Yohimbine Inhibits PDGF-Induced Vascular Smooth Muscle Cell Proliferation and Migration via FOXO3a Factor.

Yohimbine (YHB) has been reported to possess anti-inflammatory, anticancer, and cardiac function-enhancing properties. Additionally, it has been reported to inhibit the proliferation, migration, and neointimal formation of vascular smooth muscle cells (VSMCs) induced by platelet-derived growth factor (PDGF) stimulation by suppressing the phospholipase C-gamma 1 pathway. However, the transcriptional regulatory mechanism of YHB controlling the behavior of VSMCs is not fully understood. In this study, YHB downregulated the expression of cell cycle regulatory proteins, such as proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin-dependent kinase 4 (CDK4), and cyclin E, by modulating the transcription factor FOXO3a in VSMCs induced by PDGF. Furthermore, YHB decreased p-38 and mTOR phosphorylation in a dose-dependent manner. Notably, YHB significantly reduced the phosphorylation at Y397 and Y925 sites of focal adhesion kinase (FAK), and this effect was greater at the Y925 site than Y397. In addition, the expression of paxillin, a FAK-associated protein known to bind to the Y925 site of FAK, was significantly reduced by YHB treatment in a dose-dependent manner. A pronounced reduction in the migration and proliferation of VSMCs was observed following co-treatment of YHB with mTOR or p38 inhibitors. In conclusion, this study shows that YHB inhibits the PDGF-induced proliferation and migration of VSMCs by regulating the transcription factor FOXO3a and the mTOR/p38/FAK signaling pathway. Therefore, YHB may be a potential therapeutic candidate for preventing and treating cardiovascular diseases such as atherosclerosis and vascular restenosis.

Near-infrared light-responsive hydrogels for on-demand dual delivery of proangiogenic growth factors.

Achieving precise spatiotemporal control over the release of proangiogenic factors is crucial for vasculogenesis, the process of de novo blood vessel formation. Although various strategies have been explored, there is still a need to develop cell-laden biomaterials with finely controlled release of proangiogenic factors at specific locations and time points. We report on the developed of a near-infrared (NIR) light-responsive collagen hydrogel comprised of gold nanorods (GNRs)-conjugated liposomes containing proangiogenic growth factors (GFs). We demonstrated that this system enables on-demand dual delivery of GFs at specific sites and over selected time intervals. Liposomes were strategically formulated to encapsulate either platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF), each conjugated to gold nanorods (GNRs) with distinct geometries and surface plasmon resonances at 710 nm (GNR710) and 1064 nm (GNR1064), respectively. Using near infrared (NIR) irradiation and two-photon (2P) luminescence imaging, we successfully demonstrated the independent release of PDGF from GNR710 conjugated liposomes and VEGF from GNR1064-conjugated liposomes. Our imaging data revealed rapid release kinetics, with localized PDGF released in approximately 4 min and VEGF in just 1 and a half minutes following NIR laser irradiation. Importantly, we demonstrated that the release of each GF could be independently triggered using NIR irradiation with the other GF formulation remaining retained within the liposomes. This light-responsive collagen hydrogels holds promise for various applications in regenerative medicine where the establishment of a guided vascular network is essential for the survival and integration of engineered tissues. STATEMENT OF SIGNIFICANCE: In this study, we have developed a light-responsive system with gold nanorods (GNRs)-conjugated liposomes in a collagen hydrogel, enabling precise dual delivery of proangiogenic growth factors (GFs) at specific locations and timepoints. Liposomes, containing platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF), release independently under near- infrared irradiation. This approach allows external activation of desired GF release, ensuring high cell viability. Each GF can be triggered independently, retaining the other within the liposomes. Beyond its application in establishing functional vascular networks, this dual delivery system holds promise as a universal platform for delivering various combinations of two or more GFs.

Characterization of PDGF-Induced Subcellular Calcium Regulation through Calcium Channels in Airway Smooth Muscle Cells by FRET Biosensors.

