Galectin-1 Attenuates PDGF-Mediated AKT Signaling in Retinal Pigment Epithelial Cells.

Galectins have the potential to interact with transmembrane glycoproteins to modulate their functions. Since galectin-1 interacts with PDGF-Rß, we analyzed the effect of galectin-1 on PDGF-BB-mediated AKT signaling in primary human retinal pigment epithelial (RPE) cells and galectin-1-deficient immortalized human RPE cells (LGALS1-/-/ARPE-19) following incubation with PDGF-BB and galectin-1. Expression and localization of galectin-1, PDGF-Rß and pAKT were investigated using western blot analysis and immunohistochemical staining. Cell proliferation of RPE cells was analyzed using BrdU ELISA. Following treatment of human RPE cells with human recombinant (hr)-galectin-1 and PDGF-BB, an intense clustering of PDGF-Rß and colocalization with galectin-1 were detected. By Western blot analysis and immunocytochemistry of human RPE cells, an enhanced PDGF-BB-mediated expression of pAKT was observed, which was substantially reduced by additional incubation with hr-galectin-1. Vice versa, in LGALS1-/-/ARPE-19 cells, the PDGF-BB-induced pAKT signal was enhanced compared to wild-type cells. Furthermore, a decreased expression of PDGF-Rß in human RPE cells was observed after treatment with PDGF-BB and hr-galectin-1, while in untreated LGALS1-/-/ARPE-19 cells, its constitutive expression was increased. In addition, after treatment of RPE cells with hr-galectin-1, the PDGF-BB-induced proliferation was markedly reduced. In summary, galectin-1 has the distinct potential to reduce PDGF-mediated pAKT signaling and proliferation in human RPE cells-an effect that is most likely facilitated via a decreased expression of PDGF-Rß.

MiRNA-132/212 encapsulated by adipose tissue-derived exosomes worsen atherosclerosis progression.

BACKGROUND: Visceral adipose tissue in individuals with obesity is an independent cardiovascular risk indicator. However, it remains unclear whether adipose tissue influences common cardiovascular diseases, such as atherosclerosis, through its secreted exosomes. METHODS: The exosomes secreted by adipose tissue from diet-induced obesity mice were isolated to examine their impact on the progression of atherosclerosis and the associated mechanism. Endothelial apoptosis and the proliferation and migration of vascular smooth muscle cells (VSMCs) within the atherosclerotic plaque were evaluated. Statistical significance was analyzed using GraphPad Prism 9.0 with appropriate statistical tests. RESULTS: We demonstrate that adipose tissue-derived exosomes (AT-EX) exacerbate atherosclerosis progression by promoting endothelial apoptosis, proliferation, and migration of VSMCs within the plaque in vivo. MicroRNA-132/212 (miR-132/212) was detected within AT-EX cargo. Mechanistically, miR-132/212-enriched AT-EX exacerbates palmitate acid-induced endothelial apoptosis via targeting G protein subunit alpha 12 and enhances platelet-derived growth factor type BB-induced VSMC proliferation and migration by targeting phosphatase and tensin homolog in vitro. Importantly, melatonin decreases exosomal miR-132/212 levels, thereby mitigating the pro-atherosclerotic impact of AT-EX. CONCLUSION: These data uncover the pathological mechanism by which adipose tissue-derived exosomes regulate the progression of atherosclerosis and identify miR-132/212 as potential diagnostic and therapeutic targets for atherosclerosis.

Nanographene Oxide Promotes Angiogenesis by Regulating Osteoclast Differentiation and Platelet-Derived Growth Factor Secretion.

An imbalanced system of angiogenesis-osteoblasts-osteoclasts is regarded as the main factor in bone remodeling dysfunction diseases or osseointegration loss. Osteoclast precursors are the key cells that accelerate bone-specific angiogenesis and maintain normal osteoblast and osteoclast function. Graphene oxide is an effective scaffold surface modification agent with broad application prospects in bone tissue engineering. However, the effect of graphene oxide on the interaction between osteoclasts and angiogenesis has not yet been elucidated. In this study, a rat calvarial defect model was established and treated with an electrochemically derived nanographene oxide (ENGO) hydrogel. Higher angiogenesis and platelet-derived growth factor (PDGF) B in preosteoclasts were observed in the ENGO group compared with that in the control group. Moreover, in vitro experiments demonstrate the efficacy of ENGO in substantially reducing the expression of the receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclast-associated markers and inhibiting bone resorption activity. Additionally, ENGO enhances the secretion of the osteoclast-derived coupling factor PDGF-BB and promotes angiogenesis. Our investigation revealed the crucial role of isocitrate dehydrogenase 1 (IDH1) in the ENGO-mediated regulation of osteoclast differentiation and PDGF-BB secretion. The decreased expression of IDH1 reduces the level of histone lysine demethylase 7A (KDM7A) and subsequently increases the H3K9me2 level in the cathepsin K promoter region. In summary, we found that ENGO promotes angiogenesis by inhibiting the maturity of RANKL-induced osteoclasts and enhancing PDGF-BB secretion. These results indicate that ENGO holds promise for the application in fostering osteoclast-endothelial cell crosstalk, providing an effective strategy for treating bone resorption and osteoclast-related bone loss diseases.

