Expression In Endothelial Cells Research Articles

Inhibition of IFITM3 in cerebrovascular endothelium alleviates Alzheimer's-related phenotypes.

Interferon-induced transmembrane protein 3 (IFITM3) modulates γ-secretase in Alzheimer's Disease (AD). Although IFITM3 knockout reduces amyloid β protein (Aβ) production, its cell-specific effect on AD remains unclear. Single nucleus RNA sequencing (snRNA-seq) was used to assess IFITM3 expression. Adeno-associated virus-BI30 (AAV-BI30) was injected to reduce IFITM3 expression in the cerebrovascular endothelial cells (CVECs). The effects on AD phenotypes in cells and AD mice were examined through behavioral tests, two-photon imaging, flow cytometry, Western blot, immunohistochemistry, and quantitative polymerase chain reaction assay (qPCR). IFITM3 expression was increased in the CVECs of patients with AD. Overexpression of IFITM3 in primary endothelial cells enhanced Aβ generation through regulating beta-site APP cleaving enzyme 1 (BACE1) and γ-secretase. Aβ further increased IFITM3 expression, creating a vicious cycle. Knockdown of IFITM3 in CVECs decreased Aβ accumulation within cerebrovascular walls, reduced Alzheimer's-related pathology, and improved cognitive performance in AD transgenic mice. Knockdown of IFITM3 in CVECs alleviates AD pathology and cognitive impairment. Targeting cerebrovascular endothelial IFITM3 holds promise for AD treatment. Interferon-induced transmembrane protein 3 (IFITM3) expression was increased in the cerebrovascular endothelial cells (CVECs) of patients with Alzheimer's Disease (AD). Cerebrovascular endothelial IFITM3 regulates amyloid β protein (Aβ) generation through regulating beta-site APP cleaving enzyme 1 (BACE1) and γ-secretase. Knockdown of IFITM3 in CVECs reduces Aβ deposits and improves cognitive impairments in AD transgenic mice. Cerebrovascular endothelial IFITM3 could be a potential target for the treatment of AD.

Gasoline exhaust particles induce MMP1 expression via Nox4-derived ROS-ATF3-linked pathway in human umbilical vein endothelial cells.

Gasoline exhaust particles (GEP) are risk factors for cardiovascular disease. Activating transcription factor 3 (ATF3) is a transcription factor known to form a heterodimer with AP-1 transcription factors for its target gene expression. However, the involvement of ATF3 in GEP-induced gene expression in human umbilical vein endothelial cells (HUVECs) has not been investigated. In this study, we found that GEP, at IC50 value of 59μg/ml, induced the expression of ATF3, which led to the expression of matrix metalloproteinase 1 (MMP1) in HUVECs. GEP induce an interaction between c-Jun and ATF3, and c-Jun depletion attenuates GEP-induced MMP1 expression. Depletion of NADPH oxidase 4 (Nox4) suppressed GEP-induced reactive oxygen species (ROS) generation and the subsequent upregulation of ATF3 and MMP1, suggesting that Nox4-derived ROS play a role as upstream regulators of GEP-induced ATF3 expression and MMP1 upregulation. Furthermore, Nox4 depletion attenuated the interaction between ATF3 and c-Jun and their binding to the AP-1 binding site of the MMP1 promoter. Taken together, these findings demonstrate that GEP induce the expression of MMP1 by generating Nox4-dependent ROS, which subsequently increase ATF3 expression and its interaction with c-Jun. This leads to their binding to the promoter region of MMP1 and its transcription. These findings suggest that Nox4-derived ROS and ATF3 are critical for GEP-induced MMP1 expression.

6-Nitrodopamine is an endogenous mediator of rat seminal vesicles contractility.

