Erchen decoction alleviates the progression of NAFLD by inhibiting lipid accumulation and iron overload through Caveolin-1 signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: A combination of 6 different Chinese herbs known as Erchen decoction (ECD) has been traditionally used to treat digestive tract diseases and found to have a protective effect against nonalcoholic fatty liver disease (NAFLD). Despite its efficacy in treating NAFLD, the precise molecular mechanism by which Erchen Decoction regulated iron ion metabolism to prevent disease progression remained poorly understood. AIM OF STUDY: Our study attempted to confirm the specific mechanism of ECD in reducing lipid and iron in NAFLD from the perspective of regulating the expression of Caveolin-1 (Cav-1). STUDY DESIGN: In our study, the protective effect of ECD was investigated in Palmitic Acid + Oleic Acid-induced hepatocyte NAFLD model and high-fat diet-induced mice NAFLD model. To investigate the impact of Erchen Decoction (ECD) on lipid metabolism and iron metabolism via mediating Cav-1 in vitro, Cav-1 knockdown cell lines were established using lentivirus-mediated transfection techniques. MATERIALS AND METHODS: We constructed NAFLD model by feeding with high-fat diet for 12 weeks in vivo and Palmitic Acid + Oleic Acid treatment for 24 h in vitro. The regulation of Lipid and iron metabolism results by ECD were detected by serological diagnosis, immunofluorescent and immunohistochemical staining, and western blotting. The binding ability of 6 small molecules of ECD to Cav-1 was analyzed by molecular docking. RESULTS: We demonstrated that ECD alleviated the progression of NAFLD by inhibiting lipid accumulation, nitrogen oxygen stress, and iron accumulation in vivo and in vitro experiments. Furthermore, ECD inhibited lipid and iron accumulation in liver by up-regulating the expression of Cav-1, which indicated that Cav-1 was an important target for ECD to exert its curative effect. CONCLUSIONS: In summary, our study demonstrated that ECD alleviated the accumulation of lipid and iron in NAFLD through promoting the expression of Cav-1, and ECD might serve as a novel Cav-1 agonist to treat NAFLD.

Impact of NB-UVB phototherapy on Caveolin-1 expression in chronic plaque psoriasis.

BACKGROUND: Caveolin-1 (Cav-1) is a significant structural and regulatory constituent of cell membranes that has been implicated in cell kinetics and inflammation. OBJECTIVE: To assess Cav-1 expression in psoriasis before and after phototherapy. PATIENTS AND METHODS: Thirty psoriasis cases and 30 healthy controls were recruited. Cases were managed with narrow band-ultraviolet B (NB-UVB) phototherapy at frequency three times per week for 12 weeks. From every case, two biopsy specimens were gained from psoriatic lesions (pre and post phototherapy), in addition to one from apparently normal skin of psoriasis cases. Regarding the control group, one biopsy was taken from a matched site. All were studied for Cav-1 antibody immuno-expression. RESULTS: There was a significant decrease in Cav-1 expression in psoriatic lesions compared to both the apparently normal skin of psoriasis patients and standard control skin of healthy individuals. After NB-UVB phototherapy, significant upregulation of Cav-1 immunostaining score was observed in previously psoriatic skin when compared to that before treatment. In addition, there were significant negative correlations between Cav-1 immunostaining score and the clinical scores of psoriasis severity including; the erythema, scaling, and induration (ESI) score and the patient psoriasis area and severity index (PASI) score. CONCLUSION: Induction of Cav-1 expression may be a likely pathway for the effectiveness of NB-UVB in psoriasis. Cav-1 may be a useful marker for evaluation of psoriasis severity, disease progression, and therapeutic efficacy.

Tiao-bu-fei-shen formula promotes downregulation of the caveolin 1-p38 mapk signaling pathway in COPD - Associated tracheobronchomalacia cell model.

