Overexpression Of Caveolin-1 Research Articles

Caveolin-1 ameliorates hepatic injury in non-alcoholic fatty liver disease by inhibiting ferroptosis via the NOX4/ROS/GPX4 pathway

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease globally, with a complex and contentious pathogenesis. Caveolin-1 (CAV1) is an important regulator of liver function and can mitigate liver injury by scavenging reactive oxygen species (ROS). Evidence suggests that NOX4 is a source of ROS production, that oxidative stress and ferroptosis are closely related, and that both are involved in the onset and progression of NAFLD. However, whether CAV1 attenuates liver injury in NAFLD caused by high-fat diet via the NOX4/ROS/GPX4 pathway remains unclear. An in vivo fatty liver model was established by feeding mice with a high-fat diet for 16 weeks. In addition, an in vitro fatty liver model was established by incubating AML-12 cells with free fatty acids for 24 h using an in vitro culture method. In our study, it was observed that a high-fat diet induces mitochondrial damage and worsens oxidative stress in NAFLD. This diet also hinders GPX4 expression, leading to an escalation of ferroptosis and lipid accumulation. To counteract these effects, intraperitoneal administration of CSD peptide in mice attenuated the high-fat diet-induced liver mitochondrial damage and ferroptosis. Likewise, overexpression of CAV1 resulted in an increase in GPX4 expression and a reduction in levels of ROS-mediated iron metamorphosis, thus mitigating the progression of the disease. However, the effects of CAV1 on GPX4-mediated ferroptosis and lipid deposition could be reversed by CAV1 small interfering RNA (SiRNA). Finally, NOX4 inhibitor (GLX351322) treatment increased CAV1 siRNA-mediated GPX4 expression and decreased the level of ROS-mediated ferroptosis. These findings suggest a potential mechanism underlying the protective role of CAV1 against high-fat diet-induced hepatotoxicity in NAFLD, shedding new light on the interplay between CAV1, GPX4, and ferroptosis in liver pathology.

Nebulization of Hypoxic hUCMSC-EVs Attenuates Airway Epithelial Barrier Defects in Chronic Asthma Mice by Transferring CAV-1.

Nebulization of hypoxic human umbilical cord mesenchymal stem cell-derived extracellular vesicles (Hypo-EVs) can suppress airway inflammation and remodeling in a chronic asthmatic mouse; however, the exact mechanism remains unclear. Recently, airway epithelial barrier defects have been regarded as crucial therapeutic targets in asthma. The aim of this study was to investigate whether and how Hypo-EVs protect against the disruption of the airway epithelial barrier under asthmatic conditions. The therapeutic effects of Hypo-EVs on airway epithelial barrier defects were evaluated in ovalbumin (OVA)-induced asthmatic mice and in IL-4 and IL-13-induced HBE135-E6E7 cell models by detecting cell monolayer leakage and junctional protein expression. The protein levels in Hypo-EVs were determined by Western blotting, and a gene knockdown approach was used to investigate the biofactors in Hypo-EVs. Nebulization of Hypo-EVs directly alleviated airway epithelial barrier defects in asthmatic mice, as evidenced by colocalization with bronchial epithelial cells, decreased albumin concentration, and increased ZO-1 and E-cadherin expression. In vitro, Hypo-EV treatment dramatically rescued the increase in airway cell permeability, and upregulated the ZO-1 and E-cadherin protein expressions. Based on WB analysis, we found that caveolin-1 (CAV-1) was strongly enriched in Hypo-EVs. The knockdown of CAV-1 protein levels in Hypo-EVs significantly impaired Hypo-EV-mediated barrier protection in vitro and in vivo. Moreover, CAV-1 knockdown significantly abolished the beneficial effects of Hypo-EVs on airway inflammation and remodeling in asthmatic mice. In addition, we showed that IL-4/IL-13-induced airway epithelial barrier defects were mainly related to activation of STAT6 phosphorylation (p-STAT6), and overexpression of CAV-1 or Hypo-EV treatment inhibited the levels of p-STAT6 in IL-4/IL-13-induced HBE135-E6E7 cells. Nebulization of Hypo-EVs can attenuate airway epithelial barrier defects in asthma by delivering CAV-1 to inhibit p-STAT6 expression and may be used to treat other barrier defect diseases.