6-Nitrodopamine (6-ND) released from rat vas deferens acts an endogenous modulator of vas deferens contractility. To investigate whether rat isolated seminal vesicles (RISV) releases 6-ND, the mechanisms involved in the release, and the modulatory role of 6-ND on tissue contractility. Rat seminal vesicles were removed and placed in Krebs-Henseleit's solution at 37°C for 30 min, and an aliquot was used to analyze the concentrations of 6-ND, dopamine, noradrenaline, and adrenaline by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The effect of mechanical removal of the epithelium and the effects of pre-incubation of RISV strips with Nω-nitro-L-arginine methyl ester (L-NAME; in combination or not with L-arginine), tetrodotoxin (TTX), GKT137831, and hydrogen peroxide (H2O2) on 6-ND release were evaluated. For functional studies, RISV strips were mounted in an organ bath and tied to an isometric force transducer. The expressions of tyrosine hydroxylase and endothelial nitric oxide synthase (eNOS, type III NOS) were investigated by immunohistochemistry and/or fluorescence in situ hybridization (FISH). 6-ND was the major released catecholamine from RISV strips compared with noradrenaline, adrenaline, and dopamine. Epithelium removal significantly reduced the release of 6-ND, noradrenaline and dopamine. In RISV strips obtained from animals chronically treated with L-NAME, the 6-ND release significantly reduced. Pre-incubation with L-NAME reduced 6-ND release, which was partly restored by co-incubation with L-arginine. Pre-incubation with TTX had no effect on the release of any catecholamine, whereas GKT137831 and H2O2 significantly increased 6-ND release. All catecholamines produced concentration-dependent RISV contractions, but 6-ND was approximately 30× less potent than the others. 6-ND (0.1 nM) significantly potentiated noradrenaline-, adrenaline-, and dopamine-induced contractions, with such potentiations inhibited by TTX. Immunohistochemistry and FISH assays in RISV tissues identified tyrosine hydroxylase in epithelial cells and eNOS expression in both epithelial and endothelial cells. This is the first demonstration that epithelial-derived 6-ND modulates rat seminal vesicle contractility.

Relationship between Oxidized Low-Density Lipoprotein Treatment and Hepatocellular Carcinoma Associated Transcript 1 Expression

Long non-coding RNAs (lncRNAs) have multiple biological functions in the vascular system including in endothelial cells (ECs). Hepatocellular carcinoma associated transcript 1 (HULC) is a lncRNA and highly up-regulated in liver cancer. Oxidized low-density lipoprotein (ox-LDL) is a remarkable risk factor for various disease. We investigated and compared HULC expression in human umbilical vein endothelial cells (HUVECs) treated with two different concentration of ox-LDL. We used quantitative polymerase chain reaction (qPCR) method to detect HULC expression level in HUVECs. HULC expression was found to be statistic significantly up-regulated in HUVECs treated with higher concentration of ox-LDL (P

Cadmium Reduces VE-Cadherin Expression in Endothelial Cells Through Activation of the Notch Signaling Pathway.

Cadmium (Cd) is a toxic heavy metal which induces vascular disorders. Previous studies suggest that Cd in the bloodstream affects vascular endothelial cells (ECs), potentially contributing to vascular-related diseases. However, the molecular mechanisms of effects of Cd on ECs remain poorly understood. Notch signaling pathway abnormalities have been implicated in ECs disruption. The present study aims to investigate the effect of low Cd concentrations on the Notch signaling pathway in ECs. Mice were treated with low concentration of Cd (2.28 mg/kg), and tissues were collected for examination of mRNA and protein levels of Notch pathway components and VE-cadherin, a major junctional protein in ECs. We found that Cd treatment increases expression of NICD1, Hes1, Hey1, Hey2 and decreases expression of VE-cadherin in brain and kidney tissues. In vitro, a low concentration of Cd (1 μM) also induces increase expression of NICD1, Hes1, Hey1, Hey2, and decrease expression of VE-cadherin in human umbilical vein endothelial cells (HUVECs). Low concentration of Cd increased the permeability of HUVECs. We also found that Notch signaling negatively regulates the expression of VE-cadherin. In addition, DAPT, a Notch pathway inhibitor, prevents Cd-induced reduction in VE-cadherin expression in HUVECs. In summary, these findings revealed that Cd exposure decreases VE-cadherin expression through activation of the Notch signaling pathway.