ETHNOPHARMACOLOGICAL RELEVANCE: The Tiao-bu-fei-shen (TBFS) formula, extensively used in Traditional Chinese Medicine (TCM), can enhance therapeutic efficacy and reduce the frequency of acute exacerbations of lung-kidney Qi deficiency in patients with chronic obstructive pulmonary disease (COPD). According to both TCM theory and long-term observation of practice, TBFS has become an effective treatment for COPD-associated tracheobronchomalacia (TBM). AIM OF THE STUDY: To investigate the mechanism of the TBFS formula in treating COPD-associated TBM based on caveolin 1-p38 MAPK signaling and apoptosis. MATERIALS AND METHODS: A rat COPD model was prepared by exposure to smoking combined with tracheal lipopolysaccharide injection. The trachea or bronchus chondrocytes from COPD rats were isolated, cultured, and treated with 10 ng/mL IL-1ß for 24 h to develop a model of COPD-associated TBM. Normal rats were administered TBFS to prepare drug-containing serum, and CCK8 assays were used to screen the optimal drug-containing serum concentration and SB203580 dose. TBFS drug-containing serum and SB203580 were processed separately for the control, model, drug-containing serum, blocker, and drug-containing serum combined with blocker groups. Flow cytometry and CCK8 assays were used to detect apoptosis and proliferative activity. Toluidine blue staining and immunohistochemistry were used to analyze the chondrocyte proteoglycan and type II collagen content. Western blotting was used to detect the expression of caveolin 1, p-p38 MAPK, TNF-α, IL-1ß, MMP-13, Bax, and Bcl-2 proteins. Quantitative PCR was used to detect the expression of caveolin 1, p38 MAPK, IL-1ß, MMP-13, Bax, Bcl-2, and miR-140-5p. RESULTS: The isolation and identification of bronchial chondrocytes from COPD rats revealed that 10 ng/mL IL-1ß can produce a stable COPD-associated TBM model. Screened via the CCK8 method, fourth-generation bronchial chondrocytes were determined as the optimal cells, and 5 µM SB203580 and 5% low-dose drug-containing serum were the optimal intervention doses. The experimental chondrocytes of each group were treated separately for 48 h. Toluidine blue staining and immunohistochemical analysis revealed that TBFS drug-containing serum, SB203580, and TBFS drug-containing serum combined with SB203580 can effectively increase the proteoglycan and type II collagen content after chondrocyte degradation. Flow cytometry of cells treated with SB203580 and TBFS drug-containing serum combined with SB203580 revealed significantly reduced cell apoptosis and enhanced cell proliferation activity. Western blot and qPCR analyses revealed that the TBFS drug-containing serum, SB203580, and TBFS drug-containing serum combined with SB203580 effectively inhibit the expression of caveolin 1, p-p38 MAPK, MMP-13, IL-1ß, TNF-α, and Bax proteins while promoting Bcl -2 protein expression. Treatment with TBFS drug-containing serum and SB203580 effectively inhibited the expression of MMP-13, p38 MAPK, caveolin 1, and Bax genes, and promoted the expression of Bcl-2 and miR-140-5p genes. CONCLUSIONS: A concentration of 10 ng/mL of IL-1ß can generate a stable COPD-associated TBM cell model. TBFS can improve the proteoglycan and type II collagen content, increase cell activity, and reduce the amount of chondrocyte apoptosis. The role of TBFS may be related to mechanisms of inhibiting the expression of the key signaling molecules caveolin 1 and p-p38 MAPK in the caveolin 1-p38 MAPK signaling pathway, thereby reducing the expression of the downstream effector products MMP-13, IL-1ß, and TNF-α, while inhibiting the expression of the apoptotic gene Bax and improving the expression of Bcl-2 and miR-140-5p genes.

A novel mitochondrial Kv1.3-caveolin axis controls cell survival and apoptosis.

The voltage-gated potassium channel Kv1.3 plays an apparent dual physiological role by participating in activation and proliferation of leukocytes as well as promoting apoptosis in several types of tumor cells. Therefore, Kv1.3 is considered a potential pharmacological target for immunodeficiency and cancer. Different cellular locations of Kv1.3, at the plasma membrane or the mitochondria, could be responsible for such duality. While plasma membrane Kv1.3 facilitates proliferation, the mitochondrial channel modulates apoptotic signaling. Several molecular determinants of Kv1.3 drive the channel to the cell surface, but no information is available about its mitochondrial targeting. Caveolins, which are able to modulate cell survival, participate in the plasma membrane targeting of Kv1.3. The channel, via a caveolin-binding domain (CDB), associates with caveolin 1 (Cav1), which localizes Kv1.3 to lipid raft membrane microdomains. The aim of our study was to understand the role of such interactions not only for channel targeting but also for cell survival in mammalian cells. By using a caveolin association-deficient channel (Kv1.3 CDBless), we demonstrate here that while the Kv1.3-Cav1 interaction is responsible for the channel localization in the plasma membrane, a lack of such interaction accumulates Kv1.3 in the mitochondria. Kv1.3 CDBless severely affects mitochondrial physiology and cell survival, indicating that a functional link of Kv1.3 with Cav1 within the mitochondria modulates the pro-apoptotic effects of the channel. Therefore, the balance exerted by these two complementary mechanisms fine-tune the physiological role of Kv1.3 during cell survival or apoptosis. Our data highlight an unexpected role for the mitochondrial caveolin-Kv1.3 axis during cell survival and apoptosis.