The homeostasis of cellular calcium is fundamental for many physiological processes, while the calcium levels remain inhomogeneous within cells. During the onset of asthma, epithelial and inflammatory cells secrete platelet-derived growth factor (PDGF), inducing the proliferation and migration of airway smooth muscle (ASM) to the epidermal layer, narrowing the airway. The regulation of ASM cells by PDGF is closely related to the conduction of calcium signals. In this work, we generated subcellular-targeted FRET biosensors to investigate calcium regulation in the different compartments of ASM cells. A PDGF-induced cytoplasmic calcium [Ca2+]C increase was attributed to both extracellular calcium influx and endoplasmic reticulum (ER) calcium [Ca2+]ER release, which was partially regulated by the PLC-IP3R pathway. Interestingly, the removal of the extracellular calcium influx led to inhibited ER calcium release, likely through inhibitory effects on the calcium-dependent activation of the ER ryanodine receptor. The inhibition of the L-type calcium channel on the plasma membrane or the SERCA pump on the ER resulted in both reduced [Ca2+]C and [Ca2+]ER from PDGF stimulation, while IP3R channel inhibition led to reduced [Ca2+]C only. The inhibited SERCA pump caused an immediate [Ca2+]C increase and [Ca2+]ER decrease, indicating active calcium exchange between the cytosol and ER storage in resting cells. PDGF-induced calcium at the outer mitochondrial membrane sub-region showed a similar regulatory response to cytosolic calcium, not influenced by the inhibition of the mitochondrial calcium uniporter channel. Therefore, our work identifies calcium flow pathways among the extracellular medium, cell cytosol, and ER via regulatory calcium channels. Specifically, extracellular calcium flow has an essential function in fully activating ER calcium release.

Bergenin alleviates proliferative arterial diseases by modulating glucose metabolism in vascular smooth muscle cells.

BACKGROUND: Vascular smooth muscle cell (VSMC) proliferation and phenotypic switching are key mechanisms in the development of proliferative arterial diseases. Notably, reprogramming of the glucose metabolism pattern in VSMCs plays an important role in this process. PURPOSE: The aim of this study is to investigate the therapeutic potential and the mechanism underlying the effect of bergenin, an active compound found in Bergenia, in proliferative arterial diseases. METHODS: The effect of bergenin on proliferative arterial disease was evaluated using platelet-derived growth factor (PDGF)-stimulated VSMCs and a mouse model of carotid artery ligation. VSMC proliferation and phenotypic switching were evaluated in vitro using cell counting kit-8, 5-ethynyl-2-deoxyuridine incorporation, scratch, and transwell assays. Carotid artery neointimal hyperplasia was evaluated in vivo using hematoxylin and eosin staining and immunofluorescence. The expression of proliferation and VSMC contractile phenotype markers was evaluated using PCR and western blotting. RESULTS: Bergenin treatment inhibited PDGF-induced VSMC proliferation and phenotypic switching and reduced neointimal hyperplasia in the carotid artery ligation model. Additionally, bergenin partially reversed the PDGF-induced Warburg-like glucose metabolism pattern in VSMCs. RNA-sequencing data revealed that bergenin treatment significantly upregulated Ndufs2, an essential subunit of mitochondrial complex I. Ndufs2 knockdown attenuated the inhibitory effect of bergenin on PDGF-induced VSMC proliferation and phenotypic switching, and suppressed neointimal hyperplasia in vivo. Conversely, Ndufs2 overexpression enhanced the protective effect of bergenin. Moreover, Ndufs2 knockdown abrogated the effects of bergenin on the regulation of glucose metabolism in VSMCs. CONCLUSION: These findings suggest that bergenin is effective in alleviating proliferative arterial diseases. The reversal of the Warburg-like glucose metabolism pattern in VSMCs during proliferation and phenotypic switching may underlie this therapeutic mechanism.

Kisspeptin/KISS1R Signaling Modulates Human Airway Smooth Muscle Cell Migration.

Airway remodeling is a cardinal feature of asthma, associated with increased airway smooth muscle (ASM) cell mass and upregulation of extracellular matrix deposition. Exaggerated ASM cell migration contributes to excessive ASM mass. Previously, we demonstrated the alleviating role of Kp (kisspeptin) receptor (KISS1R) activation by Kp-10 in mitogen (PDGF [platelet-derived growth factor])-induced human ASM cell proliferation in vitro and airway remodeling in vivo in a mouse model of asthma. Here, we examined the mechanisms by which KISS1R activation regulates mitogen-induced ASM cell migration. KISS1R activation using Kp-10 significantly inhibited PDGF-induced ASM cell migration, further confirmed using KISS1R shRNA. Furthermore, KISS1R activation modulated F/G actin dynamics and the expression of promigration proteins like CDC42 (cell division control protein 42) and cofilin. Mechanistically, we observed reduced ASM RhoA-GTPAse with KISS1R activation. The antimigratory effect of KISS1R was abolished by PKA (protein kinase A)-inhibitory peptide. Conversely, KISS1R activation significantly increased cAMP and phosphorylation of CREB (cAMP-response element binding protein) in PDGF-exposed ASM cells. Overall, these results highlight the alleviating properties of Kp-10 in the context of airway remodeling.

