Caveolin-1 Levels Research Articles

Caveolin-1 Level in Children and Adolescents with Type 1 Diabetes

Abstract Background Diabetic nephropathy is a major vascular related complication of diabetes and the most common cause of end-stage renal disease. Caveolin-1 is a significant regulator of cellular adhesion and migration, playing a key role in signal transduction. Aim Assess caveolin level among children and adolescents with type 1 diabetes and highlight the relation between caveolin level and urinary albumin excretion rate (UAER). Methodology A comparative cross-sectional study recruiting a total of 50 participants with type1 diabetes and 25 age and gender matched controls. Participants with type1 diabetes were equally divided into a normoalbuminuric and a microalbuminuric group according to (UAER). Caveolin level was measured by enzyme-linked immunoassay. Results Caveolin levels were higher in patients with diabetes compared to healthy controls (p < 0.01). Among patients with type 1 diabetes, caveolin levels were significantly higher in patients with diabetic nephropathy compared to patients without diabetic nephropathy (p < 0.001). ROC curve analysis showed that a cut off value of caveolin more than 6 ng/ml best differentiated patients with diabetic nephropathy from those without nephropathy with a specificity of 96%. Additionally, data from the current showed that caveolin levels positively correlated with (UAER) and HbA1c. Conclusion Caveolin levels are significantly associated with UAE in patients with type 1 diabetes. These findings may support the concept that elevated caveolin may be associated with diabetic angiopathy and could serve as a potential therapeutic target.

Effect of nystatin on invasion of <i>Serratia grimesii</i> and <i>Serratia proteamaculans</i> bacteria into epithelial cells

BACKGROUND: Bacteria use various endocytic pathways during entering non-phagocytic cells. The involvement of caveolae/lipid rafts in bacterial invasion has been demonstrated for many bacterial pathogens. However, for bacteria of the genus Serratia, the involvement of membrane microdomains in the process of bacterial internalization has been poorly studied. AIM: To evaluate the involvement of caveolae/lipid rafts in the invasion of S. grimesii and S. proteamaculans bacteria into non-phagocytic epithelial Caco-2 and M-HeLa cells using nystatin. MATERIALS AND METHODS: M-HeLa and Caco-2 epithelial cells were incubated with 50 μM nystatin for 1 hour at 37 ºC, after which they were infected with the bacteria S. grimesii strain 30063 and S. proteamaculans strain 94, the multiplicity of infection was 100 bacteria per cell. The number of intracellular bacteria was assessed using gentamicin protection assay. The level of caveolin-1 in cells was visualized using confocal microscopy and Western blotting. The expression of Toll-like receptors genes were measured by real-time RT-PCR. RESULTS: Treatment of epithelial cells with nystatin reduces the internalization of S. grimesii and S. proteamaculans into M-HeLa cells by 30% and does not affect penetration into Caco-2 cells. At the same time, nystatin does not affect the redistribution / the integrity impairment of lipid rafts and does not lead to the cytoskeleton reorganization of eukaryotic cells. The addition of nystatin increases the level of caveolin-1 in M-HeLa cells (caveolin-1 is not expressed in Caco-2), which leads to a change plasma membrane fluidity. Nystatin promotes the secretion of proinflammatory cytokines interleukin-6 and interleukin-8 in both cell lines. Infection of M-HeLa cells pretreated with nystatin with the studied bacteria leads to an increase in the expression of tlr2 and tlr4 genes, but does not exceed the level of their expression in control samples. Therefore, it is impossible to speak unambiguously about the participation of Toll-like receptors in the invasion of Serratia bacteria. CONCLUSIONS: The results obtained suggest that the interaction of bacteria with eukaryotic cells induces the expression of caveolin-1, which leads to a change plasma membrane components mobility. This may be due to the fact that β1-integrin is involved in the invasion of the studied bacteria, which should be stabilized at the plasma membrane upon binding of the ligand due to the formation of a cholesterol- and sphingolipid-rich membrane microenvironment.

Aging kidneys reveal underlying mechanisms of endothelial dysfunction

Jiang etal. show that zinc finger FYVE-type containing 21, a Rab5 effector in glomerular endothelial cells is involved in the maintenance of glomerular filtration barrier homeostasis through the stabilization of activated endothelial nitric oxide synthase on subcellular vesicles. The study demonstrates that zinc finger FYVE-type containing 21 could modulate the levels of caveolin-1 in glomerular endothelial cells using vesicle-based trafficking, thereby supporting endothelial nitric oxide synthase activity. The authors provide evidence that decreased zinc finger FYVE-type containing 21 expression in glomerular endothelial cells could play a role in aging-related glomerular filtration barrier dysfunction.

