels of LUM and FMOD were higher in DN than IgA nephropathy, membranous nephropathy, and normal controls. CONCLUSION: By using WGCNA approach, we identified LUM and FMOD related to ECM accumulation and were specific for DN. These 2 genes may represent potential candidate diagnostic biomarkers of DN.

Extracellular matrix components and elasticity regulate mouse vaginal epithelial differentiation induced by mesenchymal cells†.

Oviduct, uterus, and vagina are derived from Müllerian ducts. But only in the vagina, the epithelium differentiates into stratified layers. Organ-specific secreted factors derived from the stroma of a neonatal mouse induce epithelial differentiation in the female reproductive tracts. However, the effects of the components and mechanical property of extracellular matrix (ECM) on the regulation of gene expression in the mesenchymal cells of neonatal stroma and differentiation of epithelium in the female reproductive tracts have been overlooked. In the present study, we have developed a simple 3D neonatal vaginal model using clonal cell lines to study the effect of ECM's components and stiffness on the epithelial stratification. Transcriptome analysis was performed by DNA-microarray to identify the components of ECM involved in the differentiation of vaginal epithelial stratification. The knockdown experiment of the candidate genes relating to vaginal epithelial stratification was focused on fibromodulin (Fmod), a collagen cross-linking protein. FMOD was essential for the expression of Bmp4, which encodes secreted factors to induce the epithelial stratification of vaginal mesenchymal cells. Furthermore, stiffer ECM as a scaffold for epithelial cells is necessary for vaginal epithelial stratification. Therefore, the components and stiffness of ECM are both crucial for the epithelial stratification in the neonatal vagina.

Influence of microcurrent on the modulation of remodelling genes in a wound healing assay.

The literature has shown the beneficial effects of microcurrent (MC) therapy on tissue repair. We investigated if the application of MC at 10 µA/90 s could modulate the expression of remodeling genes transforming growth factor beta (Tgfb), connective tissue growth factor (Ctgf), insulin-like growth factor 1 (Igf1), tenascin C (Tnc), Fibronectin (Fn1), Scleraxis (Scx), Fibromodulin (Fmod) and tenomodulin in NIH/3T3 fibroblasts in a wound healing assay. The cell migration was analyzed between days 0 and 4 in both fibroblasts (F) and fibroblasts + MC (F+MC) groups. On the 4th day, cell viability and gene expression were also analyzed after daily MC application. Higher expression of Ctgf and lower expression of Tnc and Fmod, respectively, were observed in the F+MC group in relation to F group (p < 0.05), and no difference was observed between the groups for the genes Tgfb, Fn1 and Scx. In cell migration, a higher number of cells in the scratch region was observed in group F+MC (p < 0.05) compared to group F on the 4th day, and the cell viability assay showed no difference between the groups. In conclusion, MC therapy at an intensity/time of 10 µA/90 s with 4 daily applications did not affect cell viability, stimulated fibroblasts migration with the involvement of Ctgf, and reduced the Tnc and Fmod expression.

A-kinase anchoring protein 13 interacts with the vitamin D receptor to alter vitamin D-dependent gene activation in uterine leiomyoma cells.

OBJECTIVE: To determine if A-kinase anchoring protein 13 (AKAP13) interacts with the vitamin D receptor (VDR) to alter vitamin D-dependent signaling in fibroid cells. Uterine leiomyomas (fibroids) are characterized by a fibrotic extracellular matrix and are associated with vitamin D deficiency. Treatment with vitamin D (1,25-dihydroxyvitamin D3) reduces fibroid growth and extracellular matrix gene expression. A-kinase anchoring protein 13 is overexpressed in fibroids and interacts with nuclear hormone receptors, but it is not known whether AKAP13 may interact with the VDR to affect vitamin D signaling in fibroids. DESIGN: Laboratory studies. SETTING: Translational science laboratory. INTERVENTION(S): Human immortalized fibroid or myometrial cells were treated with 1,25-hydroxyvitamin D3 (1,25(OH)2D3) and transfected using expression constructs for AKAP13 or AKAP13 mutants, RhoQL, C3 transferase, or small interfering ribonucleic acids (RNAs). MAIN OUTCOME MEASURE(S): Messenger ribonucleic acid (mRNA) levels of AKAP13, fibromodulin, and versican as measured by quantitative real-time polymerase chain reaction. Glutathione S-transferase-binding assays. Vitamin D-dependent gene activation as measured by luciferase assays. RESULT(S): 1,25(OH)2D3 resulted in a significant reduction in mRNA levels encoding AKAP13, versican, and fibromodulin. Small interfering RNA silencing of AKAP13 decreased both fibromodulin and versican mRNA levels. Glutathione S-transferase-binding assays revealed that AKAP13 bound to the VDR through its nuclear receptor interacting region. Cotransfection of AKAP13 and VDR significantly reduced vitamin D-dependent gene activation. RhoA pathway inhibition partially relieved repression of vitamin D-dependent gene activation by AKAP13. CONCLUSION(S): These data suggest that AKAP13 inhibited the vitamin D receptor activation by a mechanism that required, at least in part, RhoA activation.