Caveolin 1 ameliorates nonesterified fatty acid-induced oxidative stress via the autophagy regulator Beclin 1 in bovine mammary gland epithelial cells

High blood concentrations of nonesterified fatty acids (NEFA) during ketosis enhance uptake by the mammary gland and impair autophagy while causing oxidative stress. Caveolin 1 (CAV1) is closely related to autophagy and plays a role in regulating oxidative stress. The aim of this study was to explore the potential role of CAV1 on oxidative stress and autophagy during a high NEFA challenge in the immortalized bovine mammary epithelial cell line MAC-T. Mammary gland tissue biopsies and blood samples were collected from healthy (n = 15) and clinically ketotic (n = 15) Holstein cows at 3 to 10 (average = 6) days in milk. Compared with healthy cows, ketotic cows had lower dry matter intake (DMI), daily milk yield, serum glucose and greater serum NEFA and BHBA, accompanied by greater milk fat and lower milk protein. Malondialdehyde (MDA) was greater but activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH) were lower in cows with clinical ketosis. A lower protein abundance of CAV1, Beclin 1, autophagy relative gene 5 (ATG5), and microtubule-associated protein 1 light chain 3 (LC3) as well as greater protein abundance of sequestosome-1 (SQSTM1, also called p62) were detected in mammary tissue of cows with clinical ketosis. In vitro, the MAC-T cells were treated with 0, 0.6 and 1.2 mM NEFA for 12 h or treated with 1.2 mM NEFA for various time points (0, 0.5, 1, 2, 4, 8, 12 and 24 h). Compared with 0 mM NEFA, protein abundance of CAV1, Beclin 1, ATG5 and LC3 was greater in the MAC-T challenged with 0.6 mM NEFA, but lower in the 1.2 mM NEFA group. Protein abundance of p62 was lower with 0.6 mM NEFA, but higher with 1.2 mM NEFA. In response to increasing doses of NEFA, mRNA abundance of CAV1, total antioxidant capacity (T-AOC) and SOD activity decreased while the level of reactive oxygen species (ROS) and content of MDA increased. The protein abundance of CAV1, Beclin 1, ATG5 and LC3 peaked at 0.5 h and 1 h, resulting in both linear and quadratic effects. The protein abundance of p62 decreased, reaching a nadir at 4 h in both a linear and quadratic manner. The silencing of CAV1 in MAC-T cells aggravated the 1.2 mM NEFA-induced decrease in Beclin 1 expression, impaired autophagy, and increase in oxidative stress, whereas the overexpression of CAV1 alleviated these effects. Pretreatment of MAC-T cells with Beclin 1 siRNA (si-Beclin 1) and overexpressing CAV1 followed by challenged with 1.2 mM NEFA reversed the CAV1 induced autophagy, thereby enhancing oxidative stress. Overall, these data suggest that CAV1 protects bovine mammary epithelial cells from NEFA-induced oxidative stress through enhancing the expression of Beclin 1 and activating autophagy.

Caveolin 1 in bovine liver is associated with fatty acid-induced lipid accumulation and the ER unfolded protein response: role in fatty liver development

Disruption of endoplasmic reticulum (ER) homeostasis, i.e., ER stress, is intrinsically linked with lipid metabolism disorders in dairy cows. Caveolin 1 (CAV1) is a ubiquitously-expressed membrane-associated scaffolding protein involved in regulating the secretory pathway within the ER. Whether inhibiting the activity of CAV1 affects the ER and its potential role in hepatic lipid deposition in dairy cows is unknown. Biopsies of liver tissue from Holstein cows (days in milk: median = 13 d, range = 5 to 21) diagnosed as healthy (n = 6, hepatic TAG levels < 1%, milk production: median = 38.9 kg/day, Interquartile range = 38.0 and 40.8) or suffering from fatty liver (n = 6, hepatic TAG levels > 5%, milk production: median = 36.6 kg/day, Interquartile range = 35.7 and 38.1) revealed that fatty liver was associated with lower abundance of CAV1 gene and protein, higher phosphorylation (p) levels of PERK and IRE1α, and increased abundance of ATF6, GRP78, CHOP protein, and several unfolded protein response (UPR) genes (ATF4, sXBP1, and GRP78). Proteins related to de novo fatty acid synthesis, including ACC1, SREBP-1c, PPARγ, and downstream targets genes of SREBP1 (ACACA and FASN) also had greater abundance. This in vivo analysis highlighted a mechanistic link between CAV1 protein abundance, ER stress, and lipid metabolism during fatty liver. A mechanistic study was then performed in vitro with primary hepatocytes isolated from 5 healthy calves (weight, 40-45 kg; 1 d old). Initially, hepatocytes were treated with FFA (1.2 mM) for 1, 3, 6, or 12 h. FFA treatment reduced CAV1 protein abundance linearly while it reduced abundance of ER stress-related proteins, p-IRE1α, p-PERK, GRP78, ATF6, and CHOP. Proteins related to de novo fatty acid synthesis (ACC1, SREBP-1c, PPARγ) also increased linearly, and lipid droplets accumulated progressively over time following FFA treatment. Subsequently, to assess the role of CAV1 in FFA-induced ER stress and de novo fatty acid synthesis, hepatocytes were transfected with pCMV-CAV1 (cattle)-3 × FLAG-Neo (pc-CAV1) plasmid to overexpress CAV1 or with siRNA to silence CAV1 (siCAV1) transcription. Overexpression of CAV1 alleviated ER stress by reducing levels of p-PERK and p-IRE1α, as well as the protein abundance of ATF6, GRP78, CHOP, and several UPR genes (GRP78, ATF4, and sXBP1). Similarly, CAV1 overexpression decreased protein abundance of ACC1, SREBP-1c, PPARγ, and downstream targets genes of SREBP1 (ACACA and FASN). Conversely, silencing CAV1 exacerbated FFA-induced ER stress and de novo fatty acid synthesis. Considering the negative role of FFA-induced ER stress on lipid accumulation in hepatocytes, a second in vitro experiment involved hepatocytes treated with 0.5 μg/mL tunicamycin (TM, a typical ER stress inducer) for 24 h with or without overexpressing CAV1 (pc-CAV1). Overexpressing caveolin 1 reversed TM-induced increases in mRNA and protein associated with ER stress and de novo fatty acid synthesis. Furthermore, use of hepatocytes transfected with pc-CAV1 for 48 h and subjected to co-immunoprecipitation revealed that CAV1 interacts with IRE1α and ATF6. Overall, the data suggest that CAV1 may help reduce hepatic ER stress and mitigate fatty acid synthesis by binding to and inhibiting IRE1α and ATF6 signaling.