Abstract MP02: Inhibition of RORγt Ameliorates Angiotensin II-Induced Blood-Brain Barrier Disruption and Microglia Activation by Reducing Interleukin-17A Production in Rats

Inflammation-induced blood-brain barrier (BBB) disruption and microglial activation in the autonomic and cardiovascular brain centers contribute largely to sympathetic excitation and hypertension. We recently reported that interleukin (IL)-17A, a major mediator of tissue inflammation, promotes BBB disruption, neuroinflammation, and sympathetic activation in angiotensin (ANG) II-induced hypertension and myocardial infarction-induced heart failure. The nuclear receptor retinoid-related orphan receptor γt (RORγt) has been identified as a master transcription factor regulating the differentiation of T helper 17 cells, the primary producer of IL-17A. The present study sought to determine whether inhibition of RORγt to suppress IL-17A production can ameliorate BBB disruption and attenuate microglia activation in ANG II-induced hypertension model. SD rats were treated with a 2-week subcutaneous (SC) infusion of ANG II (150 ng/kg/min) via mini-pumps, combined with daily SC injections of RORγt inhibitor digoxin or vehicle (VEH). Compared to the VEH control, IL-17A levels in plasma and cerebrospinal fluid were significantly (*P<0.05) elevated in ANG II+VEH rats and were reduced in ANG II + digoxin rats. In ANG II+VEH rats, BBB permeability, measured by fluorescein isothiocyanate-dextran (FITC) 10 kDa, was elevated (6.82±0.61%* vs. 2.36±0.28% FITC10 extravasation), along with increased mRNA levels of caveolin-1 (a transcytosis marker, 2.26±0.39* vs. 1.07±0.17) and decreased mRNA levels of mfsd2a (a BBB-specific lipid transporter and inhibitor of transcytosis, 0.55±0.04* vs. 1.06±0.09) in the hypothalamic paraventricular nucleus (PVN). However, BBB permeability and mRNA levels of caveolin-1 and mfsd2a in the PVN were reversed in ANG II + digoxin rats. Immunostaining revealed that both caveolin-1 and mfsd2a were primarily located in the endothelial BBB within the PVN. Microglia activation, assessed by the number of branches (26±2* vs. 37±4) and total branch length (184±15* vs. 250±23), as well as the mRNA levels of tumor necrosis factor-α (2.78±0.45* vs. 1.04±0.12) and IL-1β (2.57±0.53* vs. 1.03±0.14) in the PVN were augmented in ANG II+VEH rats but were attenuated (40-58%*) in ANG II + digoxin rats. Additionally, ANG II-induced hypertension and sympathetic tone were attenuated by digoxin. These data suggest that inhibiting RORγt diminishes BBB disruption, microglial activation and sympathetic excitation induced by ANG II, likely via reducing IL-17A production.

Hypoxia-induced LAMB2-enriched extracellular vesicles promote peritoneal metastasis in gastric cancer via the ROCK1-CAV1-Rab11 axis.

Peritoneal metastasis is one of the most common risk factors contributing to the poor prognosis of gastric cancer. We previously reported that extracellular vesicles from gastric cancer cells could facilitate peritoneal metastasis. However, their impact on gastric cancer-induced peritoneal metastasis under hypoxic conditions remains unclear. This study aims to elucidate how hypoxia-resistant gastric cancer cell-derived extracellular vesicles affect the peritoneal metastasis of normoxic gastric cancer cells. Proteomic analysis revealed elevated levels of Caveolin1 and Laminin β2 in hypoxia-resistant gastric cancer cells and their corresponding extracellular vesicles. Importantly, Caveolin1 was found to play a central role in mediating Laminin β2 sorting into extracellular vesicles derived from hypoxia-resistant gastric cancer cells, and subsequently, extracellular vesicle-associated Laminin β2 promoted peritoneal metastasis in normoxic gastric cancer cells by activating the AKT pathway. Further investigation confirmed that Caveolin1 activation by Rho-related Coiled-coil kinase 1-mediated phosphorylation of Y14 residue is a key factor facilitating Laminin β2 sorting into extracellular vesicles. Moreover, Y14 phosphorylated- Caveolin1 enhanced Laminin β2 sorting by activating Rab11. Finally, our study demonstrated that a combined assessment of plasma extracellular vesicle-associated Caveolin1 and extracellular vesicle-associated Laminin β2 could provide an accurate predictive tool for peritoneal metastasis occurrence in gastric cancer.

