Role of caveolin 3 in diabetic cardiomyopathy in mice: relationship with endoplasmic reticulum stress / 中华麻醉学杂志

Objective:To evaluate the role of caveolin 3 (Cav-3) in diabetic cardiomyopathy and the relationship with endoplasmic reticulum stress in mice.Methods:This experiment was performed in two parts. Part Ⅰ in vivo experiment Sixteen clean-grade healthy adult male wild type mice weighing 18-20 g, were divided into 2 groups ( n=8 each) using a random number table method: control group(Control group) and diabetic cardiomyopathy group (DCM group). Another 8 Cav-3 KO mice were selected and served as Cav-3 KO + diabetic cardiomyopathy group (Cav-3 KO+ DCM group). Type 2 diabetic models were developed by high fat diet combined with intraperitoneal injection of streptozotocin (100 mg/kg). The left ventricular ejection fraction (EF), left ventricular short axis shortening rate (FS), left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) were measured by B ultrasound at 8 weeks. Then the mice were sacrificed, and the myocardial histomorphology was observed using HE staining. Part Ⅱ in vitro experiment HL-1 cardiomyocytes were divided into 3 groups ( n=6 each)using a random number table method: normal glucose group (NG group), high glucose group (HG group) and high glucose+ methyl-β-cyclodextrin group (HG+ β-CD group). The high glucose model was prepared by adding 50% glucose to a specialized culture medium until the final concentration reached 30 mmol/L, and HL-1 cardiomyocytes were continuously cultivated for 36 h. The cellular injury was assessed using LDH and CCK8 kits. The expression of endoplasmic reticulum stress-related proteins binding immunoglobulin protein (BiP), C/EBP-homologous protein (CHOP) and X-box binding protein 1 (XBP1-s) in myocardial tissues and HL-1 cells was detected by Western blot. Results:In vivo experiment Compared with Control group, the food intake, water intake, and heart mass/body mass were significantly increased, EF and FS were decreased, LVESD and LVEDD were increased, the expression of BiP, CHOP and XBP1-s was up-regulated, the expression of Cav-3 was down-regulated ( P<0.05), and the pathological damage was aggravated in DCM group and Cav-3 KO+ DCM group. Compared with DCM group, EF and FS were significantly decreased, LVESD and LVEDD were increased, the expression of BiP, CHOP and XBP1-s was up-regulated, the expression of Cav-3 was down-regulated ( P<0.05), and the pathological damage was aggravated in Cav-3 KO+ DCM group. In vitro experiment Compared with NG group, the cell viability was significantly decreased, LDH activity was increased, the expression of BiP, CHOP and XBP1-s was up-regulated, and the expression of Cav-3 was down-regulated in HG group and HG+ β-CD group ( P<0.05). Compared with HG group, the cell viability was significantly decreased, LDH was increased, the expression of BiP, CHOP and XBP1-s was up-regulated, and the expression of Cav-3 was down-regulated in HG+ β-CD group ( P<0.05). Conclusions:Down-regulation of Cav-3 expression aggravates myocardial injury in diabetes mellitus, and the mechanism is related to excessive activation of endoplasmic reticulum stress in mice.

Caveolinas y modulación del sistema del óxido nítrico en el hipotiroidismo según avanza la edad / Age-related Influence of Hypothyroidism on Caveolins and Nitric Oxide Modulation

Introducción El hipotiroidismo y la edad impactan sobre la producción de óxido nítrico (NO) cardíaco y renal. Las caveolinas, moduladores negativos de la actividad enzimática de la NO sintetasa (NOS), se afectan con ambos factores. Objetivos Evaluar la implicación de las caveolinas (cav) en la modulación de la actividad de la NOS cardíaca y renal en animales hipotiroideos adultos. Material y métodos Se utilizaron ratas macho Sprague-Dawley eutiroideas e hipotiroideas [metimazol 0,02% (v/v) en el agua de bebida durante 28 días]. Los animales fueron sacrificados para extraer el corazón y los riñones. Resultados La actividad de la NOS en la aurícula derecha disminuyó con la edad y el hipotiroidismo. La expresión de cav-1 aumentó con la edad y el hipotiroidismo. La actividad de la NOS en el ventrículo izquierdo aumentó con el avance de la edad y el hipotiroidismo. La expresión de ambas caveolinas disminuyó en los grupos adulto e hipotiroideo. En la médula renal, el hipotiroidismo disminuyó la actividad de la NOS en jóvenes y la aumentó en adultos. La expresión de cav-1 disminuyó con la edad y en jóvenes hipotiroideos. Los niveles proteicos de cav-3 disminuyeron en animales adultos hipotiroideos. Conclusiones El hipotiroidismo impacta sobre la actividad de la NOS y de sus moduladores, las caveolinas, en el sistema cardiovascular y renal. El hipotiroidismo intensifica los efectos del avance de la edad en ambos sistemas.

