Search Results (4,111)

Alopecia profoundly impacts psychological well-being and quality of life, yet current therapeutic options such as minoxidil and finasteride exhibit limited efficacy. Fibroblast growth factor 7 (FGF-7), also known as keratinocyte growth factor (KGF), is a paracrine growth factor secreted by dermal papilla cells that specifically activates the epithelial receptor FGFR2b. Receptor engagement triggers multiple downstream signaling cascades, including the MAPK/ERK, PI3K/Akt, and Wnt/β-catenin pathways, promoting keratinocyte proliferation, stem cell activation, and the transition of hair follicles into the anagen phase. Both in vitro and in vivo animal studies consistently demonstrate that FGF-7 accelerates telogen-to-anagen transition and enhances follicular regeneration. FGF-7 acts synergistically with insulin-like growth factor 1 (IGF-1) and vascular endothelial growth factor (VEGF) to sustain nutrient delivery and cell proliferation. Human scalp studies further reveal a strong association between the FGF-7/FGFR2b signaling and follicular activity; however, clinical trials remain scarce. Topical application of FGF-7 has demonstrated an excellent safety profile, whereas systemic administration necessitates careful monitoring. Future directions include the development of engineering to extend the systemic half-life, advanced delivery systems, and gene or mRNA-based therapeutic approaches. Thus, the FGF-7/FGFR2b axis is a highly compelling molecular target for next-generation hair regeneration therapies. Full article

Background/Objectives: Wound healing proceeds in a timely and sequential manner through four well-defined phases: hemostasis, inflammation, proliferation, and remodeling. To explore the therapeutic efficacy and underlying mechanism of a novel monoacylglycerol lipase (MAGL) inhibitor (designated as MAGL11), a diabetic mouse model of skin wounds was established. Methods: Wound healing progression was assessed via gross observation, while histological analyses (including HE staining and Masson staining) were conducted to evaluate tissue repair. Additionally, proteomic analysis and in vitro experiments were employed to validate the therapeutic effects and clarify the molecular mechanism of MAGL11. Results: In vivo studies revealed that treatment with MAGL11 significantly accelerated wound closure in diabetic mice. Compared with the control group, MAGL11-treated wounds exhibited notably increased granulation tissue formation and collagen deposition, which was accompanied by a distinct anti-inflammatory effect. Results from proteomic profiling and in vitro experiments further demonstrated that MAGL11 exerted its pro-healing effects by promoting the activation of the Rap1/PI3K/Akt signaling pathway. Specifically, MAGL11 enhanced the migration and chemotaxis of fibroblasts (NIH3T3), human umbilical vein endothelial cells (HUVECs), and keratinocytes (HaCaT) while simultaneously inhibiting cellular apoptosis—all of which collectively contributed to improved wound healing. Conclusions: These findings suggest that MAGL11 holds promise as a potential candidate for diabetic wound therapy, primarily through its ability to promote angiogenesis, fibroblast activation, and epithelial regeneration. Full article

Background: Acacetin, a naturally occurring flavone present in various plants, is known as a promising drug candidate for cardiovascular disorders. Our previous study demonstrated that acacetin ameliorates atherosclerosis through endothelial cell protection; however, its pharmacological effects on vascular smooth muscle cells (VSMCs) remain unexplored. This study investigates the therapeutic potential of acacetin against lysophosphatidylcholine (LysoPC)-induced VSMC injury and elucidates the underlying molecular mechanisms. Methods and Results: Multiple biochemical techniques were employed in the present study. The results showed that acacetin significantly attenuated LysoPC-induced apoptosis and reactive oxygen species (ROS) generation in cultured VSMCs. Western blot analysis revealed that the cytoprotection of acacetin was associated with upregulated expression of antioxidant defense proteins, including nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), NADPH quinone oxidoreductase 1 (NQO-1), and superoxide dismutase 1 (SOD1). Nrf2 silencing completely abolished these protective effects. Mechanistically, siRNA-silencing of Sirtuin 1 (Sirt1) abrogated acacetin-induced modulation of the Nrf2/Keap1/p62 signaling. In vivo validation using aortic tissues from high-fat-diet-fed ApoE^−/− mice confirmed that acacetin effectively suppressed VSMC apoptosis and ROS overproduction associated with restoring the downregulated Sirt1 expression levels. Conclusions: These findings establish a novel mechanistic paradigm wherein acacetin confers protection against LysoPC-induced VSMC apoptosis and oxidative stress through Sirt1-dependent activation of the Nrf2/p62 signaling pathway, suggesting that acacetin is a promising therapeutic drug candidate for atherosclerotic plaque stabilization. Full article