Radiation-induced effects on TGF-ß and PDGF receptor signaling in cancer-associated fibroblasts.

BACKGROUND: Cancer-associated fibroblasts (CAFs) consist of heterogeneous connective tissue cells and are often constituting the most abundant cell type in the tumor stroma. Radiation effects on tumor stromal components like CAFs in the context of radiation treatment is not well-described. AIM: This study explores potential changes induced by ionizing radiation (IR) on platelet-derived growth factor (PDGF)/PDGFRs and transforming growth factor-beta (TGF-ß)/TGFßRs signaling systems in CAFs. METHODS AND RESULTS: Experiments were carried out by employing primary cultures of human CAFs isolated from freshly resected non-small cell lung carcinoma tumor tissues. CAF cultures from nine donors were treated with one high (1 × 18 Gy) or three fractionated (3 × 6 Gy) radiation doses. Alterations in expression levels of TGFßRII and PDGFRα/ß induced by IR were analyzed by western blots and flow cytometry. In the presence or absence of cognate ligands, receptor activation was studied in nonirradiated and irradiated CAFs. Radiation exposure did not exert changes in expression of PDGF or TGF-ß receptors in CAFs. Additionally, IR alone was unable to trigger activation of either receptor. The radiation regimens tested did not affect PDGFRß signaling in the presence of PDGF-BB. In contrast, signaling via pSmad2/3 and pSmad1/5/8 appeared to be down-regulated in irradiated CAFs after stimulation with TGF-ß, as compared with controls. CONCLUSION: Our data demonstrate that IR by itself is insufficient to induce measurable changes in PDGF or TGF-ß receptor expression levels or to induce receptor activation in CAFs. However, in the presence of their respective ligands, exposure to radiation at certain doses appear to interfere with TGF-ß receptor signaling.

PDGF-D Is Dispensable for the Development and Progression of Murine Alport Syndrome.

Alport syndrome is an inherited kidney disease, which can lead to glomerulosclerosis and fibrosis, as well as end-stage kidney disease in children and adults. Platelet-derived growth factor-D (PDGF-D) mediates glomerulosclerosis and interstitial fibrosis in various models of kidney disease, prompting investigation of its role in a murine model of Alport syndrome. In vitro, PDGF-D induced proliferation and profibrotic activation of conditionally immortalized human parietal epithelial cells. In Col4a3-/- mice, a model of Alport syndrome, PDGF-D mRNA and protein were significantly up-regulated compared with non-diseased wild-type mice. To analyze the therapeutic potential of PDGF-D inhibition, Col4a3-/- mice were treated with a PDGF-D neutralizing antibody. Surprisingly, PDGF-D antibody treatment had no effect on renal function, glomerulosclerosis, fibrosis, or other indices of kidney injury compared with control treatment with unspecific IgG. To characterize the role of PDGF-D in disease development, Col4a3-/- mice with a constitutive genetic deletion of Pdgfd were generated and analyzed. No difference in pathologic features or kidney function was observed in Col4a3-/-Pdgfd-/- mice compared with Col4a3-/-Pdgfd+/+ littermates, confirming the antibody treatment data. Mechanistically, lack of proteolytic PDGF-D activation in Col4a3-/- mice might explain the lack of effects in vivo. In conclusion, despite its established role in kidney fibrosis, PDGF-D, without further activation, does not mediate the development and progression of Alport syndrome in mice.

Platelet-derived growth factor signaling in pericytes promotes hypothalamic inflammation and obesity.