Canonical and noncanonical TGF-ß signaling regulate fibrous tissue differentiation in the axial skeleton.

Previously, we showed that embryonic deletion of TGF-ß type 2 receptor in mouse sclerotome resulted in defects in fibrous connective tissues in the spine. Here we investigated how TGF-ß regulates expression of fibrous markers: Scleraxis, Fibromodulin and Adamtsl2. We showed that TGF-ß stimulated expression of Scleraxis mRNA by 2 h and Fibromodulin and Adamtsl2 mRNAs by 8 h of treatment. Regulation of Scleraxis by TGF-ß did not require new protein synthesis; however, protein synthesis was required for expression of Fibromodulin and Adamtsl2 indicating the necessity of an intermediate. We subsequently showed Scleraxis was a potential intermediate for TGF-ß-regulated expression of Fibromodulin and Adamtsl2. The canonical effector Smad3 was not necessary for TGF-ß-mediated regulation of Scleraxis. Smad3 was necessary for regulation of Fibromodulin and Adamtsl2, but not sufficient to super-induce expression with TGF-ß treatment. Next, the role of several noncanonical TGF-ß pathways were tested. We found that ERK1/2 was activated by TGF-ß and required to regulate expression of Scleraxis, Fibromodulin, and Adamtsl2. Based on these results, we propose a model in which TGF-ß regulates Scleraxis via ERK1/2 and then Scleraxis and Smad3 cooperate to regulate Fibromodulin and Adamtsl2. These results define a novel signaling mechanism for TGFß-mediated fibrous differentiation in sclerotome.

[Effect of Silencing FMOD on Proliferation and Migration of H322 Cells and Its Mechanism].

OBJECTIVE: To investigate the regulation of fibromodulin (FMOD) on proliferation, adhesion and migration of non-small cell lung cancer cell line H322, and discuss its action mechanism. METHODS: H322 cells were randomly divided into control group, small interfering RNA (siRNA) silencing FMOD ( FMOD siRNA) group and control siRNA (Con siRNA) group. FMOD siRNA and Con siRNA were transfected into H322 cells. The cell viability of each group was detected by CCK-8 method. The adhesion ability of cells was detected by fluorescein diacetate (FDA) fluorescent staining. The cell migration ability was detected by Transwell method. Real time-PCR was used to detect the mRNA expressions of Cyclin D1, intercellular adhesion molecule -1 （ICAM-1）, E-cadherin, FMOD, transforming growth factor-ß (TGF-ß), Smad2, Smad3, Smad4 and Smad7 in cells. The protein expressions of Cyclin D1, ICAM-1, E-cadherin, FMOD, TGF-ß1, Smad2, Smad3, Smad4 and Smad7 were detected by Western blot. RESULTS: Compared with the Con siRNA group, the cell viability, cell adhesion and migration ability of the FMOD siRNA group were decreased, and the difference was statistically significant ( P<0.01). There was no significant difference between the control group and the Con siRNA group. Real time-PCR and Western blot results showed that the mRNA and protein expression levels of Cyclin D1, ICAM-1, TGF-ß1, Smad2, Smad3 and Smad4 were decreased in FMOD siRNA group, compared with Con siRNA group, while the mRNA and protein expression levels of E-cadherin and Smad7 are elevated. CONCLUSION: Silencing of the FMOD gene significantly reduces the proliferation, adhesion and migration of H322 cells, which may be conducted by inhibiting the TGF-ß/Smad signaling pathway.

Fibromodulin is upregulated by oxidative stress through the MAPK/AP-1 pathway to promote pancreatic stellate cell activation.

