Search Results (987)

Cardiac fibrosis is a central determinant of heart failure progression and arises from pathological remodeling characterized by fibroblast activation, myofibroblast differentiation, and excessive extracellular matrix deposition. In contrast, physiological remodeling permits adaptive cardiac growth without net fibrosis. Pregnancy represents an underexplored physiological model of reversible cardiac remodeling. In response to hemodynamic load, the maternal heart undergoes hypertrophic growth that resolves postpartum, constituting a natural paradigm of fibrosis-resistant cardiac adaptation. Pregnancy and lactation are accompanied by profound endocrine and immune reprogramming of maternal tissues. We propose that this hormonal milieu orchestrates coordinated crosstalk among endothelial cells, fibroblasts, and immune cell populations to suppress profibrotic pathways and preserve extracellular matrix homeostasis. Candidate regulators include estrogen, progesterone, prolactin family peptides, relaxin, oxytocin, and components of the renin–angiotensin–aldosterone system. During the postpartum and lactational period, prolactin and oxytocin may further promote reverse remodeling. These hormones likely act by modulating local cytokine and growth factor networks that otherwise drive fibroblast activation. By focusing on non-myocyte cardiac cells and extracellular matrix dynamics, this review positions pregnancy as a translational model to uncover endogenous anti-fibrotic mechanisms and identify novel therapeutic strategies for cardiac fibrosis. Full article

Corneal alkali burn induces severe inflammation and tissue damage, leading to loss of corneal transparency and vision impairment. In this study, we evaluated the therapeutic potential of rapamycin (RAPA) compared with cyclosporine A (CsA) in a mouse model of corneal alkali burn, focusing on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)–mediated inflammatory signaling and its impact on corneal wound healing and repair. Notably, RAPA robustly suppressed NF-κB activation, reduced infiltration of F4/80 macrophages and MPO neutrophils, and downregulated pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6. RAPA also markedly inhibited corneal neovascularization, as evidenced by decreased VEGF expression, reduced CD31 vessel formation, and suppression of Ang-2. RAPA substantially inhibited pathological fibrotic remodeling by reducing TGF-β1 expression, attenuating myofibroblast activation (α-SMA), decreasing collagen III deposition, and modulating matrix remodeling through suppression of MMP-9. Crucially, RAPA preserved epithelial barrier integrity by maintaining occludin expression, supported proper epithelial differentiation through sustained expression of CK12, and enhanced mucin layer stability by increasing MUC1 expression. It also restored tear production, reduced apoptotic cell death (TUNEL), and decreased dysregulated epithelial proliferation (Ki67). In conclusion, RAPA showed superior efficacy compared with CsA, primarily by enhancing corneal wound healing and facilitating structural and functional outcomes in the burned cornea. These findings underscore RAPA as a promising therapeutic candidate for ocular surface repair and vision restoration in extensive corneal injury. Full article

Severe full-thickness corneal lacerations disrupt the tight cellular and extracellular matrix (ECM) organization required for corneal transparency. Following injury, an influx of transforming growth factor beta (TGFβ) into the corneal stroma signals the formation of haze-inducing myofibroblasts, resulting in excessive stromal remodeling and corneal haze. We hypothesized that MasR activation using NorLeu³Angiotensin (1-7) (NLE) engages the pro-resolving arm of the renin–angiotensin system (RAS) to minimize fibrotic corneal repair. In this study, 6 mm stellate-shaped, full-thickness corneal lacerations were induced in New Zealand Black (NZB) rabbits and treated with topical vehicle, or 0.1%, 0.3%, or 0.45% NLE. Corneal healing was evaluated using noninvasive corneal imaging, histology, and the gene expression of RAS- and fibrosis-related targets (MasR, AT1R, TGFβR1). Corneal imaging revealed significantly decreased corneal haze (p < 0.05) and increased keratocyte density with 0.1% NLE treatment (p < 0.05). Immunofluorescence showed significantly reduced α-smooth muscle actin (αSMA), indicating decreased myofibroblast formation (p < 0.05). Additionally, 0.1% NLE reduced stromal TGFβR1, suggesting that NLE mediates its activity by disrupting the TGFβ/TGFβR axis. MasR and AT1R gene expression were downregulated, which contributes to a reduction in fibrosis. Collectively, these findings suggest that the NLE activation of MasR modulates RAS and TGFβ/TGFβR signaling to reduce myofibroblast activity and fibrosis following severe corneal trauma. Full article

