Cav-1 Expression Research Articles

Dysregulated Rbfox2 produces aberrant splicing of CaV1.2 calcium channel in diabetes-induced cardiac hypertrophy

BackgroundL-type Ca2+ channel CaV1.2 is essential for cardiomyocyte excitation, contraction and gene transcription in the heart, and abnormal functions of cardiac CaV1.2 channels are presented in diabetic cardiomyopathy. However, the underlying mechanisms are largely unclear. The functions of CaV1.2 channels are subtly modulated by splicing factor-mediated alternative splicing (AS), but whether and how CaV1.2 channels are alternatively spliced in diabetic heart remains unknown.MethodsDiabetic rat models were established by using high-fat diet in combination with low dose streptozotocin. Cardiac function and morphology were assessed by echocardiography and HE staining, respectively. Isolated neonatal rat ventricular myocytes (NRVMs) were used as a cell-based model. Cardiac CaV1.2 channel functions were measured by whole-cell patch clamp, and intracellular Ca2+ concentration was monitored by using Fluo-4 AM.ResultsWe find that diabetic rats develop diastolic dysfunction and cardiac hypertrophy accompanied by an increased CaV1.2 channel with alternative exon 9* (CaV1.2E9*), but unchanged that with alternative exon 8/8a or exon 33. The splicing factor Rbfox2 expression is also increased in diabetic heart, presumably because of dominate-negative (DN) isoform. Unexpectedly, high glucose cannot induce the aberrant expressions of CaV1.2 exon 9* and Rbfox2. But glycated serum (GS), the mimic of advanced glycation end-products (AGEs), upregulates CaV1.2E9* channels proportion and downregulates Rbfox2 expression in NRVMs. By whole-cell patch clamp, we find GS application hyperpolarizes the current-voltage curve and window currents of cardiac CaV1.2 channels. Moreover, GS treatment raises K+-triggered intracellular Ca2+ concentration ([Ca2+]i), enlarges cell surface area of NRVMs and induces hypertrophic genes transcription. Consistently, siRNA-mediated knockdown of Rbfox2 in NRVMs upregulates CaV1.2E9* channel, shifts CaV1.2 window currents to hyperpolarization, increases [Ca2+]i and induces cardiomyocyte hypertrophy.ConclusionsAGEs, not glucose, dysregulates Rbfox2 which thereby increases CaV1.2E9* channels and hyperpolarizes channel window currents. These make the channels open at greater negative potentials and lead to increased [Ca2+]i in cardiomyocytes, and finally induce cardiomyocyte hypertrophy in diabetes. Our work elucidates the underlying mechanisms for CaV1.2 channel regulation in diabetic heart, and targeting Rbfox2 to reset the aberrantly spliced CaV1.2 channel might be a promising therapeutic approach in diabetes-induced cardiac hypertrophy.

PABPC1 promotes cell proliferation and metastasis in pancreatic adenocarcinoma by regulating COL12A1 expression.

The expression of cytoplasmic poly (A) binding protein-1 (PABPC1) has been reported in multiple cancer types. This protein is known to modulate cancer progression. However, the effects of PABPC1 expression in pancreatic adenocarcinoma (PAAD) have not been investigated. Here, we investigate the regulatory targets and molecular mechanisms of PABPC1 in PAAD. PABPC1 and collagen type XII α1 chain (COL12A1) expression in PAAD and their role in tumor prognosis and tumor stage were investigated using The Cancer Genome Atlasdatabase analysis. After silencing PABPC1, messenger RNA sequencing and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed. The expression of differentially expressed genes (DEGs), cell viability, apoptosis, and cell migration and invasion were explored using reverse transcription-quantitative polymerase chain reaction, Cell Counting Kit-8assay, flow cytometry assay, and transwell assay, respectively. The relationship between PABPC1 and COL12A1 expression was assessed by Pearson's correlation analysis. The regulatory function of COL12A1 in PABPC1-affected BXPC3 cell behavior was studied after COL12A1 was overexpressed. PABPC1 and COL12A1 expression was upregulated in patients with PAAD and was linked to poor prognosis. Four hundred and seventy-four DEGs were observed in BXPC3 cells after PABPC1 silencing. GO and KEGG analyses revealed that the top 10 DEGs were enriched in cell adhesion pathways. Additionally, PABPC1 silencing inhibited cell viability, migration, and invasion and accelerated apoptosis in BXPC3 cells. PABPC1 silencing increased AZGP1 and ARHGAP30 expression and decreased CAV1 and COL12A1 expression in BXPC3 cells. PABPC1 positively mediated COL12A1 expression, whereas PABPC1 knockdown induced the inhibition of BXPC3 cell proliferation, migration, and invasion. The results of this study indicate that PABPC1 may function as a tumor promoter in PAAD, accelerating BXPC3 cell proliferation and metastasis by regulating COL12A1 expression.