BACKGROUND/OBJECTIVES: Fibromodulin (FMOD) expression in chronic pancreatitis (CP) tissues and its effect on PSC was unknown. Our aim was to investigate the role of FMOD in regulating PSC profibrogenic phenotype and the molecular mechanism of CP. METHODS: Rat CP models were induced by dibutyltin dichloride. Pancreatic fibrosis was evaluated by Sirius Red staining. The expression of FMOD and α-SMA was measured, the correlation between FMOD expression and fibrosis was investigated in CP models and CP patients. The effects of FMOD on PSCs were examined by CCK-8 and migration assays. We investigated the mechanisms underlying FMOD expression using MND and a MAPK pathway inhibitor. Luciferase reporter and chromatin immunoprecipitation assays were used to investigate the effects of AP-1 on FMOD expression. RESULTS: Sirius Red staining revealed high collagen deposition in model rats. Higher expression of FMOD and α-SMA was observed in fibrotic tissues, and the expression of FMOD was correlated with that of α-SMA and the areas of Sirius Red staining. Upregulation of FMOD increased the expression of collagen I and α-SMA and the proliferation and migration of PSCs. MND induced FMOD and α-SMA expression, and knockdown of FMOD abated α-SMA expression. ERK and JNK inhibitors attenuated FMOD expression as induced by MND. AP-1 upregulated the expression of FMOD. AP-1 binds to the FMOD promoter and transcriptionally regulates FMOD expression. CONCLUSION: FMOD levels are upregulated in fibrosis tissues in CP and it is a critical downstream mediator of oxidative stress. FMOD induces PSC activation and maintains the fibrosis phenotype of PSCs.

CDKN2B upregulation prevents teratoma formation in multipotent fibromodulin-reprogrammed cells.

Tumorigenicity is a well-documented risk to overcome for pluripotent or multipotent cell applications in regenerative medicine. To address the emerging demand for safe cell sources in tissue regeneration, we established a novel, protein-based reprogramming method that does not require genome integration or oncogene activation to yield multipotent fibromodulin (FMOD)-reprogrammed (FReP) cells from dermal fibroblasts. When compared with induced pluripotent stem cells (iPSCs), FReP cells exhibited a superior capability for bone and skeletal muscle regeneration with markedly less tumorigenic risk. Moreover, we showed that the decreased tumorigenicity of FReP cells was directly related to an upregulation of cyclin-dependent kinase inhibitor 2B (CDKN2B) expression during the FMOD reprogramming process. Indeed, sustained suppression of CDKN2B resulted in tumorigenic, pluripotent FReP cells that formed teratomas in vivo that were indistinguishable from iPSC-derived teratomas. These results highlight the pivotal role of CDKN2B in cell fate determination and tumorigenic regulation and reveal an alternative pluripotent/multipotent cell reprogramming strategy that solely uses FMOD protein.

Transcriptomics Analysis Reveals New Insights into the Roles of Notch1 Signaling on Macrophage Polarization.

Naïve macrophages (Mφ) polarize in response to various environmental cues to a spectrum of cells that have distinct biological functions. The extreme ends of the spectrum are classified as M1 and M2 macrophages. Previously, we demonstrated that Notch1 deficiency promotes Tgf-ß2 dependent M2-polarization in a mouse model of abdominal aortic aneurysm. The present studies aimed to characterize the unique set of genes regulated by Notch1 signaling in macrophage polarization. Bone marrow derived macrophages isolated from WT or Notch1+/- mice (n = 12) were differentiated to Mφ, M1 or M2-phenotypes by 24 h exposure to vehicle, LPS/IFN-γ or IL4/IL13 respectively and total RNA was subjected to RNA-Sequencing (n = 3). Bioinformatics analyses demonstrated that Notch1 haploinsufficiency downregulated the expression of 262 genes at baseline level, 307 genes with LPS/IFN-γ and 254 genes with IL4/IL13 treatment. Among these, the most unique genes downregulated by Notch1 haploinsufficiency included fibromodulin (Fmod), caspase-4, Has1, Col1a1, Alpl and Igf. Pathway analysis demonstrated that extracellular matrix, macrophage polarization and osteogenesis were the major pathways affected by Notch1 haploinsufficiency. Gain and loss-of-function studies established a strong correlation between Notch1 haploinsufficiency and Fmod in regulating Tgf-ß signaling. Collectively, our studies suggest that Notch1 haploinsufficiency increases M2 polarization through these newly identified genes.

Long noncoding RNA Bmncr regulates mesenchymal stem cell fate during skeletal aging.