Oxymatrine improves blood-brain barrier integrity after cerebral ischemia-reperfusion injury by downregulating CAV1 and MMP9 expression.

BACKGROUND: Ischemic stroke (IS) is a major neurological condition associated with extremely high morbidity and mortality worldwide. Oxymatrine (OMT), a quinolizidine alkaloid extracted from the root of Sophora flavescens, has neuroprotective properties and protects against IS. However, whether its protective effect involves alterations in the integrity of the blood-brain barrier (BBB) is unknown. PURPOSE: Here, we used in vivo and in vitro models of IS to evaluate the protective effects of OMT and to establish whether its effects are mediated via the modulation of the BBB function. METHODS: We assessed the effects of OMT by using neurological function scores, triphenyltetrazolium chloride staining, Nissl staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling. RESULTS: OMT significantly prevented cellular damage, improved neurological function, and reduced BBB permeability in a mouse model of cerebral ischemia-reperfusion. Additionally, OMT protected the function of the tight junctions of bEend.3 cells against the consequences of oxygen-glucose deprivation. Furthermore, intracranial lentivirus injection of short hairpin RNA targeting Cav1 decreased caveolin-1 expression and inhibited the neuroprotective effects of OMT. CONCLUSIONS: OMT attenuated ischemia-reperfusion injury-induced damage to the BBB, and this neuroprotective action was at least partially dependent on the expression levels of CAV1 and MMP9 proteins. Therefore, OMT may offer effective protection against BBB injury induced by ischemia-reperfusion episodes.

Caveolin-1 stabilizes ATP7A, a copper transporter for extracellular SOD, in vascular tissue to maintain endothelial function.

Caveolin-1 (Cav-1) is a scaffolding protein and a major component of caveolae/lipid rafts. Previous reports have shown that endothelial dysfunction in Cav-1-deficient (Cav-1-/-) mice is mediated by elevated oxidative stress through endothelial nitric oxide synthase (eNOS) uncoupling and increased NADPH oxidase. Oxidant stress is the net balance of oxidant generation and scavenging, and the role of Cav-1 as a regulator of antioxidant enzymes in vascular tissue is poorly understood. Extracellular SOD (SOD3) is a copper (Cu)-containing enzyme that is secreted from vascular smooth muscle cells/fibroblasts and subsequently binds to the endothelial cells surface, where it scavenges extracellular [Formula: see text] and preserves endothelial function. SOD3 activity is dependent on Cu, supplied by the Cu transporter ATP7A, but whether Cav-1 regulates the ATP7A-SOD3 axis and its role in oxidative stress-mediated vascular dysfunction has not been studied. Here we show that the activity of SOD3, but not SOD1, was significantly decreased in Cav-1-/- vessels, which was rescued by re-expression of Cav-1 or Cu supplementation. Loss of Cav-1 reduced ATP7A protein, but not mRNA, and this was mediated by ubiquitination of ATP7A and proteasomal degradation. ATP7A bound to Cav-1 and was colocalized with SOD3 in caveolae/lipid rafts or perinucleus in vascular tissues or cells. Impaired endothelium-dependent vasorelaxation in Cav-1-/- mice was rescued by gene transfer of SOD3 or by ATP7A-overexpressing transgenic mice. These data reveal an unexpected role of Cav-1 in stabilizing ATP7A protein expression by preventing its ubiquitination and proteasomal degradation, thereby increasing SOD3 activity, which in turn protects against vascular oxidative stress-mediated endothelial dysfunction.

Multifaceted Functions of Host Cell Caveolae/Caveolin-1 in Virus Infections.

Virus infection has drawn extensive attention since it causes serious or even deadly diseases, consequently inducing a series of social and public health problems. Caveolin-1 is the most important structural protein of caveolae, a membrane invagination widely known for its role in endocytosis and subsequent cytoplasmic transportation. Caveolae/caveolin-1 is tightly associated with a wide range of biological processes, including cholesterol homeostasis, cell mechano-sensing, tumorigenesis, and signal transduction. Intriguingly, the versatile roles of caveolae/caveolin-1 in virus infections have increasingly been appreciated. Over the past few decades, more and more viruses have been identified to invade host cells via caveolae-mediated endocytosis, although other known pathways have been explored. The subsequent post-entry events, including trafficking, replication, assembly, and egress of a large number of viruses, are caveolae/caveolin-1-dependent. Deprivation of caveolae/caveolin-1 by drug application or gene editing leads to abnormalities in viral uptake, viral protein expression, or virion release, whereas the underlying mechanisms remain elusive and must be explored holistically to provide potential novel antiviral targets and strategies. This review recapitulates our current knowledge on how caveolae/caveolin-1 functions in every step of the viral infection cycle and various relevant signaling pathways, hoping to provide a new perspective for future viral cell biology research.