High Caveolin-1 mRNA expression in triple-negative breast cancer is associated with an aggressive tumor microenvironment, chemoresistance, and poor clinical outcome.

Currently, there are few treatment-predictive and prognostic biomarkers in triple-negative breast cancer (TNBC). Caveolin-1 (CAV1) is linked to chemoresistance and several important processes involved in tumor progression and metastasis, such as epithelial-mesenchymal transition (EMT). Herein, we report that high CAV1 gene expression is an independent factor of poor prognosis in TNBC. CAV1 gene expression was compared across different molecular features (e.g., PAM50 subtypes). CAV1 expression was assessed in relation to clinical outcomes using Cox regression adjusted for clinicopathological predictors. Differential gene expression and gene set enrichment analyses were applied to compare high- and low-expressing CAV1 tumors. Tumor microenvironment composition of high- and low-expressing CAV1 tumors was estimated using ECOTYPER. Tumor tissue microarrays were used to evaluate CAV1 protein levels in stromal and malignant cells. In the SCAN-B (n = 525) and GSE31519 (n = 327) cohorts, patients with CAV1-high tumors had an increased incidence of early recurrence adjusted HR 1.78 (95% CI 1.12-2.81) and 2.20 (95% CI 1.39-3.47), respectively. In further analysis, high CAV1 gene expression was associated with a molecular profile indicating altered metabolism, neovascularization, chemoresistance, EMT, suppressed immune response, and active tumor microenvironment. Protein levels of CAV1 in malignant and stromal cells were not correlated with CAV1 gene expression. CAV1 gene expression in TNBC is a biomarker that merits further investigation in clinical trials and as a therapeutic target.

Low caveolin-1 levels and symptomatic intracranial haemorrhage risk in large-vessel occlusive stroke patients after endovascular thrombectomy.

Caveolin-1 (Cav-1) is reported to mediate blood-brain barrier integrity after ischaemic stroke. Our purpose was to assess the role of circulating Cav-1 levels in predicting symptomatic intracranial haemorrhage (sICH) amongst ischaemic stroke patients after endovascular thrombectomy (EVT). Patients with large-vessel occlusive stroke after EVT from two stroke centres were prospectively included. Serum Cav-1 level was tested after admission. sICH was diagnosed according to the Heidelberg Bleeding Classification. Of 325 patients (mean age 68.6 years; 207 men) included, 47 (14.5%) were diagnosed with sICH. Compared with patients without sICH, those with sICH had a lower concentration of Cav-1. After adjusting for potential confounders, multivariate regression analysis demonstrated that the increased Cav-1 level was associated with a lower sICH risk (odds ratio 0.055; 95% confidence interval 0.005-0.669; p = 0.038). Similar results were obtained when Cav-1 levels were analysed as a categorical variable. Using a logistic regression model with restricted cubic splines, a linear and negative association of Cav-1 concentration was found with sICH risk (p = 0.001 for linearity). Furthermore, the performance of the conventional risk factors model in predicting sICH was substantially improved after addition of the Cav-1 levels (integrated discrimination index 2.7%, p = 0.002; net reclassification improvement 39.7%, p = 0.007). Our data demonstrate that decreased Cav-1 levels are related to sICH after EVT. Incorporation of Cav-1 into clinical decision-making may help to identify patients at a high risk of sICH and warrants further consideration.

ZFYVE21 promotes endothelial nitric oxide signaling and vascular barrier function in the kidney during aging

ZFYVE21 is an ancient, endosome-associated protein that is highly expressed in endothelial cells (ECs) but whose function(s) invivo are undefined. Here, we identified ZFYVE21 as an essential regulator of vascular barrier function in the aging kidney. ZFYVE21 levels significantly decline in ECs in aged human and mouse kidneys. To investigate attendant effects, we generated EC-specific Zfyve21-/- reporter mice. These knockout mice developed accelerated aging phenotypes including reduced endothelial nitric oxide (ENOS) activity, failure to thrive, and kidney insufficiency. Kidneys from Zfyve21 EC-/- mice showed interstitial edema and glomerular EC injury. ZFYVE21-mediated phenotypes were not programmed developmentally as loss of ZFYVE21 in ECs during adulthood phenocopied its loss prenatally, and a nitric oxide donor normalized kidney function in adult hosts. Using live cell imaging and human kidney organ cultures, we found that in a GTPase Rab5- and protein kinase Akt-dependent manner, ZFYVE21 reduced vesicular levels of inhibitory caveolin-1 and promoted transfer of Golgi-derived ENOS to a perinuclear Rab5+ vesicular population to functionally sustain ENOS activity. Thus, our work defines a ZFYVE21- mediated trafficking mechanism sustaining ENOS activity and demonstrates the relevance of this pathway for maintaining kidney function with aging.