Protein corona potentiates the recovery of nanoparticle-induced disrupted tight junctions in endothelial cells.

Nanoparticle interactions with biological systems are intricate processes influenced by various factors, among which the formation of protein corona plays a pivotal role. This research investigates a novel aspect of nanoprotein corona-cell interactions, focusing on the impact of the protein corona on the recovery of disrupted tight junctions in endothelial cells. We demonstrate that the protein corona formed on the surface of star-shaped nanoparticles induces the aggregates of ZO-1, which is quite important for the barriers' integrity. Our research emphasizes that the APOA1 pre-coating on the nanoparticles reduces the ZO-1 expression of endothelial cells offering a promising strategy for overcoming the bio barriers. These findings contribute to our understanding of the interplay between nanoparticles, protein corona, and endothelial cell junctions, offering insights for developing innovative therapeutic approaches targeting the blood-brain barrier integrity. Our study holds promise for the future of nanomedicine, nano drug delivery systems and development of strategies to mitigate potential adverse effects.

Ghrelin Promotes Lipid Uptake into White Adipose Tissue via Endothelial Growth Hormone Secretagogue-Receptor in Mice.

Background/Objectives: Endothelial peroxisome proliferator-activated receptor gamma (PPARγ) regulates adipose tissue by facilitating lipid uptake into white adipocytes, but the role of endothelial lipid transport in systemic energy balance remains unclear. Ghrelin conveys nutritional information through the central nervous system and increases adiposity, while deficiency in its receptor, growth hormone secretagogue-receptor (GHSR), suppresses adiposity on a high-fat diet. This study aims to examine the effect of ghrelin/GHSR signaling in the endothelium on lipid metabolism. Methods: We compared the effects of ghrelin on adiposity and lipid uptake into adipocytes in wild-type and GHSR-null mice. Transgenic mice expressing GHSR selectively in endothelial cells were also generated and compared with global GHSR-null and wild-type mice. The impact of ghrelin on lipid uptake-related genes was assessed in cultured endothelial cells. Results: Ghrelin increased adiposity and triglyceride clearance in wild-type but not in GHSR-null mice. GHSR-null mice showed higher serum triglyceride after olive oil gavage and lower white adipose tissue (WAT) weight on a high-fat diet, suggesting impaired lipid uptake. Restoring GHSR expression in endothelial cells increased lipoprotein lipase activity, lipid uptake into WAT, and WAT weight. Ghrelin enhanced free fatty acid uptake and the expression of lipid uptake genes in cultured endothelial cells, whereas these effects were absent in GHSR-null mice-derived endothelial cells. Knockdown of PPARγ revealed that ghrelin/GHSR signaling in endothelial cells promoted lipid uptake via endothelial PPARγ. Conclusions: Endothelial GHSR is key for regulating lipid metabolism via PPARγ in response to ghrelin and for the role of endothelium in regulating white adipocyte metabolism. Targeting endothelial ghrelin signaling may be a promising therapeutic approach for managing excessive adiposity and associated metabolic disorders.

Aspects of the Clinical use of the Import-Substituted Radiopharmaceutical Agent 18F-PSMA in Prostate Cancer

