Knockdown of FBLN2 suppresses TGF-β1-induced MRC-5 cell migration and fibrosis by downregulating VTN

Targeting extracellular matrix components to attenuate microglia neuroinflammation: A study of fibulin-2 and CSPGs in a model of multiple sclerosis

The extracellular matrix (ECM) plays an important role in the central nervous system (CNS), shaping tissue structure and functions as well as contributing to the pathology of chronic diseases such as multiple sclerosis (MS). ECM components, including fibulin-2 (FBLN2) and chondroitin sulfate proteoglycans (CSPGs), may impact neuroinflammation and remyelination. We investigated the capacity of FBLN2 to modulate immune responses and evaluated its interaction with CSPGs in experimental autoimmune encephalomyelitis (EAE), a common model for MS. We show that FBLN2 deficiency in EAE mice reduced microglial pro-inflammatory activity, while effects on monocyte-derived macrophages and border-associated macrophages were less pronounced. Targeting FBLN2 and CSPGs individually, using FBLN2-/- mice and the CSPG-synthesis inhibitor difluorosamine (DIF), respectively, enhanced recovery of disability and reduced neuroinflammation in EAE mice. However, their combined targeting did not result in additive therapeutic effects beyond either alone. This study underscores the complex regulatory roles of ECM components on neuroinflammation and provides insights into potential therapeutic strategies for neuroinflammatory diseases.

OM85 ameliorates bleomycin-induced pulmonary fibrosis in mice by inhibiting Notch expression and modulating the IFN-γ/IL-4 ratio

Th1/Th2 balances may play a vital role in the processes of inflammation and fibrosis. The Th1/Th2 paradigm can be evaluated by representing IFN-γ for Th1 and IL-4 for Th2. OM-85 BV encouraged preferential development of the Th1-type immunity characterized by amplified IFN-γ and decreased IL-4 production. This study aimed to evaluate the inhibitory effect of OM85 on bleomycin (BLM)-induced pulmonary fibrosis in C57 and its possible mechanisms. In vitro experiments demonstrated that OM85 exhibited no significant toxicity to HELF cells. OM-85 inhibited the TGF-β1-induced protein expression of Notch1 and Hes1 and reduced the fibrosis-related marker profiles, such as collagen I, collagen III, fibronectin, P21, and α-SMA, following TGF-β1 treatment of these cells. Immunofluorescence also revealed that OM-85 decreased the expression of α-SMA induced by TGF-β1 in HELF cells. In the vivo experiments, a pulmonary fibrosis model was established by administering three intratracheal doses of BLM (1 mg/kg). The BLM-OM85 group was exposed to an aerosol containing 10.5 mg of OM-85 dissolved in 10 mL of sterile PBS on days 42, 44, 46, 49, 51, and 53. BLM-induced pulmonary fibrosis, leading to increased levels of lung hydroxyproline, total cell count, macrophages, neutrophils, lymphocytes, and the expression of TGF-β1 as well as Notch1 and Hes1 in lung tissue, along with fibrosis-associated proteins such as collagen I, collagen III, fibronectin, P21, and α-SMA. Additionally, the Th1 response was suppressed, as evidenced by decreased IFN-γ in the bronchoalveolar lavage fluid (BALF), while the Th2 response was amplified, marked by increased IL-4 levels in BALF. Moreover, morphological assessments showed that BLM caused increased Ashcroft scores, relative collagen content, and an expanded damaged area, as well as an increased optical density (OD) of collagen I. The administration of OM-85 significantly mitigated these effects. These findings suggest that OM-85 holds therapeutic potential for BLM-induced pulmonary fibrosis in female C57 mice, partly due to the inhibition of Notch1 and Hes1 expression and the modulation of the IFN-γ/IL-4 ratio.

C2C12 myoblasts differentiate into myofibroblasts via the TGF-β1 signaling pathway mediated by Fibulin2

Myoblasts play a critical role in the regeneration of skeletal muscle following injury. It has been reported that local elevation of transforming growth factor-β1 (TGF-β1) after skeletal muscle injury induces differentiation of myoblasts into myofibroblasts. However, the mechanisms underlying this differentiation process remain incompletely understood. In this study, we found that Fibulin2 expression significantly increases in myoblasts in response to TGF-β1 stimulation. Elevated Fibulin2 levels enhance the expression of fibrotic markers. Conversely, downregulation of Fibulin2 in myoblasts inhibits the upregulation of fibrotic markers induced by TGF-β1 stimulation. Extracellular secretion of Fibulin2 activates the TGF-β1-Smad2 pathway, thereby promoting the upregulation of fibrotic markers. Hence, Fibulin2 and TGF-β1 form a positive feedback loop that facilitates differentiation of myoblasts into myofibroblasts.