Distinctive roles of L-type calcium channels subtypes within the dorsal hippocampus in formation of morphine withdrawal-induced aversion in rats

Although the negative effects coming along with opiate withdrawal are in part modulated by L-type calcium channels (LTCCs), the distinctive physiological properties and functions of LTCCs subtypes suggest differential roles of subtypes during withdrawal. The present study aimed to examine the contributions of LTCC subtypes, Cav1.2 and Cav1.3, within the dorsal hippocampus (DH) in naloxone-precipitated morphine withdrawal using the conditioned place aversion (CPA) paradigm. Firstly, we injected the non-specific LTCCs antagonist verapamil into the DH of morphine-dependent rats before conditioning an environment with naloxone-precipitated withdrawal. Our results showed that verapamil blocked the acquisition of CPA. Then, to explore the molecular mechanisms of LTCCs subtypes during withdrawal, we measured the protein expression of Cav1.2 and Cav1.3 in morphine-dependent rats under different conditions. In morphine-dependent rats, conditioning with withdrawal increased Cav1.2 expression in the membrane, while only acute naloxone injection increased the membrane expression of Cav1.3. To further determine the causal roles of LTCCs subtypes in the withdrawal process, we used Cav1.2 siRNA or Cav1.3 shRNA to knock down the expression of subtypes and detected the effects on CPA and somatic withdrawal signs in morphine-dependent rats. Cav1.2 siRNA, but not Cav1.3 shRNA, inhibited the acquirement of CPA and relieved somatic withdrawal symptoms. Together, our findings reveal that Cav1.2, but not Cav1.3 plays an important role in mediating morphine withdrawal, suggesting this subtype may serve as a potential therapeutic target for the treatment of negative effects in opiate dependence.

Silencing information regulator 1 ameliorates lipopolysaccharide-induced acute lung injury in rats via the upregulation of caveolin-1

BackgroundAcute lung injury (ALI) is an intractable medical problem linked with to high morbidity and mortality all over the worldglobally. The prognosis of advanced acute lung injury remains persistently poor due to its underlying mechanisms remain unclear.Despite advancements in medical research, the its prognosis of advanced ALI remains persistently poor due to unclear underlying mechanisms. We aimed to investigate the protective effects of silencing information regulator 1 (SIRT1) on lipopolysaccharide (LPS)-induced acute lung injuryALI and to reveal its underlying molecular mechanism. MethodsMale Sprague-–Dawley rats were divided grouped into 4 groupsfour: normal saline group (group NS), lipopolysaccharide group (group L), SIRT1 activator SRT1720-pretreated group (group S), and SIRT1 inhibitor EX527- pretreated group (group E). Rats They were intranasally dripped with LPS to establish the model of ALI modelsacute lung injury respectively. We investigated the effect of SIRT1 on acute lung injury by analysing We analyzed the CT images of the rat lungs and used, HE staining, lung wet-to-dry ratio, inflammatory factor expression, lung injury marker expression, immunohistochemistry, and related mRNA expression to determine the effect of SIRT1 on ALI. ResultsOur results show that LPS induction produced resulted in acute lung injury, ALI and disrupting disrupted normal SIRT1 expression, which led to the overexpression of STAT3, TLR4, TNF-ɑ, and IL-6 and suppression of Cav-1 expression. Upregulation The upregulation of Cav-1 protein and mRNA following the administration of an SIRT1 agonist resulted in reduced lung injury. SRT1720 pretreatment was closely associated with reduced expressions of STAT3,TLR4, TNF-ɑ, and IL-6. ALI lung injury was more severeworsened after administration of SIRT1 inhibitors, and the changes in the above indicators were reversed. ConclusionsThese results suggest that SIRT1 may protect against LPS-induced acute lung injuryALI via by counteracting inflammatory remissionion, and this protective effect might may be mediated by suppressing STAT3 to activate the expression ofinduce Cav-1 expression.

Interleukin-37 inhibits desmoglein-3 endocytosis and keratinocyte dissociation via upregulation of Caveolin-1 and inhibition of the STAT3 pathway.