Inhibition of enhanced green fluorescent protein cytosolic delivery mediated by modified cell-penetrating peptide due to high overexpression of Caveolin-1

The modified cell-penetrating peptide Pas2r12 can deliver antibodies (IgG, 150 kDa) and enhanced green fluorescent protein (EGFP1, 27 kDa) into the cytosol through caveolae-dependent endocytosis. In this study, we determined the effect of Caveolin-1 overexpression on the cytosolic delivery of EGFP by Pas2r12. Three types of Caveolin-1 overexpressing strains were isolated, including Cav1L (low), Cav1M (medium), and Cav1H (high), using HEK293 as the parent cell line. We found that the number of caveolae on the surface of the Caveolin-1-overexpressing strains was similar to that of HEK293. We examined the cytosolic delivery rate of EGFP by Pas2r12. In the Cav1L and Cav1M cells, there was little change compared with HEK293; however, in Cav1H, the rate was significantly decreased. Moreover, the amount of EGFP uptake into the cells (total intracellular EGFP) showed an increasing trend in Cav1H compared with HEK293. These results indicate that in Cav1H, the amount of EGFP uptake into the cells increases, whereas the cytosolic delivery rate of EGFP decreases. This suggests that high overexpression of Caveolin-1 inhibits the transition of EGFP from endosomes to the cytosol.

Cinobufagin disrupts the stability of lipid rafts by inhibiting the expression of caveolin-1 to promote non-small cell lung cancer cell apoptosis.

The study was designed to explore how cinobufagin (CB) regulates the development of non-small cell lung cancer (NSCLC) cells through lipid rafts. The effects of CB at gradient concentrations (0, 0.5, 1 and 2 µM) on NSCLC cell viability, apoptosis, reactive oxygen species (ROS) level, phosphorylation of Akt, and apoptosis- and lipid raft-related protein expression were assessed by MTT assay, flow cytometry and Western blot. Cholesterol and sphingomyelin were labeled with BODIPY to evaluate the effect of CB (2 µM) on them. Sucrose density gradient centrifugation was used to extract lipid rafts. The effect of CB on the expression and distribution of caveolin-1 was determined by immunofluorescence, quantitative reverse transcription polymerase chain reaction and Western blot. After overexpression of caveolin-1, the above experiments were performed again to observe whether the regulatory effect of CB was reversed. CB inhibited NSCLC cell viability while promoting apoptosis and ROS level. CB redistributed the lipid content on the membrane surface and reduced the content of caveolin-1 in the cell membrane. In addition, CB repressed the activation of AKT. However, caveolin-1 overexpression reversed the effects of CB on apoptosis, AKT activation and lipid raft. CB regulates the activity of Akt in lipid rafts by inhibiting caveolin-1 expression to promote NSCLC cell apoptosis.

CAV3 alleviates diabetic cardiomyopathy via inhibiting NDUFA10-mediated mitochondrial dysfunction

BackgroundThe progression of diabetic cardiomyopathy (DCM) is noticeably influenced by mitochondrial dysfunction. Variants of caveolin 3 (CAV3) play important roles in cardiovascular diseases. However, the potential roles of CAV3 in mitochondrial function in DCM and the related mechanisms have not yet been elucidated.MethodsCardiomyocytes were cultured under high-glucose and high-fat (HGHF) conditions in vitro, and db/db mice were employed as a diabetes model in vivo. To investigate the role of CAV3 in DCM and to elucidate the molecular mechanisms underlying its involvement in mitochondrial function, we conducted Liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis and functional experiments.ResultsOur findings demonstrated significant downregulation of CAV3 in the cardiac tissue of db/db mice, which was found to be associated with cardiomyocyte apoptosis in DCM. Importantly, cardiac-specific overexpression of CAV3 effectively inhibited the progression of DCM, as it protected against cardiac dysfunction and cardiac remodeling associated by alleviating cardiomyocyte mitochondrial dysfunction. Furthermore, mass spectrometry analysis and immunoprecipitation assays indicated that CAV3 interacted with NDUFA10, a subunit of mitochondrial complex I. CAV3 overexpression reduced the degradation of lysosomal pathway in NDUFA10, restored the activity of mitochondrial complex I and improved mitochondrial function. Finally, our study demonstrated that CAV3 overexpression restored mitochondrial function and subsequently alleviated DCM partially through NDUFA10.ConclusionsThe current study provides evidence that CAV3 expression is significantly downregulated in DCM. Upregulation of CAV3 interacts with NDUFA10, inhibits the degradation of lysosomal pathway in NDUFA10, a subunit of mitochondrial complex I, restores the activity of mitochondrial complex I, ameliorates mitochondrial dysfunction, and thereby protects against DCM. These findings indicate that targeting CAV3 may be a promising approach for the treatment of DCM.

