Induction of corneal myofibroblasts by lens-derived transforming growth factor beta1 (TGFbeta1): a transgenic mouse model

Comparison of ovarian preservation versus oophorectomy on fertility outcomes in patients with endometriosis post-laparoscopic surgery: A prospective study

BACKGROUND

Endometriosis is a chronic inflammatory condition affecting a significant proportion of women of reproductive age. Although laparoscopic surgery is commonly the preferred treatment, the decision to preserve or remove the ovaries remains controversial. Previous studies have yielded inconsistent results regarding the impact of ovarian preservation vs oophorectomy on fertility outcomes and disease recurrence. This prospective study aimed to address this knowledge gap by comparing the effects of these surgical approaches on spontaneous pregnancy rates, time to pregnancy, recurrence rates, and postoperative pain in patients with endometriosis.

AIM

To compare the reproductive outcomes and recurrence rates between ovarian preservation and oophorectomy in women undergoing laparoscopic surgery for endometriosis.

METHODS

This study was conducted at a tertiary care hospital between January 2019 and December 2023. A total of 312 women aged 18 to 40 years, diagnosed with endometriosis and undergoing laparoscopic surgery, were included. The patients were categorized into the ovarian preservation group (n = 204) and the oophorectomy group (n = 108). The primary outcome measure was the achievement of spontaneous pregnancy within 24 months post-surgery. Secondary outcomes included time to spontaneous pregnancy, recurrence rates, and postoperative pain scores.

RESULTS

The ovarian preservation group exhibited a significantly higher spontaneous pregnancy rate than that in the oophorectomy group (43.6% vs 28.7%, P = 0.006). Moreover, the median time to spontaneous pregnancy was shorter in the ovarian preservation group (8.2 months vs 11.4 months, P = 0.018). Nonetheless, endometriosis recurrence was more prevalent in the ovarian preservation group (22.1% vs 11.1%, P = 0.014). The postoperative pain scores demonstrated similar improvements in both groups, with no significant differences observed. Subgroup analyses indicated that the benefit of ovarian preservation on spontaneous pregnancy rates was more evident among younger women (≤ 35 years) and those with advanced-stage endometriosis.

CONCLUSION

Ovarian preservation is associated with a high spontaneous pregnancy rate and a short time to pregnancy. However, because of the increased risk of recurrence, the decision should be based on age, fertility aspirations, and disease severity.

Cell derived matrices from bovine corneal endothelial cells as a model to study cellular dysfunction

PURPOSE

Fuchs endothelial corneal dystrophy (FECD) is a progressive corneal disease that impacts the structure and stiffness of the Descemet's membrane (DM), the substratum for corneal endothelial cells (CECs). These structural alterations of the DM could contribute to the loss of the CECs resulting in corneal edema and blindness. Oxidative stress and transforming growth factor-β (TGF-β) pathways have been implicated in endothelial cell loss and endothelial to mesenchymal transition of CECs in FECD. Ascorbic acid (AA) is found at high concentrations in FECD and its impact on CEC survival has been investigated. However, how TGF-β and AA effect the composition and rigidity of the CEC's matrix remains unknown.

METHODS

In this study, we investigated the effect of AA, TGF-β1 and TGF-β3 on the deposition, ultrastructure, stiffness, and composition of the extracellular matrix (ECM) secreted by primary bovine corneal endothelial cells (BCECs).

RESULTS

Immunofluorescence and electron microscopy post-decellularization demonstrated a robust deposition and distinct structure of ECM in response to treatments. AFM measurements showed that the modulus of the matrix in BCECs treated with TGF-β1 and TGF-β3 was significantly lower than the controls. There was no difference in the stiffness of the matrix between the AA-treated cell and controls. Gene Ontology analysis of the proteomics results revealed that AA modulates the oxidative stress pathway in the matrix while TGF-β induces the expression of matrix proteins collagen IV, laminin, and lysyl oxidase homolog 1.

CONCLUSIONS

Molecular pathways identified in this study demonstrate the differential role of soluble factors in the pathogenesis of FECD.

Interleukin-1 and Transforming Growth Factor Beta: Commonly Opposing, but Sometimes Supporting, Master Regulators of the Corneal Wound Healing Response to Injury

Purpose

Interleukin (IL)-1α/IL-1β and transforming growth factor (TGF)β1/TGFβ2 have both been promoted as “master regulators” of the corneal wound healing response due to the large number of processes each regulates after injury or infection. The purpose of this review is to highlight the interactions between these systems in regulating corneal wound healing.