Pemphigus vulgaris (PV) is a potentially fatal autoimmune bullous disease primarily caused by acantholysis of keratinocytes attributed to pathogenic desmoglein-3 (Dsg3) autoantibodies. Interleukin-37 (IL-37) reportedly plays important roles in a variety of autoimmune diseases, but its role in PV is not clear. To investigate whether IL-37 plays a role in the occurrence and progression of PV. HaCaT keratinocytes were stimulated with anti-Dsg3 antibody to establish an in vitro PV model, which was defined as anti-Dsg3 group. Cells incubated with medium without anti-Dsg3 treatment were used as control. IL-37 was cultured with these cells infected with or without lentiviral vector shRNA-Caveolin-1 (sh-Cav-1-LV). Cell dissociation assay and immunocytofluorescence were performed to assess keratinocyte dissociation, keratin retraction and Dsg3 endocytosis. Real-time PCR was used to detect the mRNA level of Cav-1, and western blot was used to determine the protein expression of Cav-1, Dsg3, STAT3 and phosphorylated-STAT3 (p-STAT3). The anti-Dsg3 group showed more cell debris, increased keratin retraction, increased Dsg3 endocytosis, reduced Cav-1 expression and co-localization than the control group, while IL-37 treatment neutralized all of these changes. Interestingly, Cav-1 knockdown supressed the inhibitory effect of IL-37 on keratinocyte dissociation and Dsg3 internalization. The protein expression of p-STAT3 was increased in keratinocytes of the PV model but decreased by IL-37. Re-activation of the STAT3 pathway by colivelin supressed the inhibitory effect of IL-37 on keratinocyte dissociation and Dsg3 internalization, along with upregulation of Cav-1 and Dsg3. IL-37 inhibited keratinocyte dissociation and Dsg3 endocytosis in an in vitro PV model through the upregulating Cav-1 and inhibiting STAT3 pathway.

Calcium Handling Remodeling Underlies Impaired Sympathetic Stress Response in Ventricular Myocardium from Cacna1c Haploinsufficient Rats.

CACNA1C encodes the pore-forming α1C subunit of the L-type Ca2+ channel, Cav1.2. Mutations and polymorphisms of the gene are associated with neuropsychiatric and cardiac disease. Haploinsufficient Cacna1c+/- rats represent a recently developed model with a behavioral phenotype, but its cardiac phenotype is unknown. Here, we unraveled the cardiac phenotype of Cacna1c+/- rats with a main focus on cellular Ca2+ handling mechanisms. Under basal conditions, isolated ventricular Cacna1c+/- myocytes exhibited unaltered L-type Ca2+ current, Ca2+ transients (CaTs), sarcoplasmic reticulum (SR) Ca2+ load, fractional release, and sarcomere shortenings. However, immunoblotting of left ventricular (LV) tissue revealed reduced expression of Cav1.2, increased expression of SERCA2a and NCX, and augmented phosphorylation of RyR2 (at S2808) in Cacna1c+/- rats. The β-adrenergic agonist isoprenaline increased amplitude and accelerated decay of CaTs and sarcomere shortenings in both Cacna1c+/- and WT myocytes. However, the isoprenaline effect on CaT amplitude and fractional shortening (but not CaT decay) was impaired in Cacna1c+/- myocytes exhibiting both reduced potency and efficacy. Moreover, sarcolemmal Ca2+ influx and fractional SR Ca2+ release after treatment with isoprenaline were smaller in Cacna1c+/- than in WT myocytes. In Langendorff-perfused hearts, the isoprenaline-induced increase in RyR2 phosphorylation at S2808 and S2814 was attenuated in Cacna1c+/- compared to WT hearts. Despite unaltered CaTs and sarcomere shortenings, Cacna1c+/- myocytes display remodeling of Ca2+ handling proteins under basal conditions. Mimicking sympathetic stress with isoprenaline unmasks an impaired ability to stimulate Ca2+ influx, SR Ca2+ release, and CaTs caused, in part, by reduced phosphorylation reserve of RyR2 in Cacna1c+/- cardiomyocytes.

Prenatal dexamethasone exposure impaired vascular reactivity in adult male offspring cerebral arteries

BackgroundCerebrovascular disease is one of the leading causes of death worldwide. Middle cerebral artery (MCA) is the largest and most complex of cerebral arteries. The prenatal period is a critical time for development, which largely determines lifelong health. Clinically, glucocorticoids (GCs) administration to accelerate preterm fetal lung maturation has become standard practice. Prenatal GCs administration increases cardiovascular risks in offspring, but little is known regarding the side effects on offspring MCA function. ObjectiveWe investigated the alterations of MCA reactivity following prenatal GCs administration in postnatal offspring. Method and resultsPregnant Sprague-Dawley rats received synthetic GCs (dexamethasone, DEX) during the last week of pregnancy, and we examined vascular reactivity, cellular electrophysiology, and gene promoter epigenetic modifications in the male offspring MCA. Our results showed that prenatal DEX exposure increased the sensitivity of offspring MCA to Angiotensin II, which was resulted from the increased Cav1.2 (L-type Ca2+ channels subunit alpha1 C). Mechanistically, prenatal DEX exposure resulted in a transcriptionally active chromatin structure at the Cav1.2 gene promoter by altering histone modifications. This activation led to increased expression of vascular Cav1.2 gene, ultimately resulting in increased MCA contractility in offspring. ConclusionThe present study is the first to demonstrate that the adverse effects of prenatal GCs administration on cerebrovascular tone persist into adulthood, providing new insights into developmental origins of cerebrovascular disease.