Caveolin-1 promotes glioma proliferation and metastasis by enhancing EMT via mediating PAI-1 activation and its correlation with immune infiltrates

Glioma is typically characterized by a poor prognosis and is associated with a decline in the quality of life as the disease advances. However, the development of effective therapies for glioma has been inadequate. Caveolin-1 (CAV-1) is a membrane protein that plays a role in caveolae formation and interacts with numerous signaling proteins, compartmentalizing them in caveolae and frequently exerting direct control over their activity through binding to its scaffolding domain. Although CAV-1 is a vital regulator of tumour progression, its role in glioma remains unclear. Our findings indicated that the knockdown of CAV-1 significantly inhibits the proliferation and metastasis of glioma. Subsequent mechanistic investigations demonstrated that CAV-1 promotes proliferation and metastasis by activating the photoshatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Furthermore, we demonstrated that CAV-1 overexpression upregulates the expression of serpin peptidase inhibitor, class E, member 1 (SERPINE1, also known as PAI-1), which serves as a marker for the epithelial-mesenchymal transition (EMT) process. Further research showed that PAI-1 knockdown abolished the CAV-1 mediated activation of PI3K/Akt signaling pathway. In glioma tissues, CAV-1 expression exhibited a correlation with unfavorable prognosis and immune infiltration among glioma patients. In summary, our study provided evidence that CAV-1 activates the PI3K/Akt signaling pathway by upregulating PAI-1, thereby promoting the proliferation and metastasis of glioma through enhanced epithelial-mesenchymal transition (EMT) and angiogenesis, and CAV-1 is involved in the immune infiltration.

Caveolae and caveolin-1 as targets of dietary polyphenols for protection against vascular endothelial dysfunction.

Caveolae, consisting of caveolin-1 proteins, are ubiquitously present in endothelial cells and contribute to normal cardiovascular functions by acting as a platform for cellular signaling pathways as well as transcytosis and endocytosis. However, caveolin-1 is thought to have a proatherogenic role by inhibiting endothelial nitric oxide synthase activity and Nrf2 activation, or by promoting inflammation through NF-κB activation. Dietary polyphenols were suggested to exert anti-atherosclerotic effects by a mechanism involving the inhibition of endothelial dysfunction, by which they can regulate redox-sensitive signaling pathways in relation to NF-κB and Nrf2 activation. Some monomeric polyphenols and microbiota-derived catabolites from monomeric polyphenols or polymeric tannins might be responsible for the inhibition, because they can be transferred into the circulation from the digestive tract. Several polyphenols were reported to modulate caveolin-1 expression or its localization in caveolae. Therefore, we hypothesized that circulating polyphenols affect caveolae functions by altering its structure leading to the release of caveolin-1 from caveolae, and attenuating redox-sensitive signaling pathway-dependent caveolin-1 overexpression. Further studies using circulating polyphenols at a physiologically relevant level are necessary to clarify the mechanism of action of dietary polyphenols targeting caveolae and caveolin-1.

Anticancer role of lidocaine in oral squamous cell carcinoma through IGF2BP2-mediated CAV1 stability.

Lidocaine, a common local anesthetic in medical practice, exhibits anticancer properties across various tumor types. In this study, we aimed to investigate the effects and mechanisms of lidocaine on oral squamous cell carcinoma. Cell viability and proliferation were assessed through CCK-8 and EdU assays. Transwell assays were used to analyze cell migration and invasion. Immunofluorescence assays were conducted to determine MMP9 levels. Invivo tumor growth was evaluated using a tumor xenograft model, and Ki67 and MMP9 levels were determined using immunohistochemistry. N6-methyladenosine levels were assessed using dot plots and ELISA. mRNA and protein levels were examined through reverse transcription-quantitative PCR or western blot analysis. The association between IGF2BP2 and caveolin-1 was validated through RIP and luciferase reporter assays. Lidocaine exhibited suppressive effects on the viability, migration, invasion, and tumor formation of oral squamous cell carcinoma. IGF2BP2 expression correlated with poor survival and was downregulated by lidocaine. Lidocaine reduced caveolin-1 stability by decreasing IGF2BP2 levels. Caveolin-1 overexpression partially reversed the suppressive effects of lidocaine on the progression of oral squamous cell carcinoma cells. Lidocaine exerts an anticancer role in oral squamous cell carcinoma via IGF2BP2-mediated regulation of caveolin-1 stability.