A one-stop integrated natural antimicrobial microneedles with anti-inflammatory, pro-angiogenic and long-term moisturizing properties to accelerate diabetic wound healing.

Diabetic ulcers present a formidable obstacle in diabetes management, typically leading to high mortality and amputation rates. To overcome traditional monotherapy drawbacks, We developed a novel microneedle strategy for combined antimicrobial action: ingeniously integrating quercetin with Platelet-derived Growth Factor-BB(PDGF-BB) and Sucrose Octasulfate(SOS) into the microneedle system(QPS MN). This method allows to penetrate through biofilms, administering quercetin nanocrystals and PDGF-BB deep into the tissue to combat microbial infection, mitigate inflammation, and promote angiogenesis. The accompanying backing material contains SOS, which absorbs wound exudate and forms a dressing that provides a moist environment for wound healing In an in vitro wound-scratch assay demonstrated that co-cultivating Human Umbilical Vein Endothelial Cells(HUVEC) with QPS MN for 48 h (90.3 ± 2.51 %) significantly enhanced cell migration compared to the control group (20.2 ± 1.41 %). Moreover, treatment of streptozotocin-induced diabetic wounds in rats with QPS MN for 14 days resulted in a wound healing rate of 96.56 ± 3.44 %, far surpassing the healing rate of only 40.34 ± 7.26 % observed in the untreated control group. Furthermore, the QPS MN treated wounds exhibited a notable increase in skin appendages and neovascularisation, indicating promising potential for achieving complete wound healing. These results suggest that QPS MN may offer substantial therapeutic benefits for addressing diabetic wounds.

Hsa_circ_0007765 Promotes Platelet-Derived Growth Factor-BB-Induced Proliferation and Migration of Human Aortic Vascular Smooth Muscle Cells in Atherosclerosis.

Human aortic vascular smooth muscle cells (HA-VSMCs) play vital roles in the pathogenesis of vascular diseases, including Atherosclerosis (AS). Circular RNAs (circRNAs) have been reported to regulate the biological functions of HA-VSMCs. Therefore, this study aimed to explore the role and mechanism of hsa_circRNA_102353 (circ_0007765) in platelet-derived growth factor-BB (PDGF-BB)-induced HA-VSMCs. Circ_0007765, microRNA-654-3p (miR-654-3p), and Fibroblast Growth Factor Receptor Substrate 2 (FRS2) expression were measured using real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferative ability, invasion, and migration were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and wound healing assays. CyclinD1, MMP2, and FRS2 protein levels were assessed using a Western blot assay. Binding between miR-654-3p and circ_0007765 or FRS2 was predicted by Circinteractome or TargetScan, and verified using dual-luciferase reporter and RNA pull-down assays. PDGF-BB induced HA-VSMC proliferation, invasion, and migration. Circ_0007765 and FRS2 expression levels were increased in PDGF-BB-treated HA-VSMCs, and the miR-654-3p level was reduced. Moreover, circ_0007765 absence hindered PDGF-BB-induced HA-VSMC proliferation, invasion, and migration in vitro. At the molecular level, circ_0007765 increased FRS2 expression by acting as a sponge for miR-654-3p. Our findings revealed that circ_0007765 boosted PDGF-BB-induced HA-VSMC proliferation and migration through elevating FRS2 expression via adsorbing miR-654-3p, providing a feasible therapeutic strategy for AS.

M2 Macrophage-Derived Exosomes Inhibit Atherosclerosis Progression by Regulating the Proliferation, Migration, and Phenotypic Transformation of Smooth Muscle Cells.