One of the most common types of radionuclide studies, which are gaining traction in oncology, is positron emission tomography combined with computed tomography. The most significant and promising radiopharmaceutical agent in the radionuclide diagnosis of prostate cancer is 18F-PSMA. A high sensitivity and specificity of this radiopharmaceutical agent for prostate cancer are due to the prostate-specific membrane antigen, which is the second type of transmembrane glycoprotein with a high expression in endothelial cells during neoangiogenesis. The purpose is to develop a domestic import–substituted radiopharmaceutical agent 18F-PSMA, manufactured in the system of the Federal Medical and Biological Agency of Russia using domestic substances and excipients. Materials and methods. The syntheses were carried out on the Fastlab GE Healthcare module. This module has been repeatedly used to manufacture the radiopharmaceutical agent 18F-PSMA-1007 using original ABX cassettes. The reagent kit consisted of a vial with the precursor 18F-PSMA-1007, a vial with dimethyl sulfoxide for dissolving the precursor, and a vial with a solution of tetrabutylammonium in ethanol. Additional vials used outside the cassette and connected by connecting tubes with needles contained ethanol solutions with concentrations of 5 and 30%, a phosphate buffer solution. A QMA (quaternary methylamonium) cartridge was used to isolate fluorine-18. Sequentially connected PS-H+ and C18 extraction cartridges were used to isolate and purify the final product. Consumables included a «skeleton» with rotary valves, a housing, a three-necked reactor flask, glass vials, connecting tubes and adapters. Results. The process of synthesizing a radiopharmaceutical agent using domestic reagents was similar to the original one. A comparative analysis of the synthesis charts, a comparative analysis of the activity and yield of RFP made from domestic and imported reagents, and an assessment of radiochemical purity were carried out. The physiological and pathological distribution of the domestic radiopharmaceutical agent, as well as its comparison to the original drug, were carried out in the clinical part of the study, during which no side effects and adverse events were noted in patients. Conclusions. The radiopharmaceutical preparation made from domestic reagents using adapted technology for the original cassette is identical to the original in all quality indicators and corresponds to approved regulatory values.

MSC-derived exosomal circMYO9B accelerates diabetic wound healing by promoting angiogenesis through the hnRNPU/CBL/KDM1A/VEGFA axis

Diabetic foot ulcer (DFU) is a common but devastating complication of diabetes mellitus and might ultimately lead to amputation. Elucidating the regulatory mechanism of wound healing in DFU is quite important for developing DFU management strategies. Here, we show, mecenchymal stem cell (MSC)-derived exosomes promoted the proliferation, migration and angiogenesis of high glucose-treated endothelial cells and reduced cell apoptosis. These effects were further enhanced by MSC-derived exosomes carrying circMYO9B overexpression. Mechanistically, circMYO9B promoted the translocation of hnRNPU from nucleus to cytoplasm and consequently destabilized CBL, thereby reducing the ubiquitination and degradation of KDM1A to promote VEGFA expression in endothelial cells. MSC-derived exosomes carrying circMYO9B promotes angiogenesis and thus accelerates diabetic wound healing through regulating the hnRNPU/CBL/KDM1A/VEGFA axis, indicating potential therapeutic targets and strategies for DFU treatment.

Prostanoid signaling in retinal cells elicits inflammatory responses relevant to early-stage diabetic retinopathy

AbstractInflammation is a critical driver of the early stages of diabetic retinopathy (DR) and offers an opportunity for therapeutic intervention before irreversible damage and vision loss associated with later stages of DR ensue. Nonsteroidal anti-inflammatory drugs (NSAIDs) have shown mixed efficacy in slowing early DR progression, notably including severe adverse side effects likely due to their nonselective inhibition of all downstream signaling intermediates. In this study, we investigated the role of prostanoids, the downstream signaling lipids whose production is inhibited by NSAIDs, in promoting inflammation relevant to early-stage DR in two human retinal cell types: Müller glia and retinal microvascular endothelial cells. When cultured in multiple conditions modeling distinct aspects of systemic diabetes, Müller glia significantly increased production of prostaglandin E2 (PGE2), whereas retinal endothelial cells significantly increased production of prostaglandin F2α (PGF2α). Müller glia stimulated with PGE2 or PGF2α increased proinflammatory cytokine levels dose-dependently. These effects were blocked by selective antagonists to the EP2 receptor of PGE2 or the FP receptor of PGF2α, respectively. In contrast, only PGF2α stimulated adhesion molecule expression in retinal endothelial cells and leukocyte adhesion to cultured endothelial monolayers, effects that were fully prevented by FP receptor antagonist treatment. Together these results identify PGE2-EP2 and PGF2α-FP signaling as novel, selective targets for future studies and therapeutic development to mitigate or prevent retinal inflammation characteristic of early-stage DR.