Introduction Hypothyroidism and age impact on cardiac and renal nitric oxide (NO) production. Caveolins, which are negative modulators of NO synthase (NOS) activity, are affected by both factors. Objectives The aim of this study was to evaluate caveolin (CAV) participation in the modulation of renal and cardiac NOS activity in adult hypothyroid animals. Methods Euthyroid and hypothyroid [methimazole 0.02% (v/v) in the drinking water during 28 days] male Sprague-Dawley rats were used. Animals were sacrificed to remove the heart and kidneys. Results Right atrial NOS activity decreased with age and hypothyroi-dism. Caveolin-1 expression increased with age and hypothyroidism. Conversely, left ventricular NOS activity increased with aging and hypothyroidism and the expression of both CAV isoforms decreased in adult and hypothyroid groups. In the renal medulla, hypothyroidism reduced NOS activity in young and raised it in adult animals and CAV-1 expression decreased with age and in hypothyroid young animals. Caveolin-3 protein levels decreased in adult hypothyroid animals. Conclusions Hypothyroidism impacts on NOS activity and on that of its modulators, caveolins, in the cardiovascular and renal systems. Hypothyroidism enhances the effects of aging in both systems.

Culture and biological characteristics of neural stem cells from caveolin-1 knockout embryonic mice / 中国组织工程研究

BACKGROUND:Caveolin-1 is expressed in mammalian brain and involved in the normal development of the brain, which can affect the proliferation of neural stem cells in the brain. OBJECTIVE:To acquire neural stem cells from caveolin-1 knockout embryonic mice in vitro and study their biological characteristics. METHODS:The whole brain was separated from C57BL/6 mice and caveolin-1 knockout C57BL/6 mice respectively at encyesis 14-16 days. Single cellsuspension was obtained by enzyme digestion, and cultured in the conditioned medium of neural stem cells. Fol owing 7 days of primary culture, the cells were induced in Dulbecco’s modified Eagle’s medium/Ham’s nutrient mixture F-12 containing 10%fetal bovine serum for 7 days. RESULTS AND CONCLUSION:The major cells of the cellsuspensions from the fetal mouse brain were dead at 1 day after culture, and some single cells floated in the medium and their transmittance were better, and then they gradual y formed multicellular bal s after 3 days. A smal amount of cells were adhered at the bottom of culture plate after passage, and a great amount of cellbal s appeared after 7 days. The proliferation rate of neural stem cells from caveolin-1 knockout mice was higher than that from normal mice. The cellbal s were nestin-positive and their differentiated cells was positive for neurofilament 200, glial fibril ary acidic protein or O4, respectively. Al of the cells from normal mouse brain were positive for caveolin-1, but the cells from caveolin-1 knockout mice were negative for caveolin-1 by immunocytochemistry. Moreover, the speed of cellbal formation and the number of cellbal s in neural stem cells from caveolin-1 knockout mice were better than those from normal mice. Caveolin-1 negative neural stem cells were cultured successful y from caveolin-1 knockout mouse brain, and the results show that caveolin-1 can promote the proliferation of neural stem cells and inhibit their differentiation in vitro.

Differential expression of caveolins and myosin heavy chains in response to forced exercise in rats / 한국실험동물학회지

Exercise training can improve strength and lead to adaptations in the skeletal muscle and nervous systems. Skeletal muscles can develop into two types: fast and slow, depending on the expression pattern of myosin heavy chain (MHC) isoforms. Previous studies reported that exercise altered the distribution of muscle fiber types. It is not currently known what changes in the expression of caveolins and types of muscle fiber occur in response to the intensity of exercise. This study determined the changes in expression of caveolins and MHC type after forced exercise in muscular and non-muscular tissues in rats. A control (Con) group to which forced exercise was not applied and an exercise (Ex) group to which forced exercise was applied. Forced exercise, using a treadmill, was introduced at a speed of 25 m/min for 30 min, 3 times/day (07:00, 15:00, 23:00). Homogenized tissues were applied to extract of total RNA for further gene analysis. The expression of caveolin-3 and MHC2a in the gastrocnemius muscle of female rats significantly increased in the Ex group compared with the Con group (P<0.05). Furthermore, in the gastrocnemius muscle of male rats, the expression of MHC2x was significantly different between the two groups (P<0.05). There was an increased expression in caveolin-3 and a slightly decreased expression in TGFbeta-1 in muscular tissues implicating caveolin-3 influences the expression of MHC isoforms and TGFbeta-1 expression. Eventually, it implicates that caveolin-3 has positive regulatory function in muscle atrophy induced by neural dysfunction with spinal cord injury or stroke.