Background and Clinical Significance: Nodular fasciitis is a benign, self-limited myofibroblastic proliferation that frequently mimics malignant soft-tissue tumors both clinically and radiologically. Although it has been well described in the extremities, its uncommon occurrence in the submandibular region poses a diagnostic challenge. Case Presentation: We report the case of a 22-year-old male patient, presenting with a rapidly enlarging painless swelling in the left submandibular region. Ultrasound demonstrated a well-defined subcutaneous lesion, while magnetic resonance imaging revealed heterogeneous enhancement with diffusion restriction, suggesting inflammatory or neoplastic pathology. Fine-needle aspiration cytology showed spindle-cell proliferation with pseudosarcomatous features, warranting histological examination to exclude malignancy. Surgical resection was performed. Histopathological examination demonstrated a myofibroblastic proliferation with tissue culture-like morphology. Immunohistochemistry showed diffuse SMA positivity while many other immunohistological markers were negative, arguing against several histologic mimics. Fluorescence in situ hybridization confirmed USP6 gene rearrangement, establishing the diagnosis of nodular fasciitis. Conclusions: This case highlights the diagnostic challenges posed by nodular fasciitis in the head and neck region and emphasizes the importance of correlating imaging, cytology, histopathology, and molecular findings to avoid overtreatment. The literature review further supports the benign clinical course of this rare entity in the submandibular region and underscores the value of including it in the differential diagnosis of submandibular masses. Full article

Systemic sclerosis (SSc) is a multi-organ autoimmune disease characterized by fibrosis of the skin and internal organs. Interstitial lung disease (ILD) is a major complication and leading cause of mortality in SSc. Transforming growth factor-β (TGF-β) has been implicated as a central mediator of fibrosis; however, while TGF-β1 has been extensively studied, the roles of TGF-β2 and TGF-β3 remain incompletely defined. Here, we systematically compared the effects of TGF-β1, TGF-β2, and TGF-β3 in dermal and lung fibroblasts, evaluating extracellular matrix synthesis and contraction, cytokine secretion, proliferation, and myofibroblast differentiation. TGF-β2 and TGF-β3 induced greater profibrotic cytokine release of Interleukin (IL)-6 and IL-11 and increased collagen-I and fibronectin synthesis compared with TGF-β1 in dermal and lung fibroblasts (all p < 0.05). TGF-β2 and TGF-β3 stimulated greater collagen-I contraction in dermal fibroblasts (p < 0.05), but greater myofibroblast differentiation in lung fibroblasts (p < 0.05). The TGF-β isoforms did not affect proliferation. All TGF-β isoforms activated SMAD2/3 signalling; however, TGF-β2 and TGF-β3 reduced expression of TGF-β Receptor II and the inhibitory regulator, SMAD7. In summary, TGF-β2 and TGF-β3 have a more pronounced profibrotic effect than TGF-β1 on dermal and lung fibroblast functions, making them potential targets for treatment for skin and lung fibrosis in diseases such as SSc. Full article