Methods

We conducted a systematic review of the literature.

Results

Both regulator pairs bind to receptors expressed on keratocytes, corneal fibroblasts, and myofibroblasts, as well as bone marrow-derived cells that include fibrocytes. IL-1α and IL-1β modulate healing functions, such as keratocyte apoptosis, chemokine production by corneal fibroblasts, hepatocyte growth factor (HGF), and keratinocyte growth factor (KGF) production by keratocytes and corneal fibroblasts, expression of metalloproteinases and collagenases by corneal fibroblasts, and myofibroblast apoptosis. TGFβ1 and TGFβ2 stimulate the development of myofibroblasts from keratocyte and fibrocyte progenitor cells, and adequate stromal levels are requisite for the persistence of myofibroblasts. Conversely, TGFβ3, although it functions via the same TGF beta I and II receptors, may, at least in some circumstances, play a more antifibrotic role—although it also upregulates the expression of many profibrotic genes.

Conclusions

The overall effects of these two growth factor-cytokine-receptor systems in controlling the corneal wound healing response must be coordinated during the wound healing response to injury or infection. The activities of both systems must be downregulated in coordinated fashion to terminate the response to injury and eliminate fibrosis.

Translational Relevance

A better standing of the IL-1 and TGFβ systems will likely lead to better approaches to control the excessive healing response to infections and injuries leading to scarring corneal fibrosis.

A Systematic Review on Cornea Epithelial-Stromal Homeostasis

INTRODUCTION

This review aims to summarise the role of different cells, genes, proteins and lipid in regulating cornea epithelial-stromal homeostasis.

METHODS

We performed an Entrez PubMed literature search using keywords "human," "cornea," "epithelial," "stromal," "homeostasis," "fibrosis response," and "pathogenesis" on 24th of September 2019, resulting in 35 papers, of which 18 were chosen after filtering for "English language" and "published within 10 years" as well as curation for relevance by the authors.

RESULTS

The 18 selected papers showed that corneal epithelial cells, fibroblasts and telocytes, together with genes such as Klf4, Pax6 and Id found in the cells, play important roles in achieving homeostasis to maintain corneal integrity and transparency. Proteins classified as pro-fibrotic ligands and anti-fibrotic ligands are responsible for regulating cornea stromal fibrosis and extracellular matrix deposition, thus regulators of scar formation during wound healing. Anti-inflammatory ligands and wound repairing ligands are critical in eliciting protective inflammation and promoting epithelial healing, respectively. Protein receptors located on cellular membrane play a role in maintaining intercellular connections as well as corneal hydration.

DISCUSSION/CONCLUSION

These studies prompt development of novel therapeutic strategies such as tear drops or ointments that target certain proteins to maintain corneal homeostasis. However, more in vitro and in vivo studies are required to prove the effectiveness of exogenous administration of molecules in improving healing outcome. Hence, future investigations of the molecular pathways highlighted in this review will reveal novel therapeutic tools such as gene or cell therapy to treat corneal diseases.

A Novel CD147 Inhibitor, SP-8356, Attenuates Pathological Fibrosis in Alkali-Burned Rat Cornea

The corneal fibrotic responses to corneal damage often lead to severe corneal opacification thereby resulting in severe visual impairment or even blindness. The persistence of corneal opacity depends heavily on the activity of corneal myofibroblast. Myofibroblasts are opaque and synthesize a disorganized extracellular matrix (ECM) and thus promoting opacification. Cluster of differentiation 147 (CD147), a member of the immunoglobulin superfamily, is known to play important roles in the differentiation process from fibroblast to myofibroblast in damaged cornea and may therefore be an effective target for treatment of corneal opacity. Here, we examined the therapeutic efficacy of novel CD147 inhibiting verbenone derivative SP-8356 ((1S,5R)-4-(3,4-dihydroxy-5-methoxystyryl)-6,6-dimethylbicyclo[3.1.1]hept-3-en-2-one) on corneal fibrosis. Topical SP-8356 significantly reduced corneal haze and fibrosis in the alkali-burned cornea. In detail, SP-8356 inhibited both alpha-smooth muscle actin (α-SMA) expressing myofibroblast and its ECM-related products, such as matrix-metalloproteinase-9 and collagen type III and IV. Similar to SP-8356, topical corticosteroid (prednisolone acetate, PA) also reduced the ECM-related products and opacification. However, prednisolone acetate failed to decrease the population of α-SMA-positive corneal myofibroblast. In conclusion, SP-8356 is capable enough to prevent corneal haze by preventing pathological fibrosis after severe corneal damage. Therefore, SP-8356 could be a potentially promising therapeutic drug for corneal fibrosis.