Evaluation of the Anticancer Activity of Calcium Ions Introduced into Human Breast Adenocarcinoma Cells MCF-7/WT and MCF-7/DOX by Electroporation.

Breast cancer ranks among the top three most common malignant neoplasms in Poland. The use of calcium ion-assisted electroporation is an alternative approach to the classic treatment of this disease. The studies conducted in recent years confirm the effectiveness of electroporation with calcium ions. Electroporation is a method that uses short electrical pulses to create transitional pores in the cell membrane to allow the penetration of certain drugs. The aim of this study was to investigate the antitumor effects of electroporation alone and calcium ion-assisted electroporation on human mammary adenocarcinoma cells that are sensitive (MCF-7/WT) and resistant to doxorubicin (MCF-7/DOX). The cell viability was assessed using independent tests: MTT and SRB. The type of cell death after the applied therapy was determined by TUNEL and flow cytometry (FACS) methods. The expression of Cav3.1 and Cav3.2 proteins of T-type voltage-gated calcium channels was assessed by immunocytochemistry, and changes in the morphology of CaEP-treated cells were visualized using a holotomographic microscope. The obtained results confirmed the effectiveness of the investigated therapeutic method. The results of the work constitute a good basis for planning research at the in vivo level and in the future to develop a more effective and safer method of breast cancer treatment for patients.

Yue-bi-tang attenuates adriamycin-induced nephropathy edema through decreasing renal microvascular permeability via inhibition of the Cav-1/ eNOS pathway.

Edema is one of the most typical symptoms of nephrotic syndrome. Increased vascular permeability makes a significant contribution to the progression of edema. Yue-bi-tang (YBT) is a traditional formula with excellent clinical efficacy in the treatment of edema. This study investigated the effect of YBT on renal microvascular hyperpermeability-induced edema in nephrotic syndrome and its mechanism. In our study, the content of target chemical components of YBT was identified using UHPLC-Q-Orbitrap HRMS analysis. A nephrotic syndrome model was replicated based on male Sprague-Dawley rats with Adriamycin (6.5mg/kg) by tail vein injection. The rats were randomly divided into control, model, prednisone, and YBT (22.2g/kg, 11.1g/kg, and 6.6g/kg) groups. After 14d of treatment, the severity of renal microvascular permeability, edema, the degree of renal injury, and changes in the Cav-1/eNOS pathway were assessed. We found that YBT could regulate renal microvascular permeability, alleviate edema, and reduce renal function impairment. In the model group, the protein expression of Cav-1 was upregulated, whereas VE-cadherin was downregulated, accompanied by the suppression of p-eNOS expression and activation of the PI3K pathway. Meanwhile, an increased NO level in both serum and kidney tissues was observed, and the above situations were improved with YBT intervention. It thus indicates YBT exerts therapeutic effects on the edema of nephrotic syndrome, as it improves the hyperpermeability of renal microvasculature, and that YBT is engaged in the regulation of Cav-1/eNOS pathway-mediated endothelial function.

BS-454195-1 ADRENERGIC MODULATION OF CONDUCTION DURING CARDIAC STRESS IS MEDIATED BY CALCIUM CHANNEL AUTOREGULATION OF INTERCALATED DISC NANODOMAINS