The transition from acute kidney injury (AKI) to chronic kidney disease (CKD) represents a dynamic and multistage pathological process driven by maladaptive intercellular communication. Rather than resulting from isolated cellular injury, AKI-CKD progression unfolds through a spatially and temporally coordinated dysregulation of cellular networks. In the acute phase, damaged tubular epithelial cells act as instigators, releasing damage-associated molecular patterns (DAMPs) and activating a storm of inflammatory crosstalk among immune cells, endothelium, and fibroblasts. During the subacute repair phase, imbalance in macrophage polarization (M1 persistence/M2 dysfunction) and the emergence of senescent tubular cells with a senescence-associated secretory phenotype (SASP) together create a pro-fibrotic microenvironment. In the chronic phase, activated myofibroblasts—derived from multiple sources—establish self-sustaining feedback loops via autocrine signaling, mechanical memory from the stiffened extracellular matrix (ECM), and ongoing dialogue with immune and resident cells, ultimately leading to irreversible fibrosis. Current therapeutic strategies focused on single molecular targets often fail to disrupt this resilient network homeostasis. Therefore, we propose a paradigm shift toward spatiotemporally precise network-remodeling therapies, which require integrated use of liquid biopsy-based staging, smart nanocarriers for cell-specific delivery, and AI-powered multi-omics modeling. This review systematically delineates the evolving cell-to-cell communication networks across AKI-CKD continuum and highlights innovative strategies to intercept disease progression by targeting the pathophysiology of cellular crosstalk. Full article

Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) are emerging as potent acellular therapeutics; however, their rapid clearance hinders their clinical translation. To address this issue, 3D-bioprinted genipin-crosslinked gelatin (GECL) was engineered for human health. GECL hydrogels were functionalised with human umbilical cord MSC-derived sEVs (hUCMSC-sEVs) to create a bioactive wound-healing platform. These hydrogels demonstrated favourable physicochemical, mechanical, and biodegradable properties while providing an extracellular matrix (ECM)-mimetic environment conducive to tissue regeneration. MSCs were isolated from the umbilical cords, and their small extracellular vesicles (sEVs) were extracted and incorporated into gelatin-based hydrogels via 3D bioprinting. These sEV-loaded scaffolds were embedded in full-thickness wounds in mice, and healing was evaluated through macroscopic observation, histological analysis, collagen deposition, and angiogenesis assessment. Compared with the untreated controls, both the hydrogel-only (B) and sEV-loaded hydrogel (BE) groups significantly accelerated in vivo wound healing. Notably, the BE group achieved complete wound closure within 14 days, restoring the skin architecture, which closely resembled the native tissue with well-organised epidermal and dermal layers, optimal thickness, and skin appendages. Histological and ultrastructural assessments revealed an increased collagen type I deposition, a reduced α-smooth muscle actin (α-SMA) expression, and a robust neovascularisation. The TEM revealed tight junctions and active cellular infiltration, indicating scaffold integration and functional remodelling. Immunohistochemistry further revealed an upregulated CD31 expression with a balanced α-smooth muscle actin (α-SMA) expression, reflecting coordinated angiogenesis and myofibroblast regulation. These results highlight sEV-functionalised GECL hydrogels as robust and clinically translatable acellular therapeutic green products for accelerated wound closure and functional skin regeneration, advancing the fields of regenerative medicine and life expectancy. Full article

Elevated levels of platelet-derived growth factor (PDGF) isoforms in fibrosis are implicated in driving a dysfunctional profibrotic fibroblast phenotype. This study investigated the differential effects of the five PDGF isoforms (AA, AB, BB, CC, and DD) in inducing neonatal dermal and fetal lung fibroblast contraction, proliferation, cytokine production, myofibroblast differentiation, and extracellular matrix (ECM) deposition. All PDGF isoforms, except PDGF-AA, increased contraction of 3-dimensional collagen I gels by dermal (p < 0.01) and lung fibroblasts (p < 0.05) compared to media control. PDGF-AB, BB, and CC enhanced proliferation only in dermal fibroblasts (p < 0.05). PDGF-BB induced profibrotic IL-11 cytokine release in dermal and lung fibroblasts (p < 0.0001) and IL-6 cytokine release in dermal fibroblasts (p < 0.05) compared to media control. None of the PDGF isoforms affected ECM synthesis or myofibroblast differentiation. Dermal fibroblasts exhibited elevated PDGF Receptor-β (PDGFRβ) expression (p < 0.01) and increased basal ERK1/2 phosphorylation (p < 0.05) compared to lung fibroblasts. In summary, PDGF modulates fibroblast functions in a tissue-specific manner, with PDGF-BB driving profibrotic processes in dermal fibroblasts through high PDGFRβ expression and ERK1/2 signalling. Further research is needed to explore the benefit of tissue and isoform-specific PDGF inhibition strategies in skin and lung fibrosis. Full article