Effect of Gubi prescription on caveolin-1 expression and phosphoinositide 3 kinase/protein kinase B and Fas signal pathways in rats with knee osteoarthritis.

OBJECTIVE: To investigate the effects of Gubi prescription on the expression of caveolin-1, and the phosphoinositide 3 kinase/protein kinase B (PI3K/Akt) and Fas signal pathways in rats with knee osteoarthritis (KOA). METHODS: Forty KOA model rats were established using a modification of Hulth's method. Rats were divided into five groups by the random number method: model, positive drug (Vicolli group), and high-, medium-, and low-dose Gubi prescription groups (n = 8/group). In the sham surgery group (n = 8), only anterior and posterior cruciate ligaments of rats were exposed during surgery. A normal group (n = 8) consisted of rats with no treatment. Rats were intragastrically administered corresponding drugs once every day for eight consecutive weeks. Then, rat synovial membranes were extracted and histomorphological changes were recorded. mRNA expression was measured by q-PCR. Serum superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), and interleukin 1ß (IL-1ß) levels were measured. Western blotting determined the effects of Gubi prescription on protein expressions of caveolin-1, Bax, Bcl-2, Fas, and caspase-3 in chondrocytes from KOA rats. The knee cartilage of rats was excised and cultured under aseptic conditions. After coincubation of chondrocytes with Gubi prescription-containing serum, IL-1ß, and siRNA, Western blotting was used to determine the protein expressions of caveolin-1, Bax, Bcl-2, Fas, and caspase-3. RESULTS: The morphological score of the articular synovium in the model group was significantly higher than in the normal group (P < 0.01). The morphological score in the high- and medium-dose Gubi prescription groups was lower than in the model group (P < 0.05). Chondrocytes from the decoction-containing serum group had a lower expression of Bax (P < 0.05), and higher expressions of Bcl-2 (P < 0.05) and caspase-3 (P < 0.05) compared with the model group. Chondrocytes in the decoction-containing serum group had higher expressions of Bax and Bcl-2 (P < 0.01) and lower expressions of caveolin-1 and Fas (P < 0.05) compared with the model group. Compared with the model group, Bax and caspase-3 expressions were reduced in the chondrocytes of all three Gubi prescription groups (P < 0.05) whereas Bcl-2 expression was increased (P < 0.05). Compared with the model group, the expressions of caveolin-1 and Fas (P < 0.05) were reduced in groups that received high- and medium-doses of Gubi prescription. Gubi prescription increased the serum level of SOD and significantly reduced those of MDA, NO and IL-1ß (P < 0.05). CONCLUSION: Gubi prescription suppressed the chondrocyte-related PI3K/Akt and Fas signal pathways and inhibited the overexpression of caveolin-1 in rat chondrocytes.

Altered Lipid Domains Facilitate Enhanced Pulmonary Vasoconstriction after Chronic Hypoxia.

Chronic hypoxia (CH) augments depolarization-induced pulmonary vasoconstriction through superoxide-dependent, Rho kinase-mediated Ca2+ sensitization. Nicotinamide adenine dinucleotide phosphate oxidase and EGFR (epidermal growth factor receptor) signaling contributes to this response. Caveolin-1 regulates the activity of a variety of proteins, including EGFR and nicotinamide adenine dinucleotide phosphate oxidase, and membrane cholesterol is an important regulator of caveolin-1 protein interactions. We hypothesized that derangement of these membrane lipid domain components augments depolarization-induced Ca2+ sensitization and resultant vasoconstriction after CH. Although exposure of rats to CH (4 wk, ∼380 mm Hg) did not alter caveolin-1 expression in intrapulmonary arteries or the incidence of caveolae in arterial smooth muscle, CH markedly reduced smooth muscle membrane cholesterol content as assessed by filipin fluorescence. Effects of CH on vasoreactivity and superoxide generation were examined using pressurized, Ca2+-permeabilized, endothelium-disrupted pulmonary arteries (∼150 µm inner diameter) from CH and control rats. Depolarizing concentrations of KCl evoked greater constriction in arteries from CH rats than in those obtained from control rats, and increased superoxide production as assessed by dihydroethidium fluorescence only in arteries from CH rats. Both cholesterol supplementation and the caveolin-1 scaffolding domain peptide antennapedia-Cav prevented these effects of CH, with each treatment restoring membrane cholesterol in CH arteries to control levels. Enhanced EGF-dependent vasoconstriction after CH similarly required reduced membrane cholesterol. However, these responses to CH were not associated with changes in EGFR expression or activity, suggesting that cholesterol regulates this signaling pathway downstream of EGFR. We conclude that alterations in membrane lipid domain signaling resulting from reduced cholesterol content facilitate enhanced depolarization- and EGF-induced pulmonary vasoconstriction after CH.