During stress, adrenergic signaling enhances cardiac conduction, although the mechanisms are not fully understood. Reducing extracellular calcium in the heart widens an intercalated disc (ID) nanodomain adjacent to gap junctions known as the perinexus. Under acute cardiac stress, the perinexus adaptively remodels; preventing this response by experimentally changing calcium levels slows conduction and increases arrhythmia risk. This raises the question of whether myocytes autoregulate calcium-mediated ID adhesion to stabilize conduction during cardiac stress. The cardiac voltage gated calcium channel (Cav1.2) is a primary source of calcium influx and a key target during adrenergic signaling. Expression of Cav1.2 within the ID has not been described. To test the hypothesis that Cav1.2 is expressed in the ID and autoregulates myocyte adhesion and conduction in the adrenergic response to cardiac stress. Ex vivo guinea pig hearts were Langendorff-perfused and ventricular tissue harvested for microscopy. Cav1.2 cellular localization was quantified by spinning disk confocal microscopy (n=5), conduction velocity (CV) was measured by optical mapping (n=9), and ID ultrastructure was quantified from transmission electron micrographs (n=17). Cav1.2 function was modulated by perfusion with the β-adrenergic agonist isoproterenol (Iso, 0.6μM), the Cav1.2 agonist BayK8644 (BayK, 0.5μM), or the Cav1.2 antagonist verapamil (Ver, 2μM). Super resolution confocal microscopy demonstrated that 2.5% of total Cav1.2 signal co-occurred with connexin43 and N-cadherin. At baseline, CV slowed at shorter CLs (150 vs 300ms = 4% slower), consistent with CV restitution. Treatment with Iso increased both Wp (20.2 vs 17.0 nm at baseline) and CV (300ms: 113% of baseline). Iso reversed CV restitution such that CV increased by 4%. Activation of Cav1.2 by BayK widened Wp to the same degree as Iso (20.1 vs 20.2 nm). Verapamil prevented both the Iso-induced increase in Wp (17.0 nm) and CV (93.9% of baseline), and exacerbated CV restitution. A subpopulation of Cav1.2 was identified within the ID. Adrenergic stimulation widened perinexal width, increased conduction, and reversed CV restitution. Blocking Cav1.2 prevented the adrenergic-mediated change in perinexal structure and conduction. Thus, Cav1.2 function regulates ID ultrastructure and may serve as an adaptive response to enhance conduction during conditions of acute cardiac stress.

Abstract 3604: Epithelial Caveolin-1 regulates lung metastasis in advanced stages of breast cancer

Abstract Organotypic metastasis is a well-orchestrated sequence of events that takes place in tumors. The interplay between secretory factors from the primary tumor and the microenvironment of a distant organ determines the fate of metastasis. A significant concern in effective triple-negative breast cancer (TNBC) treatment is lung metastasis. Caveolin-1 (Cav-1), a lipid raft protein, is an important component of the metastatic interplay and is reported to be upregulated in the advanced metastatic stage of breast cancer. Although Cav-1 has been shown to have oncogenic potential, its role in TNBC lung metastasis is not fully understood. Our data illustrates, knocking out Cav-1 in the 4T1 cells (a mouse breast cancer cell line) affects cell morphology, extracellular vesicle formation, and MMP release in vitro. Furthermore, a wound healing/cell migration assay showed reduced migration in Cav-1 KO 4T1 cells when compared to control 4T1 cells, and these findings were validated using Cav-1 siRNA. For investigating the metastatic role, we injected Cav-1 KO 4T1 and control 4T1 cells into the mammary fat pad of female BALB/c mice, a syngeneic mouse model of triple-negative breast cancer. We found no evidence of lung metastasis in Cav-1 KO 4T1 injected mice when compared to control 4T1 injected mice. This was further supported by mRNA profiling of the tumor. We observed 21 epithelial cell migration genes that are differentially expressed in Cav-1 KO tumors when compared to WT tumors. Correlation analysis from Breast Cancer Gene-Expression Miner v4.8 (bc-GenExMiner), a human database, showed a significant correlation between Cav-1 expression and several of the 21 epithelial cell migration genes, along with integrin 3 alpha (ITGα3). Interestingly, in silico protein docking predicted an interaction between Cav-1 and ITGα3, which was later confirmed by co-immunoprecipitation. The role of ITGα3 in metastasis was further corroborated by cell migration assay, which was affected when siRNA was used to silence ITGα3 gene expression. Collectively, these findings provide evidence that Cav-1 KO, along with ITGa3, plays an important role in distant lung metastasis in the 4T1 tumor-induced mice model. Citation Format: Dhirendra Pratap Singh, Rashmi Pathak, Abhishek Pandit, Philip J. Ebenezer, Nithya Jambunathan, Sanjay Kumar, Alexander Du Plooy, Joseph Francis, Mary E. White. Epithelial Caveolin-1 regulates lung metastasis in advanced stages of breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3604.

Caveolin-1 Promotes the Imbalance of Th17/Treg in Chronic Obstructive Pulmonary Disease by Regulating Hsp70 Expression.

