Bacteremia induced by periodontal infection is an important factor for periodontitis to threaten general health. P. gingivalis DNA/virulence factors have been found in the brain tissues from patients with Alzheimer's disease (AD). The blood-brain barrier (BBB) is essential for keeping toxic substances from entering brain tissues. However, the effect of P. gingivalis bacteremia on BBB permeability and its underlying mechanism remains unclear. In the present study, rats were injected by tail vein with P. gingivalis three times a week for eight weeks to induce bacteremia. An in vitro BBB model infected with P. gingivalis was also established. We found that the infiltration of Evans blue dye and Albumin protein deposition in the rat brain tissues were increased in the rat brain tissues with P. gingivalis bacteremia and P. gingivalis could pass through the in vitro BBB model. Caveolae were detected after P. gingivalis infection in BMECs both in vivo and in vitro. Caveolin-1 (Cav-1) expression was enhanced after P. gingivalis infection. Downregulation of Cav-1 rescued P. gingivalis-enhanced BMECs permeability. We further found P. gingivalis-gingipain could be colocalized with Cav-1 and the strong hydrogen bonding between Cav-1 and arg-specific-gingipain (RgpA) were detected. Moreover, P. gingivalis significantly inhibited the major facilitator superfamily domain containing 2a (Mfsd2a) expression. Mfsd2a overexpression reversed P. gingivalis-increased BMECs permeability and Cav-1 expression. These results revealed that Mfsd2a/Cav-1 mediated transcytosis is a key pathway governing BBB BMECs permeability induced by P. gingivalis, which may contribute to P. gingivalis/virulence factors entrance and the subsequent neurological impairments.
Animals ; Rats ; Bacteremia/metabolism* ; Blood-Brain Barrier/microbiology* ; Caveolin 1/metabolism* ; Gingipain Cysteine Endopeptidases/metabolism* ; Permeability ; Porphyromonas gingivalis/pathogenicity* ; Transcytosis ; Virulence Factors/metabolism*

Objective: To investigate the effects and mechanism of negative pressure microenvironment on the neogenesis of human umbilical vein endothelial cells (HUVECs). Methods: The experimental research methods were adopted. The third to the fifth passage of HUVECs in the logarithmic growth stage were used for the subsequent experiments. Three batches of cells were taken, with each batch of cells being divided into normal control group and negative pressure treatment alone group (both routinely cultured for 24 h), and 17-allylamino-17-demethoxy-geldanamycin (17-AAG) alone group and 17-AAG+negative pressure treatment group (both cultured with 17-AAG for 24 h). In addition, the intermittent negative pressure suction, with the negative pressure value of -5.33 kPa (suction for 30 s, pause for 10 s) was continuously applied for 8 h on cells in the two negative pressure treatment groups using an automatic three-dimensional cell gradient negative pressure loading device designed and developed by ourselves. After the treatment of the first batch of cells, the cell proliferation level was detected by cell counting kit 8 method at 0 (immediately), 24, 48, and 72 h of culture, with the number of samples being 6. After the treatment of the second batch of cells, the scratch experiment was performed. At 12 h after scratching, the cell migration was observed under an inverted phase contrast microscope and the cell migration rate was calculated, with the number of samples being 3. After the treatment of the third batch of cells, the tubule formation experiment was conducted. After 6 h of culture, the tubulogenesis was observed under an inverted phase contrast microscope and the total tubule length and the number of branch nodes of cells were calculated, with the number of samples being 3. The cells were taken and divided into normal control group, negative pressure treatment alone group, and 17-AAG+negative pressure treatment group. The cells were treated the same as in the previous corresponding group. After the treatment, Western blotting was used to detect the protein expressions of heat shock protein 90 (HSP90), caveolin 1, endothelial nitric oxide synthase (eNOS), and eNOS phosphorylation site 1177 in the cells, and the eNOS phosphorylation site 1177/eNOS ratio was calculated, with the number of samples being 3; co-immunoprecipitation (co-precipitating HSP90 and caveolin 1, caveolin 1 and eNOS) and Western blotting were used to detect the protein expressions of caveolin 1 and eNOS in the cells, with the number of samples being 3; the protein co-localization of HSP90 and caveolin 1 and that of caveolin 1 and eNOS in the cells was assessed by immunofluorescence double staining. The molecular docking prediction of caveolin 1 and eNOS was processed by HADDOCK 2.4 protein-protein docking program. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, and least significant difference method. Results: Compared with that in normal control group, the cell proliferation level in 17-AAG alone group was significantly decreased at culture hour of 24, 48, and 72 after the treatment (P<0.01), while the cell proliferation level in negative pressure treatment alone group was significantly increased at culture hour of 24, 48, and 72 after the treatment (P<0.01). Compared with that in 17-AAG alone group, the cell proliferation level in 17-AAG+negative pressure treatment group was significantly increased at culture hour of 48 and 72 after the treatment (P<0.05 or P<0.01). Compared with that in negative pressure treatment alone group, the cell proliferation level in 17-AAG+negative pressure treatment group was significantly decreased at culture hour of 24, 48, and 72 after the treatment (P<0.01). At 12 h after scratching, compared with (39.9±2.7)% in normal control group, the cell migration rate in 17-AAG alone group was significantly decreased ((10.7±2.7)%, P<0.01), while the cell migration rate in negative pressure treatment alone group was significantly increased ((61.9±2.4)%, P<0.01). Compared with those in 17-AAG alone group, the cell migration rate in 17-AAG+negative pressure treatment group was significantly increased ((37.7±3.7)%, P<0.01). Compared with that in negative pressure treatment alone group, the cell migration rate in 17-AAG+negative pressure treatment group was significantly decreased (P<0.01). At culture hour of 6 after the treatment, compared with those in normal control group, the total length of the tube formed by the cells in 17-AAG alone group was significantly shortened (P<0.05) and the number of branch nodes was significantly reduced (P<0.05), while the total length of the tube formed by the cells in negative pressure treatment alone group was significantly prolonged (P<0.01) and the number of branch nodes was dramatically increased (P<0.01). Compared with that in 17-AAG alone group, the number of branch nodes of the tube formed by the cells was significantly increased in 17-AAG+negative pressure treatment group (P<0.05). Compared with those in negative pressure treatment alone group, the total length of the tube formed by the cells in 17-AAG+negative pressure treatment group was significantly shortened (P<0.01) and the number of branch nodes was significantly reduced (P<0.01). Western blotting detection showed that after treatment, the overall comparison of eNOS and caveolin 1 protein expressions among the three groups of cells showed no statistically significant differences (P>0.05). The expression of HSP90 protein and the eNOS phosphorylation site 1177/eNOS ratio in the cells of negative pressure treatment alone group were significantly increased (P<0.01) compared with those in normal control group. Compared with those in negative pressure treatment alone group, the HSP90 protein expression and the eNOS phosphorylation site 1177/eNOS ratio in the cells of 17-AAG+negative pressure treatment group were significantly decreased (P<0.01). Co-immunoprecipitation and Western blotting detection after the treatment showed that compared with those in normal control group, the expression of caveolin 1 protein in the cells of negative pressure treatment alone group was significantly increased (P<0.01), while the protein expression of eNOS was significantly decreased (P<0.05). Compared with those in negative pressure treatment alone group, the expression of caveolin 1 protein in the cells of 17-AAG+negative pressure treatment group was significantly decreased (P<0.01), while the protein expression of eNOS was significantly increased (P<0.01). After the treatment, compared with those in normal control group, the co-localization of HSP90 and caveolin 1 protein in the cells of negative pressure treatment alone group was significantly increased, while the co-localization of caveolin 1 and eNOS protein was significantly decreased. Compared with those in negative pressure treatment alone group, the co-localization of HSP90 and caveolin 1 protein in the cells of 17-AAG+negative pressure treatment group was significantly decreased, while the co-localization of caveolin 1 and eNOS protein was significantly increased. Molecular docking prediction suggested that caveolin 1 interacted strongly with eNOS and inhibited the 1177 site phosphorylation of eNOS. Conclusions: The negative pressure microenvironment may inhibit the binding of caveolin 1 to eNOS by promoting the binding of HSP90 to caveolin 1 in HUVECs, so as to relieve the inhibition of 1177 site phosphorylation of eNOS by caveolin 1, thereby promoting the proliferation, migration, and tubulogenesis of HUVECs, and ultimately promoting the neogenesis of HUVECs.