#123 : Caveolin-1 Function and Regulation in Mouse Uterus During Early Pregnancy and Under Human In Vitro Decidualization

Background and Aims: Endometrial decidualization is a step in establishing and maintaining pregnancy. Senescence was considered to accompany with decidualization. Failure to clear senescence during decidualization could cause pregnancy abnormalities. Caveolin-1, as a scaffold protein, play a role in senescence, but the expression, regulation and function were not very clear in uterine endometrium. Here, we investigated the profile of Caveolin-1 in mouse and human decidualization to tease out the potential relationship among the Caveolin-1, senescence and decidualization. Method: ICR strain mice and immortalized human endometrial stromal cells (ESCs) were used. Immunofluorescence, Western-Blot, Real-time PCR were used to detect the levels of molecules. Results: In endometrium of mice during early pregnancy, the expression of Caveolin-1 gradually decreased in stroma and epithelium before embryo implantation. However, the level of Caveolin-1 converts in stromal cell after implantation. Estrogen could stimulate expression of Caveolin-1 in epithelium and progesterone could up-regulate level of Caveolin-1 in endometrial stromal cells. In vitro, expression of Caveolin-1 was up-regulated during decidualization in mESCs, while the level of Caveolin-1 was reduced during decidualization in hESCs. siRNA of Caveolin-1 could promote the expression of IGFBP-1 (decidualization biomarker) and senescence in hESCs, while over-expression of Caveolin-1 had the opposite results. In mESCs, Caveolin-1 seems to play a different role in decidualization, over-expression of Caveolin-1 could promote decidualization and senescence in mESCs, but siRNA depressed it. Blastocysts-derived TNF and hCG stimulated Caveolin-1 in mice and depressed it in human decidual cells, respectively. Caveolin-1 levels are also regulated by high glucose and insulin. Conclusion: Caveolin-1 play a role in ESCs decidualization, but the mode of action was different between species. A low level of Caveolin-1 will benefit for human decidualization, disorder of Caveolin-1 could impair decidualization.

Lentinan alleviates diabetic cardiomyopathy by suppressing CAV1/SDHA-regulated mitochondrial dysfunction

Diabetic cardiomyopathy (DCM), characterized by mitochondrial dysfunction and impaired energetics as contributing factors, significantly contributes to high mortality in patients with diabetes. Targeting key proteins involved in mitochondrial dysfunction might offer new therapeutic possibilities for DCM. Lentinan (LNT), a β-(1,3)-glucan polysaccharide obtained from lentinus edodes, has demonstrated biological activity in modulating metabolic syndrome. In this study, the authors investigate LNT's pharmacological effects on and mechanisms against DCM. The results demonstrate that administering LNT to db/db mice reduces cardiomyocyte apoptosis and mitochondrial dysfunction, thereby preventing DCM. Notably, these effects are fully negated by Caveolin-1 (CAV1) overexpression both in vivo and in vitro. Further studies and bioinformatics analysis uncovered that CAV1 bound with Succinate dehydrogenase subunit A (SDHA), triggering the following ubiquitination and degradation of SDHA, which leads to mitochondrial dysfunction and mitochondria-derived apoptosis under PA condition. Silencing CAV1 leads to reduced apoptosis and improved mitochondrial function, which is blocked by SDHA knockdown. In conclusion, CAV1 directly interacts with SDHA to promote ubiquitination and proteasomal degradation, resulting in mitochondrial dysfunction and mitochondria-derived apoptosis, which was depressed by LNT administration. Therefore, LNT may be a potential pharmacological agent in preventing DCM, and targeting the CAV1/SDHA pathway may be a promising therapeutic approach for DCM.

Caveolin-1 protects against liver damage exacerbated by acetaminophen in non-alcoholic fatty liver disease by inhibiting the ERK/HIF-1α pathway

Acetaminophen (APAP) is a common antipyretic and analgesic drug that can cause long-term liver damage after an overdose. Non-alcoholic fatty liver disease (NAFLD) increases susceptibility to APAP. In NAFLD, excessive accumulation of lipids leads to an abnormal increase in hypoxia-inducible factor-1α (HIF-1α). Caveolin-1 (CAV1) may protect against NAFLD by inhibiting HIF-1α. This research aimed to determine whether CAV1 could attenuate APAP-exacerbated liver injury in NAFLD by inhibiting oxidative stress involving HIF-1α. In this study, 7-week-old C57BL/6 mice were fed a high-fat diet (HFD) for eight weeks, followed by the instillation of APAP. Levels of oxidative stress and liver lipid deposition were determined, and p-ERK1/2 and HIF-1α protein expression were measured by the Western blot (WB) method. In the APAP-treated group, the level of CAV1 was decreased, while the levels of HIF-1α and reactive oxygen species (ROS) were significantly increased. AML12 cells were treated with a mixture of palmitic acid (PA) and oleic acid (OA) (1:2 mix) for 48 h, and APAP was added for the last 24 h. Overexpression of CAV1 in AML12 cells significantly inhibited the expression of ROS and HIF-1α. And the results of immunofluorescence after treatment with CAV1-SiRNA showed that the HIF-1α levels were significantly increased in mitochondria. In conclusion, our experimental results suggest that CAV1 has a protective function in the fatty liver based on preventing oxidative stress, which involves HIF-1α. Thus, upregulation of CAV1 may attenuate APAP-exacerbated liver injury in NAFLD.