To investigate whether the expression of Hsp70 is associated with Cav-1 in promoting the imbalance of Th17/Treg cells in COPD. The plasma Cav-1, Hsp70 expression were quantified by enzyme-linked immunosorbent assay (ELISA). The frequencies of circulating Th17, Treg cells and Th17/Treg ratio were determined by flow cytometry. Peripheral blood mononuclear cells (PBMCs) from subjects were transfected with Cav-1 or control plasmids and Hsp70 plasmid. We found that Cav-1 expression was lower but the levels of Hsp70 and Th17 cells were higher in COPD than in healthy control (HC). Hsp70 expressions were positively correlated with Cav-1 levels, Th17 cells, and Th17/Treg ratio in COPD but not in HC. Cav-1 over-expression resulted in an increase in Hsp70 and Th17 levels. Suppressing Hsp70 expressing by small interfering RNA (siRNA), the decline of Th17 frequency was observed in Cav-1-overexpressed PBMCs. Collectively, our results illuminate that Cav-1 contributes to the imbalance of Th17/Treg through potentially regulating Hsp70 expression.

Decreased Expression of Urethral Caveolin-1, -2, and -3 in the Rat Model of Overactive Bladder: Potential Mediator of Functional Interaction of Urethra and Urinary Bladder.

To investigate the effect of detrusor overactivity (DO) on the urethral expression of caveolin (CAV)-1, -2, and -3 of urethra in an animal model of cyclophosphamide (CYP)-induced cystitis rat. Female Sprague-Dawley rats were divided into the control group (n=20) and the cystitis group (n=20). Cystitis was induced by intraperitoneal injection of CYP (200 mg/kg). An urodynamic study was done 3 days after the CYP injection to measure functional change of the urinary bladder and urethra. Cellular localization and expression of CAV-1, -2, and -3 in the rat urethra were determined by immunohistochemistry (IHC) and Western blot. Urodynamic experiments demonstrated a decreased contraction interval in the cystitis group compared to the control (3.9±1.0 minutes vs. 6.6±1.2 minutes, P<0.05). Conversely, contraction pressure increased significantly in the cystitis group compared to the control (22.4±0.7 mmHg vs. 11.5±0.4 mmHg, P<0.05). The urethral pressure was decreased in the cystitis group compared to the control (4.05 ±2.5 mmHg vs. 5.8 ±2.8 mmHg, P <0.05). The IHC and Western blot data showed that CAV-1, -2, and -3 expression decreased significantly in the cystitis group compared control group (P<0.05). The decreased urethral CAV-1, -2, and -3 in the DO rats suggests that CAVs might be related with the functional change of urethra in association with DO of urinay bladder.

Fibrillin-1 mutation contributes to Marfan syndrome by inhibiting Cav1.2-mediated cell proliferation in vascular smooth muscle cells

ABSTRACT Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder caused by mutation in fibrillin-1 (FBN1). However, the molecular mechanism underlying MFS remains poorly understood. The study aimed to explore how the L-type calcium channel (CaV1.2) modulates disease progression of MFS and to identify a potential effective target for attenuating MFS. KEGG enrichment analysis showed that the calcium signaling pathway gene set was significantly enriched. We demonstrated that FBN1 deficiency exhibited inhibition on both the expression of Cav1.2 and proliferation of vascular smooth muscle cells (VSMCs). Then, we examined whether FBN1 mediates Cav1.2 via regulating TGF-β1. Higher levels of TGF-β1 were observed in the serum and aortic tissues from patients with MFS. TGF-β1 modulated Cav1.2 expression in a concentration-dependent manner. We evaluated the role of Cav1.2 in MFS by small interfering RNA and Cav1.2 agonist Bay K8644. The effect of Cav1.2 on cell proliferation was dependent on c-Fos activity. These results demonstrated FBN1 deficiency decreased the expression levels of Cav1.2 via regulation of TGF-β1, and downregulation of Cav1.2 inhibited cell proliferation of human aortic smooth muscle cells (HASMCs) in MFS patients. These findings suggest that Cav1.2 may be an appealing therapeutic target for MFS.

Decrease in cholesterol in the cell membrane is essential for Nrf2 activation by quercetin

Quercetin is a flavonoid with various cytoprotective effects. We previously reported that quercetin exerts anti-allergic, anti-oxidative, and anti-fibrotic activities via the induction of heme oxygenase (HO)-1. However, the mechanisms by which quercetin induces HO-1 to exhibit cytoprotective effects are poorly understood. We focused on its action on the cell membrane, which is the first part of the cell to interact with the extracellular environment. The cell membrane contains lipid rafts and caveolae, which play important roles in cellular signaling. A recent study showed that nuclear factor E2-related factor 2 (Nrf2), a transcription factor regulating anti-oxidative enzymes including HO-1, interacts with caveolin-1 (Cav-1), a component of caveolae, to regulate cellular anti-oxidative capacity. In this study, we investigated the changes in the cell membrane that leads to the induction of HO-1 by quercetin. Quercetin decreased the amount of cholesterol in the raft fractions, which in turn promoted the induction of HO-1. It also changed the composition of the lipid rafts and decreased and increased the expression of Cav-1 in the raft and non-raft fractions, respectively. Nrf2, which was localized in the cell membrane under resting conditions, was translocated along with Cav-1 to the nucleus after exposure to quercetin. These findings indicate for the first time that the HO-1-dependent cytoprotective effects of quercetin are mediated by the structural changes in lipid rafts brought about by decreasing the amount of cholesterol in the cell membrane, which thereby results in the translocation of the Cav-1-Nrf2 complex to the nucleus and induces the expression of HO-1.