Caveolin 1/metabolism* ; Cells, Cultured ; HSP90 Heat-Shock Proteins/metabolism* ; Human Umbilical Vein Endothelial Cells/metabolism* ; Humans ; Molecular Docking Simulation ; Phosphorylation

OBJECTIVES: The liver X receptors (LXRs) are members of the nuclear hormone receptor superfamily, and LXR-β is an important receptor for cholesterol content in brain cells. LXR-β/retinoic X receptor (RXR-α)/ATP binding cassette transporter A1 (ABCA1) cholesterol transmembrane transport system is closely related to the occurrence and development of Alzheimer's disease (AD). LXR agonist TO901317 can affect the accumulation of β- amyloid protein in the brain tissue of APP/PS1 double transgenic AD mice. However, the molecular mechanism is not clarified in detail. This study aims to evaluate the effects of LXR agonist TO901317 on the cognitive function of AD mice fed with high cholesterol diet, and to explore its possible mechanism from the perspective of cholesterol metabolism. METHODS: Twenty four male 6-month-old APP/PS1 double transgenic AD mice were randomly divided into 4 groups, 6 mice in each group: a control group (fed with normal diet), a cholesterol rich diet (CRD) group, a TO901317 group (fed with CRD combined with TO901317), and a GSK2033 group (fed with CRD combined with TO901317 and LXR antagonist GSK2033). The mice were fed with pellet feed made of high cholesterol feed, mixed with lard, egg yolk powder, and cod liver oil twice a day. TO901317 and GSK2033 were dissolved and diluted to a final concentration at 0.03%. The drugs were given to the mice daily through gastric tube according to their body weight. Meanwhile, the mice in the drug group were fed with high cholesterol diet . After feeding for 3 months, Morris water maze was used to observe the changes of spatial exploration and memory ability of AD mice in each group. The contents of TC, LDL, and HDL in serum of mice in each group were detected by cholesterol enzyme colorimetry, and the differences among the groups were compared. The expression of Aβ₄₂ in the brain of AD mice was detected by ELISA. Western blotting was used to detect the protein levels of LXR-β, RXR-α, ABCA1, and Caveolin-1 in the brain of each group. RESULTS: Morris water maze results showed that the times, distance and the duration of mice crossing the platform in the CRD group were significantly decreased compared with the control group (all P<0.05), while these three figures in TO901317 group were significantly increased compared with the CRD group (all P<0.05). Compared with the TO901317 group, there was a decrease of these figures in the GSK2033 group (all P<0.05). The serum TC and LDL levels in the CRD group were significantly higher than those in the control group, while HDL levels were significantly lower (all P<0.001). The figures of the TC and LDL contents level in the TO901317 group were lower than those in the CRD group, while HDL levels were higher (all P<0.001). Compared with TO901317 group, the contents of the TC and LDL in GSK2033 group were significantly increased, while HDL content was significantly decreased (all P<0.001). ELISA results showed that the production of Aβ₄₂ peptides in the brain of CRD group was the highest while the content in the TO901317 group was significantly decreased (P<0.001), which was the lowest among the groups. The figure in the control group was close to the GSK2033 group. Western blotting results showed that the protein levels of LXR-β, RXR-α, and ABCA1 in the CRD group were significantly decreased compared with the control group, but the protein level of Caveolin-1 was increased (all P<0.01). After TO901317 treatment, the protein levels of LXR-β, RXR-α and ABCA1 were significantly increased, while the protein level of Caveolin-1 was decreased partially (all P<0.001). In the GSK2033 group, the effect of TO901317 on AD mice was partially reversed by GSK2033. Compared to TO901317 group, the protein levels of LXR-β, RXR-α, and ABCA1 showed a decrease trend, while the protein level of Caveolin-1 showed an increase state (all P<0.05). CONCLUSIONS High cholesterol diet leads to severer spatial exploration, learning and memory impairment in transgenic AD mice, while the LXR agonist TO901317 attenuates this effect. The mechanism may be that TO901317 promotes cholesterol efflux by activating LXR-β/RXR-α/ABCA1 transmembrane transport system, reduces the expression of Caveolin-1, improves the composition of lipid raft, and ultimately reduces the production of Aβ₄₂ in the brain.