Endocytosing Escherichia coli as a Whole-Cell Biocatalyst of Fatty Acids.

Whole cell biocatalysts can be used to convert fatty acids into various value-added products. However, fatty acid transport across cellular membranes into the cytosol of microbial cells limits substrate availability and impairs membrane integrity, which in turn decreases cell viability and bioconversion activity. Because these problems are associated with the mechanism of fatty acid transport through membranes, a whole-cell biocatalyst that can form caveolae-like structures was generated to promote substrate endocytosis. Caveolin-1 ( CAV1) expression in Escherichia coli increased both the fatty acid transport rate and intracellular fatty acid concentrations via endocytosis of the supplemented substrate. Furthermore, fatty-acid endocytosis alleviated substrate cytotoxicity in E. coli. These traits attributed to bacterial endocytosis resulted in dramatically elevated biotransformation efficiencies in fed-batch and cell-recycle reaction systems when caveolae-forming E. coli was used for the bioconversion of ricinoleic acid (12-hydroxyoctadec-9-enoic acid) to ( Z)-11-(heptanoyloxy) undec-9-enoic acid. We propose that CAV1-mediated endocytosing E. coli represents a versatile tool for the biotransformation of hydrophobic substrates.

Stimulation of Caveolin-1 Signaling Improves Arteriovenous Fistula Patency.

Objective- Arteriovenous fistulae (AVF) are the most common access created for hemodialysis; however, many AVF fail to mature and require repeated intervention, suggesting a need to improve AVF maturation. Eph-B4 (ephrin type-B receptor 4) is the embryonic venous determinant that is functional in adult veins and can regulate AVF maturation. Cav-1 (caveolin-1) is the major scaffolding protein of caveolae-a distinct microdomain that serves as a mechanosensor at the endothelial cell membrane. We hypothesized that Cav-1 function is critical for Eph-B4-mediated AVF maturation. Approach and Results- In a mouse aortocaval fistula model, both Cav-1 mRNA and protein were increased in the AVF compared with control veins. Cav-1 KO (knockout) mice showed increased fistula wall thickening ( P=0.0005) and outward remodeling ( P<0.0001), with increased eNOS (endothelial NO synthase) activity compared with WT (wild type) mice. Ephrin-B2/Fc inhibited AVF outward remodeling in WT mice but not in Cav-1 KO mice and was maintained in Cav-1 RC (Cav-1 endothelial reconstituted) mice (WT, P=0.0001; Cav-1 KO, P=0.7552; Cav-1 RC, P=0.0002). Cavtratin-a Cav-1 scaffolding domain peptide-decreased AVF wall thickness in WT mice and in Eph-B4 het mice compared with vehicle alone (WT, P=0.0235; Eph-B4 het, P=0.0431); cavtratin also increased AVF patency (day 42) in WT mice ( P=0.0275). Conclusions- Endothelial Cav-1 mediates Eph-B4-mediated AVF maturation. The Eph-B4-Cav-1 axis regulates adaptive remodeling during venous adaptation to the fistula environment. Manipulation of Cav-1 function may be a translational strategy to enhance AVF patency.

Curcumin promotes burn wound healing in mice by upregulating caveolin-1 in epidermal stem cells.

We aimed to explore the effect of curcumin on epidermal stem cells (ESCs) in regulating wound healing and the underlying molecular mechanism. We treated mouse ESCs isolated from skin tissues with curcumin, and then assessed the proliferation ability of cells induced by epidermal growth factor using cell counting kit-8 assay. The pluripotency of ESCs was evaluated as well through examination of Nanog expression in ESCs. Further, mice with skin burns were treated with ESCs with or without curcumin pretreatments. Histological evaluations were then preformed to determine wound scores, cell proliferation, reepithelialization, and capillary density in wounds. Curcumin treatment promoted the proliferative ability of ESCs and conditioned medium from curcumin-treated ESCs enhanced human umbilical vein endothelial cell (HUVEC) tube formation. We also found curcumin treatment elevated caveolin-1 expression in ESCs, which was required for the beneficial effect of curcumin on ESC proliferation and HUVEC tube formation. Next, using a mouse model of burn wound healing, curcumin-treated ESCs exhibited enhanced wound closure, which also required caveolin-1 expression. Our current study demonstrates the beneficial effect of curcumin on burn wound healing in mice, which is mediated by upregulating caveolin-1 in ESCs, and supports the potential therapeutic role of curcumin in ESC-based treatment against skin wound healing.