Corneal chemical burn treatment through a delivery system consisting of TGF-β1 siRNA: in vitro and in vivo

Chemical burns are major causes of corneal blindness. Transforming growth factor beta-1 (TGFβ₁) plays an important role in induction of corneal inflammation-related-fibrosis leading to the blindness. Here, a topical delivery system consisting anti-fibrotic TGF-β₁ siRNA, an inflammatory suppressing gene, was designed for treatment of corneal injuries. TGF-β₁ siRNA loaded in nanoparticles (NPs) made up of polyethyleneimine polymer demonstrated high fibroblast transfection efficiency. Moreover, TGF-β₁ and PDGF genes and ECM deposition were suppressed in isolated human corneal fibroblasts. NPs inhibited proliferation and transformation of fibroblasts to myofibroblasts by S-phase arrest and α-SMA suppression in vitro, respectively. The mentioned finding was also confirmed in vivo, addressing high wound-healing potential of prepared gene delivery system which was superior to conventional betamethasone treatment. Besides, CD4⁺ and α-SMA antibody staining showed inhibited angiogenesis and myofibroblast accumulation in treated corneas. This study opens a new way for treating corneal fibrosis through topical siRNA delivery.

Assessment of Corneal Stromal Remodeling and Regeneration after Photorefractive Keratectomy

This study utilizes high resolution multi-dimensional imaging to identify temporal and spatial changes in cell/extracellular matrix (ECM) patterning mediating cell migration, fibrosis, remodeling and regeneration during wound healing. Photorefractive keratectomy (PRK) was performed on rabbits. In some cases, 5([4,6-dichlorotriazin-2yl]-amino)fluorescein (DTAF) was applied immediately after surgery to differentiate native vs. cell-secreted collagen. Corneas were assessed 3–180 days postoperatively using in vivo confocal microscopy, and cell/ECM patterning was evaluated in situ using multiphoton and second harmonic generation (SHG) imaging. 7 days post-PRK, migrating fibroblasts below the ablation site were co-aligned with the stromal lamellae. At day 21, randomly patterned myofibroblasts developed on top of the ablation site; whereas cells underneath were elongated, co-aligned with collagen, and lacked stress fibers. Over time, fibrotic tissue was remodeled into more transparent stromal lamellae. By day 180, stromal thickness was almost completely restored. Stromal regrowth occurred primarily below the ablation interface, and was characterized by co-localization of gaps in DTAF labeling with elongated cells and SHG collagen signaling. Punctate F-actin labeling was detected along cells co-aligned with DTAF and non-DTAF labeled collagen, suggesting cell-ECM interactions. Overall, collagen lamellae appear to provide a template for fibroblast patterning during wound healing that mediates stromal repopulation, regeneration and remodeling.

Effect of TGF-β1 on the Migration and Recruitment of Mesenchymal Stem Cells after Vascular Balloon Injury: Involvement of Matrix Metalloproteinase-14

Restenosis or occlusion after vascular procedures is ascribed to intimal hyperplasia. Transforming growth factor (TGF)-β1 is involved in recruitment of mesenchymal stem cells (MSCs) following arterial injury, and its release from latent TGF-binding protein by matrix metalloproteinase (MMP)-14-induced proteolysis contributes to neointima formation. However, the relationship between MMP-14 and TGF-β1 activation in restenosis is unknown. This study investigated the relationship using a rat model of balloon-induced injury. Rats were assigned to vehicle-, SB431542 (SB)-, or recombinant human (rh)TGF-β1-treated groups and examined at various time points after balloon-induced injury for expression of TGF-β1/Smad signalling pathway components, MMP-14 and MSCs markers including Nestin, CD29, and Sca1⁺CD29⁺CD11b/c⁻CD45⁻. Intimal hyperplasia was reduced in SB- and rhTGF-β1-treated rats. The expression of TGF-β1, TGF-β1RI, and Smad2/3 was decreased, but the levels of phosphorylated Smad2/3 were higher in SB-treated rats than vehicle-treated after 7 days to 14 days. rhTGF-β1 administration decreased the expression of TGF-β1/Smad pathway proteins, except for TGF-β1RI. Nestin and CD29 expression and the number of Sca1⁺CD29⁺CD11b⁻CD45⁻ cells were reduced, whereas MMP-14 expression was increased after SB431542 and rhTGF-β1 administration. These results suggest that TGF-β1/Smad signalling and MMP-14 act to recruit MSCs which differentiate to vascular smooth muscle cells and mesenchymal-like cells that participate in arterial repair/remodelling.