BACKGROUND: Vascular smooth muscle cell (VSMC) intimal migration, proliferation, and phenotypic transformation from a contractile to a synthetic state are hallmarks of the progression of atherosclerotic plaques. This study aims to explore the effects of exosomes derived from M2 macrophages (ExoM2) on the pathological changes of VSMCs in atherosclerosis (AS). METHODS: Cell Counting Kit-8 (CCK8) and wound healing assays were used to examine the impact of ExoM2 on platelet-derived growth factor-BB (PDGF-BB)-induced VSMC proliferation and migration, respectively. Western blotting was employed to analyze changes in the expression levels of contractile markers (e.g., alpha-smooth muscle actin [α-SMA]) and synthetic ones (e.g., osteopontin [OPN]) in VSMCs with or without ExoM2 treatment. ApoE-⁣/- mice on a high fat diet were utilized to observe the effects of ExoM2 on plaque progression and stability. Serial histopathological analysis was performed to elucidate the cellular mechanisms underlying the atheroprotective effects of ExoM2. RESULTS: Compared with controls, ExoM2 significantly inhibited PDGF-BB-induced VSMC proliferation, migration, and phenotypic transformation in vitro. In ApoE-⁣/- mice, ExoM2 treatment led to a marked reduction in plaque size, necrotic core area, the CD68/α-SMA ratio, and matrix metalloproteinase 9 (MMP9) and OPN levels, while enhancing plaque stability. CONCLUSIONS: ExoM2 inhibit AS progression by regulating VSMC proliferation, migration, and phenotypic transformation.

[Mechanism of salidroside in inhibiting proliferation, migration and promoting phenotypic switching of arterial smooth muscle cells].

This study aims to examine the effect of salidroside(SAL) on the phenotypic switching of human aortic smooth muscle cells(HASMC) induced by the platelet-derived growth factor-BB(PDGF-BB) and investigate the pharmacological mechanism. Firstly, the safe concentration of SAL was screened by the lactate dehydrogenase release assay. HASMC were divided into control, model, and SAL groups, and the cells in other groups except the control group were treated with PDGF-BB for the modeling of phenotypic switching. Cell proliferation and migration were detected by the cell-counting kit(CCK-8) assay and Transwell assay, respectively. The cytoskeletal structure was observed by F-actin staining with fluorescently labeled phalloidine. The protein levels of proliferating cell nuclear antigen(PCNA), migration-related protein matrix metalloprotein 9(MMP-9), fibronectin, α-smooth muscle actin(α-SMA), and osteopontin(OPN) were determined by Western blot. To further investigate the pharmacological mechanism of SAL, this study determined the expression of protein kinase B(Akt) and mammalian target of rapamycin(mTOR), as well as the upstream proteins phosphatase and tensin homologue(PTEN) and platelet-derived growth factor receptor ß(PDGFR-ß) and the downstream protein hypoxia-inducible factor-1α(HIF-1α) of the Akt/mTOR signaling pathway. The results showed that the HASMCs in the model group presented significantly increased proliferation and migration, the switching from a contractile phenotype to a secretory phenotype, and cytoskeletal disarrangement. Compared with the model group, SAL weakened the proliferation and migration of HASMC, promoted the expression of α-SMA(a contractile phenotype marker), inhibited the expression of OPN(a secretory phenotype marker), and repaired the cytoskeletal disarrangement. Furthermore, compared with the control group, the modeling up-regulated the levels of phosphorylated Akt and mTOR and the relative expression of PTEN, HIF-1α, and PDGFR-ß. Compared with the model group, SAL down-regulated the protein levels of phosphorylated Akt and mTOR, PTEN, PDGFR-ß, and HIF-1α. In conclusion, SAL exerts a protective effect on the HASMCs exposed to PDGF-BB by regulating the PDGFR-ß/Akt/mTOR/HIF-1α signaling pathway.

Inositol 1,4,5-Trisphosphate Receptors Regulate Vascular Smooth Muscle Cell Proliferation and Neointima Formation in Mice.

BACKGROUND: Vascular smooth muscle cell (VSMC) proliferation is involved in many types of arterial diseases, including neointima hyperplasia, in which Ca2+ has been recognized as a key player. However, the physiological role of Ca2+ release via inositol 1,4,5-trisphosphate receptors (IP3Rs) from endoplasmic reticulum in regulating VSMC proliferation has not been well determined. METHODS AND RESULTS: Both in vitro cell culture models and in vivo mouse models were generated to investigate the role of IP3Rs in regulating VSMC proliferation. Expression of all 3 IP3R subtypes was increased in cultured VSMCs upon platelet-derived growth factor-BB and FBS stimulation as well as in the left carotid artery undergoing intimal thickening after vascular occlusion. Genetic ablation of all 3 IP3R subtypes abolished endoplasmic reticulum Ca2+ release in cultured VSMCs, significantly reduced cell proliferation induced by platelet-derived growth factor-BB and FBS stimulation, and also decreased cell migration of VSMCs. Furthermore, smooth muscle-specific deletion of all IP3R subtypes in adult mice dramatically attenuated neointima formation induced by left carotid artery ligation, accompanied by significant decreases in cell proliferation and matrix metalloproteinase-9 expression in injured vessels. Mechanistically, IP3R-mediated Ca2+ release may activate cAMP response element-binding protein, a key player in controlling VSMC proliferation, via Ca2+/calmodulin-dependent protein kinase II and Akt. Loss of IP3Rs suppressed cAMP response element-binding protein phosphorylation at Ser133 in both cultured VSMCs and injured vessels, whereas application of Ca2+ permeable ionophore, ionomycin, can reverse cAMP response element-binding protein phosphorylation in IP3R triple knockout VSMCs. CONCLUSIONS: Our results demonstrated an essential role of IP3R-mediated Ca2+ release from endoplasmic reticulum in regulating cAMP response element-binding protein activation, VSMC proliferation, and neointima formation in mouse arteries.