Caveolin-1 aggravates neurological deficits by activating neuroinflammation following experimental intracerebral hemorrhage in rats

BackgroundIntracerebral hemorrhage (ICH) is one of the stroke subtypes with the highest mortality. Secondary brain injury is associated with neurological dysfunction and poor prognosis after ICH. Caveolin-1 (CAV1) is the key protein of Caveolae. Previous studies have shown that CAV1 plays an important role in central nervous system diseases, and pointed out that in a collagenase-induced ICH model in vivo, CAV1 is associated with neuroinflammatory activation and poor neurological prognosis. In this study, we explore the role and the molecular mechanism of CAV1 in brain injury via a rat autologous whole blood injection model and an in vitro model of ICH. MethodsAdult male Sprague-Dawley rats ICH model was induced through autologous whole blood injecting into the right basal ganglia. The changes in protein levels of CAV1 in brain tissues of ICH rats were detected by western blot analysis. The immunofluorescent staining was used to explore the changes of CAV1 in microglia/macrophages (Iba1+ cells). Lentivirus vectors were administered by intracerebroventricular injection to induce CAV1 overexpression and knockdown respectively. The western blot analysis, immunofluorescence staining, enzyme-linked immunosorbent assay, terminal deoxynucleotidyl transferase dUTP nick end labeling and Nissl staining were performed to explore the role of CAV1 in secondary brain injury after ICH. Meanwhile, the rotarod test, foot fault test, adhesive-removal test, and Modified Garcia Test, as well as Morris Water Maze test, were performed to evaluate the behavioral cognitive impairment of ICH rats after genetic intervention. Additionally, BV-2 cells treated with oxygen hemoglobin for 24 h, were used as an in vitro model of ICH in this study to explore the molecular mechanism of CAV1 in brain injury; we performed western blot analysis after precise regulation of CAV1 in BV2 cells to observe changes in protein levels and phosphorylated levels of C-Src, IKK-β, and NF-κB. ResultsThe expression of CAV1 in microglia/macrophages (Iba1+ cells) was elevated and reached the peak at 24 h after ICH. CAV1 knockdown ameliorated ICH-induced neurological deficits, while CAV1 overexpression significantly worsened neurological dysfunction of ICH rats. CAV1 knockdown attenuated cellular apoptosis and promoted neuronal survival in brain tissues of ICH rats, while the ICH rats with CAV1 overexpression presented more cellular apoptosis and neuronal loss. Meanwhile, CAV1 knockdown inhibited the microglia activation and neuroinflammatory response, while CAV1 overexpression abolished these effects and aggravated neuroinflammation in brain tissues of ICH rats. Additionally, by inducing to CAV1 knockdown in BV2 cells in an in vitro model of ICH, the levels of p-C-Src, CAV-1, p-CAV-1, and p-IKK-β in cytoplasm and the level of NF-κB p65 in nucleus of BV2 cells were significantly decreased, while they were increased by inducing to CAV1 overexpression. ConclusionsOur research revealed CAV1 aggravated neurological dysfunction in a rat ICH model. CAV1 knockdown exerted neuroprotective effect by suppressing microglia activation and neuroinflammation after ICH might via the C-Src/CAV1/IKK-β/NF-κB signaling pathway.

Positive association between circulating Caveolin-1 and microalbuminuria in overt diabetes mellitus in pregnancy.

Mounting evidence has shown that caveolin-1 plays a pathological role in the progression of albuminuria. Our study aimed to provide clinical evidence showing whether circulating caveolin-1 levels were associated with microalbuminuria (MAU) in women with overt diabetes mellitus in pregnancy (ODMIP). A total of 150 pregnant women were enrolled in different groups, including 40 women with ODMIP and MAU (ODMIP + MAU), 40 women with ODMIP, and 70 women without ODMIP (Non-ODMIP). Plasma caveolin-1 levels were determined by ELISA. The presence of caveolin-1 in the human umbilical vein vascular wall was evaluated by immunohistochemical and western blot analysis, respectively. Albumin transcytosis across endothelial cells was measured using an established nonradioactive in vitro approach. Significantly increased levels of plasma caveolin-1 were detected in ODMIP + MAU women. The Pearson's correlation analysis revealed a positive correlation between plasma caveolin-1 levels and Hemoglobin A1c (HbA1c %) as well as with MAU in the ODMIP + MAU group. Simultaneously, experimental knockdown or overexpression of caveolin-1 significantly decreased or increased the level of albumin transcytosis across both human and mouse glomerular endothelial cells (GECs), respectively. Our data showed a positive association between plasma caveolin-1 levels and microalbuminuria in ODMIP + MAU.