Expression and clinical significance of Caveolin-1 in prostate Cancer after transurethral surgery.

BACKGROUND: Prostate cancer is a common malignancy of the male genitourinary system that occurs worldwide. The current research aims to investigate caveolin-1 expression in prostate cancer tissue and its relationship with pathological grade, clinical pathologic staging, and preoperative prostate-specific antigen (PSA) levels. METHODS: From January 2012 to December 2014, samples from 47 patients with prostate cancer who had received transurethral prostatic resection (TURP) and 20 patients with benign prostatic hyperplasia were collected at the First Affiliated Hospital of Guangxi Medical University. Caveolin-1 was detected by streptavidin-perosidase (SP) immunohistochemical staining in pathological tissue slices. The results were statistically analyzed for pathological grade, clinical stage, and preoperative PSA level. RESULTS: The expression of caveolin-1 was significantly higher in prostate cancer samples than in benign prostatic hyperplasia samples (P < 0.05), and caveolin-1 expression was significantly different among the pathological grades of poorly, moderately and well-differentiated prostate cancer (P < 0.05). The difference in caveolin-1 expression was significant for different clinical stages (T1-T2 and T3-T4) of prostate cancer (P < 0.05). The difference in caveolin-1 expression was not significant among samples with different preoperative PSA levels (0-10, 10-100 and > 100 µg/L) (P > 0.05). CONCLUSIONS: Caveolin-1 is closely related to the pathological grade and clinical stage of prostate cancer after transurethral surgery, and it may be a novel tumor marker for prostate cancer. The expression of caveolin-1 is not associated with preoperative serum PSA levels.

Curcumin Decreases Hyperphosphorylation of Tau by Down-Regulating Caveolin-1/GSK-3ß in N2a/APP695swe Cells and APP/PS1 Double Transgenic Alzheimer's Disease Mice.

Caveolin-1, the marker protein of membranal caveolae, is not only involved in cholesterol regulation, but also participates in the cleavage of amyloid [Formula: see text]-protein precursor (APP) and the generation of [Formula: see text]-amyloid peptide. It has been reported to be tightly related with Tau. In our previous studies, curcumin has been confirmed to play a neuroprotective role in Alzheimer's disease (AD), but its effects on Caveolin-1, Tau and their correlation, and the mechanism is still unknown. As such, in the present study, N2a/WT cells, N2a/APP695swe cell and six-month-old APP/PS1 double transgenic mice were enrolled. After curcumin treatment, the expression of Caveolin-1, Tau and their relationship was detected, and the potential mechanisms were explored. The results showed that in the N2a/APP695swe cells, curcumin not only decreased the number of caveolae, but also made their membrane to be thinner; and curcumin could decreased the expression of phosphorylated Tau (P-Tau(ser404)/Tau) and Caveolin-1 ([Formula: see text]), but the expression of phosphorylated GSK-3[Formula: see text] (P-GSK-3[Formula: see text]/GSK-3[Formula: see text] was increased ([Formula: see text]). In APP/PS1 transgenic mice, the same results were observed. Taken together, our data suggest that curcumin may play an important role in AD via reducing Caveolin-1, inactivating GSK-3[Formula: see text] and inhibiting the abnormal excessive phosphorylation of Tau, which will provide a new theory for AD treatment with curcumin.

Cholesterol regulates polymodal sensory transduction in Müller glia.

Over- and underexposure to cholesterol activates glia in neurodegenerative brain and retinal diseases but the molecular targets of cholesterol in glial cells are not known. Here, we report that disruption of unesterified membrane cholesterol content modulates the transduction of chemical, mechanical and temperature stimuli in mouse Müller cells. Activation of TRPV4 (transient receptor potential vanilloid type 4), a nonselective polymodal cation channel was studied following the removal or supplementation of cholesterol using the methyl-beta cyclodextrin (MßCD) delivery vehicle. Cholesterol extraction disrupted lipid rafts and caveolae without affecting TRPV4 trafficking or membrane localization protein. However, MßCD suppressed agonist (GSK1016790A)- and temperature-evoked elevations in [Ca2+ ]i , and suppressed transcellular propagation of Ca2+ waves. Lowering the free membrane cholesterol content markedly prolonged the time-course of the glial swelling response, whereas MßCD:cholesterol supplementation enhanced agonist- and temperature-induced Ca2+ signals and shortened the swelling response. Taken together, these data show that membrane cholesterol modulates polymodal transduction of agonists, swelling and temperature stimuli in retinal radial glia and suggest that dyslipidemic retinas might be associated with abnormal glial transduction of ambient sensory inputs.