Male ; Animals ; Mice ; Liver X Receptors/metabolism* ; Mice, Transgenic ; Alzheimer Disease/genetics* ; Caveolin 1/metabolism* ; Hydrocarbons, Fluorinated/pharmacology* ; Cognition ; Amyloid beta-Peptides/metabolism* ; Cholesterol

To explore whether paeonol can play an anti-atherosclerotic role by regulating the expression of aortic caveolin-1 and affecting NF-κB pathway, so as to inhibit the inflammatory response of vascular endothelium in atherosclerotic rats. The atherosclerotic model of rats was induced by high-fat diet and vitamin D_2. The primary culture of vascular endothelial cells(VECs) was carried out by tissue block pre-digestion and adherent method. The injury model of VECs was induced by lipopolysaccharide(LPS), and filipin, a small concave protein inhibitor, was added for control. HE staining was used to observe pathological changes of aorta. TNF-α, IL-6 and VCAM-1 were detected by ELISA. Western blot assay was used to detect the protein expression levels of caveolin-1 and p65 in aorta and VECs. The results showed that as compared with model group, paeonol significantly reduced aortic plaque area and lesion degree in rats, decreased the level of serum TNF-α, IL-6 and VCAM-1 in the rats and enhanced the relative expression level of caveolin-1, decreased p65 expression conversely(P<0.05 or P<0.01). In vitro, as compared to model group, paeonol obviously improved cell morphology, decreased the secretion of TNF-α, IL-6 and VCAM-1 in VECs, increased caveolin-1 expression, and decreased p65 protein expression(P<0.05 or P<0.01). Furthermore, filipin could reverse the effect of paeonol on expression of inflammatory factors and proteins(P<0.05 or P<0.01). According to the results, it was found that paeonol could play the role of anti-atherosclerosis by up-regulating the expression of caveolin-1 and inhibiting the activation of NF-κB pathway to reduce vascular inflammation in atherosclerotic rats.
Acetophenones ; Animals ; Caveolin 1 ; Endothelial Cells ; Endothelium, Vascular ; Inflammation ; NF-kappa B ; Rats ; Signal Transduction ; Tumor Necrosis Factor-alpha ; Up-Regulation

Aberrant oxidative metabolism in cells is one of the hallmarks of cancer. Overproduction of reactive species promotes carcinogenesis by inducing genetic mutations and activating oncogenic pathways, and thus, antioxidant therapy is considered as an important strategy for cancer prevention and treatment. Caveolin-1 (Cav-1), a constituent protein of caveolae, is involved in not only the formation of the caveolae, vesicular transport, maintaining cholesterol homeostasis directly, but also many cellular physiological and pathological processes including growth, regulation of mitochondrial antioxidant level, apoptosis and carcinomas by interacting with a lot of signaling molecules through caveolin scaffolding domain. Cav-1 has also been shown to mediate tumor genesis and progression through oxidative stress modulation, while Cav-1-targeted treatment could scavenge the reactive species. Intracellular reactive species could modulate the expression, degradation, post-translational modifications and membrane trafficking of Cav-1. More importantly, emerging evidence has indicated that multiple antioxidants could exert antitumor activities in cancer cells by modulating the signaling of Cav-1. This paper reviewed the research progresses on the roles of Cav-1 and oxidative stress in tumorigenesis and development, and would provide new insights on designing strategies for cancer prevention or treatment.