MiR-411-5p Promotes Vascular Smooth Muscle Cell Phenotype Switch by Inhibiting Expression of Calmodulin Regulated Spectrin-Associated Protein-1.

When stimulated, vascular smooth muscle cells (VSMCs) change from a differentiated to a dedifferentiated phenotype. Dedifferentiated VSMCs have a key activity in cardiovascular diseases such as in-stent restenosis. MicroRNAs (miRNAs) have crucial functions in conversion of differentiated VSMCs to a dedifferentiated phenotype. We investigated the activity of miR-411-5p in the proliferation, migration, and phenotype switch of rat VSMCs.Based on a microRNA array assay, miR-411-5p expression was found to be significantly increased in cultured VSMCs stimulated by platelet-derived growth factor-BB (PDGF-BB). A CCK-8 assay, transwell assay, and scratch test were performed to measure the effect of miR-411-5p on the proliferation and migration of PDGF-BB-treated VSMCs. MiR-411-5p promoted expression of dedifferentiated phenotype markers such as osteopontin and tropomyosin 4 in PDGF-BB-treated VSMCs. Using mimics and inhibitors, we identified the target of miR-411-5p in PDGF-BB-treated VSMCs and found that calmodulin-regulated spectrin-associated protein-1 (CAMSAP1) was involved in the phenotypic switch mediated by PDGF-BB.By inhibiting expression of CAMSAP1, miR-411-5p enhanced the proliferation, migration, and phenotype switch of VSMCs.Blockade of miR-411-5p interaction with CAMSAP1 is a promising approach to treat in-stent restenosis.

AKAP1 alleviates VSMC phenotypic modulation and neointima formation by inhibiting Drp1-dependent mitochondrial fission.

The roles and mechanisms of A-kinase anchoring protein 1 (AKAP1) in vascular smooth muscle cell (VSMC) phenotypic modulation and neointima formation are currently unknown. AKAP1 is a mitochondrial PKA-anchored protein and maintains mitochondrial homeostasis. This study aimed to investigate how AKAP1/PKA signaling plays a protective role in inhibiting VSMC phenotypic transformation and neointima formation by regulating mitochondrial fission. The results showed that both PDGF-BB treatment and balloon injury reduced the transcription, expression, and mitochondrial anchoring of AKAP1. In vitro, the overexpression of AKAP1 significantly inhibited PDGF-BB mediated VSMC proliferation and migration, whereas AKAP1 knockdown further aggravated VSMC phenotypic transformation. Additionally, in the balloon injury model in vivo, AKAP1 overexpression reduced neointima formation, the muscle fiber area ratio, and rat VSMC proliferation and migration. Furthermore, PDGF-BB and balloon injury inhibited Drp1 phosphorylation at Ser637 and promoted Drp1 activity and mitochondrial midzone fission; AKAP1 overexpression reversed these effects. AKAP1 overexpression also inhibited the distribution of mitochondria at the plasma membrane and the reduction of PKARIIß expression induced by PDGF-BB, as evidenced by an increase in mitochondria-plasma membrane distance as well as PKARIIß protein levels. Moreover, the PKA agonist promoted Drp1 phosphorylation (Ser637) and inhibited PDGF-BB-mediated mitochondrial fission, cell proliferation, and migration. The PKA antagonist reversed the increase in Drp1 phosphorylation (Ser637) and the decline in mitochondrial midzone fission and VSMC phenotypic transformation caused by AKAP1 overexpression. The results of this study reveal that AKAP1 protects VSMCs against phenotypic modulation by improving Drp1 phosphorylation at Ser637 through PKA and inhibiting mitochondrial fission, thereby preventing neointima formation.

Basal ATP release signals through the P2Y2 receptor to maintain the differentiated phenotype of vascular smooth muscle cells.