Upregulation of caveolin-1 by mulberry leaf extract and its major components, chlorogenic acid derivatives, attenuates alcoholic steatohepatitis via inhibition of oxidative stress.

Excessive alcohol uptake exerts hepatocellular toxicity, ultimately leading to multiple liver diseases such as steatohepatitis and liver cirrhosis. Here, we aimed to explore the effects of mulberry leaf extract (MLE) and its major components chlorogenic acid (CGA) and neochlorogenic acid (nCGA) on alcoholic steatohepatitis. We determined the composition of MLE using liquid chromatography-mass spectrometric (LC-MS) analysis, which showed that MLE consisted of mainly chlorogenic acid derivatives and other polyphenols. Next, we utilized a high alcohol-fed mouse model and demonstrated that MLE alleviated alcohol-induced hepatocellular disorders, resulting in lowered hepatic injury markers and lipid accumulation. In addition, MLE reduced lipid peroxidation and meanwhile elevated hepatic superoxide dismutase (SOD). Immunohistochemical (IHC) staining revealed that MLE elevated the expression of caveolin-1 but reduced the expressions of epidermal growth factor receptor (EGFR), signal transducer and activator of transcription (STAT), inducible nitric oxide synthase (iNOS) and receptor interacting protein (RIP) 1/3. Major components of MLE, CGA and nCGA, not only exerted a similar biological activity as MLE but also inhibited alcohol-induced pro-apoptotic signals. Involvement of caveolin-1 in MLE, CGA and nCGA was demonstrated by using specific small inhibitory RNA. In conclusion, MLE and its chlorogenic derivatives CGA and nCGA upregulate caveolin-1 expression and diminish EGFR/STAT3/iNOS signalling, which may contribute to lowered hepatic lipid accumulation and peroxidation and inhibited pro-apoptotic cascades.

Extract of Clinopodium bolivianum protects against E. coli invasion of uroepithelial cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Clinopodium bolivianum is a South American plant with anti-inflammatory and anti-infective activities. The increasing antibiotic resistance urges for alternative therapy. Based on its use in traditional medicine, we investigated the effect of C. bolivianum on the ability to defend bladder epithelial cells from E. coli infection. MATERIALS AND METHODS: The extract was analyzed by LC-MS. Bladder epithelial cell lines T24 and 5637 and uropathogenic E. coli No. 12, its isogenic mutant WE16 csgBA bscA::Cm and CFT073 were used to investigate the effect of C. bolivianum on uroepithelial infection. Bacterial adherence and invasion to cells treated with C. bolivianum were analyzed. Expression of uroplakin 1a, ß1 integrin, caveolin-1, IL-8 and antimicrobial peptides in response to C. bolivianum treatment was assessed using RT-PCR. Protein expression was confirmed by Western blot analysis or ELISA. The antimicrobial effects of C. bolivianum on bacteria and fungus were investigated using minimum inhibitory concentration. Furthermore, the formation of biofilm was investigated with crystal violet assay. RESULTS: C. bolivianum extract consisted of more than 70 different types of phytochemicals including sugars and phenolic compounds. The extract decreased the uroplakin 1a expression and E. coli adhesion and invasion of uroepithelial cells while up-regulated caveolin-1. In uninfected C. bolivianum treated cells, IL-8 was lower than in non-treated cells. In infected cells, however, no difference was observed between treated and non-treated cells. Further, C. bolivianum treatment reduced uropathogenic E. coli (UPEC) biofilms but did not inhibit bacterial growth. CONCLUSIONS: Our results show that C. bolivianum has a protective role on bladder epithelial cells against UPEC infection by decreasing the bacterial adhesion, invasion and biofilm formation.