CD2AP deficiency aggravates Alzheimer’s disease phenotypes and pathology through p38 MAPK activation

BackgroundAlzheimer’s disease (AD) is the most common form of neurodegenerative disorder, which is characterized by a decline in cognitive abilities. Genome-wide association and clinicopathological studies have demonstrated that the CD2-associated protein (CD2AP) gene is one of the most important genetic risk factors for AD. However, the precise mechanisms by which CD2AP is linked to AD pathogenesis remain unclear.MethodsThe spatiotemporal expression pattern of CD2AP was determined. Then, we generated and characterized an APP/PS1 mouse model with neuron-specific Cd2ap deletion, using immunoblotting, immunofluorescence, enzyme-linked immunosorbent assay, electrophysiology and behavioral tests. Additionally, we established a stable CD2AP-knockdown SH-SY5Y cell line to further elucidate the specific molecular mechanisms by which CD2AP contributes to AD pathogenesis. Finally, the APP/PS1 mice with neuron-specific Cd2ap deletion were treated with an inhibitor targeting the pathway identified above to further validate our findings.ResultsCD2AP is widely expressed in various regions of the mouse brain, with predominant expression in neurons and vascular endothelial cells. In APP/PS1 mice, neuronal knockout of Cd2ap significantly aggravated tau pathology, synaptic impairments and cognitive deficits. Mechanistically, the knockout of Cd2ap activated p38 mitogen-activated protein kinase (MAPK) signaling, which contributed to increased tau phosphorylation, synaptic injury, neuronal apoptosis and cognitive impairment. Furthermore, the phenotypes of neuronal Cd2ap knockout were ameliorated by a p38 MAPK inhibitor.ConclusionOur study presents the first in vivo evidence that CD2AP deficiency exacerbates the phenotypes and pathology of AD through the p38 MAPK pathway, identifying CD2AP/p38 MAPK as promising therapeutic targets for AD.

Fluorinated Porcine Bone-Derived Hydroxyapatite Promotes Vascularized Osteogenesis by Coordinating Human Bone Marrow Mesenchymal Stem Cell/Human Umbilical Vein Endothelial Cell Complexes.

Biogenic hydroxyapatite is known for its osteoinductive potential due to its similarity to human bone and biocompatibility, but insufficient vascularization compared to autogenous bone during early implantation limits bone integration and osteogenesis. Fluorine has been shown to improve hydroxyapatite's mechanical properties and the coupling of osteogenic and angiogenic cells. In this study, fluorine-modified biogenic hydroxyapatite (FPHA) with varying fluorine concentrations was prepared and tested for its ability to promote vascularized osteogenesis. FPHA prepared in this study retained the natural porous structure of biological cancellous bone and released F- ions when immersed in cell culture medium. The extraction solutions of FPHA0.25 and FPHA0.50 promoted the formation of capillary-like tubes by human umbilical vein endothelial cells (HUVECs), with FPHA0.25 significantly upregulating vegf mRNA and VEGF protein levels in co-cultured human bone marrow mesenchymal stem cells (HBMSCs). Additionally, FPHA0.25 and FPHA0.50 upregulated pdgf-bb mRNA and PDGF-BB protein levels in HUVECs. In vivo experiments using a rabbit cranial defect model demonstrated that FPHA0.25 promoted early bone formation and angiogenesis in the defect area, enhanced VEGF secretion, and increased PDGFR-β expression in endothelial and mesenchymal cells. These findings suggest that fluorine-modified biogenic hydroxyapatite with an optimal fluorine concentration (FPHA0.25) may offer a promising strategy to enhance the body's innate bone-healing potential by accelerating vascularization.

Mineralocorticoid receptor antagonism prevents coronary microvascular dysfunction in intermittent hypoxia independent of blood pressure.