BACKGROUND: Pericytes are a vital component of the blood-brain barrier, and their involvement in acute inflammation was recently suggested. However, it remains unclear whether pericytes contribute to hypothalamic chronic inflammation and energy metabolism in obesity. The present study investigated the impact of pericytes on the pathophysiology of obesity by focusing on platelet-derived growth factor (PDGF) signaling, which regulates pericyte functions. METHODS: Tamoxifen-inducible systemic conditional PDGF receptor ß knockout mice (Pdgfrb∆SYS-KO) and Calcium/calmodulin-dependent protein kinase type IIa (CaMKIIa)-positive neuron-specific PDGF receptor ß knockout mice (Pdgfrb∆CaMKII-KO) were fed a high-fat diet, and metabolic phenotypes before and 3 to 4 weeks after dietary loading were examined. Intracellular energy metabolism and relevant signal transduction in lipopolysaccharide- and/or platelet-derived growth factor-BB (PDGF-BB)-stimulated human brain pericytes (HBPCs) were assessed by the Seahorse XFe24 Analyzer and Western blotting. The pericyte secretome in conditioned medium from HBPCs was studied using cytokine array kit, and its impact on polarization was examined in bone marrow-derived macrophages (BMDMs), which are microglia-like cells. RESULTS: Energy consumption increased and body weight gain decreased after high-fat diet loading in Pdgfrb∆SYS-KO mice. Cellular oncogene fos (cFos) expression increased in proopiomelanocortin (POMC) neurons, whereas microglial numbers and inflammatory gene expression decreased in the hypothalamus of Pdgfrb∆SYS-KO mice. No significant changes were observed in Pdgfrb∆CaMKII-KO mice. In HBPCs, a co-stimulation with lipopolysaccharide and PDGF-BB shifted intracellular metabolism towards glycolysis, activated mitogen-activated protein kinase (MAPK), and modulated the secretome to the inflammatory phenotype. Consequently, the secretome showed an increase in various proinflammatory chemokines and growth factors including Epithelial-derived neutrophil-activating peptide 78 (C-X-C motif chemokine ligand (CXCL)5), Thymus and activation-regulated chemokine (C-C motif chemokine (CCL)17), Monocyte chemoattractant protein 1 (CCL2), and Growth-regulated oncogene α (CXCL1). Furthermore, conditioned medium from HBPCs stimulated the inflammatory priming of BMDMs, and this change was abolished by the C-X-C motif chemokine receptor (CXCR) inhibitor. Consistently, mRNA expression of CXCL5 was elevated by lipopolysaccharide and PDGF-BB treatment in HBPCs, and the expression was significantly lower in the hypothalamus of Pdgfrb∆SYS-KO mice than in control Pdgfrbflox/flox mice (FL) following 4 weeks of HFD feeding. CONCLUSIONS: PDGF receptor ß signaling in hypothalamic pericytes promotes polarization of macrophages by changing their secretome and contributes to the progression of obesity.

SCUBE1 promotes pulmonary artery smooth muscle cell proliferation and migration in acute pulmonary embolism by modulating BMP7.

Objectives: After an episode of acute pulmonary embolism (APE), activated platelets have the ability to release various bioactive factors that can stimulate both proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). SCUBE1 has been previously reported to engage in platelet-platelet interactions, potentially contributing to the activation of platelets in early onset thrombi. The purpose of this study was to examine the alterations in SCUBE1 expression in PASMCs after APE, as well as understand the mechanism behind these changes. Methods: The platelet-rich plasma samples of both APE patients and healthy individuals were collected. A hyperproliferative model of PASMCs was established by using platelet-derived growth factor (PDGF) as a stimulator and various assays were used to investigate how SCUBE1-mediated BMP7 can regulate PDGF-induced PASMC proliferation and migration. Results: Elevated level of SCUBE1 were observed in platelet-rich plasma from patients with APE and in PASMCs induced by PDGF. SCUBE1 interference ameliorated PDGF-driven cell proliferation and migration, and also downregulated PCNA expression. Additionally, mechanistic studies demonstrated that SCUBE1 could directly bind to bone morphogenetic protein 7 (BMP7) and enhance BMP7 expression, which completely abolished the impact of SCUBE1 silencing on proliferation and migration ability of PASMCs after PDGF treatment. Conclusion: In the PDGF-induced proliferation of PASMCs, the expression of SCUBE1 and BMP7 was upregulated. Silencing of SCUBE1 impeded PDGF-induced proliferation and migration of PASMCs by restraining BMP7.

Platelet-Derived Growth Factor Nanocapsules with Tunable Controlled Release for Chronic Wound Healing.