Thrombotic cardiovascular diseases are frequent side effects of cancer therapy with cytotoxic drugs such as Doxorubicin. Endothelial cell senescence is emerging as a critical mechanism underlying endothelial dysfunction in this context. Senescent cells, although unable to proliferate, secrete bioactive molecules that alter the tissue microenvironment, a feature known as the senescence-associated secretory phenotype (SASP). Besides soluble molecules, senescent cells also release extracellular vesicles (EVs). Previous studies indicate that senescent endothelial cells produce a secretome that promotes platelet activation; however, the contribution of EVs remains unclear. Here, we show that human microvascular endothelial cells (HMEC-1) exposed to Doxorubicin undergo senescence, display endothelial dysfunction, and release EVs. We found no differences in the concentration or size distribution of EVs from senescent and non-senescent cells. Nevertheless, EVs from senescent HMEC-1 promoted platelet activation more strongly than EVs from control cells. Notably, EVs alone did not induce platelet aggregation, suggesting that soluble factors are also required to support platelet-dependent hemostasis. These findings reveal that EVs from senescent endothelial cells contribute to platelet activation, a process that may favor thrombosis in patients receiving Doxorubicin-based chemotherapy. Full article

Pulmonary hypertension (PH) causes morbidity and mortality in sickle cell disease (SCD). The release of heme during hemolysis triggers endothelial dysfunction and contributes to PH. Long non-coding RNAs (lncRNAs) may play a pivotal role in endothelial dysfunction and PH pathogenesis. This study assessed the regulatory role of the lncRNA–heme oxygenase-1 (HMOX1) axis in SCD-associated PH pathogenesis. Total RNAs were isolated from the lungs of 15–17-week-old sickle cell (SS) mice and littermate controls (AA) mice and subjected to lncRNA expression profiling using the Arrystar™ lncRNA array. Volcano plot filtering was used to screen for differentially expressed lncRNAs and mRNAs with statistical significance (fold change > 1.8, p < 0.05). A total of 3915 lncRNAs were upregulated and a total of 3545 lncRNAs were downregulated in the lungs of SS mice compared to AA mice. To validate differentially expressed lncRNAs, six upregulated lncRNAs and six downregulated lncRNAs were selected for quantitative PCR. MALAT1 expression was significantly upregulated in the lungs of SS mice and in hemin-treated human pulmonary artery endothelial cells (HPAECs), suggesting that hemolysis induces MALAT1. Functional studies revealed that MALAT1 depletion increased, while MALAT1 overexpression decreased, the endothelial dysfunction markers endothelin-1 (ET-1) and vascular cell adhesion molecule-1 (VCAM1), indicating a protective role of MALAT1 in maintaining endothelial homeostasis. In vivo, adenoviral MALAT1 overexpression attenuated PH, right ventricular hypertrophy (RVH), vascular remodeling, and reduced ET-1 and VCAM1 expression in SS mice. Given that HMOX1 protects endothelial cells during hemolysis, we observed that HMOX1 expression and activity were elevated in SS mouse lungs and hemin-treated HPAECs. HMOX1 knockdown enhanced ET-1 and VCAM1 expression, confirming its endothelial-protective function. Importantly, MALAT1 overexpression increased HMOX1 expression and activity, whereas MALAT1 knockdown reduced HMOX1 levels and mRNA stability. Collectively, these findings identify MALAT1 as a protective regulator that mitigates endothelial dysfunction, vascular remodeling, and PH in SCD, at least in part through the induction of HMOX1. These results suggest that SCD modulates the MALAT1–HMOX1 axis, and further characterization of MALAT1 function may provide new insights into SCD-associated endothelial dysfunction and PH pathogenesis, as well as identify novel therapeutic targets. Full article