Antioxidants ; Apoptosis ; Carcinogenesis ; Carcinoma ; pathology ; Caveolin 1 ; Humans ; Mitochondria ; Neoplasms ; pathology ; Oxidative Stress ; Signal Transduction

BACKGROUND: Striatin and caveolin-1 (cav-1) are scaffolding/regulating proteins that are associated with salt-sensitive high blood pressure and promote renal sodium and water reabsorption, respectively. The mineralocorticoid receptor (MR) interacts with striatin and cav-1, while aldosterone increases striatin and cav-1 levels. However, no in vivo data have been reported for the levels of these proteins in the kidney. METHODS: Male Wistar rats were intraperitoneally injected with normal saline solution, aldosterone alone (Aldo: 150 µg/kg body weight), or aldosterone after pretreatment with eplerenone, an MR blocker, 30 minutes before the aldosterone injection (eplerenone [Ep.]+Aldo). Thirty minutes after the aldosterone injection, the amount and localization of striatin and cav-1 were determined by Western blot analysis and immunohistochemistry, respectively. RESULTS: Aldosterone increased striatin levels by 150% (P<0.05), and cav-1 levels by 200% (P<0.001). Eplerenone had no significant effect on striatin levels, but partially blocked the aldosterone-induced increase in cav-1 levels. Aldosterone stimulated striatin and cav-1 immunoreactivity in both the cortex and medulla. Eplerenone reduced cav-1 immunostaining in both areas; however, striatin intensity was reduced in the cortex, but increased in the medulla. CONCLUSION: This is the first in vivo study demonstrating that aldosterone rapidly enhances renal levels of striatin and cav-1. Aldosterone increases striatin levels via an MR-independent pathway, whereas cav-1 is partially regulated through MR.
Aldosterone ; Animals ; Blotting, Western ; Caveolin 1 ; Humans ; Hypertension ; Immunohistochemistry ; Kidney ; Male ; Rats ; Rats, Wistar ; Receptors, Mineralocorticoid ; Sodium ; Sodium Chloride ; Water

Ubiquitin C-terminal hydrolase L1 (UCH-L1) is a deubiquitinating enzyme that is highly expressed in neurons, and gathering evidence indicates that UCH-L1 may play pathogenic roles in many neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease (PD). Additionally, lipid rafts have attracted interest in neurodegeneration as playing a common role in many neurodegenerative diseases. In the present study, we demonstrated that UCH-L1 associates with lipid rafts as with other PD-associated gene products. In addition, UCH-L1 regulates lipid raft-dependent endocytosis and it is not dependent on the expression and degradation of caveolin-1 or flotillin-1. Finally, UCH-L1 regulates cell-to-cell transmission of α-synuclein. This study provides evidence that many PD-associated gene products share common signaling pathways to explain the pathogenesis of PD.