Sphere-forming cells from peripheral cornea demonstrate a wound-healing response to injury

The cornea is the initial refractive interface of the eye. Its transparency is critical for clear vision and is maintained by stem cells which also act to repair injury inflicted by external insults, such as chemical and thermal burns. Damage to the epithelium compromises its clarity and can reduce or eliminate the stem cell population, diminishing the ability for self-repair. This condition has been termed "limbal stem cell deficiency"; severe cases can lead to corneal blindness. Sphere-forming cells isolated from peripheral cornea are a potential source of stem and progenitor cells for corneal repair. When provided with appropriate substrate, these spheres have the ability to adhere and for cells to migrate outwards akin to that of their natural environment. Direct compression injury and remote scratch injury experiments were conducted on the sphere cells to gauge their wound healing capacity. Measures of proliferation, differentiation, and migration were assessed by immunohistochemical detection of EdU incorporation, α-smooth muscle actin expression and confocal image analysis, respectively. Both modes of injury were observed to draw responses from the spheres indicating wound healing processes. Direct wounding induced a rapid, but transient increase in expression of α-SMA, a marker of corneal myofibroblasts, followed by a proliferative and increasing migratory response. The spheres were observed to respond to remote injury as entire units, with no directional response seen for targeted repair over the scratch injury area. These results give strength to the future use of these peripheral corneal spheres as transplantable units for the regeneration of corneal tissue.

Notch signal regulates corneal endothelial-to-mesenchymal transition

Endothelial-to-mesenchymal transition (EnMT) is a cell transformation process involved in both morphogenesis and pathogenesis. EnMT of corneal endothelial cells happens after endothelial injury and during ex vivo culture. Previous studies have shown that the transforming growth factor-β signaling pathway is involved in this transition. In this study, we found that rat corneal endothelial cells could spontaneously undergo EnMT during ex vivo culture. This change in rat corneal endothelial cells was associated with Notch signaling pathway activation after the first passage, which was blocked by the Notch inhibitor N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT). This inhibitor also prevented transforming growth factor β1-, β2-, and β3-induced EnMT and reversed transformed rat corneal endothelial cells to a normal phenotype. Furthermore, DAPT treatment blocked retrocorneal membrane formation in a rat corneal endothelium damage model. Our study indicates that the Notch signaling pathway is involved in the corneal EnMT process, which may be a novel therapeutic target for treating corneal endothelial fibrogenic disorders.

α-2-Macroglobulin: a physiological guardian

Alpha macroglobulins are large glycoproteins which are present in the body fluids of both invertebrates and vertebrates. Alpha-2-macroglobulin (α2 M), a key member of alpha macroglobulin superfamily, is a high-molecular weight homotetrameric glycoprotein. α2 M has many diversified and complex functions, but it is primarily known by its ability to inhibit a broad spectrum of proteases without the direct blockage of the protease active site. α2 M is also known to be involved in the regulation, transport, and a host of other functions. For example, apart from inhibiting proteinases, it regulates binding of transferrin to its surface receptor, binds defensin and myelin basic protein, etc., binds several important cytokines, including basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), nerve growth factor (NGF), interleukin-1β (IL-1β), and interleukin-6 (IL-6), and modify their biological activity. α2 M also binds a number of hormones and regulates their activity. α2 M is said to protect the body against various infections, and hence, can be used as a biomarker for the diagnosis and prognosis of a number of diseases. However, this multipurpose antiproteinse is not "fail safe" and could be damaged by reactive species generated endogenously or exogenously, leading to various pathophysiological conditions.

Differential expression of the Slc4 bicarbonate transporter family in murine corneal endothelium and cell culture

PURPOSE

To characterize the relative expression levels of all the solute carrier 4 (Slc4) transporter family members (Slc4a1-Slc4a11) in murine corneal endothelium using real-time quantitative (qPCR), to identify further important members besides Slc4a11 and Slc4a4, and to explore how close to the baseline levels the gene expressions remain after cells have been subjected to expansion and culture.