Our laboratory identified the susceptible allelic variant of equine CXCL16 protein (EqCXCL16S) as an entry receptor for equine arteritis virus (EAV). However, EAV has a broad host cell tropism and infects cells that lack EqCXCL16S. Thus, we hypothesized that EAV interacts with other host cell protein(s) that facilitate EAV infection. A virus overlay protein-binding assay in combination with a Far-Western blot from EAV-susceptible equine pulmonary artery endothelial cells (EECs) and equine dermal fibroblasts (E. Derm) identified a 57 kDa protein, present in the membrane fraction of the protein lysate, as a possible EAV-binding protein. Subsequent LC-MS/MS analysis identified this 57 kDa protein as vimentin. Screening of different mammalian cell lines has shown that only cells expressing vimentin are susceptible to EAV infection. Pre-treatment of EECs with an anti-vimentin polyclonal antibody and Withaferin A partially inhibit EAV infection. Finally, the overexpression of equine vimentin (EqVim) in HEK-293 cells increases their susceptibility to EAV infection. Overall, our data strongly indicate that EAV binds to the host cell protein equine vimentin, which actively participates in EAV infection, potentially serving as an attachment factor. The data suggest that EAV interacts with various host cell proteins to achieve its diverse cell tropism. Full article

Dorsomorphin, a pyrazolo[1,5-a]pyrimidine derivative, inhibits the bone morphogenetic protein (BMP) pathway by targeting the type I BMP receptors active in receptor-like kinases. However, the investigation of its—and its derivatives’—antiproliferative activity towards endothelial and cancer cell lines still requires reinforcement with additional studies. In the presented work, several dorsomorphin derivatives have been efficiently synthesized, based on a previously reported synthetic protocol with minor modifications. The endeavor was reinforced by a molecular docking study on the interactions of the designed derivatives with various protein targets, while the inhibitory effects of the synthesized novel molecules on the proliferation of murine leukemia cells (L1210), human T-lymphocyte cells (CEM), human cervix carcinoma cells (HeLa), and endothelial cells (human dermal microvascular, HMEC-1, and bovine aortic endothelial cells, BAECs) were investigated. Among the compounds tested, diphenol 22, emerged as the most promising bioactive lead since it demonstrated half-maximal inhibitory concentration (IC₅₀) values below 9 μM in all tested lines except HeLa cells. In the same context, the carbamate derivative 6 was determined as a potent inhibitor of endothelial cell proliferation in BAECs at a low micromolar range. In conclusion, the presented work not only reveals promising antiproliferative dorsomorphin derivatives but also sets the basis for further exploitation of dorsomorphin’s bioactive portfolio, based on bioactivity results and molecular modeling calculations. Full article

The transcription factor NRF2 orchestrates diverse cellular homeostatic networks, but its role in angiogenesis remains poorly understood. Genetic and pharmacological modulation of NRF2 in mouse neuroendothelial cells altered the expression of several genes involved in endothelial biology. Among these, the TIE2/Tek receptor, essential for vascular development and integrity, was downregulated upon NRF2 activation, accompanied by changes in adherens and tight junction gene expression. Hemin treatment and knockdown revealed that TIE2/Tek repression is independent of the NRF2 repressor BACH1. mRNA stability and ChIP analyses indicated no post-transcriptional or direct transcriptional repression by NRF2. These findings suggest an alternative NRF2-dependent mechanism affecting TIE2/Tek levels and potentially influencing angiogenic regulation. Full article