alpha-Synuclein ; Alzheimer Disease ; Caveolin 1 ; Endocytosis* ; Neurodegenerative Diseases ; Neurons ; Parkinson Disease ; Prion Diseases ; Ubiquitin Thiolesterase* ; Ubiquitin*

Objective: To investigate whether androgens can regulate the expression of eNOS in rat corpus cavernosum through AKT3, PIK3CA, CALM, and CAV1 and influence erectile function. METHODS: Thirty-six 8-week-old male SD rats were randomly divided into groups A (4-week control), B (6-week control), C (4-week castration), D (6-week castration), E (4-week castration + testosterone replacement), and F (6-week castration + testosterone replacement). Both the testis and epididymis were removed from the rats in groups C, D, E and F, and on the second day after surgery, the animals of groups E and F were subcutaneously injected with testosterone propionate at 3 mg per kg of the body weight qd alt while all the others with isodose oil instead. At 4 weeks (for groups A, C and E) and 6 weeks (for groups B, D and F) after treatment, we detected the maximum intracavernous pressure (ICPmax), the mean carotid arterial pressure (MAP) and their ratio (ICPmax/MAP), measured the level of serum testosterone (T), and determined the expressions of eNOS, P-eNOS, AKT3, PIK3CA, CALM and CAV1 in the corpus cavernosum by Western blot and immunohistochemistry. RESULTS: No statistically significant differences were observed in the body weight and MAP among different groups. The serum T level and ICPmax/MAP were remarkably lower in groups C and D than in the other four groups (P<0.01) as well as in groups E and F than in A and B (P<0.05) but exhibited no significant differences either between E and F or between A and B. Immunohistochemistry showed that eNOS and P-eNOS were mainly expressed in the vascular endothelial cell membrane and cavernous vascular lumen, while AKT3, PIK3CA, CALM and CAV1 chiefly in the vascular endothelial cell cytoplasm and membrane, with a few in the smooth muscle cells. Western blot analysis manifested that the expressions of eNOS, P-eNOS, AKT3, PIK3CA, CALM and CAV1 were markedly lower in groups C and D than in A, B, E and F (P<0.01) as well as in D than in C (P<0.05) but those in groups E and F did not showed any significant difference from those in A and B, nor E from F or A from B. CONCLUSIONS Androgens can improve erectile function by upregulating the expressions of AKT3, PIK3CA, CALM and CAV1 protein molecules and activating eNOS after its phosphorylation, though the exact molecular mechanisms are yet to be further studied.
Animals ; Blood Pressure ; Blotting, Western ; Caveolin 1 ; metabolism ; Class I Phosphatidylinositol 3-Kinases ; metabolism ; Erectile Dysfunction ; Hormone Replacement Therapy ; Male ; Monomeric Clathrin Assembly Proteins ; metabolism ; Myocytes, Smooth Muscle ; Nitric Oxide Synthase Type III ; metabolism ; Orchiectomy ; Penile Erection ; physiology ; Penis ; enzymology ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Testosterone Propionate ; administration & dosage

Caveolin-1 (Cav-1) is a trans-membrane protein that is a major component of the caveolae structure on the plasma membrane. Cav-1 is involved in the regulation of various cellular processes, including cell growth, differentiation, endocytosis, and in particular it has been implied in cellular senescence. Here we review current knowledge about Cav-1 in cellular signaling and discuss the role of Cav-1 in aging-related diseases.
Caveolae ; Caveolin 1 ; Cell Aging ; Cell Membrane ; Endocytosis

BACKGROUND/AIMS:: We demonstrated the role of caveolin-1 involved in high glucose (HG)-induced glomerular mesangial cells (GMCs) senescence. METHODS:: HG was used to stimulate GMCs. The telomere lengths were analyzed by Southern blot. β-Galactosidase staining was determined. The expressions of caveolin-1 and P53 proteins were determined by Western blot. RESULTS:: Treatment with high concentrations of glucose induced GMC senescence accompanied by shortened telomere length and increase of β-galactosidase staining as well as P53 protein, which was abrogated after application of caveolin-1-siRNA. CONCLUSIONS:: This study proved that HG induced cell senescence in GMCs. The caveolin-1 is involved in HG-induced mesangial cell senescence, and blocking caveolin-1 significantly reduced cell senescence. The effect of caveolin-1 is mediated by P53 pathway.
Aging* ; Blotting, Southern ; Blotting, Western ; Caveolin 1* ; Cell Aging ; Glucose* ; Humans* ; Mesangial Cells* ; Telomere