Chronic wounds have emerged as an increasingly critical clinical challenge over the past few decades, due to their increasing incidence and socioeconomic burdens. Platelet-derived growth factor (PDGF) plays a pivotal role in regulating processes such as fibroblast migration, proliferation, and vascular formation during the wound healing process. The delivery of PDGF offers great potential for expediting the healing of chronic wounds. However, the clinical effectiveness of PDGF in chronic wound healing is significantly hampered by its inability to maintain a stable concentration at the wound site over an extended period. In this study, a controlled PDGF delivery system based on nanocapsules is proposed. In this system, PDGF is encapsulated within a degradable polymer shell. The release rate of PDGF from these nanocapsules can be precisely adjusted by controlling the ratios of two crosslinkers with different degradation rates within the shells. As demonstrated in a diabetic wound model, improved therapeutic outcomes with PDGF nanocapsules (nPDGF) treatment are observed. This research introduces a novel PDGF delivery platform that holds promise for enhancing the effectiveness of chronic wound healing.

Functional characterization of the dimeric form of PDGF-derived fusion peptide fabricated based on theoretical arguments.

A skin wound leads to the loss of skin integrity and the influx of pathogens into the tissue. Platelet-derived growth factors (PDGFs) are cytokines released from alpha granules during wound healing and interact with their cell surface receptors and activate signals involved in chemotaxis, growth, proliferation, and differentiation pathways. Due to the low stability of growth factors (GFs), a new peptide-derived PDGF-BB was designed, expressed in the Shuffle strain of E. coli, and purified by Ni-NTA agarose affinity column chromatography. The effect of fusion peptide was then evaluated on L929 fibroblast cells and animal models with skin lesions. In vitro, studies showed that the peptide led to an increase in the migration of fibroblast cells in the scratch assay. Its positive effect on wound healing was also observed in the skin-injured rats after 3, 7, and 12 days. A significant rise in neutrophils and granular tissue formation, re-epithelialization, angiogenesis, and collagen formation was exhibited on the third day of treatment when compared to the control group. The results showed that, despite reducing PDGF size, the fusion peptide was able to maintain at least some of the known functions attributed to full-length PDGF and showed positive results in wound healing.

Physicochemical, in vitro and in vivo evaluation of VEGF loaded PCL-mPEG and PDGF loaded PCL-Chitosan dual layered vascular grafts.

The present study has attempted to evaluate the endothelialization and smooth muscle regeneration efficiency of a novel dual-layer small-diameter vascular graft. Two types of layers (PCL-mPEG-VEGF and PCL-Chitosan-PDGF) were fabricated to find out the best layer giving endothelialization support for the lumen and unique contractile function for outer layer of blood vessels. Platelet-derived growth factor (PDGF) and chitosan were immobilized onto PCL surface by aminolysis-based surface modification technique. Besides, Poly (ethylene glycol) methyl ether (mPEG) and vascular endothelial growth factor (VEGF) were directly blended with PCL. Morphological analysis of membranes ensured consistency of average fibers diameter with native extracellular matrix. A favorable interaction of PCL-mPEG-VEGF with cow pulmonary endothelial cells (CPAEs) and PCL-Chitosan-PDGF with rat bone marrow mesenchymal stem cells (RBMSCs) was obtained during in vitro study. Controlled growth factor release patterns were found from both layers. Further, PCL-mPEG-VEGF exhibited endothelial markers expression properties from RBMSCs. Up-regulation of SMCs markers expression was significantly ensured by the PCL-Chitosan-PDGF membrane. Thus, PCL-mPEG-VEGF and PCL-Chitosan-PDGF were preferred as inner and outer layers respectively of a finally prepared tubular hybrid tissue engineered small diameter vascular graft. Finally, the dual-layer vascular graft was implanted onto a rat abdominal aorta model for 2 months. The extracted samples exhibited the presence of endothelial marker (ICAM 1) in the inner layer and smooth muscle cell marker (αSMA) in the outer layer as well as substantial amount of collagen deposition was observed in the both layers.

A Comparative Study on Platelet-Rich Plasma From Elderly Individuals and Young Adults to Treat Pressure Ulcers in Mice.