The influence of selected microRNAs on the expression profile of genes and proteins related to the tumor necrosis factor-alpha signaling pathways in endometrioid endometrial cancer.

Tumor necrosis factor exerts many adverse biological effects, from cell proliferation to cell death. Accurate diagnosis and treatment are therefore difficult due to many factors influencing tumor necrosis factor-alpha (TNF-α) signaling, including microRNAs (miRNAs), especially in tumors. The aim of the study was to determine the influence of miRNAs on the expression profile of genes and proteins related to TNF-α signaling in endometrial cancer. The material consisted of 45 endometrioid endometrial cancer and 45 normal endometrium tissue samples. Gene expression was determined with microarrays and then validated for TNF-α, tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2), caveolin 1 (CAV1), nuclear factor kappa B subunit 1 (NFKB1), and TGF-beta activated kinase 1 (MAP3K7)-binding protein 2 (TAB2) using real-time quantitative reverse transcription reaction (RT-qPCR). The protein concentration was assessed by enzyme-linked immunosorbent assay (ELISA). In addition, differentiating miRNAs were identified using miRNA microarrays and their relationships with TNF-α signaling genes were evaluated using the mirDIP tool. TNF-α, TNFR1, TNFR2, CAV1, NFKB1, and TAB2 were upregulated both on the mRNA and protein levels. The decrease in the activity of miR-1207-5p, miR-1910-3p, and miR-940 may be related to CAV1 overexpression. Similarly for miR-572 and NFKB1 as well as miR-939-5p and TNF-α. In turn, miR-3178 may partially inhibit TNFR1 activity up to grade 2 cancer. TNF-α signaling, especially the TNF-α/NF-κB axis, is disrupted in endometrial cancer and worsens with disease progression. The observed changes may be the result of miRNAs' activity in the initial stage of endometrial cancer and its gradual loss in later grades.

Caveolin-1 ameliorates acetaminophen-aggravated inflammatory damage and lipid deposition in non-alcoholic fatty liver disease via the ROS/TXNIP/NLRP3 pathway.

The overuse of acetaminophen (APAP) may cause more severe hepatotoxicity in patients with non-alcoholic fatty liver disease (NAFLD). Caveolin-1 (CAV1), is an essential regulator of metabolic function, which can alleviate liver damage by scavenging reactive oxygen species (ROS). Evidence suggests that the NOD-like receptor family pyrin domain-containing 3 (NLRP3) -mediated pyroptosis is involved in the development of NAFLD. Moreover, thioredoxin-interactive protein (TXNIP) activation is a key event linking ROS to NLRP3 inflammasome. However, whether CAV1 alleviates APAP-aggravated hepatotoxicity in NAFLD via the ROS/TXNIP/NLRP3 pathway remains unclear. An in vivo fatty liver model was established by feeding mice a high-fat diet for 56days. Additionally, using in vitro approach, AML-12 cells were incubated with free fatty acids for 48h and APAP was added during the last 24h. We found that the overuse of APAP in NAFLD not only induced oxidative stress, but also increased TXNIP expression, NLRP3-mediated pyroptosis, and lipid deposition. In addition to inhibiting ROS generation and lipid deposition, overexpression of CAV1 reduced the elevated levels of TXNIP expression and NLRP3-mediated pyroptosis. However, the effect of CAV1 on TXNIP expression, NLRP3-mediated pyroptosis, and lipid deposition was reversed by CAV1 small interfering RNA (siRNA) intervention. Finally, N-acetyl cysteine (NAC) treatment reduced CAV1 siRNA-mediated changes in TXNIP expression and NLRP3-mediated pyroptosis levels. These results demonstrate that the inhibitory effect of CAV1 on NLRP3-mediated pyroptosis may be mediated through the ROS/TXNIP axis. Moreover, the current study provides novel mechanistic insights into the protective effects of CAV1 on APAP-aggravated hepatotoxicity in NAFLD.

Caveolin-1 alleviates acetaminophen-induced vascular oxidative stress and inflammation in non-alcoholic fatty liver disease