Celastrol mediates CAV1 to attenuate pro-tumorigenic effects of senescent cells

BackgroundCellular senescence is an emerging hallmark of cancers, primarily fuels cancer progression by expressing senescence-associated secretory phenotype (SASP). Caveolin-1 (CAV1) is a key mediator of cell senescence. Previous studies from our group have evidenced that the expression of CAV1 is downregulated by Celastrol (CeT). PurposeTo investigate the impact of CeT on cellular senescence and its subsequent influence on post-senescence-driven invasion, migration, and stemness of clear cell renal cell carcinoma (ccRCC). Study design and methodsThe expression levels of CAV1, canonical senescence markers, and markers associated with epithelial-mesenchymal transition (EMT) and stemness in clinical samples were assessed through Pearson correlation analysis. Senescent cell models were induced using DOX, and their impact on migration, invasion, and stemness was evaluated. The effects of CeT treatment on senescent cells and their pro-tumorigenic effects were examined. Subsequently, the underlying mechanism of CeT were explored using lentivirus transfection and CRISPR/Cas9 technology to silence CAV1. ResultsIn human ccRCC clinical samples, the expression of the canonical senescence markers p53, p21, and p16 are associated with ccRCC progression. Senescent cells facilitated migration, invasion, and enhanced stemness in both ccRCC cells and ccRCC tumor-bearing mice. As expected, CeT treatment reduced senescence markers (p16, p53, p21, SA-β-gal) and SASP factors (IL6, IL8, CXCL12), alleviating cell cycle arrest. However, it did not restore the proliferation of senescent cells. Additionally, CeT suppressed senescence-driven migration, invasion, and stemness. Further investigations into the underlying mechanism demonstrated that CAV1 is a critical mediator of cell senescence and represents a potential target for CeT to attenuate cellular senescence. ConclusionsThis study presents a pioneering investigation into the intricate interplay between cellular senescence and ccRCC progression. We unveil a novel mechanism of CeT to mitigate cellular senescence by downregulating CAV1, thereby inhibiting the migration, invasion and stemness of ccRCC driven by senescent cells. These findings provide valuable insights into the underlying mechanisms of CeT and its potential as a targeted therapeutic approach for alleviating the aggressive phenotypes associated with senescent cells in ccRCC.

Cryptomphalus aspersa Egg Extract Protects against Human Stem Cell Stress-Induced Premature Senescence.

Cellular senescence is a tightly regulated pathophysiologic process and is caused by replicative exhaustion or external stressors. Since naturally derived bioactive compounds with anti-ageing properties have recently captured scientific interest, we analysed the anti-ageing and antioxidant efficacy of Cryptomphalus aspersa egg extract (CAEE). Its effects on stemness, wound-healing properties, antioxidant defense mechanisms, and DNA damage repair ability of Human Wharton's jelly mesenchymal stem cells (WJ-MSCs) were analysed. Our results revealed that CAEE fortifies WJ-MSCs stemness, which possibly ameliorates their wound-healing ability. Additionally, we show that CAEE possesses a strong antioxidant capacity as demonstrated by the elevation of the levels of the basic antioxidant molecule, GSH, and the induction of the NRF2, a major antioxidant regulator. In addition, CAEE alleviated cells' oxidative stress and therefore prevented stress-induced premature senescence (SIPS). Furthermore, we demonstrated that the prevention of SIPS could be mediated via the extract's ability to induce autophagy, as indicated by the elevation of the protein levels of all basic autophagic molecules and the increase in formation of autophagolysosomes in CAEE-treated WJ-MSCs. Moreover, CAEE-treated cells exhibited decreased Caveolin-1 levels. We propose that Cryptomphalus aspersa egg extract comprises bioactive compounds that can demonstrate strong antioxidant/anti-ageing effects by regulating the Caveolin-1-autophagy-senescence molecular axis.