Quercetin (Q), a bioactive flavonoid, exerts potent antioxidant and redox-modulating effects by activating the nuclear factor erythroid 2-related factor 2/antioxidant response Element (Nrf2/ARE) pathway and upregulating endogenous antioxidant defenses, including enzymatic antioxidants such as superoxide dismutase (SOD) and catalase (CAT), as well as non-enzymatic glutathione (GSH) and lipid peroxidation (MDA). Gemcitabine (Gem), a widely used antimetabolite chemotherapeutic, often shows limited efficacy under hypoxic and oxidative stress conditions driven by hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF)-mediated angiogenesis. This study investigated the redox-mediated synergistic effects of Q and Gem in MDA-MB-231 human breast cancer cells. Combination treatment significantly reduced cell viability beyond the expected Bliss value, indicating a synergistic interaction and enhanced apoptosis compared with single-agent treatments. Increased reactive oxygen species (ROS) production was accompanied by depletion of GSH and accumulation of MDA, establishing a pro-apoptotic oxidative stress environment. Q alone enhanced SOD and CAT activities, whereas the combination induced exhaustion of antioxidant defenses under oxidative load, reflecting a redox-adaptive response. Molecular analyses revealed downregulation of HIF-1α and VEGF, alongside upregulation of Bax and Caspase-3, confirming suppression of hypoxia-driven survival and activation of the intrinsic apoptotic pathway. Transcriptomic and enrichment analyses further identified modulation of oxidative stress- and apoptosis-related pathways, including phosphoinositide-3-kinase–protein kinase B/Akt (PI3K/Akt), HIF-1 and VEGF signaling. Collectively, these results indicate that Q potentiates Gem cytotoxicity via redox modulation, promoting controlled ROS elevation and apoptosis while suppressing hypoxia-induced survival mechanisms, highlighting the therapeutic potential of redox-based combination strategies against chemoresistant breast cancer. Full article

Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b viruses spread efficiently via migratory wild birds and increasingly infect mammals. The leopard cat (Prionailurus bengalensis) is an endangered mesopredator in South Korea that frequents wetland–forest ecotones and overlaps with wild waterbirds, placing it at risk of exposure. We describe a fatal HPAI H5N1 infection in a free-ranging leopard cat detected through national wildlife surveillance during a period of widespread H5N1 activity in wild birds along the East Asian–Australasian Flyway. The animal showed acute neurological and respiratory signs and died shortly after rescue. H5 viral RNA was detected by RT-qPCR in all examined tissues, with the highest load in the brain, and infectious virus was isolated from the brain, bronchoalveolar lavage fluid, and nasal swab. Pathology revealed acute serofibrinous pneumonia, severe nonsuppurative meningoencephalitis, necrotizing vasculitis with thrombosis, and necrotizing enteritis with secondary mesenteritis. Immunohistochemistry demonstrated abundant viral antigen in nasal and olfactory epithelium, olfactory bulb, neurons, endothelial cells, and bronchial and bronchiolar epithelium, supporting combined olfactory and hematogenous dissemination. This clinicopathological description expands the spectrum of HPAI-associated lesions in felids and underscores the value of wild carnivores as bioindicators of avian influenza spillover in a One Health context. Full article

Diabetes mellitus severely impairs skeletal muscle regeneration after injury, limiting satellite cell activation and angiogenesis and disrupting barrier integrity while increasing fibrosis. Hypobaric hypoxia has been proposed to improve the regenerative microenvironment through hypoxia-responsive signaling, but its temporal effects and the coordination between vascular and myogenic programs in diabetic muscle remain unclear. To clarify these processes, adult male mice were divided into five groups: diabetes mellitus control (DM), cardiotoxin-injured (CTX) diabetes assessed on days 7 and 14 (CTX7, CTX14), and hypobaric-hypoxia-treated diabetic injury assessed on days 7 and 14 (H+CTX7, H+CTX14). Animals in the hypoxia groups were exposed to a hypobaric hypoxia chamber for 8 h per day for 14 days. Fibrosis, angiogenic and myogenic markers, and endothelial junctional genes were examined using histology, immunofluorescence, immunoblotting, and qRT-PCR (Quantitative Real-Time PCR). Hypobaric hypoxia on day 7 enhanced HIF-1α (hypoxia-inducible factor 1 alpha), VEGF (vascular endothelial growth factor), eNOS (endothelial nitric oxide synthas), Kdr (kinase insert domain receptor, VEGFR-2), and Angpt2 (angiopoietin-2) expression, accompanied by simultaneous endothelial sprouting and early myogenic stimulation compared to CTX7. Improvements were observed in Angpt1 (angiopoietin-1), Cdh5 (cadherin-5, VE-cadherin), Emcn (endomucin), the Angpt1/Angpt2 ratio, and CD31 density. Myogenin and MyHC (myosin heavy chain) were induced with a reduction in eMyHC (embryonic myosin heavy chain) in accordance with stabilization of endothelium and maturation of fibers, which occurred by day 14. A decrease in fibrosis and an increase in the myofiber cross-sectional area occurred. These findings suggest that hypobaric hypoxia modulates HIF-1α signaling, which in turn induces the VEGF-Kdr-eNOS pathway and the angiopoietin–Tie2–VE-cadherin pathway. Together, these pathways coordinate vascular remodeling and myogenic regeneration, ultimately improving the structural and functional recovery of diabetic muscle. Full article