OBJECTIVE: The aim of the present study was to compare the therapeutic effects of activated platelet-rich plasma (PRP) prepared from elderly individuals and young adults to treat pressure ulcers (PUs), and to accumulate a theoretical basis for allogeneic PRP treatment of PUs in elderly patients. MATERIALS AND METHODS: Whole blood was extracted from elderly individuals aged >65 y and young adult volunteers for PRP preparation, and platelet concentrations in whole blood and PRP were compared. Growth factors released from activated PRP were assayed using the enzyme-linked immunosorbent assay. C57BL/6 mice were divided into three groups: the control saline, elderly-PRP (Group A), and young adult-PRP (Group B). Ischemia-reperfusion injury-induced PUs were established on the backs of mice. PUs were photographed on days 0, 5, and 10 to assess their sizes. Specimens were collected on day 10 and subjected to hematoxylin and eosin and Masson's staining. Immunohistochemical staining for CD31 was conducted to evaluate vascular formation, and cell invasion was assessed using a Transwell assay. The action of PRP on transforming growth factor-beta (TGF-ß)-dependent fibroblast activity and epithelial-mesenchymal transition was analyzed using immunofluorescence and Western blotting in vitro. RESULTS: The platelet concentrations in whole blood and PRP of young adults were significantly higher than that in elderly individuals. The two PRP treatment groups had similar platelet enrichment coefficients of PRP. After activation, PRP from young adults produced significantly higher levels of platelet-derived growth factor, TGF-ß, and vascular endothelial growth factor than PRP from elderly individuals (P < 0.05). The concentrations of platelet-derived growth factor, TGF-ß, and vascular endothelial growth factor were positively correlated with the platelet concentrations in whole blood and PRP. The effects of PRP in regulating the expressions of TGF-ß, α-smooth muscle actin, vimentin, and E-cadherin were observed in vivo and in vitro. The two PRP treatment groups exhibited better wound healing than the control group, as evidenced by more re-epithelialization, higher collagen content, skin fibrosis, and more blood vessel formation over time. Group B exhibited better wound healing than Group A (P < 0.05). CONCLUSION: PRP exhibits potent wound healing ability in PU therapy, and PRP from young adults is seemingly superior to that from elderly individuals because of a higher concentration of platelets and increased production of growth factors.

Estrogen receptors differentially modifies lamellipodial and focal adhesion dynamics in airway smooth muscle cell migration.

Sex-steroid signaling, especially estrogen, has a paradoxical impact on regulating airway remodeling. In our previous studies, we demonstrated differential effects of 17ß-estradiol (E2) towards estrogen receptors (ERs: α and ß) in regulating airway smooth muscle (ASM) cell proliferation and extracellular matrix (ECM) production. However, the role of ERs and their signaling on ASM migration is still unexplored. In this study, we examined how ERα versus ERß affects the mitogen (Platelet-derived growth factor, PDGF)-induced human ASM cell migration as well as the underlying mechanisms involved. We used Lionheart-FX automated microscopy and transwell assays to measure cell migration and found that activating specific ERs had differential effects on PDGF-induced ASM cell migration. Pharmacological activation of ERß or shRNA mediated knockdown of ERα and specific activation of ERß blunted PDGF-induced cell migration. Furthermore, specific ERß activation showed inhibition of actin polymerization by reducing the F/G-actin ratio. Using Zeiss confocal microscopy coupled with three-dimensional algorithmic ZEN-image analysis showed an ERß-mediated reduction in PDGF-induced expressions of neural Wiskott-Aldrich syndrome protein (N-WASP) and actin-related proteins-2/3 (Arp2/3) complex, thereby inhibiting actin-branching and lamellipodia. In addition, ERß activation also reduces the clustering of actin-binding proteins (vinculin and paxillin) at the leading edge of ASM cells. However, cells treated with E2 or ERα agonists do not show significant changes in actin/lamellipodial dynamics. Overall, these findings unveil the significance of ERß activation in regulating lamellipodial and focal adhesion dynamics to regulate ASM cell migration and could be a novel target to blunt airway remodeling.

Ubiquinol attenuates γ-radiation induced coronary and aortic changes via PDGF/p38 MAPK/ICAM-1 related pathway.

Endothelial vascular injury is one of the most pivotal disorders emerging during radiotherapy. It is crucial to rely on strong antioxidants to defend against vascular damage. The current study was carried out to investigate the ameliorative effect of ubiquinol (Ubq) against gamma (γ)-radiation induced aortic and coronary changes, with highlighting its role in suppression of p38 mitogen activated protein kinase (MAPK). Exposure to γ-radiation was adopted as a potent detrimental model that induces vascular tissue damage. Concisely, male albino rats were irradiated at a dose level of 7 Gy and treated daily with Ubq (10 mg/kg/day, p.o.) for 7 days pre-and post-irradiation. At the end of the experiment, lipid profile, 8-hydroxydeoxyguanosine (8-OHdG), gene expression of intercellular adhesion molecule (ICAM-1), platelet derived growth factor (PDGF), p38 MAPK and matrix metalloproteinase-9 (MMP-9) were estimated. Exposure to radiation significantly deteriorates aortic and coronary tissues. Conversely, administration of Ubq significantly reduced serum t-cholesterol, LDL and triglycerides (p = 0.001). In addition, Ubq prevented oxidative DNA damage (8-OHdG) (p = 0.1) and reduced serum MMP-9 (p = 0.001) which contributed to the endothelial cells damage. The positive impact of Ubq was more apparent in suppression of both PDGF (p = 0.001) and p38 MAPK (p = 0.1) protein concentrations, leading subsequently in reduction of ICAM-1 (p = 0.001) gene expression. As a conclusion, vascular endothelial damage brought on by γ-radiation is one of the leading causes of coronary and aortic deteriorations which could be successfully mitigated by Ubq.