Protective Effect of Ginsenoside Rg1 on Bleomycin-Induced Pulmonary Fibrosis in Rats: Involvement of Caveolin-1 and TGF-ß1 Signal Pathway.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with poor prognosis and high mortality rate. Panax Notoginseng Saponins (PNS), extracted from Panax Notoginseng as a traditional Asian medicine, displayed a significant anti-fibrosis effect in liver and lung. However, whether Ginsenoside Rg1 (Rg1), an important and active ingredient of PNS, exerts anti-fibrotic activity on IPF still remain unclear. In this study, we investigated the effect of Rg1 on bleomycin-induced pulmonary fibrosis in rats. Bleomycin (5 mg/kg body weight) was intratracheally administrated to male rats. Rg1 (18, 36 and 72 mg/kg) was orally administered on the next day after bleomycin. Lungs were harvested at day 7 and 28 for the further experiments. Histological analysis revealed that bleomycin successfully induced pulmonary fibrosis, and that Rg1 restored the histological alteration of bleomycin-induced pulmonary fibrosis (PF), significantly decreased lung coefficient, scores of alveolitis, scores of PF as well as contents of alpha smooth muscle actin (α-SMA) and hydroxyproline (Hyp) in a dose-dependent manner in PF rats. Moreover, Rg1 increased the expression levels of Caveolin-1 (Cav-1) mRNA and protein, lowered the expression of transforming growth factor-ß1 (TGF-ß1) mRNA and protein in the lung tissues of PF rats. These data suggest that Rg1 exhibits protective effect against bleomycin-induced PF in rats, which is potentially associated with the down-regulation of TGF-ß1 and up-regulation of Cav-1.

Modified Panax ginseng Extract Inhibits uPAR-Mediated α[Formula: see text]ß1-Integrin Signaling by Modulating Caveolin-1 to Induce Early Apoptosis in Lung Cancer Cells.

Urokinase receptor (uPAR) is enhanced in many human cancer cells and is frequently an indicator of poor prognosis. Activation of [Formula: see text]1-integrin requires caveolin-1 and is regulated by uPAR. However, the underlying molecular mechanism responsible for the interaction between uPAR and [Formula: see text]1-integrin remains obscure. We found that modified regular Panax ginseng extract (MRGX) had a negative modulating effect on the uPAR/[Formula: see text]1-integrin interaction, disrupted the uPAR/integrin interaction by modulating caveoline-1, and caused early apoptosis in cancer cells. Additionally, we found that siRNA-mediated caveoline-1 downregulation inhibited uPAR-mediated [Formula: see text]1-integrin signaling, whereas caveoline-1 up-regulation stimulated the signaling, which suppressed p53 expression, thereby indicating negative crosstalk exists between the integrin [Formula: see text]1 and the p53 pathways. Thus, these findings identify a novel mechanism whereby the inhibition of [Formula: see text]1 integrin and the activation of p53 modulate the expression of the anti-apoptotic proteins that are crucially involved in inducing apoptosis in A549 lung cancer cells. Furthermore, MRGX causes changes in the expressions of members of the Bcl-2 family (Bax and Bcl-2) in a pro-apoptotic manner. In addition, MGRX-mediated inhibition of [Formula: see text]1 integrin attenuates ERK phosphorylation (p-ERK), which up-regulates caspase-8 and Bax. Therefore, ERK may affect mitochondria through a negative regulation of caspase-8 and Bax. Taken together, these findings reveal that MRGX is involved in uPAR-[Formula: see text]1-integrin signaling by modulating caveolin-1 signaling to induce early apoptosis in A549 lung-cancer cells and strongly indicate that MRGX might be useful as a herbal medicine and may lead to the development of new herbal medicine that would suppress the growth of lung-cancer cells.

Caveolin-1 is a checkpoint regulator in hypoxia-induced astrocyte apoptosis via Ras/Raf/ERK pathway.

Astrocytes, the most numerous cells in the human brain, play a central role in the metabolic homeostasis following hypoxic injury. Caveolin-1 (Cav-1), a transmembrane scaffolding protein, has been shown to converge prosurvival signaling in the central nerve system. The present study aimed to investigate the role of Cav-1 in the hypoxia-induced astrocyte injury. We also examined how Cav-1 alleviates apoptotic astrocyte death. To this end, primary astrocytes were exposed to oxygen-glucose deprivation (OGD) for 6 h and a subsequent 24-h reoxygenation to mimic hypoxic injury. OGD significantly reduced Cav-1 expression. Downregulation of Cav-1 using Cav-1 small interfering RNA dramatically worsened astrocyte cell damage and impaired cellular glutamate uptake after OGD, whereas overexpression of Cav-1 with Cav-1 scaffolding domain peptide attenuated OGD-induced cell apoptosis. Mechanistically, the expressions of Ras-GTP, phospho-Raf, and phospho-ERK were sequestered in Cav-1 small interfering RNA-treated astrocytes, yet were stimulated after supplementation with caveolin peptide. MEK/ERK inhibitor U0126 remarkably blocked the Cav-1-induced counteraction against apoptosis following hypoxia, indicating Ras/Raf/ERK pathway is required for the Cav-1's prosurvival role. Together, these findings support Cav-1 as a checkpoint for the in hypoxia-induced astrocyte apoptosis and warrant further studies targeting Cav-1 to treat hypoxic-ischemic brain injury.