Exosomal Prostate-Specific Membrane Antigen (PSMA) and Caveolin-1 as Potential Biomarkers of Prostate Cancer-Evidence from Serbian Population.

Prostate-specific membrane antigen (PSMA) and caveolin-1 are membrane proteins that are overexpressed in prostate cancer (PCa) and are involved in tumor growth and increase in aggressiveness. The aim of the present study is therefore to evaluate PSMA and caveolin-1 proteins from plasma exosomes as effective liquid biopsy biomarkers for PCa. This study included 39 patients with PCa and 33 with benign prostatic hyperplasia (BPH). The shape and size of the exosomes were confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analysis. Immunogold analysis showed that PSMA is localized to the membrane of exosomes isolated from the plasma of both groups of participants. The relative protein levels of PSMA and caveolin-1 in the plasma exosomes of PCa and BPH patients were determined by Western blot analysis. The relative level of the analyzed plasma exosomal proteins was compared between PCa and BPH patients and the relevance of the exosomal PSMA and caveoin-1 level to the clinicopathological parameters in PCa was investigated. The analysis performed showed an enrichment of exosomal PSMA in the plasma of PCa patients compared to the exosomes of men with BPH. The level of exosomal caveolin-1 in plasma was significantly higher in PCa patients with high PSA levels, clinical-stage T3 or T4 and in the group of PCa patients with aggressive PCa compared to favorable clinicopathological features or tumor aggressiveness. Plasma exosomes may serve as a suitable object for the identification of potential biomarkers for the early diagnosis and prognosis of PCa as well as carriers of therapeutic agents in precision medicine of PCa treatment.

ROCK1 deficiency preserves caveolar compartmentalization of signaling molecules and cell membrane integrity.

In this study, we investigated the roles of ROCK1 in regulating structural and functional features of caveolae located at the cell membrane of cardiomyocytes, adipocytes, and mouse embryonic fibroblasts (MEFs) as well as related physiopathological effects. Caveolae are small bulb-shaped cell membrane invaginations, and their roles have been associated with disease conditions. One of the unique features of caveolae is that they are physically linked to the actin cytoskeleton that is well known to be regulated by RhoA/ROCKs pathway. In cardiomyocytes, we observed that ROCK1 deficiency is coincident with an increased caveolar density, clusters, and caveolar proteins including caveolin-1 and -3. In the mouse cardiomyopathy model with transgenic overexpressing Gαq in myocardium, we demonstrated the reduced caveolar density at cell membrane and reduced caveolar protein contents. Interestingly, coexisting ROCK1 deficiency in cardiomyocytes can rescue these defects and preserve caveolar compartmentalization of β-adrenergic signaling molecules including β1-adrenergic receptor and type V/VI adenylyl cyclase. In cardiomyocytes and adipocytes, we detected that ROCK1 deficiency increased insulin signaling with increased insulin receptor activation in caveolae. In MEFs, we identified that ROCK1 deficiency increased caveolar and total levels of caveolin-1 and cell membrane repair ability after mechanical or chemical disruptions. Together, these results demonstrate that ROCK1 can regulate caveolae plasticity and multiple functions including compartmentalization of signaling molecules and cell membrane repair following membrane disruption by mechanical force and oxidative damage. These findings provide possible molecular insights into the beneficial effects of ROCK1 deletion/inhibition in cardiomyocytes, adipocytes, and MEFs under certain diseased conditions.

Altered platelet-megakaryocyte endocytosis and trafficking of albumin and fibrinogen in RUNX1 haplodeficiency