Radiotherapy is essential for treating head and neck cancer but frequently leads to radiation-induced fibrosis (RIF) in salivary glands (SGs). RIF develops through a cascade of radiation-triggered events, including DNA damage, excessive oxidative stress, and epithelial cell death. Persistent injury can cause cells to become senescent and release inflammatory signals, fueling chronic inflammation. These processes activate pathways, particularly TGF-β/SMAD, resulting in fibroblast activation, myofibroblast differentiation, and extracellular matrix accumulation. Potential treatments include drugs, mesenchymal stem/stromal cell (MSC) therapy, and gene-transfer approaches. In which, MSC therapy is particularly promising as MSCs can migrate to injured tissue and support epithelial regeneration. Yet progress is limited by the difficulty of expanding human acinar cells (ACs) in vitro. To address this gap, tunable alginate–gelatin–hyaluronic acid (AGHA) bioink hydrogels have emerged as a suitable system as gelatin provides adhesion sites for AC attachment and 3D organoid formation, alginate offers tunable mechanical support through ionic crosslinking, and hyaluronic acid contributes essential cues for cell adhesion, migration, and morphogenesis. The aim of this review is to synthesize current understanding of the mechanisms driving RIF, evaluate available therapeutic strategies, and highlight the role of AGHA in generating engineered SG constructs to test MSC therapies for RIF. Full article

Cutaneous fibrosis is characterized by aberrant wound healing with excessive extracellular matrix deposition, sustained inflammation, and oxidative stress, while currently available therapies show limited efficacy and safety. A Dual Hyaluronic Acid Compound (DHC), consisting of high-molecular-weight, low-molecular-weight, and minimally cross-linked hyaluronic acid, has demonstrated regenerative and antioxidant properties, but its anti-fibrotic effects have not been fully explored. This study investigated the anti-fibrotic potential of DHC using a bleomycin-induced murine dermal fibrosis model and a UVB-irradiated ex vivo human skin model. In C57BL/6 mice, dermal fibrosis was induced by daily bleomycin injections for three weeks, followed by intradermal DHC administration. Histological and biomechanical analyses showed that DHC significantly reduced dermal thickness, collagen deposition, and skin hardness compared with untreated fibrotic controls. DHC decreased α-SMA expression and increased MMP1 levels, indicating attenuation of myofibroblast activation and enhanced matrix remodeling. It also reduced macrophage markers (CD68, CD163) and pro-inflammatory cytokines (IL-1β, TNF-α). Furthermore, DHC restored superoxide dismutase (SOD) and catalase (CAT) activity and upregulated NRF2, HO-1, and NQO1 expression in the in vivo model. Similarly, DHC upregulated SOD and CAT activity and reduced pro-inflammatory cytokines (IL-6, TNF-α) in the ex vivo human skin model. These findings suggest that DHC exerts multimodal anti-fibrotic effects through coordinated regulation of fibroblast activation, inflammation, and oxidative stress, supporting its potential as a therapeutic approach for cutaneous fibrosis. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease characterized by irreversible fibrosis. Aberrant cell differentiation plays a crucial role in the development of IPF. Although recent studies have suggested that mitochondrial dysfunction may play a role in IPF, its direct impact on fibrosis remains unclear. This study aimed to clarify the role of mitochondria in lung cell differentiation and pulmonary fibrosis development by employing mito-mice ND6^M, in which the activity of respiratory chain complex I is decreased due to a mitochondrial DNA mutation (G13997A). Pulmonary fibrosis was induced by administering bleomycin (BLM) to both wild-type and mito-mice ND6^M. Bone marrow-derived macrophages and primary lung fibroblasts, generated from both types of mice, were analyzed to evaluate M1/M2 polarization and myofibroblast differentiation, respectively. Compared to wild-type mice, mito-mice ND6^M exhibited more severe fibrosis and lower survival rates following BLM inoculation. Lactate production in the lungs after BLM administration was significantly higher in mito-mice ND6^M than in wild-type mice. TGF-β1-treated fibroblasts from mito-mice ND6^M exhibited increased α-smooth muscle actin expression. While type I collagen expression was not different between these mice, TGF-β1-induced expression of phosphoserine phosphatase and serine hydroxymethyltransferase2, two of the enzymes involved in the serine–glycine pathway, was significantly higher in mito-mice ND6^M than in wild-type mice. On the other hand, mitochondrial dysfunction had a small effect on pulmonary inflammation and on M1/M2 macrophage polarization. In conclusion, mitochondrial dysfunction promotes TGF-β1-induced myofibroblast differentiation and BLM-induced pulmonary fibrosis. Mitochondria-dependent metabolic reprogramming may therefore represent a promising therapeutic target in IPF. Full article