BACKGROUND AND AIMS: Vascular smooth muscle cell (VSMC) dedifferentiation contributes substantively to vascular disease. VSMCs spontaneously release low levels of ATP that modulate vessel contractility, but it is unclear if autocrine ATP signaling in VSMCs is critical to the maintenance of the VSMC contractile phenotype. METHODS: We used pharmacological inhibitors to block ATP release in human aortic smooth muscle cells (HASMCs) for studying changes in VSMC differentiation marker gene expression. We employed RNA interference and generated mice with SMC-specific inducible deletion of the P2Y2 receptor (P2Y2R) gene to evaluate resulting phenotypic alterations. RESULTS: HASMCs constitutively release low levels of ATP that when blocked results in a significant decrease in VSMC differentiation marker gene expression, including smooth muscle actin (SMA), smooth muscle myosin heavy chain (SMMHC), SM-22α and calponin. Basal release of ATP represses transcriptional activation of the Krüppel-Like Factor 4 (KFL4) thereby preventing platelet-derived growth factor-BB (PDGF-BB) from inhibiting expression of SMC contractile phenotype markers. SMC-restricted conditional deletion of P2Y2R evoked dedifferentiation characterized by decreases in aortic contractility and contractile phenotype markers expression. This loss was accompanied by a transition to the synthetic phenotype with the acquisition of extracellular matrix (ECM) proteins characteristic of dedifferentiation, such as osteopontin and vimentin. CONCLUSIONS: Our data establish the first direct evidence that an autocrine ATP release mechanism maintains SMC cytoskeletal protein expression by inhibiting VSMCs from transitioning to a synthetic phenotype, and further demonstrate that activation of the P2Y2R by basally released ATP is required for maintenance of the differentiated VSMC phenotype.

Macrophage-derived PDGF-BB modulates glycolytic enzymes expression and pyroptosis in nucleus pulposus cells via PDGFR-ß/TXNIP pathway.

OBJECTIVE: Intervertebral Disc Degeneration (IVDD) is one of the leading causes of low back pain, significantly impacting both individuals and society. This study aimed to investigate the significance of macrophage infiltration and the role of macrophage-secreted platelet-derived growth factor-BB (PDGF-BB) in IVDD progression. METHODS: To confirm the protective function of macrophage-derived PDGF-BB on nucleus pulposus cells (NPCs), we employed Lysm-Cre transgenic mice to genetically ablate PDGF-B within the myeloid cells. Immunohistochemistry was utilized to detect the expression of glycolytic enzymes and pyroptosis-related proteins during the process of IVDD. Western blot, RT-PCR, ELISA and immunofluorescence were used to detect the protective effect of recombinant PDGF-BB on NPCs. RESULTS: Macrophage-derived PDGF-BB deficiency resulted in the loss of NPCs and the increased ossification of cartilage endplates during lumbar disc degeneration. Also, PDGF-BB deficiency triggered the inhibition of glycolytic enzymes' expression and the activation of pathways related to pyroptosis in the nucleus pulposus. Mechanistically, our results suggest that PDGF-BB predominantly conveys its protective influence on NPCs through the PDGF receptor- beta (PDGFR-ß)/ thioredoxin-interacting protein pathway. CONCLUSIONS: The absence of PDGF-BB originating from macrophages expedites the advancement of IVDD, whereas the application of PDGF-BB treatment holds the potential for retarding intervertebral disc degeneration in the human body.

Kanglexin counters vascular smooth muscle cell dedifferentiation and associated arteriosclerosis through inhibiting PDGFR.

BACKGROUND: Dysregulation of vascular smooth muscle cell (VSMC) function leads to a variety of diseases such as atherosclerosis and hyperplasia after injury. However, antiproliferative drug targeting VSMC exhibits poor specificity. Therefore, there is an urgent to develop highly specific antiproliferative drugs to prevention and treatment VSMC dedifferentiation associated arteriosclerosis. Kanglexin (KLX), a new anthraquinone compound designed by our team, has potential to regulate VSMC phenotype according to the physicochemical properties. PURPOSE: This project aims to evaluate the therapeutic role of KLX in VSMC dedifferentiation and atherosclerosis, neointimal formation and illustrates the underlying molecular mechanism. METHODS: In vivo, the ApoE-/- mice were fed with high-fat diet (HFD) for a duration of 13 weeks to establish the atherosclerotic model. And rat carotid artery injury model was performed to establish the neointimal formation model. In vitro, PDGF-BB was used to induce VSMC dedifferentiation. RESULTS: We found that KLX ameliorated the atherosclerotic progression including atherosclerotic lesion formation, lipid deposition and collagen deposition in aorta and aortic sinus in atherosclerotic mouse model. In addition, The administration of KLX effectively ameliorated neointimal formation in the carotid artery following balloon injury in SD rats. The findings derived from molecular docking and surface plasmon resonance (SPR) experiments unequivocally demonstrate that KLX had potential to bind PDGFR-ß. Mechanism research work proved that KLX prevented VSMC proliferation, migration and dedifferentiation via activating the PDGFR-ß-MEK -ERK-ELK-1/KLF4 signaling pathway. CONCLUSION: Collectively, we demonstrated that KLX effectively attenuated the progression of atherosclerosis in ApoE-/- mice and carotid arterial neointimal formation in SD rats by inhibiting VSMC phenotypic conversion via PDGFR-ß-MEK-ERK-ELK-1/KLF4 signaling. KLX exhibits promising potential as a viable therapeutic agent for the treatment of VSMC phenotype conversion associated arteriosclerosis.