AbstractPlatelet α-granules have numerous proteins, some synthesized by megakaryocytes (MK) and others not synthesized but incorporated by endocytosis, an incompletely understood process in platelets/MK. Germ line RUNX1 haplodeficiency, referred to as familial platelet defect with predisposition to myeloid malignancies (FPDMMs), is associated with thrombocytopenia, platelet dysfunction, and granule deficiencies. In previous studies, we found that platelet albumin, fibrinogen, and immunoglobulin G (IgG) were decreased in a patient with FPDMM. We now show that platelet endocytosis of fluorescent-labeled albumin, fibrinogen, and IgG is decreased in the patient and his daughter with FPDMM. In megakaryocytic human erythroleukemia (HEL) cells, small interfering RNA RUNX1 knockdown (KD) increased uptake of these proteins over 24 hours compared with control cells, with increases in caveolin-1 and flotillin-1 (2 independent regulators of clathrin-independent endocytosis), LAMP2 (a lysosomal marker), RAB11 (a marker of recycling endosomes), and IFITM3. Caveolin-1 downregulation in RUNX1-deficient HEL cells abrogated the increased uptake of albumin, but not fibrinogen. Albumin, but not fibrinogen, partially colocalized with caveolin-1. RUNX1 KD resulted in increased colocalization of albumin with flotillin and fibrinogen with RAB11, suggesting altered trafficking of both proteins. The increased uptake of albumin and fibrinogen, as well as levels of caveolin-1, flotillin-1, LAMP2, and IFITM3, were recapitulated by short hairpin RNA RUNX1 KD in CD34+-derived MK. To our knowledge, these studies provide first evidence that platelet endocytosis of albumin and fibrinogen is impaired in some patients with RUNX1-haplodeficiency and suggest that megakaryocytes have enhanced endocytosis with defective trafficking, leading to loss of these proteins by distinct mechanisms. This study provides new insights into mechanisms governing endocytosis and α-granule deficiencies in RUNX1-haplodeficiency.

Abstract A006: Spatial localization of Caveolin-1 protein in triple negative breast cancer is related to different molecular features

Abstract Background: Triple negative breast cancer (TNBC) is an aggressive and heterogeneous form of breast cancer with few targeted therapies and clinically used biomarkers. Caveolin-1 (CAV1) is a marker of stromal activation and vascularization. Molecular features of the tumor microenvironment (TME), important for tumor metastasis, may improve precision oncology in TNBC. CAV1 protein levels have previously been reported as a potential biomarker in breast cancer depending on their localization. Therefore, we aimed to investigate CAV1 protein levels in malignant and stromal cells of TNBC and their relation to CAV1 gene expression, clinicopathological factors, and molecular features. Methods: Tumor-specific CAV1 protein levels were evaluated with immunohistochemistry in malignant and stromal cells in tumor tissue microarrays from a cohort of 242 TNBC patients (inclusion 2010-2015, Sweden) from SCAN-B (NCT03758976). The protein levels of CAV1 in malignant and stromal cells were dichotomized as ‘strong’ (1) vs ‘negative to moderate’ (0) The CAV1 categories in malignant and stromal cells, respectively, were combined to create a joint CAV1 status with four categories: malignant/stromal cells, 0/0, 0/1, 1/0, and 1/1. Gene expression profiles from massive parallel paired-end sequencing of mRNA (RNA-seq) were available for all the tumors and from which PAM50 category and TNBC subtype were assigned. CAV1 status in malignant and stromal cells in relation to clinicopathological factors was analyzed using Chi-Square test. CAV1 mRNA expression in relation to CAV1 status in malignant and stromal cells was evaluated using Kruskal-Wallis test. Results: CAV1 status could be evaluated in 231/242 tumors. Strong CAV1 staining in malignant cells was associated with higher histological grade but no axillary lymph node involvement (both P <0.007). In contrast, strong CAV1 staining in stromal cells was associated with lower histological grade but axillary lymph node involvement (both P <0.001). Strong CAV1 staining in stromal cells was also associated with higher age at diagnosis (P =0.025). With regards to PAM50 subtypes, CAV1 in malignant cells was positively associated with the basal subtype while CAV1 in malignant cells was positively associated with the HER2 enriched subtype (P <0.001). Depending on localization, CAV1 expression was associated with different TNBCsubtypes. CAV1 in malignant cells was positively associated with the mesenchymal and negatively associated with the immunomodulatory subtype (P <0.001). CAV1 in stromal cells was positively associated with the luminal androgen (LAR) subtype (P <0.001). Neither CAV1 protein levels in malignant cells nor in stromal cells were correlated with CAV1 gene expression in the tumors, and the combined CAV1 status was not associated with CAV1 gene expression. Conclusion: CAV1 protein levels in malignant cells were related to different molecular features of TNBC compared to CAV1 protein levels in stromal cells. The results suggest that depending on localization, CAV1 protein levels function as two distinct biomarkers. Citation Format: Christopher Godina, Somayeh Khazaei, Mattias Belting, Johan Vallon-Christersson, Björn Nodin, Karin Jirström, Karolin Isaksson, Ana Bosch, Helena Jernström. Spatial localization of Caveolin-1 protein in triple negative breast cancer is related to different molecular features [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A006.