Obstructive sleep apnea (OSA), characterized by intermittent hypoxia (IH), and is associated with increased cardiovascular mortality that may not be reduced by standard therapies. Inappropriate activation of the renin-angiotensin-aldosterone system occurs in IH, and mineralocorticoid receptor (MR) blockade has been shown to improve vascular outcomes in cardiovascular disease. Thus, we hypothesized that MR inhibition prevents coronary and renal vascular dysfunction in mice exposed to chronic IH. Human and mouse coronary vascular cells and male C57BL/6J mice were exposed to IH or room air (RA) for 12 hours/day for 3 days (in vitro) and 6 weeks with or without treatments with spironolactone (SPL) or hydrochlorothiazide (HTZ). In vitro studies demonstrated that IH increased MR gene expression in human and mouse coronary artery endothelial and smooth muscle cells. Exposure to IH in mice increased blood pressure, reduced coronary flow velocity reserve (CFVR), and attenuated endothelium-dependent dilation and enhanced vasoconstrictor responsiveness in coronary, but not renal arteries. Importantly, SPL treatment prevented altered coronary vascular function independent of blood pressure as normalization of BP with HTZ did not improve CFVR or coronary vasomotor function. These data demonstrate that chronic IH, which mimics the hypoxia-reoxygenation cycles of moderate-to-severe OSA, increases coronary vascular MR expression in vitro. It also selectively promotes coronary vascular dysfunction in mice. Importantly, this dysfunction is sensitive to MR antagonism by SPL, independent of blood pressure. These findings suggest that MR blockade could serve as an adjuvant therapy to improve long-term cardiovascular outcomes in patients with OSA.

Arginase-II gene deficiency reduces skeletal muscle aging in mice.

Age-associated sarcopenia decreases mobility and is promoted by cell senescence, inflammation, and fibrosis. The mitochondrial enzyme arginase-II (Arg-II) plays a causal role in aging and age-associated diseases. Therefore, we aim to explore the role of Arg-II in age-associated decline of physical activity and skeletal muscle aging in a mouse model. Young (4-6 months) and old (20-24 months) wild-type (wt) mice and mice deficient in arg-ii (arg-ii-/-) of both sexes are investigated. We demonstrate a decreased physical performance of old wt mice, which is partially prevented in arg-ii-/- animals, particularly in males. The improved phenotype of arg-ii-/- mice in aging is associated with reduced sarcopenia, cellular senescence, inflammation, and fibrosis, whereas age-associated decline of microvascular endothelial cell density, satellite cell numbers, and muscle fiber types in skeletal muscle is prevented in arg-ii-/- mice. Finally, we demonstrate an increased arg-ii gene expression level in aging skeletal muscle and found Arg-II protein expression in endothelial cells and fibroblasts, but not in skeletal muscle fibers, macrophages, and satellite cells. Our results suggest that increased Arg-II in non-skeletal muscle cells promotes age-associated sarcopenia, particularly in male mice.

Association of ten VEGF family genes with Alzheimer's disease endophenotypes at single cell resolution.

Using a single-nucleus transcriptome derived from the dorsolateral prefrontal cortex of 424 Religious Orders Study and the Rush Memory and Aging Project (ROS/MAP) participants, we investigated the cell type-specific effect of ten vascular endothelial growth factor (VEGF) genes on Alzheimer's disease (AD) endophenotypes. Negative binomial mixed models were used for differential gene expression and association analysis with AD endophenotypes. VEGF-associated intercellular communication was also profiled. Higher microglia FLT1, endothelial FLT4, and oligodendrocyte VEGFB are associated with greater amyloid beta (Aβ) load, whereas higher VEGFB expression in inhibitory neurons is associated with lower Aβ load. Higher astrocyte NRP1 is associated with lower tau density. Higher microglia and endothelial FLT1 are associated with worse cognition performance. Endothelial and microglial FLT1 expression was upregulated in clinical AD patients compared to cognitively normal controls. Finally, AD cells showed a significant reduction in VEGF signaling compared to controls. Our results highlight key changes in VEGF receptor expression in endothelial and microglial cells during AD, and the potential protective role of VEGFB in neurons. The prefrontal cortical expression of FLT1 and FLT4 was associated with worse cross-sectional global cognitive function, longitudinal cognitive trajectories, and more Alzheimer's disease (AD) neuropathology. The associations between FLT1 or FLT4 and AD endophenotypes appear to be driven by endothelial and microglial cells. VEGFB expression seems to have opposing effects on the Aβ burden in AD depending on cell types, highlighting its potential protective role in neurons.