Modeling immune cell recruitment within a wound-relevant microenvironment remains challenging. Here, we developed a novel skin-derived extracellular matrix (ECM) hydrogel model to study monocyte (THP-1) entry and phenotypic changes within a dermal fibroblast-populated (NHDF) matrix. The main novelty of this study is that it compares the effects of fibroblast-derived soluble signals and active monocyte infiltration in a 3D biomimetic model. Signaling by fibroblast-secreted soluble factors enhanced a pro-angiogenic secretome (e.g., >3-fold upregulation of VEGFA at day 1) and promoted endothelial tube formation (increasing network junctions to 1.16 ± 0.16 vs. 0.93 ± 0.23 in monoculture). In contrast, this paracrine signaling did not induce the matrix-driven pro-fibrotic response in hydrogels. Crucially, physical immune infiltration restricted monocyte penetration (mean depth of 8.92 ± 2.27 μm vs. 121.1 ± 15.9 μm in monoculture at day 5), reduced hydrogel-induced myofibroblast activation (decreasing α-SMA+ cells from 79.1% to 54.3% upon initial contact), and was associated with slower collagen loss during the early phase. (retaining a high-density collagen ratio of 3.46 ± 0.33 vs. 2.02 ± 0.29 in monoculture at day 1). These observations were accompanied by a shift toward a matrix-stabilizing profile, including increased TIMP expression and reduced pro-fibrotic markers. (ACTA2 and COL1A1). By including active immune infiltration (which was absent in previous tSVF models), we capture the transition from inflammation to the proliferation stage. Although the later stages of extensive ECM remodeling appear suppressed here, they may occur as repair progresses. Overall, our findings highlight that the immune cell is a key regulatory component for coordinating matrix preservation and vascular support. Importantly, this model replicates the early phases of wound healing, a stage where the monocyte–fibroblast secretome supports endothelial network formation. We established this innovative 3D ECM hydrogel system as a practical and physiologically relevant platform to investigate immune–matrix–stromal crosstalk. Full article

Background/objectives: Endostatin is a cleavage product of collagen XVIII and a potent anti-angiogenic factor. Angiogenesis is essential for adipose tissue growth and contributes to liver fibrosis and cancer, suggesting a potential therapeutic role for endostatin in obesity, chronic liver diseases, and hepatocellular carcinoma (HCC). This review article summarises published data on the role and expression of endostatin in obesity, liver injury, and HCC. Methods: PubMed and Google databases were searched using the terms “endostatin and liver”, “endostatin and HCC”, “endostatin and obesity”, and “endostatin and adipose”. Studies published in peer-reviewed journals relevant to this review were considered and reviewed for valuable insights. Results: Endostatin is much more than an inhibitor of angiogenesis; it exerts direct effects on adipocytes and myofibroblasts. Endostatin inhibits adipose tissue growth, and studies using Endostar—a modified form of endostatin approved in China for treating lung cancer—have demonstrated its protective effect in liver fibrosis. However, other studies have shown that endostatin activates hepatic stellate cells, indicating a role in tissue regeneration. Most research on endostatin has focused on cancer, and animal and human studies have shown the benefits of Endostar therapy in HCC. Conclusions: Endostar is a promising treatment for HCC and may also become an attractive drug for liver fibrosis. Hence, angiostatic therapy is not without risks and may only be suitable for selected patients. Full article