Background: Aging exerts a progressive and multifaceted impact on the microcirculatory system, undermining the structural and molecular integrity that sustains endothelial stability across both peripheral and cerebral vascular territories. A sustained shift toward oxidative imbalance, chronic low-grade inflammation, and progressive endothelial exhaustion converges to destabilize microvascular networks, linking peripheral artery disease (PAD) with heightened susceptibility to cerebral microvascular dysfunction and neurovascular decline. As redox homeostasis deteriorates, endothelial cells progressively lose barrier-selective properties, intercellular communication with pericytes weakens, and pro-thrombotic tendencies subtly emerge, creating a permissive environment for early neurovascular injury and impaired cerebrovascular resilience. Methods: This narrative review integrates mechanistic evidence derived from experimental, clinical, and translational studies examining the interplay between oxidative stress, inflammatory signaling cascades, endothelial senescence, and blood–brain barrier (BBB) disruption across peripheral and cerebral microvascular systems. A comparative framework was applied to PAD and cerebral microcirculatory pathology to identify convergent molecular drivers and systemic mechanisms underlying endothelial deterioration. Results: Accumulating evidence demonstrates that oxidative stress disrupts endothelial mitochondrial function, compromises tight junction architecture, and accelerates angiogenic failure. Concurrent inflammatory activation amplifies these alterations through cytokine-mediated endothelial activation, enhanced leukocyte adhesion, and promotion of a pro-thrombotic microenvironment. Progressive endothelial senescence consolidates these insults into a persistent state of microvascular dysfunction characterized by diminished nitric oxide bioavailability, capillary rarefaction, and compromised barrier integrity. Notably, these pathological features are shared between PAD and the aging cerebral circulation, reinforcing the concept of a unified systemic microvascular aging phenotype. Conclusions: Microvascular failure in the aging brain should be understood as an extension of systemic endothelial deterioration driven by oxidative stress, chronic inflammation, and senescence-associated vascular exhaustion. Recognizing the shared molecular architecture linking peripheral and cerebral microcirculatory dysfunction offers a strategic framework for developing targeted therapeutic interventions aimed at restoring endothelial resilience, stabilizing BBB integrity, and preserving neurovascular homeostasis in aging populations. Full article