Bone marrow mesenchymal stem cells (BMSCs) exhibit an age-related lineage switch between osteogenic and adipogenic fates, which contributes to bone loss and adiposity. Here we identified a long noncoding RNA, Bmncr, which regulated the fate of BMSCs during aging. Mice depleted of Bmncr (Bmncr-KO) showed decreased bone mass and increased bone marrow adiposity, whereas transgenic overexpression of Bmncr (Bmncr-Tg) alleviated bone loss and bone marrow fat accumulation. Bmncr regulated the osteogenic niche of BMSCs by maintaining extracellular matrix protein fibromodulin (FMOD) and activation of the BMP2 pathway. Bmncr affected local 3D chromatin structure and transcription of Fmod. The absence of Fmod modified the bone phenotype of Bmncr-Tg mice. Further analysis revealed that Bmncr would serve as a scaffold to facilitate the interaction of TAZ and ABL, and thus facilitate the assembly of the TAZ and RUNX2/PPARG transcriptional complex, promoting osteogenesis and inhibiting adipogenesis. Adeno-associated viral-mediated overexpression of Taz in osteoprogenitors alleviated bone loss and marrow fat accumulation in Bmncr-KO mice. Furthermore, restoring BMNCR levels in human BMSCs reversed the age-related switch between osteoblast and adipocyte differentiation. Our findings indicate that Bmncr is a key regulator of the age-related osteogenic niche alteration and cell fate switch of BMSCs.

Glial Cell Line-Derived Neurotrophic Factor (GDNF) Promotes Angiogenesis through the Demethylation of the Fibromodulin (FMOD) Promoter in Glioblastoma.

BACKGROUND Angiogenesis plays an important role in the progression of glioblastoma, with a high degree of malignancy. Previous studies have proved that glial cell line-derived neurotrophic factor (GDNF) and fibromodulin (FMOD) are strongly expressed in human glioblastoma. The purpose of this study was to explore the roles of GDNF and FMOD in angiogenesis and the molecular mechanisms underlying these roles in human glioblastoma. MATERIAL AND METHODS The effects of GDNF on the expression and secretion of vascular endothelial growth factor (VEGF) in human glioblastoma cell line U251 and angiogenesis in human umbilical vein endothelial cells (HUVECs) were investigated. The molecular mechanism of GDNF-induced expression of FMOD was explored. The roles of FMOD in GDNF-induced expression and secretion of VEGF and angiogenesis were also examined. RESULTS In the present study, we showed that GDNF promoted the expression and secretion of VEGF in U251 cells. VEGF mediated GDNF-induced angiogenesis in human glioblastoma. In addition, GDNF significantly upregulated the expression of FMOD in U251 cells. Mechanistically, the results of luciferase reporter assay and methylation-specific PCR (MSP) demonstrated that GDNF facilitated the demethylation of the FMOD promoter. More importantly, we found that FMOD acted as an important mediator in VEGF expression and angiogenesis induced by GDNF in human glioblastoma. CONCLUSIONS Collectively, our data show that GDNF promotes angiogenesis through demethylation of the FMOD promoter in human glioblastoma, indicating that GDNF and FMOD may be potential therapeutic targets for glioblastoma.

Downregulated microRNA-340-5p promotes proliferation and inhibits apoptosis of chondrocytes in osteoarthritis mice through inhibiting the extracellular signal-regulated kinase signaling pathway by negatively targeting the FMOD gene.

PURPOSE: Osteoarthritis (OA) is a degenerative joint disease that leads to the destruction of joint function. The aim of this study is to investigate the effects of microRNA-340-5p (miR-340-5p) and its target gene, FMOD, on the proliferation and apoptosis of chondrocytes in mice with OA through the extracellular signal-regulated kinase (ERK) signaling pathway. MATERIALS: Twenty healthy C57BL/6J mice aged 15 months with a weight of 50 ± 2 g were selected. Ten mice were treated using a unilateral knee anterior cruciate ligament transection as well as a medial meniscectomy to establish the OA model. Besides, another 10 mice were used as the control group. METHODS: A reverse transcription quantitative polymerase chain reaction and Western blot analysis methods were used to examine the expressions of related genes in cells of each group. A 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl tetrazolium bromide assay and flow cytometry were also conducted to evaluate the cell function after transfection had been completed. RESULTS: The expressions of fibromodulin (FMOD), type II collagen (Col II), B-cell lymphoma-2 (Bcl-2), sex-determining region of Y chromosome (SRY)-related high-mobility group-box gene 9 (Sox9), and proliferating cell nuclear antigen (PCNA) were decreased, whereas the expressions of miR-340-5p, runt-related transcription factor-2 (Runx2), Bcl-2-associated X protein (Bax), and ERK1/2 were elevated in the OA mice. Downregulation of miR-340-5p and upregulation of FMOD decreased the expressions of Runx2, Bax, and ERK1/2, and cell apoptosis of chondrocytes, and increased the expressions of FMOD, Col II, Bcl-2, Sox9, and PCNA, and cell proliferation. CONCLUSION: This study suggests that downregulation of miR-340-5p plays a role in promoting cell proliferation and suppressing cell apoptosis of chondrocytes in OA mice through inhibition of the ERK signaling pathway via the FMOD gene.