METHODS

Descemet's membrane-endothelial layers of 8-10-week-old C57BL6 mice were stripped from corneas and used for both primary cell culture and direct RNA extraction. Total RNA (from uncultured cells as well as cultured cells at passages 2 and 7) was reverse transcribed, and the cDNA was used for real time qPCR using specific primers for all the Slc4 family members. The geNorm method was applied to determine the most stable housekeeping genes and normalization factor, which was calculated from multiple housekeeping genes for more accurate and robust quantification.

RESULTS

qPCR analyses revealed that all Slc4 bicarbonate transporter family members were expressed in mouse corneal endothelium. Slc4a11 showed the highest expression, which was approximately three times higher than that of Slc4a4 (3.4±0.3; p=0.004). All Slc4 genes were also expressed in cultured cells, and interestingly, the expression of Slc4a11 in cultured cells was significantly reduced by approximately 20-fold (0.05±0.001; p=0.000001) in early passage and by approximately sevenfold (0.14±0.002; p=0.000002) in late passage cells.

CONCLUSIONS

Given the known involvement of SLC4A4 and SLC4A11 in corneal dystrophies, we speculate that the other two highly expressed genes in the uncultured corneal endothelium, SLC4A2 and SLC4A7, are worthy of being considered as potential candidate genes for corneal endothelial diseases. Moreover, as cell culture can affect expression levels of Slc4 genes, caution and careful design of experiments are necessary when undertaking studies of Slc4-mediated ion transport in cultured cells.

Contact lens wearing and chronic cigarette smoking positively correlate with TGF-β1 and VEGF tear levels and impaired corneal wound healing after photorefractive keratectomy

PURPOSE

To study the correlation of gender, contact lens (CL) wearing, chronic drinking and chronic smoking with wound healing cytokine levels and corneal recovery after photorefractive keratectomy (PRK).

MATERIALS AND METHODS

One hundred and twenty-eight age-matched patients (180 eyes) undergoing PRK were enrolled. PDGF, EGF, VEGF, HGF and TGF-β(1) protein levels were measured in tears by enzyme-linked immunosorbent assay either preoperatively or 2, 7 and 15 days after PRK. Patients were seen between one day and five days postoperatively for the evaluation of epithelial healing. Delayed re-epithelialization was defined as healing after day 5. All patients were followed for haze formation for a minimum of three months.

RESULTS

All cytokines increased significantly during the first two postoperative days (p < 0.001). PDGF, EGF, HGF decreased to the preoperative levels by day 7, whereas TGF-β1 and VEGF remained elevated over the entire period of observation of 15 days, although to a lesser extent than the second day after surgery, in CL-wearers and smokers, respectively (p < 0.01). The Pearson correlation analysis showed that: (i) CL-wearing positively correlated with TGF-β1 amounts, while chronic smoking positively correlated with VEGF production; (ii) CL-wearing and TGF-β1 amount were found to be associated with early haze formation, whereas chronic smoking and VEGF level with delayed re-epithelialization. No association was found between gender or alcohol consumption and cytokine levels or wound healing.

CONCLUSIONS

Our findings highlight for the first time the important role that cigarette smoking and CL wearing may have in altering the tear cytokine network and impairing corneal epithelial wound repair after surgical injury.

Corneal myofibroblast biology and pathobiology: generation, persistence, and transparency

Important advances have led to a better understanding of the biology and pathobiology of corneal myofibroblasts and their generation after surgery, injury, infection and disease. Transforming growth factor (TGF) beta, along with platelet-derived growth factor (PDGF) and interleukin (IL)-1, has been shown to regulate myofibroblast development and death in in-vitro and in-situ animal models. The myofibroblast precursor cells regulated by these cytokines include both keratocyte-derived and bone marrow-derived cells. Cytokines that promote and maintain myofibroblasts associated with late haze after photorefractive keratectomy are modulated in part by the epithelial basement membrane functioning as barrier between the epithelium and stroma. Structural and functional defects in the basement membrane likely lead to prolonged elevation of TGFβ, and perhaps other cytokine, levels in the stroma necessary to promote differentiation of myofibroblasts. Conversely, repair of the epithelial basement membrane likely leads to a decrease in stromal TGFβ levels and apoptosis of myofibroblasts. Repopulating keratocytes subsequently reorganize the associated fibrotic extracellular matrix deposited in the anterior stroma by the myofibroblasts. Investigations of myofibroblast biology are likely to lead to safer pharmacological modulators of corneal wound healing and transparency.