Is there any diagnostic value of serum caveolin-1 levels on the determination of pancreatic adenocarcinoma?

Caveolin-1 (CAV-1) is a vital component in cancer pathogenesis, as its expression determines the survival of patients with cancer. This study investigates CAV-1 serum levels in pancreatic adenocarcinoma (PA) patients and their role in tumor progression and prognostic factors. The trial included 33 patients with pathologically confirmed pancreatic cancer (PC). The enzyme-linked immunosorbent assay (ELISA) method was used to measure the concentrations of CAV-1 in the blood. The study also included 20 healthy subjects. The statistical analysis was two-sided, and a P value of ≤ 0.05 was determined as statistically significant. The median age of the subjects was 59 years (32-84 years) at the time of diagnosis. There were 13 (39%) female participants. In 21 (63%) patients, the primary focus was the pancreatic head. In 23 stage IV patients, hepatic metastasis (n = 19, 83%) was observed. Only one patient (3%) was still alive at the end of the study period. Palliative chemotherapy (CTx) was provided, with 39% of the 23 patients responding to it. The overall survival (OS) rate in this cohort was 41.3 ± 8.3 weeks at a 95% confidence interval (CI), after 25-58 weeks. Serum baseline CAV-1 values among patients with PA were significantly higher compared with controls (p = 0.009). Patients with poor performance status, a pancreatic head tumor, lower albumin levels, higher serum carcinoembryonic antigen (CEA) levels, and higher CA 19.9 levels had significantly higher serum CAV-1 levels (p = 0.01, P = 0.05, P = 0.03, P = 0.02, and P = 0.04, respectively). However, CAV-1 did not show any prognostic value (p = 0.75). Although serum CAV-1 is a useful diagnostic marker in PC patients, it is not a prognostic or predictive marker.

Ginsenoside Rb1 prevents age-related endothelial senescence by modulating SIRT1/caveolin-1/enos signaling pathway

BackgroundAdvancing age is one of the independent risk factors for cardiovascular disorders. The Compendium of Materia Medica, a classic book on traditional Chinese medicine, states that ginseng “harmonizes the five internal organs, calming the spirit and prolonging the years of life." Considered one of the primary bioactive compounds derived from Panax ginseng, ginsenoside Rb1 (g-Rb1) has been scientifically suggested to possess anti-senescence efficacy. More research is needed to explore the vascular pharmacological activity and potential clinical application value of g-Rb1. Aims of the studyOur previous study demonstrated that g-Rb1 could mitigate cellular senescence via the SIRT1/eNOS pathway. This study was performed to explore the exact mechanisms by which g-Rb1 modulates the SIRT1/eNOS pathway. Materials and methodsWe used human primary umbilical vein endothelial cells (HUVECs) to establish a replicative ageing model. Real-time (RT‒PCR), western blotting, small interfering RNA (siRNA), and immunoprecipitation were conducted to detect the effect of g-Rb1 on the SIRT1/caveolin-1/eNOS axis. ResultsG-Rb1 increased NO production and alleviated replicative senescence of HUVECs. The application of g-Rb1 elevated the mRNA and protein abundance of both SIRT1 and eNOS while concomitantly suppressing the expression of caveolin-1. Inhibition of SIRT1 and eNOS by siRNAs suppressed the anti-senescence function of g-Rb1, while caveolin-1 siRNA could enhance it. G-Rb1 decreased the acetylation level of caveolin-1 and increased NO production, which was suppressed by SIRT1 siRNA. Both g-Rb1 and caveolin-1 siRNA could reduce the acetylation level of eNOS and increase NO production. ConclusionG-Rb1 prevents age-related endothelial senescence by modulating the SIRT1/caveolin-1/eNOS signaling pathway.

What Happens to Serum Levels of Visinin-Like Protein-1, Caveolin-1 and Neuron-Specific Enolase after Supratentorial Glioma Resection: A Pilot Study.