Inhibition of Angiopoietin-2 rescues sporadic brain arteriovenous malformations by reducing pericyte loss.

Brain arteriovenous malformations (bAVMs) are a major cause of hemorrhagic stroke in children and young adults. These lesions are thought to result from somatic KRAS/BRAF mutations in brain endothelial cells (bECs). In this study, we introduce a new bAVM model by inducing a brain endothelial-specific BrafV600E mutation using the Slc1o1c1(BAC)-CreER driver line. The pathological characteristics of this model resemble human bAVMs, including dilated and hyperpermeable vessels, as well as parenchymal hemorrhage. We observed that these lesions showed a typical reduction in pericyte coverage and disruption of the pericyte-endothelial cell connection. Additionally, we found that ANGPT2 levels were significantly increased in the endothelium of bAVM lesions, which may be a critical factor in the pericyte deficits of the malformed vessels. Treatment with an ANGPT2 neutralizing antibody confirmed that blocking ANGPT2 can restore pericyte density in bAVM lesions, improve pericyte coverage around microvessels, enhance tight junction protein coverage related to endothelial cells, and normalize endothelial barrier function. In summary, our findings suggest that increased ANGPT2 expression in endothelial cells with the BrafV600E mutation is a key factor in pericyte deficiencies in bAVMs, highlighting the potential effectiveness of anti-ANGPT2 therapy in treating bAVMs.

Bioinspired adhesive polydopamine-metal-organic framework functionalized 3D customized scaffolds with enhanced angiogenesis, immunomodulation, and osteogenesis for orbital bone reconstruction

Critical-sized orbital bone defects can lead to significant maxillofacial deformities and even eye movement disorders. The challenges associated with these defects, including their complicated structure, inadequate blood supply, and limited availability of progenitor cells that hinder successful repair. To overcome these issues, we developed a novel approach using computer numerical control (CNC) material reduction manufacturing technology to produce a customized polyetheretherketone (PEEK) scaffold that conforms to the specific shape of orbital bone defects. Deferoxamine (DFO) was in situ encapsulated into polydopamine-hybridized zeolitic imidazolate framework-8 (pZIF8-DFO) nanoparticles, which was subsequently adhered to the sulfonated PEEK (sPEEK) scaffold through polydopamine modification. This functionalization enhanced drug loading efficiency and imparted anti-inflammatory properties to the nanoparticle system. Our in vitro findings demonstrated that the sustained release of DFO from the sPEEK/pZIF8-DFO scaffolds extended over 14 days and significantly promoted angiogenesis and progenitor cell recruitment, as evidenced by increased expression of HIF-1α, VEGF, and SDF-1α expression in human umbilical vein endothelial cells (HUVECs). Moreover, sPEEK/pZIF8-DFO scaffolds exhibited superior immunomodulation and osteogenic differentiation capabilities on Raw 264.7 cells and rabbit bone marrow mesenchymal stem cells (rBMSCs), respectively. Most notably, our in vivo rabbit orbital bone defects revealed that sPEEK/pZIF8-DFO scaffolds resulted in a greater volume of new bone formation than on sPEEK and sPEEK/pZIF8 scaffolds, with partial bone connection to the sPEEK/pZIF8-DFO scaffolds. In summary, we develop a novel PEEK scaffold that combines enhanced angiogenesis, stem cell recruitment, immunomodulation, and osteogenic differentiation, showcasing its promising potential for orbital bone reconstruction.