The extracellular matrix proteoglycan fibromodulin is upregulated in clinical and experimental heart failure and affects cardiac remodeling.

Pressure overload of the heart leads to cardiac remodeling that may progress into heart failure, a common, morbid and mortal condition. Increased mechanistic insight into remodeling is instrumental for development of novel heart failure treatment. Cardiac remodeling comprises cardiomyocyte hypertrophic growth, extracellular matrix alterations including fibrosis, and inflammation. Fibromodulin is a small leucine-rich proteoglycan that regulates collagen fibrillogenesis. Fibromodulin is expressed in the cardiac extracellular matrix, however its role in the heart remains largely unknown. We investigated fibromodulin levels in myocardial biopsies from heart failure patients and mice, subjected fibromodulin knock-out (FMOD-KO) mice to pressure overload by aortic banding, and overexpressed fibromodulin in cultured cardiomyocytes and cardiac fibroblasts using adenovirus. Fibromodulin was 3-10-fold upregulated in hearts of heart failure patients and mice. Both cardiomyocytes and cardiac fibroblasts expressed fibromodulin, and its expression was increased by pro-inflammatory stimuli. Without stress, FMOD-KO mice showed no cardiac phenotype. Upon aortic banding, left ventricles of FMOD-KO mice developed mildly exacerbated hypertrophic remodeling compared to wild-type mice, with increased cardiomyocyte size and altered infiltration of leukocytes. There were no differences in mortality, left ventricle dilatation, dysfunction or expression of heart failure markers. Although collagen amount and cross-linking were comparable in FMOD-KO and wild-type, overexpression of fibromodulin in cardiac fibroblasts in vitro decreased their migratory capacity and expression of fibrosis-associated molecules, i.e. the collagen-cross linking enzyme lysyl oxidase, transglutaminase 2 and periostin. In conclusion, despite a robust fibromodulin upregulation in clinical and experimental heart failure, FMOD-KO mice showed a relatively mild hypertrophic phenotype. In cultured cardiac fibroblasts, fibromodulin has anti-fibrotic effects.

Fibromodulin reduces scar size and increases scar tensile strength in normal and excessive-mechanical-loading porcine cutaneous wounds.

Hypertrophic scarring is a major postoperative complication which leads to severe disfigurement and dysfunction in patients and usually requires multiple surgical revisions due to its high recurrence rates. Excessive-mechanical-loading across wounds is an important initiator of hypertrophic scarring formation. In this study, we demonstrate that intradermal administration of a single extracellular matrix (ECM) molecule-fibromodulin (FMOD) protein-can significantly reduce scar size, increase tensile strength, and improve dermal collagen architecture organization in the normal and even excessive-mechanical-loading red Duroc pig wound models. Since pig skin is recognized by the Food and Drug Administration as the closest animal equivalent to human skin, and because red Duroc pigs show scarring that closely resembles human proliferative scarring and hypertrophic scarring, FMOD-based technologies hold high translational potential and applicability to human patients suffering from scarring-especially hypertrophic scarring.

In vivo effect of opticin deficiency in cartilage in a surgically induced mouse model of osteoarthritis.

The SLRP opticin (OPTC) has been demonstrated to be produced and degraded in osteoarthritic (OA) human cartilage. Here, we investigated the in vivo effect of OPTC deficiency in OA cartilage. OA was induced in 10-week-old Optc -/- and Optc +/+ mice. Ten weeks post-surgery, cartilage was processed for histology and immunohistochemistry. SLRP expression was determined in non-operated mouse cartilage. OA Optc -/- demonstrated significant protection against cartilage degradation. Data revealed that in non-operated Optc -/- cartilage, expression of SLRPs lumican and epiphycan was up-regulated at day 3 and in 10-week-olds (p ≤ 0.039), and fibromodulin down-regulated in 10-week-olds (p = 0.001). Immunohistochemistry of OA mice showed a similar pattern. In OA Optc -/- cartilage, markers of degradation and complement factors were all down-regulated (p ≤ 0.038). In OA Optc -/- cartilage, collagen fibers were thinner and better organized (p = 0.038) than in OA Optc +/+ cartilage. The protective effect of OPTC deficiency during OA results from an overexpression of lumican and epiphycan, known to bind and protect collagen fibers, and a decrease in fibromodulin, contributing to a reduction in the complement activation/inflammatory process. This work suggests that the evaluation of the composition of the different SLRPs in OA cartilage could be applied as a new tool for OA prognosis classification.