Integration of clinical and spatial data to explore lipid metabolism-related genes for predicting prognosis and immune microenvironment in gliomas.

Lipid metabolism is crucial to tumor growth and immune microenvironment as well as drug sensitivity in glioma. Identifying prognostic indicators of glioma and elucidating the mechanisms of glioma progression are criticalfor improving the prognosis ofglioma patients. In this study, we investigated the role and prognostic value of metabolism-related genes in glioma by integrative analysis of datasets fromGEO, CGGA, and TCGA. Based on clinical data and transcriptome data, we found that the expression pattern of three major pathways related to lipid metabolism is fatty acidhigh-phospholipidhigh-triglyceridelow, which is associated with better prognosis and immune infiltration. The genes involved inthese three pathwayswere used to generate a prognostic model, which showed highstability and efficiency in the test set and validation set. The spatial transcriptome of glioma patientsrevealed that the microenvironment of the regions with high expression of risk genes CAV1 and SCD is in a state of hypoxia, EMT, and cell cycle arrest, and thus can be used as markers of metabolic reprogramming in the tumor microenvironment. In the high-risk group, M0 macrophages and M1 macrophages were significantly enriched, and the risk score was significantly correlated with gene mutation and methylation of risk genes. We further performed drug sensitivity screening corresponding to different risk genes. This study provided novel insights into the differential immune microenvironment with different expression patternsof metablism-related genes and highlighted the spatial and temporal synergy of tumor progression and metabolic reprogramming.

Large-scale analyses of CAV1 and CAV2 suggest their expression is higher in post-mortem ALS brain tissue and affects survival.

Introduction: Caveolin-1 and Caveolin-2 (CAV1 and CAV2) are proteins associated with intercellular neurotrophic signalling. There is converging evidence that CAV1 and CAV2 (CAV1/2) genes have a role in amyotrophic lateral sclerosis (ALS). Disease-associated variants have been identified within CAV1/2 enhancers, which reduce gene expression and lead to disruption of membrane lipid rafts. Methods: Using large ALS whole-genome sequencing and post-mortem RNA sequencing datasets (5,987 and 365 tissue samples, respectively), and iPSC-derived motor neurons from 55 individuals, we investigated the role of CAV1/2 expression and enhancer variants in the ALS phenotype. Results: We report a differential expression analysis between ALS cases and controls for CAV1 and CAV2 genes across various post-mortem brain tissues and three independent datasets. CAV1 and CAV2 expression was consistently higher in ALS patients compared to controls, with significant results across the primary motor cortex, lateral motor cortex, and cerebellum. We also identify increased survival among carriers of CAV1/2 enhancer mutations compared to non-carriers within Project MinE and slower progression as measured by the ALSFRS. Carriers showed a median increase in survival of 345 days. Discussion: These results add to an increasing body of evidence linking CAV1 and CAV2 genes to ALS. We propose that carriers of CAV1/2 enhancer mutations may be conceptualised as an ALS subtype who present a less severe ALS phenotype with a longer survival duration and slower progression. Upregulation of CAV1/2 genes in ALS cases may indicate a causal pathway or a compensatory mechanism. Given prior research supporting the beneficial role of CAV1/2 expression in ALS patients, we consider a compensatory mechanism to better fit the available evidence, although further investigation into the biological pathways associated with CAV1/2 is needed to support this conclusion.