Cyclosporin A inhibits PDGF-BB induced hyaluronan synthesis in orbital fibroblasts.

Orbital connective tissue changes are contributors to the pathogenesis in thyroid eye disease (TED). Activated fibroblasts respond to immune stimuli with proliferation and increased hyaluronan (HA) production. Cyclosporin A (CsA) was reported to be beneficial in the treatment of TED. PDGF isoforms are increased in orbital tissue of TED patients and enhance HA production. We aimed to study the effect of CsA on HA production and hyaluronan synthase (HAS1, 2 and 3) and hyaluronidase (HYAL1 and 2) mRNA expressions in orbital fibroblasts (OFs). Measurements were performed in the presence or absence of CsA (10 µM) in unstimulated or PDGF-BB (10 ng/ml) stimulated OFs. The HA production of TED OFs (n = 7) and NON-TED OFs (n = 6) were measured by ELISA. The levels of mRNA expressions were examined using RT-PCR. The proliferation rate and metabolic activity were measured by BrdU incorporation and MTT assays, respectively. Treatment with CsA resulted in an average 42% decrease in HA production of OFs (p < 0.0001). CsA decreased the expression levels of HAS2, HAS3 and HYAL2 (p = 0.005, p = 0.005 and p = 0.002, respectively.) PDGF-BB increased HA production (p < 0.001) and HAS2 expression (p = 0.004). CsA could reduce the PDGF-BB-stimulated HA production (p < 0.001) and HAS2 expression (p = 0.005) below the untreated level. In addition, CsA treatment caused a decrease in proliferation potential (p = 0.002) and metabolic activity (p < 0.0001). These findings point to the fact that CsA affects HA metabolism via HAS2, HAS3 and HYAL2 inhibition in OFs. In addition to its well characterized immunosuppressant properties, CsA's beneficial effect in TED may be related to its direct inhibitory effect on basal and growth factor stimulated HA production.

Taurine attenuates activation of hepatic stellate cells by inhibiting autophagy and inducing ferroptosis.

BACKGROUND: Liver fibrosis is a compensatory response during the tissue repair process in chronic liver injury, and finally leads to liver cirrhosis or even hepatocellular carcinoma. The pathogenesis of hepatic fibrosis is associated with the progressive accumulation of activated hepatic stellate cells (HSCs), which can transdifferentiate into myofibroblasts to produce an excess of the extracellular matrix (ECM). Myofibroblasts are the main source of the excessive ECM responsible for hepatic fibrosis. Therefore, activated hepatic stellate cells (aHSCs), the principal ECM producing cells in the injured liver, are a promising therapeutic target for the treatment of hepatic fibrosis. AIM: To explore the effect of taurine on aHSC proliferation and the mechanisms involved. METHODS: Human HSCs (LX-2) were randomly divided into five groups: Normal control group, platelet-derived growth factor-BB (PDGF-BB) (20 ng/mL) treated group, and low, medium, and high dosage of taurine (10 mmol/L, 50 mmol/L, and 100 mmol/L, respectively) with PDGF-BB (20 ng/mL) treated group. Cell Counting Kit-8 method was performed to evaluate the effect of taurine on the viability of aHSCs. Enzyme-linked immunosorbent assay was used to estimate the effect of taurine on the levels of reactive oxygen species (ROS), malondialdehyde, glutathione, and iron concentration. Transmission electron microscopy was applied to observe the effect of taurine on the autophagosomes and ferroptosis features in aHSCs. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to detect the effect of taurine on the expression of α-SMA, Collagen I, Fibronectin 1, LC3B, ATG5, Beclin 1, PTGS2, SLC7A11, and p62. RESULTS: Taurine promoted the death of aHSCs and reduced the deposition of the ECM. Treatment with taurine could alleviate autophagy in HSCs to inhibit their activation, by decreasing autophagosome formation, downregulating LC3B and Beclin 1 protein expression, and upregulating p62 protein expression. Meanwhile, treatment with taurine triggered ferroptosis and ferritinophagy to eliminate aHSCs characterized by iron overload, lipid ROS accumulation, glutathione depletion, and lipid peroxidation. Furthermore, bioinformatics analysis demonstrated that taurine had a direct targeting effect on nuclear receptor coactivator 4, exhibiting the best average binding affinity of -20.99 kcal/mol. CONCLUSION: Taurine exerts therapeutic effects on liver fibrosis via mechanisms that involve inhibition of autophagy and trigger of ferroptosis and ferritinophagy in HSCs to eliminate aHSCs.