To observe changes in the serum levels of visinin-like protein-1 (VILIP-1), caveolin-1 (Cav-1) and neuron-specific enolase (NSE) after glioma resection. Consecutive 14 glioma patients with different histologic grade and 14 age and gender-matched healthy subjects were included in this pilot study. From the patients serum samples were taken in preoperative and on day 2 and 10 of postoperative periods. Healthy subjects provided serum sample once. The serum changes of three proteins were evaluated by ELISA. The results were compared between preoperative and postoperative periods and between patients and controls. Preoperative serum levels of VILIP-1 (p=0.008) and Cav-1 (p=0.012) were significantly higher in the patients. Mean serum levels of VILIP-1 (p=0.002) and Cav-1 (p=0.013) again were significantly higher than those of the controls. NSE did not show significant changes compared to controls in none of the periods. There was a steady decline regarding all three molecules from preoperative to postoperative day 10. However, statistical comparisons did not reveal any significant difference with respect the decline in any molecule. Significant positive correlation was detected between preoperative serum levels of VILIP-1 and Cav-1 (p=0.00001) in the patients and the controls (p=0.0000). This pilot study suggested that Cav-1 and particularly VILIP-1 may be used as a valuable serum biomarker for follow-up and for early detection of recurrence in high-grade gliomas. Future studies including larger cohort of patients with homogeneous group of glioma is required.

#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.

Prostaglandin E2 Exposure Disrupts E-Cadherin/Caveolin-1-Mediated Tumor Suppression to Favor Caveolin-1-Enhanced Migration, Invasion, and Metastasis in Melanoma Models.

Caveolin-1 (CAV1) is a membrane-bound protein that suppresses tumor development yet also promotes metastasis. E-cadherin is important in CAV1-dependent tumor suppression and prevents CAV1-enhanced lung metastasis. Here, we used murine B16F10 and human A375 melanoma cells with low levels of endogenous CAV1 and E-cadherin to unravel how co-expression of E-cadherin modulates CAV1 function in vitro and in vivo in WT C57BL/6 or Rag-/- immunodeficient mice and how a pro-inflammatory environment generated by treating cells with prostaglandin E2 (PGE2) alters CAV1 function in the presence of E-cadherin. CAV1 expression augmented migration, invasion, and metastasis of melanoma cells, and these effects were abolished via transient co-expression of E-cadherin. Importantly, exposure of cells to PGE2 reverted the effects of E-cadherin expression and increased CAV1 phosphorylation on tyrosine-14 and metastasis. Moreover, PGE2 administration blocked the ability of the CAV1/E-cadherin complex to prevent tumor formation. Therefore, our results support the notion that PGE2 can override the tumor suppressor potential of the E-cadherin/CAV1 complex and that CAV1 released from the complex is phosphorylated on tyrosine-14 and promotes migration/invasion/metastasis. These observations provide direct evidence showing how a pro-inflammatory environment caused here via PGE2 administration can convert a potent tumor suppressor complex into a promoter of malignant cell behavior.

Novel scoring system for early diagnosis of necrotizing enterocolitis: integrating clinical and laboratory data with urinary caveolin-1 levels.

Necrotizing enterocolitis (NEC) poses a significant threat to preterm infants, with nonspecific early manifestations complicating timely diagnosis. Therefore, this study aimed to develop a novel scoring system for early diagnosis of NEC, incorporating clinical and laboratory data with urinary caveolin-1 levels. A single-center prospective cohort study was conducted at a tertiary hospital in East Java, Indonesia. NEC diagnosis was established by Bell's criteria and proven gut dysbiosis. Urinary levels of claudin-2, caveolin-1, and epidermal growth factor (EGF) were assessed as potential indicators of tight junction disruption. The selected urine biomarker cutoff value was determined using symbolic classification analysis and combined with clinical and laboratory parameters from Bell's criteria to create an NEC scoring system, validated with the Aiken index. Sensitivity and specificity analyses were performed. Thirty-four neonates, comprising NEC, preterm non-NEC, and term infants, were included. qPCR analysis highlighted elevated Klebsiella, Lactobacillus, Clostridium, and Bacteroides levels in NEC patients, indicating a gut dysbiosis trend. Among 3 biomarkers, caveolin-1 ≥ 17.81 ng/dl on day 3 demonstrated 72.86% negative predictive value and 87.50% positive predictive value. The combined scoring system which comprised abdominal cellulitis, distension, radiology, advanced resuscitation at birth, prematurity or low birthweight, platelet count, sepsis, orogastric retention, metabolic acidosis and caveolin-1 findings exhibited an AUC of 0.922 (95% CI: 0.81-1.00, p < 0.001), with ≥ 1.81 as the cutoff, offering 93% sensitivity and 94% specificity. Urine caveolin-1 on day 3 signifies enterocyte tight junction damage and the acute phase of NEC in premature infants. The proposed scoring system demonstrates good performance in predicting NEC incidence in preterm infants.