Cadherin-11 contributes to pulmonary fibrosis: potential role in TGF-β production and epithelial to mesenchymal transition

Pulmonary fibrosis, characterized by excess deposition of extracellular matrix by myofibroblasts, is a serious component of chronic lung diseases. Cadherin-11 (CDH11) is increased in wound healing and fibrotic skin. We hypothesized that CDH11 is increased in pulmonary fibrosis and contributes its development. CDH11 expression was assessed in lung tissue from idiopathic pulmonary fibrosis patients. The role of CDH11 in lung fibrosis was determined using the bleomycin model of pulmonary fibrosis, and in vitro analyses were performed on A549 cells during the process of epithelial to mesenchymal transition (EMT). Immunohistochemical studies demonstrated CDH11 expression on fibroblasts, epithelial cells, and alveolar macrophages of patients with pulmonary fibrosis and mice given bleomycin. Interestingly, CDH11-deficient mice had decreased fibrotic endpoints in the bleomycin model of pulmonary fibrosis compared to wild-type mice. Furthermore, anti-CDH11-neutralizing monoclonal antibodies successfully treated established pulmonary fibrosis induced by bleomycin. TGF-β levels were reduced in bronchoalveolar lavage (BAL) fluid, BAL cells, and primary alveolar macrophages from CDH11-deficient mice. Mechanistic studies demonstrated that TGF-β up-regulated CDH11 expression on A549 cells, and inhibition of CDH11 expression using siRNA reduced TGF-β-induced EMT. Together, these results identify CDH11 as a novel therapeutic target for pulmonary fibrosis.

Activation of unfolded protein response in transgenic mouse lenses

PURPOSE

Overloading of unfolded or misfolded proteins in the endoplasmic reticulum (ER) can cause ER stress and activate the unfolded protein response (UPR) in the cell. The authors tested whether transgene overexpression in the mouse lens would activate the UPR.

METHODS

Transgenic mice expressing proteins that either enter the ER secretory pathway or are synthesized in cytosol were selected. Activation of the UPR was assessed by determining the expression levels of the ER chaperone protein BiP, the spliced form of X-box binding protein-1 (Xbp-1) mRNA, and the transcription factor CHOP. Changes in the ubiquitin-proteasome system in the mouse lens were detected by ubiquitin immunofluorescence.

RESULTS

BiP expression was upregulated in the fiber cells of transgenic mouse lenses expressing platelet-derived growth factor-A (PDGF-A), dominant-negative fibroblast growth factor receptor (DN-FGFR), or DN-Sprouty2 (DN-Spy2). BiP upregulation occurred around embryonic day 16.5, primarily in the fiber cells adjacent to the organelle free zone. Fiber cell differentiation was disrupted in the PDGF-A and DN-Spry2 lenses, whereas the fiber cells were degenerating in the DN-FGFR lens. High levels of UPR activation and ubiquitin-labeled protein aggregates were found in the DN-FGFR lens, indicating inefficient disposal of unfolded/misfolded proteins in the fiber cells.

CONCLUSIONS

This study implies that overexpression of some transgenes in the lens can induce ER or overall cell stress in fiber cells, resulting in the activation of UPR signaling pathways. Therefore, investigators should assess the levels of UPR activation when they analyze the downstream effects of transgene expression in the lens.

Role of myofibroblasts in vascular remodelling: focus on restenosis and aneurysm

Myofibroblasts (MFs) are contractile cells deriving from a multiplicity of resident cells and/or circulating progenitors that are known to play a key role in wound healing. They were first discovered and analysed in the early 1970s in granulation tissue. Since their first identification, the role of MF and their mechanisms of differentiation have been highlighted in a number of diseases, including organ fibrosis and tumours, with particular attention devoted to the liver, kidney, and pulmonary fibrosis. The aim of this review is to summarize the current evidence for the role played by MFs in two frequent vascular diseases related to the remodelling of the vascular wall: the different forms of arterial restenosis and the most common forms of thoracic aortic aneurysm. The in-depth knowledge of the molecular pathways involved in MF differentiation, contraction, and survival/apoptosis could contribute to the identification of novel therapeutic strategies for anti-fibrotic and anti-remodelling therapy of vascular diseases in which these cells are involved.