Caveolin-1-Mediated Cholesterol Accumulation Contributes to Exaggerated mGluR-Dependent Long-Term Depression and Impaired Cognition in Fmr1 Knockout Mice

Fragile X syndrome (FXS) is one of the most common inherited mental retardation diseases and is caused by the loss of fragile X mental retardation protein (FMRP) expression. The metabotropic glutamate receptor (mGluR) theory of FXS states that enhanced mGluR-dependent long-term depression (LTD) due to FMRP loss is involved in aberrant synaptic plasticity and autistic-like behaviors, but little is known about the underlying molecular mechanism. Here, we found that only hippocampal mGluR-LTD was exaggerated in adolescent Fmr1 KO mice, while N-methyl-D-aspartate receptor (NMDAR)-LTD was intact in mice of all ages. This development-dependent alteration was related to the differential expression of caveolin-1 (Cav1), which is essential for caveolae formation. Knockdown of Cav1 restored the enhanced mGluR-LTD in Fmr1 KO mice. Moreover, hippocampal Cav1 expression in Fmr1 KO mice induced excessive endocytosis of the α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate (AMPA) receptor subunit GluA2. This process relied on mGluR1/5 activation rather than NMDAR. Interference with Cav1 expression reversed these changes. Furthermore, massive cholesterol accumulation contributed to redundant caveolae formation, which provided the platform for mGluR-triggered Cav1 coupling to GluA2. Importantly, injection of the cholesterol scavenger methyl-β-cyclodextrin (Mβ-CD) recovered AMPA receptor trafficking and markedly alleviated hyperactivity, hippocampus-dependent fear memory, and spatial memory defects in Fmr1 KO mice. Together, our findings elucidate the important role of Cav1 in mediating mGluR-LTD enhancement and further inducing AMPA receptor endocytosis and suggest that cholesterol depletion by Mβ-CD during caveolae formation may be a novel and safe strategy to treat FXS.

Expression of Cav-1, MCT1, and MCT4 in Ductal Carcinoma In Situ of the Breast and Their Associations With Clinicopathologic Features.

Loss of caveolin-1 (Cav-1) and upregulation of monocarboxylate transporters (MCTs, especially MCT1 and MCT4) in respectively tumor-associated stromal cells and malignant epithelial cells of invasive carcinoma have been found to play an important role in the metabolic coupling. However, this phenomenon has only been scarcely described in pure ductal carcinoma in situ (DCIS) of the breast. mRNA and protein expression levels of Cav-1, MCT1, and MCT4 in nine pairs of DCIS tissues and matched normal tissues were examined by quantitative real-time polymerase chain reaction, RNAscope in situ hybridization, and immunohistochemistry. Immunohistochemical staining of Cav-1, MCT1, and MCT4 in 79 DCIS samples was also done using tissue microarray. Cav-1 mRNA expression was significantly lower in DCIS tissues than in their corresponding normal tissues. In contrast, MCT1 and MCT4 mRNA expression levels were higher in DCIS tissues than in corresponding normal tissues. Low stromal Cav-1 expression was significantly associated with high nuclear grade. High epithelial MCT4 expression was associated with larger tumor size and human epidermal growth factor 2 positivity. At a mean follow-up of 10 years, patients with high epithelial MCT1/high epithelial MCT4 expression showed shorter disease-free survival than those with other expressions. No significant association was observed between stromal Cav-1 expression and epithelial MCT 1 or MCT4 expression. Changes in Cav-1, MCT1, and MCT4 are associated with carcinogenesis of DCIS. A high epithelial MCT1/high epithelial MCT4 expression might be associated with a more aggressive phenotype.

Caveolin-3 and Caveolae regulate ventricular repolarization

RationaleFlask-shaped invaginations of the cardiomyocyte sarcolemma called caveolae require the structural protein caveolin-3 (Cav-3) and host a variety of ion channels, transporters, and signaling molecules. Reduced Cav-3 expression has been reported in models of heart failure, and variants in CAV3 have been associated with the inherited long-QT arrhythmia syndrome. Yet, it remains unclear whether alterations in Cav-3 levels alone are sufficient to drive aberrant repolarization and increased arrhythmia risk. ObjectiveTo determine the impact of cardiac-specific Cav-3 ablation on the electrophysiological properties of the adult mouse heart. Methods and resultsCardiac-specific, inducible Cav3 homozygous knockout (Cav-3KO) mice demonstrated a marked reduction in Cav-3 expression by Western blot and loss of caveolae by electron microscopy. However, there was no change in macroscopic cardiac structure or contractile function. The QTc interval was increased in Cav-3KO mice, and there was an increased propensity for ventricular arrhythmias. Ventricular myocytes isolated from Cav-3KO mice exhibited a prolonged action potential duration (APD) that was due to reductions in outward potassium currents (Ito, Iss) and changes in inward currents including slowed inactivation of ICa,L and increased INa,L. Mathematical modeling demonstrated that the changes in the studied ionic currents were adequate to explain the prolongation of the mouse ventricular action potential. Results from human iPSC-derived cardiomyocytes showed that shRNA knockdown of Cav-3 similarly prolonged APD. ConclusionWe demonstrate that Cav-3 and caveolae regulate cardiac repolarization and arrhythmia risk via the integrated modulation of multiple ionic currents.