Background: The anterior cruciate ligament (ACL) and medial collateral ligament (MCL) display strikingly different healing behaviors, despite their similar structural roles within the knee. The epiligament (EL)—a vascular and cellular envelope surrounding each ligament—has emerged as a critical determinant of repair capacity. The aim of this study was to perform a region-specific, comparative analysis of EL molecular profiles in the ACL and MCL to elucidate the mechanisms underlying their contrasting reparative outcomes. Methods: Human ACL and MCL specimens were obtained from 12 fresh knee joints. Immunohistochemical labeling for CD34, α-smooth muscle actin (α-SMA), and vascular endothelial growth factor (VEGF) was performed across proximal, mid-substance, and distal EL regions. Quantitative image analysis using IHC Profiler for ImageJ generated semiquantitative (negative, low-positive, positive) distributions, and inter-ligament comparisons were quantified using t-tests (p  <  0.05). Results: Distinct, region-specific EL signatures were identified. The ACL EL exhibited strong proximal α-SMA expression (0% neg/66.8% low+/33.2%+) and notable distal CD34 positivity (0% neg/83.3% low+/16.7%+), while VEGF expression was confined to the mid-substance (≈55% low+/26%+). In contrast, the MCL EL was largely negative for CD34 and VEGF across all regions, showing a homogeneous but functionally oriented α-SMA profile: proximally negative, sparse mid positivity, and high distal low-positive staining (93.4% low+). Differences in proximal and distal CD34 and α-SMA expression between the ACL and MCL were highly significant (p  <  0.0001–0.001), confirming a mechanistic divergence in EL organization. Conclusions: The ACL EL is regionally heterogeneous, vascularly biased, and enriched in contractile α-SMA+ cells, suggesting localized but poorly coordinated reparative potential. In contrast, the MCL EL is structurally uniform, with distributed α-SMA activity supporting stable wound contraction and tissue continuity, despite limited angiogenic signaling. These findings indicate that the ACL’s failure to heal is not attributable to the absence of progenitor or angiogenic factors, but rather to its fragmented spatial organization and dominant contractile phenotype. Therapeutically, preserving and modulating the EL, particularly its CD34+ and α-SMA+ compartments, could be key to enhancing intrinsic ACL repair and improving outcomes in ligament reconstruction and regeneration. Full article

Vascular endothelial growth factor receptor 3 (VEGFR3) assumes a pivotal role in regulating the development and maintaining the structural integrity of the lymphatic system. Decreased activity of VEGFR3 can precipitate aplasia or hypoplasia of lymphatic system components, culminating in primary lymphedema. To date, numerous genetic variants have been identified within the FLT4 gene, which encodes VEGFR3; however, the majority of these remain uncharacterised and are classified as ‘variants of uncertain significance’. In preceding investigations involving FLT4 sequence analysis conducted on individuals presenting with primary lymphedema, we identified several rare genetic variants that possess the potential to modulate the functional activity of VEGFR3, including the heterozygous variant c.3175G>C (p.A1059P). Preliminary assessments encompassing clinical characteristics, family history, and predictive computational algorithms indicated that this variant was likely pathogenic. Consequently, this study presents the results of functional evaluation of the mutant VEGFR3 activity in cell models overexpressing the FLT4 variant c.3175G>C. VEGFC-dependent VEGFR3 phosphorylation and FLT4 expression were reduced in cells with c.3175G>C FLT4 variant compared to wild-type, confirming the pathogenic role of c.3175G>C in primary lymphedema. Full article

Metal nanoparticles (NP) are increasingly used in biomedical applications. Among them, silver NPs (AgNPs) are used as active components in antibacterial coatings for wound dressings, medical devices, implants, cosmetics, textiles, and food packaging. On the other hand, AgNPs can be toxic to humans, depending on the dose and route of exposure, as agents delivering silver to cells. The cysteine residues are the primary molecular targets in such exposures, due to the high affinity of Ag⁺ ions to thiol groups. The Endothelial monocyte-activating polypeptide II (EMAP II), a cleaved C-terminal peptide of the intracellular aminoacyl-tRNA synthetase multifunctional protein AIMP1, contains five cysteines exposed at its surface. This prompted the question of whether they can be targeted by Ag⁺ ions present at the AgNPs surface or released from AgNPs in the course of oxidative metabolism of the cell. We explored the interactions between recombinant EMAP II, tRNA, and AgNPs using UV-Vis and fluorescence spectroscopy, providing insight into the effects of AgNPs dissolution kinetics on interaction EMAP II with tRNA. In addition, the EMAP II fragments binding to intact AgNPs were established by heteronuclear ¹H-¹⁵N HSQC spectra utilizing a paramagnetic probe. Structural analysis of the EMAP II reveal that the 3D structure of protein was destabilized (partially denatured) by the binding of Ag⁺ ions released from AgNPs at the most exposed cysteines. Surprisingly, this effect enhanced tRNA affinity to EMAP II, lowering its $K_d$. The course of the EMAP II/tRNA/AgNP reaction was also modulated by other factors, such as the presence of Mg²⁺ ions and TCEP, a thiol-group protector used to mimic the reducing conditions of the cell. Full article