Far-Infrared Irradiation Decreases Proliferation in Basal and PDGF-Stimulated VSMCs Through AMPK-Mediated Inhibition of mTOR/p70S6K Signaling Axis.

BACKGROUND: Far-infrared (FIR) irradiation has been reported to improve diverse cardiovascular diseases, including heart failure, hypertension, and atherosclerosis. The dysregulated proliferation of vascular smooth muscle cells (VSMCs) is well established to contribute to developing occlusive vascular diseases such as atherosclerosis and in-stent restenosis. However, the effects of FIR irradiation on VSMC proliferation and the underlying mechanism are unclear. This study investigated the molecular mechanism through which FIR irradiation inhibited VSMC proliferation. METHODS: We performed cell proliferation and cell death assay, adenosine 5'-triphosphate (ATP) assay, inhibitor studies, transfection of dominant negative (dn)-AMP-activated protein kinase (AMPK) α1 gene, and western blot analyses. We also conducted confocal microscopic image analyses and ex vivo studies using isolated rat aortas. RESULTS: FIR irradiation for 30 minutes decreased VSMC proliferation without altering the cell death. Furthermore, FIR irradiation accompanied decreases in phosphorylation of the mammalian target of rapamycin (mTOR) at Ser2448 (p-mTOR-Ser2448) and p70 S6 kinase (p70S6K) at Thr389 (p-p70S6K-Thr389). The phosphorylation of AMPK at Thr172 (p-AMPK-Thr172) was increased in FIR-irradiated VSMCs, which was accompanied by a decreased cellular ATP level. Similar to in vitro results, FIR irradiation increased p-AMPK-Thr172 and decreased p-mTOR-Ser2448 and p-p70S6K-Thr389 in isolated rat aortas. Pre-treatment with compound C, a specific AMPK inhibitor, or ectopic expression of dn-AMPKα1 gene, significantly reversed FIR irradiation-decreased VSMC proliferation, p-mTOR-Ser2448, and p-p70S6K-Thr389. On the other hand, hyperthermal stimulus (39°C) did not alter VSMC proliferation, cellular ATP level, and AMPK/mTOR/p70S6K phosphorylation. Finally, FIR irradiation attenuated platelet-derived growth factor (PDGF)-stimulated VSMC proliferation by increasing p-AMPK-Thr172, and decreasing p-mTOR-Ser2448 and p-p70S6K-Thr389 in PDGF-induced in vitro atherosclerosis model. CONCLUSION: These results show that FIR irradiation decreases the basal and PDGF-stimulated VSMC proliferation, at least in part, by the AMPK-mediated inhibition of mTOR/p70S6K signaling axis irrespective of its hyperthermal effect. These observations suggest that FIR therapy can be used to treat arterial narrowing diseases, including atherosclerosis and in-stent restenosis.

The effect of oral treatment of royal jelly on the expression of the PDGF-ß gene in the skin wound of male mice.

AIMS OF THE STUDY: Royal jelly (RJ) is one of the most widely used drugs in traditional medicine. One of its important applications is the repair of skin damage, although the path of its mechanism is still unknown. Platelet-derived growth factor-beta (PDGF-beta) is one of the important factors in wound healing and it has been observed that PDGF-ß expression decreases with increasing age. In this study, for the first time, the effect of RJ on skin wounds has been investigated through the expression of PDGF-ß and tissue studies. MATERIALS AND METHODS: 25 small laboratory male BALB/c mice were selected randomly and after creating a 5 mm wound on the back of their neck, they were treated with doses of 2.5, 10, and 40 mg/kg body weight, After sampling from the healed wound in 9th day, histopathological studies and the expression of PDGF-ß gene were performed by Real-time PCR method. RESULTS: The findings of the present study showed that royal jelly caused a significant increase in PDGF-ß (10.99 times) compared to the healthy group. Also, royal jelly increased the formation of covering tissue or epithelium, the synthesis of collagen, the presence of inflammatory cells, and the formation of new blood vessels. CONCLUSION: The oral treatment of royal jelly is probably effective in skin wound healing by changing the expression of PDGF-ß.