LSD1 deficiency in breast cancer cells promotes the formation of pre-metastatic niches

Lysine-specific demethylase 1 (LSD1), a histone demethylating enzyme, plays a crucial role in cancer metastasis. Studies show LSD1 knockout promotes breast cancer lung metastasis, but it’s unknown if it alters the lung microenvironment for metastasis. In this study, we investigated the effects of exosomes from LSD1-knockdown (LSD1 KD) breast cancer cells on pre-metastatic niche formation. Injecting exosomes from LSD1 KD cells in mice resulted in a substantial increase in lung colonization by breast cancer cells, while treatment with exosomes derived from LSD1 KD cells decreased the expression of the ZO-1 and occludin, leading to increased vascular permeability. The LSD1 KD reduced the expression of circDOCK1, which augmented the levels of miR-1270 in exosomes. And miR-1270 inhibited ZO-1 expression in human endothelial cells, which enhanced their permeability. Our study uncovered a novel mechanism in which the LSD1 promotes the formation of pre-metastatic niches via the regulation of exosomal miRNA.

Fluorescent gold nanoclusters possess multiple actions against atherosclerosis

Atherosclerosis caused major morbidity and mortality worldwide. Molecules possessing lipid-lowering and/or anti-inflammatory properties are potential druggable targets against atherosclerosis. We examined the anti-atherosclerotic effects of fluorescent gold nanoclusters (FANC), which were dihydrolipoic acid (DHLA)-capped 2-nm gold nanoparticles. We evaluated the 8-week effects of FANC in Western-type diet-fed ApoE-deficient mice by either continuous intraperitoneal delivery (20 μM, 50 μl weekly) or via drinking water (300 nM). FANC reduced aortic atheroma burden, serum total cholesterol, and oxidative stress markers malondialdehyde and 4-hydroxynonenal levels. FANC attenuated hepatic lipid deposit, with changed expression of lipid homeostasis-related genes HMGCR, SREBP, PCSK9, and LDLR in a pattern similar to mice treated with ezetimibe. FANC also inhibited intestinal cholesterol absorption, resembling the action of ezetimibe. The lipid-lowering and anti-atherosclerotic effects of FANC reappeared in Western-type diet-fed LDLr-deficient mice. FANC bound insulin receptor β (IRβ) via DHLA, leading to AKT activation. However, unlike insulin, which also bound IRβ to activate AKT to induce HO-1, activation of AKT by FANC was independent of HO-1 expression in human aortic endothelial cells (HAECs). Alternatively, FANC up-regulated NRF2, interfered the binding of KEAP1 to NRF2, and promoted KEAP1 degradation to free NRF2 for nuclear entry to induce HO-1 that suppressed the expression of ICAM-1 and VCAM-1. Consistently, FANC suppressed ox-LDL-induced enhanced attachment of THP-derived macrophages onto HAECs. In macrophages, FANC up-regulated ABCA1, and reversed ox-LDL-induced suppression of cholesterol efflux. FANC effected in vitro at nano moles. In conclusion, our findings showed novel actions and multiple mechanisms of FANC worked coherently against atherosclerosis.

OATP1A2 mediates Aβ1-42 transport and may be a novel target for the treatment of Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disease with an unknown cause. Many studies have suggested that the imbalance between the clearance and accumulation of β-amyloid protein (Aβ) in the brain of AD patients is the main cause of AD development of AD. Meanwhile, drug transporters play a key role in the transport of drugs and endogenous substances in vivo as well as in the development of many diseases. Could they be related to the imbalance between Aβ clearance and accumulation? OATP1A2 is the most abundant subfamily of organic anion transporting polypeptides (OATPs) that transport amphipathic substrates. Its high bilateral expression in brain endothelial cells suggests it plays a crucial role in delivering drugs and neuroactive peptides to brain tissue. Could it also be involved in mediating the production and accumulation of Aβ in the central system? This could lead to an imbalance between Aβ clearance and accumulation, ultimately resulting in AD development. This hypothesis would be bold and novel in the field of science. In this study, we successfully established the OATP1A2-HEK293T transgenic cell model, and found that the uptake of Aβ1-42 by OATP1A2-HEK293T cells was significantly higher than that of NC-HEK293T control cells and human astrocytes by adding different concentrations of Aβ1-42 to the cells of each group, suggesting that OATP1A2 expressed in the human brain is involved in Aβ amyloid protein transport.