Fetal Skin Wound Healing: Key Extracellular Matrix Components and Regulators in Scarless Healing

Fetal skin at early gestational stage is able to regenerate and heal rapidly after wounding. The exact mechanisms and molecular pathways involved in this process are however still largely unknown. The numerous differences in the skin of the early fetus versus skin in later developmental stages might provide clues for the mechanisms of scarless healing. This review summarizes the differences between mammalian fetal skin and the skin at later developmental phases in healthy and wounded conditions, focusing on extracellular matrix components, which are crucial factors in the microenvironment that direct cells and tissue functions and hence the wound healing process.

Metabolic and Proteomic Profiling of Coronary Microvascular Dysfunction: Insights from Rat Models

Coronary microvascular dysfunction (CMD) represents a principal etiological factor in ischemic heart disease. Nonetheless, a considerable subset of CMD patients experiences diagnostic delays attributable to the inadequacy of current diagnostic methodologies; which in turn results in deferred therapeutic interventions and elevated mortality rates. This study seeks to elucidate the distinct metabolic profile associated with CMD in rat models and to identify specific diagnostic markers that could enhance the diagnostic accuracy for CMD. In this study, 18 Wistar rats were randomly allocated into two groups: the sham group and the CMD group. The CMD group received injections of embolic microspheres into the left ventricle to establish a CMD model. Subsequently, non-targeted metabolomics and acetylated proteomics analyses were conducted. Machine-learning techniques were employed to identify the co-diagnostic markers of the disease. This study identified 53 key proteins through differential expression proteins (DEPs) and modular proteins analysis. Subsequently, four core proteins (Emc1; Ank1; Fbln2; and Hp) were determined as diagnostic markers for CMD using lasso regression, support vector machine, and random forest methodologies. Receiver operating characteristic curve analysis further demonstrated robust diagnostic performance. Gene ontology and kyoto encyclopedia of genes and genome enrichment analyses indicated that the DEPs were predominantly associated with metabolic pathways. Ultimately, the integrative analysis of proteomics and metabolomics suggested that the central metabolic mechanism underlying CMD pathogenesis may be linked to the tricarboxylic acid cycle. This study revealed specific changes in the proteomic and metabolic profiles of CMD rats and identified four diagnostic markers, which are proteins and metabolites that could be potential diagnostic biomarkers for CMD.

Analysis of joint protein expression profile in anterior disc displacement of TMJ with or without OA

OBJECTIVE

Anterior disc displacement (ADD) is a common clinical issue and may cause osteoarthritis (OA). However, the research of protein changes in synovial fluid as disease development marker and potential treatment clue is still insufficient.

MATERIALS AND METHODS

We conducted the high-resolution mass spectrometry (MS) of synovial fluid collected from 60 patients with normal disk position to ADD and ADD with osteoarthritis (OA). The proteins with significant changes among the 3 groups were analyzed by biological information and further validated by in primary rat condyle chondrocytes and OA animal model.

RESULTS

FGL2, THBS4, TNC, FN1, OMD etc. were significantly increased in ADD without OA (p < 0.05), which reflected the active extracellular matrix and collagen metabolism. FGFR1, FBLN2, GRB2 etc. were significantly increased in ADD with OA group (p < 0.05), which revealed an association with apoptosis and ferroptosis. Proteins such as P4HB, CBLN4, FHL1, VIM continuously increase in the whole disease progress (p < 0.05). Both the in vitro and in vivo results are consistent with protein changes detected in MS profile.

CONCLUSION

This study firstly provides the expression changes of proteins from normal disc condyle relationship toward ADD with OA, which can be selected and studied further as disease progress marker and potential treatment targets.

Lung Inflammatory Phenotype in Mice Deficient in Fibulin-2 and ADAMTS-12

Interaction between extracellular matrix (ECM) components plays an important role in the regulation of cellular behavior and hence in tissue function. Consequently, characterization of new interactions within ECM opens the possibility of studying not only the functional but also the pathological consequences derived from those interactions. We have previously described the interaction between fibulin2 and ADAMTS-12 in vitro and the effects of that interaction using cellular models of cancer. Now, we generate a mouse deficient in both ECM components and evaluate functional consequences of their absence using different cancer and inflammation murine models. The main findings indicate that mice deficient in both fibulin2 and ADAMTS12 markedly increase the development of lung tumors following intraperitoneal urethane injections. Moreover, inflammatory phenotype is exacerbated in the lung after LPS treatment as can be inferred from the accumulation of active immune cells in lung parenchyma. Overall, our results suggest that protective effects in cancer or inflammation shown by fibulin2 and ADAMTS12 as interactive partners in vitro are also shown in a more realistic in vivo context.