Targeting deubiquitinase OTUB1 protects vascular smooth muscle cells in atherosclerosis by modulating PDGFRß.

Atherosclerosis is a chronic artery disease that causes various types of cardiovascular dysfunction. Vascular smooth muscle cells (VSMCs), the main components of atherosclerotic plaque, switch from contractile to synthetic phenotypes during atherogenesis. Ubiquitylation is crucial in regulating VSMC phenotypes in atherosclerosis, and it can be reversely regulated by deubiquitinases. However, the specific effects of deubiquitinases on atherosclerosis have not been thoroughly elucidated. In this study, RNAi screening in human aortic smooth muscle cells was performed to explore the effects of OTU family deubiquitinases, which revealed that silencing OTUB1 inhibited PDGF-BB-stimulated VSMC phenotype switch. Further in vivo studies using Apoe-/- mice revealed that knockdown of OTUB1 in VSMCs alleviated atherosclerosis plaque burden in the advanced stage and led to a stable plaque phenotype. Moreover, VSMC proliferation and migration upon PDGF-BB stimulation could be inhibited by silencing OTUB1 in vitro. Unbiased RNA-sequencing data indicated that knocking down OTUB1 influenced VSMC differentiation, adhesion, and proliferation. Mass spectrometry of ubiquitinated protein confirmed that proteins related to cell growth and migration were differentially ubiquitylated. Mechanistically, we found that OTUB1 recognized the K707 residue ubiquitylation of PDGFRß with its catalytic triad, thereby reducing the K48-linked ubiquitylation of PDGFRß. Inhibiting OTUB1 in VSMCs could promote PDGFRß degradation via the ubiquitin-proteasome pathway, so it was beneficial in preventing VSMCs' phenotype switch. These findings revealed that knocking down OTUB1 ameliorated VSMCs' phenotype switch and atherosclerosis progression, indicating that OTUB1 could be a valuable translational therapeutic target in the future.

Curcumol reduces lower limb arteriosclerosis in rats by inhibiting human arterial smooth muscle cell activity.

Cardiovascular diseases, particularly those involving arterial stenosis and smooth muscle cell proliferation, pose significant health risks. This study aimed to investigate the therapeutic potential of curcumol in inhibiting platelet-derived growth factor-BB (PDGF-BB)-induced human aortic smooth muscle cell (HASMC) proliferation, migration and autophagy. Using cell viability assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays and Western Blot analyses, we observed that curcumol effectively attenuated PDGF-BB-induced HASMC proliferation and migration in a concentration-dependent manner. Furthermore, curcumol mitigated PDGF-BB-induced autophagy, as evidenced by the downregulation of LC3-II/LC3-I ratio and upregulation of P62. In vivo experiments using an arteriosclerosis obliterans model demonstrated that curcumol treatment significantly ameliorated arterial morphology and reduced stenosis. Additionally, curcumol inhibited the activity of the KLF5/COX2 axis, a key pathway in vascular diseases. These findings suggest that curcumol has the potential to serve as a multi-target therapeutic agent for vascular diseases.

Corosolic acid attenuates platelet-derived growth factor signaling in macrophages and smooth muscle cells of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive and life-threatening disease that is characterized by vascular remodeling of the pulmonary artery. Pulmonary vascular remodeling is primarily caused by the excessive proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), which are facilitated by perivascular inflammatory cells including macrophages. Corosolic acid (CRA) is a natural pentacyclic triterpenoid that exerts anti-inflammatory effects. In the present study, the effects of CRA on the viability of macrophages were examined using monocrotaline (MCT)-induced PAH rats and human monocyte-derived macrophages. Although we previously reported that CRA inhibited signal transducer and activator of transcription 3 (STAT3) signaling and ameliorated pulmonary vascular remodeling in PAH, the inhibitory mechanism remains unclear. Therefore, the underlying mechanisms were investigated using PASMCs from idiopathic PAH (IPAH) patients. In MCT-PAH rats, CRA inhibited the accumulation of macrophages around remodeled pulmonary arteries. CRA reduced the viability of human monocyte-derived macrophages. In IPAH-PASMCs, CRA attenuated cell proliferation and migration facilitated by platelet-derived growth factor (PDGF)-BB released from macrophages and PASMCs. CRA also downregulated the expression of PDGF receptor ß and its signaling pathways, STAT3 and nuclear factor-κB (NF-κB). In addition, CRA attenuated the phosphorylation of PDGF receptor ß and STAT3 following the PDGF-BB simulation. The expression and phosphorylation levels of PDGF receptor ß after the PDGF-BB stimulation were reduced by the small interfering RNA knockdown of NF-κB, but not STAT3, in IPAH-PASMCs. In conclusion, CRA attenuated the PDGF-PDGF receptor ß-STAT3 and PDGF-PDGF receptor ß-NF-κB signaling axis in macrophages and PASMCs, and thus, ameliorated pulmonary vascular remodeling in PAH.