Acetaminophen (APAP) is one of the most widely used drugs in the world. The literature shows that excessive or long-term use of APAP can lead to increased cardiovascular dysfunction. An acute increase in angiotensin Ⅱ (Ang Ⅱ) caused by APAP use in fatty liver disease may increase the risk and severity of vascular injury. However, the underlying mechanism remains unclear. Caveolin-1 (CAV1) is a broad-spectrum kinase inhibitor that significantly determines endothelial function. This study aimed to observe the effects of APAP on the vasculature in non-alcoholic fatty liver disease (NAFLD) and to determine whether CAV1 could alleviate vascular oxidative stress and inflammation by targeting Ang Ⅱ or its downstream pathways. In this study, 7-week-old C57BL/6 male mice (18–20 g) were administered APAP by gavage after eight weeks of a high-fat diet. Any resulting vascular oxidative stress and inflammation were assessed. Levels of Ang Ⅱ, CAV1, and other related proteins were measured using ELISA and western blotting. In APAP-treated NAFLD mice, CAV1 expression was downregulated and Ang Ⅱ expression was upregulated compared to normal APAP-treated mice. In vitro, HUVECs were incubated with Ang Ⅱ (300 nM) for 48 h. Overexpression of CAV1 in HUVECs attenuated Ang Ⅱ-induced oxidative stress and inflammation and downregulated the expression of Protein kinase C (PKC) and p-P38/P38. After intervention with CAV1-siRNA, immunofluorescence results showed that the fluorescence intensity of PKC on mitochondria was further increased, and flow cytometry results showed that the mitochondrial membrane potential increased. PKC inhibitors alleviated Ang Ⅱ-induced endothelial injury. In conclusion, our findings confirmed that CAV1 exerts a protective effect against vascular injury by inhibiting oxidative stress and inflammation through the PKC/MAPK pathway. Therefore, restoration of CAV1 may have clinical benefits in reducing APAP-induced vascular damage in NAFLD patients.

CAV-1 Overexpression Exacerbates the Manifestation in EPAC-1-Induced Chronic Postsurgical Pain in Rats.

Purpose Caveolae (CAV) are an invaginated microcapsule with the shape of Ω on the surface of the cell membrane. Caveolin-1 (CAV-1) is involved in neuropathic pain, and adenosine monophosphate (AMP)-exchange protein directly activated by cAMP1 (EPAC-1) is a potential therapeutic target for chronic pain. However, whether EPAC-1 promotes chronic postsurgical pain (CPSP) through CAV-1 has not been reported. Here, we aim to investigate the underlying mechanism of CAV in CPSP. Methods All the rats were divided into 9 groups, including the Naive group, Sham group, skin/muscle incision and retraction (SMIR) group, SMIR + CAV-1 siRNA group, SMIR + control siRNA group, SMIR (7 days)+Saline group, SMIR (7 days)+CE3F4 group, 8-PCPT group, and Saline group. The CPSP rat model was established after SMIR. A mechanical withdrawal threshold (MWT) was recorded to evaluate the animal's behavior. Western blotting and immunofluorescent were performed to detect the protein expression levels of EPAC-1 and P-CAV-1. Results EPAC-1 and CAV-1 were both overexpressed after operation, particularly in astrocytes, microglia, and neurons of spinal marrow (all P < 0.05). Interestingly, CAV-1 siRNA can partly reverse the SMIR-induced hypersensitivity, but there was no effect on EPAC-1. Besides, EPAC-1 blockage partly reversed the SMIR-induced hypersensitivity and CAV-1 overexpression, and EPAC-1 activation promoted CAV-1 overexpression and hypersensitivity in normal rats (all P < 0.05). Conclusion CAV-1 mediates the functional coupling of microglia, astrocytes, and neurons, and thus EPAC-1/CAV-1 plays an important role in CPSP exacerbation.

Caveolin-1 Alleviates Acetaminophen-Induced Hepatotoxicity in Alcoholic Fatty Liver Disease by Regulating the Ang II/EGFR/ERK Axis.

Acetaminophen (APAP) is a widely used antipyretic analgesic which can lead to acute liver failure after overdoses. Chronic alcoholic fatty liver disease (AFLD) appears to enhance the risk and severity of APAP-induced liver injury, and the level of angiotensin II (Ang II) increased sharply at the same time. However, the underlying mechanisms remain unclear. Caveolin-1 (CAV1) has been proven to have a protective effect on AFLD. This study aimed to examine whether CAV1 can protect the APAP-induced hepatotoxicity of AFLD by affecting Ang II or its related targets. In vivo, the AFLD model was established according to the chronic-plus-binge ethanol model. Liver injury and hepatic lipid accumulation level were determined. The levels of Angiotensin converting enzyme 2 (ACE2), Ang II, CAV1, and other relevant proteins were evaluated by western blotting. In vitro, L02 cells were treated with alcohol and oleic acid mixture and APAP. CAV1 and ACE2 expression was downregulated in APAP-treated AFLD mice compared to APAP-treated mice. The overexpression of CAV1 in mice and L02 cells alleviated APAP-induced hepatotoxicity in AFLD and downregulated Ang II, p-EGFR/EGFR and P-ERK/ERK expression. Immunofluorescence experiments revealed interactions between CAV1, Ang II, and EGFR. The application of losartan (an Ang II receptor antagonist) and PD98059 (an ERK1/2 inhibitor) alleviated APAP-induced hepatotoxicity in AFLD. In conclusion, our findings verified that CAV1 alleviates APAP-aggravated hepatotoxicity in AFLD by downregulating the Ang II /EGFR/ERK axis, which could be a novel therapeutic target for its prevention or treatment.