Skin fibrosis is characterized by excessive extracellular matrix (ECM) deposition, leading to tissue dysfunction and scarring. Transforming growth factor (TGF)-β is a central mediator of fibrosis. We previously identified CD109 as a TGF-β co-receptor and negative regulator of TGF-β signaling and fibrotic responses and showed that its epidermal overexpression reduces dermal fibrosis in vivo. However, the effects of CD109 loss in the dermis remain unclear. The current study investigates the impact of CD109 knockout (KO) on skin fibrosis using a bleomycin-induced fibrosis mouse model. Following bleomycin treatment, CD109 KO mice showed increased collagen I deposition and elevated fibronectin, CCN2, and α–smooth muscle actin expression in the skin, indicating enhanced ECM production and myofibroblast differentiation compared with wild-type mice. Additionally, CD109 KO mice displayed enhanced Smad1 and Smad2/3 phosphorylation in the skin, indicating heightened TGF-β signaling. In vitro, CD109 KO fibroblasts exhibited increased TGF-β-induced migration and collagen contraction. These findings suggest that CD109 deficiency exacerbates dermal fibrosis by promoting TGF-β/Smad signaling and myofibroblast activation. Given its dysregulation in fibrotic disorders such as scleroderma, our results identify CD109 as a key regulator of skin homeostasis by modulating ECM production and fibroblast activation, underscoring its potential as a therapeutic target in fibrotic disorders. Full article

Background and Objectives: Pulmonary fibrosis (PF) is an interstitial lung disease that leads to death and is characterized by excessive collagen deposition and tissue scarring. Bleomycin (BLM) is widely used to induce PF in rodent models, closely resembling human idiopathic pulmonary fibrosis. Ivermectin, a broad-spectrum antiparasitic agent, has recently attracted interest due to its reported anti-inflammatory and antifibrotic effects. The beneficial effects of ivermectin to treat PF may be attributed to suppressing the NLRP3 inflammasome. Ivermectin can cause acute toxicity, including convulsions, when overdosed in animals. In humans, it may induce neurological disorders, particularly in individuals with mutations in the ABCB1 gene. This study aimed to investigate the potential protective role of ivermectin against BLM-induced PF in rats. Materials and Methods: Forty adult male albino rats were randomly allocated into four groups (n = 10 each): control, ivermectin-treated (0.6 mg/kg, orally on days 0, 1, 7, and 8), BLM-treated (single intratracheal dose of 5 mg/kg), and BLM- and ivermectin-treated. Lung tissues were collected for histopathological analysis and Mallory trichrome staining to assess collagen deposition. Mast cell (MC) infiltration was assessed using toluidine blue. Immunohistochemistry for α-SMA and Ki-67 was used to evaluate myofibroblast and cell proliferation. Oxidative stress parameters, including serum total antioxidant capacity, lung glutathione and lung nitric oxide were measured. Results: Ivermectin treatment markedly attenuated BLM-induced lung fibrosis, showing reduced collagen accumulation, restoration of alveolar architecture, and decreased inflammatory cell infiltration. Immunohistochemical evaluation revealed decreased expression of α-SMA and Ki-67, while biochemical analyses demonstrated improved oxidative stress markers. Conclusions: Ivermectin significantly mitigates BLM-induced pulmonary fibrosis in rats through modulation of inflammation, suppression of myofibroblast proliferation, and reduction in oxidative stress and collagen deposition. These findings highlight ivermectin as a potential candidate for the management of fibrotic lung diseases, warranting further mechanistic and clinical investigations. Full article