Proteasome inhibitor bortezomib prevents proliferation and migration of pulmonary arterial smooth muscle cells.

Pulmonary vascular remodeling is a key pathological process of pulmonary arterial hypertension (PAH), characterized by uncontrolled proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs). Bortezomib (BTZ) is the first Food and Drug Administration (FDA)-approved proteasome inhibitor for multiple myeloma treatment. Recently, there is emerging evidence showing its effect on reversing PAH, although its mechanisms are not well understood. In this study, anti-proliferative and anti-migratory effects of BTZ on PASMCs were first examined by different inducers such as fetal bovine serum (FBS), angiotensin II (Ang II) and platelet-derived growth factor (PDGF)-BB, while potential mechanisms including cellular reactive oxygen species (ROS) and mitochondrial ROS were then investigated; finally, signal transduction of ERK and Akt was examined. Our results showed that BTZ attenuated FBS-, Ang II- and PDGF-BB-induced proliferation and migration, with associated decreased cellular ROS production and mitochondrial ROS production. In addition, the phosphorylation of ERK and Akt induced by Ang II and PDGF-BB was also inhibited by BTZ treatment. This study indicates that BTZ can prevent proliferation and migration of PASMCs, which are possibly mediated by decreased ROS production and down-regulation of ERK and Akt. Thus, proteasome inhibition can be a novel pharmacological target in the management of PAH.

Shenqi Yizhi prescription prevents AßO-induced memory impairment in mice by regulating the contractility of brain pericytes.

BACKGROUND: Cerebral microcirculation disturbance manifested by decrease of cerebral blood flow (CBF) is one of early features of Alzheimer's disease (AD). Shenqi Yizhi prescription (SQYZ) is widely used in the treatment of AD. However, the effect of SQYZ on the early feature of AD is not clarified. PURPOSE: To explore the effect and mechanism of SQYZ on AD-like behavior from the perspective of early pathological features of AD. METHODS: The fingerprint of SQYZ was established by ultra-high-performance liquid chromatograph. The improvement effect of SQYZ on Aß1-42 Oligomer (AßO)-induced AD-like behavior of mice was evaluated by behavioral test. The changes of CBF were detected by laser doppler meter and laser speckle imaging. The pathological changes of the hippocampus were observed by HE staining and transmission electron microscope. The expressions of intercellular communication molecules were detected by western blotting or immunofluorescence staining. The content of platelet-derived growth factor-BB (PDGF-BB) was detected by ELISA. Finally, the core components of SQYZ were docked with platelet-derived growth factor receptor beta (PDGFRß) using AutoDock Vina software. RESULTS: The similarity of the components in SQYZ extracted from different batches of medicinal materials was higher than 0.9. SQYZ administration could improve AßO-induced memory impairment and CBF reduction. Compared with the sham group, the number of neurons in the hippocampi of AßO group was significantly reduced, and the microvessels were shrunken and deformed. By contrary, SQYZ administration mitigated those pathological changes. Compared with the sham mice, the expressions of CD31, N-cadherin, PDGFRß, glial fibrillary acidic protein, phosphorylation of focal adhesion kinase, integrin ß1, and integrin α5 in the hippocampi of AßO mice were significantly increased. However, SQYZ administration significantly reduced AßO-induced expression of those proteins. Interestingly, the effect of PDGFRß inhibitor, sunitinib demonstrated a consistent modulating effect as SQYZ. Finally, the brain-entering components of SQYZ, including ginsenoside Rg5, coptisine, cryptotanshinone, dihydrotanshinone IIA, stigmasterol, and tanshinone IIA had high binding force with PDGFRß, implicating PDGFRß as a potential target for SQYZ. CONCLUSIONS: Our data indicate that SQYZ improves CBF in AßO-triggered AD-like mice through inhibiting brain pericyte contractility, indicating the treatment potential of SQYZ for AD at the early stage.