Hypoxia Treatment of Adipose Mesenchymal Stem Cells Promotes the Growth of Dermal Papilla Cells via HIF-1α and ERK1/2 Signaling Pathways.

Dermal papilla cells (DPCs) cultured in vitro induce hair follicle formation. Using a hypoxic microenvironment to culture adipose mesenchymal stem cells (ADSCs) can promote hair follicle growth. However, the exact molecular mechanisms underlying this process remain unclear. In this study, ADSCs and DPCs from Arbas Cashmere goats were used. A hypoxic microenvironment promoted the proliferation of ADSCs and increased the pluripotency of ADSCs. The growth factors vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF) were upregulated in ADSCs in the hypoxia-conditioned medium (Hypo-cm). Hypo-cm also enhanced the ability of DPCs to induce hair follicle formation. Inhibitors of the ERK1/2 signaling pathway caused the expressions of growth factors that increased in hypoxic microenvironments to decrease; moreover, hypoxia-inducible factor-1α (HIF-1α) increased the expression levels of VEGF, bFGF, and PDGF and inhibited the expression of bone morphogenic protein 7 (BMP7). In conclusion, these findings improve the theoretical basis for the development of gene therapy drugs for the treatment of alopecia areata and hair thinning.

A novel retinoic acid drug, EYE-502, inhibits choroidal neovascularization by targeting endothelial cells and pericytes.

Choroidal neovascularization (CNV) occurs in neovascular age-related macular degeneration (AMD) and often leads to permanent visual impairment. Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is the gold standard for the treatment of CNV. However, anti-VEGF treatment did not always cause vision improvement and sometimes had detrimental effects on normal retinal tissues. Herein, we identified a novel retinoic acid drug, EYE-502, which had great therapeutic effects on CNV. Administration of EYE-502 could inhibit VEGF-induced dysfunction of endothelial cells (ECs) and reduce platelet-derived growth factor (PDGF)-induced recruitment of pericytes to ECs in vitro. Administration of EYE-502 could reduce the area of choroidal sprouting and laser-induced CNV, exhibiting similar anti-angiogenic effects as aflibercept. Moreover, administration of EYE-502 could reduce pericyte coverage in the sprouting vessels and choroidal neovascularization. Mechanistically, EYE-502 primarily bound to retinoic acid receptors (RARs) and exerted the anti-angiogenic effects by targeting ECs and pericytes via affecting the activation of Wnt/ß-catenin and PDGF/PDGFR/PI3K/Akt signaling. Taken together, this study reports a novel retinoic acid drug, EYE-502, which can exert the anti-angiogenic effects by simultaneous targeting of ECs and pericytes.

Current progress in growth factors and extracellular vesicles in tendon healing.

Tendon injury healing is a complex process that involves the participation of a significant number of molecules and cells, including growth factors molecules in a key role. Numerous studies have demonstrated the function of growth factors in tendon healing, and the recent emergence of EV has also provided a new visual field for promoting tendon healing. This review examines the tendon structure, growth, and development, as well as the physiological process of its healing after injury. The review assesses the role of six substances in tendon healing: insulin-like growth factor-I (IGF-I), transforming growth factor ß (TGFß), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and EV. Different growth factors are active at various stages of healing and exhibit separate physiological activities. IGF-1 is expressed immediately after injury and stimulates the mitosis of various cells while suppressing the response to inflammation. VEGF, which is also active immediately after injury, accelerates local metabolism by promoting vascular network formation and positively impacts the activities of other growth factors. However, VEGF's protracted action could be harmful to tendon healing. PDGF, the earliest discovered cytokine to influence tendon healing, has a powerful cell chemotaxis and promotes cell proliferation, but it can equally accelerate the response to inflammation and relieve local adhesions. Also useful for relieving tendon adhesion is TGF- ß, which is active almost during the entire phase of tendon healing. As a powerful active substance, in addition to its participation in the field of cardiovascular and cerebrovascular vessels, tumour and chronic wounds, TGF- ß reportedly plays a role in promoting cell proliferation, activating growth factors, and inhibiting inflammatory response during tendon healing.