HMG-CoA Reductase Inhibitor Improves Endothelial Dysfunction in Spontaneous Hypertensive Rats Via Down-regulation of Caveolin-1 and Activation of Endothelial Nitric Oxide Synthase

Hypertension is associated with endothelial dysfunction and increased cardiovascular risk. Caveolin-1 regulates nitric oxide (NO) signaling by modulating endothelial nitric oxide synthase (eNOS). The purpose of this study was to examine whether HMG-CoA reductase inhibitor improves impaired endothelial function of the aorta in spontaneous hypertensive rat (SHR) and to determine the underlying mechanisms involved. Eight-week-old male SHR were assigned to either a control group (CON, n=11) or a rosuvastatin group (ROS, n=12), rosuvastatin (10 mg/kg/day) administered for eight weeks. Abdominal aortic rings were prepared and responses to acetylcholine (10-9-10-4 M) were determined in vitro. To evaluate the potential role of NO and caveolin-1, we examined the plasma activity of NOx, eNOS, phosphorylated-eNOS and expression of caveolin-1. The relaxation in response to acetylcholine was significantly enhanced in ROS compared to CON. Expression of eNOS RNA was unchanged, whereas NOx level and phosphorylated-eNOS at serine-1177 was increased accompanied with depressed level of caveolin-1 in ROS. We conclude that 3-Hydroxy-3-methylglutaryl Coenzyme-A (HMG-CoA) reductase inhibitor can improve impaired endothelial dysfunction in SHR, and its underlying mechanisms are associated with increased NO production. Furthermore, HMG-CoA reductase inhibitor can activate the eNOS by phosphorylation related to decreased caveolin-1 abundance. These results imply the therapeutic strategies for the high blood pressure-associated endothelial dysfunction through modifying caveolin status.

Expression of Caveolin in Hepatocellular Carcinoma: Association with Unpaired Artery Formation and Radiologic Findings / 대한간학회지

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is becoming one of the common malignant tumors worldwide, and it is characterized by its high vascularity. Caveolin is the major structural protein in caveolae, which are small omega-shaped invaginations within the plasma membrane. Caveolin has been implicated in mitogenic signaling, oncogenesis and angiogenesis. The expression of caveolin-1 and -2 in HCC and its potential relationship with angiogenesis has not been examined. METHODS: Paraffin sections of 35 HCC specimens were immunostained with caveolin-1, caveolin-2, alpha-smooth muscle actin, and CD34 antibodies. In addition, the expression of caveolin-1 and -2 mRNA in HCC was examined. The relationship between the radiological findings and the number of unpaired arteries and microvessel density (MVD) was also investigated. RESULTS: Caveolin-1 and -2 were expressed in the sinusoidal endothelial cells in 20 out of 35, and 18 out of 35 HCC specimens, respectively. Caveolin-1 and -2 were also expressed in the smooth muscle cells of the unpaired arteries in 26 out of 35, and 18 out of 35 HCC specimens, respectively. Increased expression of caveolin-1 and -2 mRNA was detected in 26.7% and 33.3% of the tumor specimens, respectively, compared with the corresponding non-tumorous adjacent liver tissues. There was a significant correlation between expression of caveolin-1, -2 in the smooth muscle cells of unpaired arteries and the number of unpaired arteries. The number of unpaired arteries in HCCs was found to be associated with the degree of contrast enhancement in the arterial phase imaging. However, it did not correlate with the degree of MVD. CONCLUSIONS: These findings suggest that the expression of caveolin-1, -2 is associated with the formation of unpaired arteries in HCC. In addition, there is a correlation between the degree of contrast enhancement of the HCC in the arterial phase image and the number of unpaired arteries.

Evidence for Cyclooxygenase-2 Association with Caveolin-3 in Primary Cultured Rat Chondrocytes

The purpose of this study was to demonstrate the cellular localization of cyclooxygenase-2 (COX-2) and caveolin-3 (Cav-3) in primarily cultured rat chondrocytes. In normal rat chondrocytes, we observed relatively high levels of Cav-3 and a very low level of COX-2 mRNA and protein. Upon treating the chondrocytes with 5 microM of CdCl2 (Cd) for 6 hr, the expressions of COX-2 mRNA and protein were increased with the decreased Cav-3 mRNA and protein expressions. The detergent insoluble caveolae-rich membranous fractions that were isolated from the rat chondrocytes and treated with Cd contained the both proteins of both COX-2 and Cav-3 in a same fraction. The immuno-precipitation experiments showed complex formation between the COX-2 and Cav-3 in the rat chondrocytes. Purified COX-2 with glutathione S-transferase-fused COX-2 also showed complex formation with Cav-3. Confocal and electron microscopy also demonstrated the co-localization of COX-2 and Cav-3 in the plasma membrane. The results from our current study show that COX-2 and Cav-3 are co-localized in the caveolae of the plasma membrane, and they form a protein-protein complex. The co-localization of COX-2 with Cav-3 in the caveolae suggests that the caveolins might play an important role for regulating the function of COX-2.

Correlation between Up-Regulation of Caveolin-1 Gene in Human Rencal Cell Carcinoma and Multi-drug Resistance / 대한비뇨기과학회지

PURPOSE: To investigate whether up-regulation of the caveolin-1 gene is associated with the resistance to the chemotherapeutic agents in human renal cell carcinomas (HRCC). MATERIALS AND METHODS: Two HRCC cell lines, SN12C and SN12CPM7, with low and high metastatic potentials, respectively, were cultured. Between these two cell lines, the cytotoxicities to doxorubicin, and the expressions of the caveolin-1 gene, were compared using the MTT assay and Northern blot analysis, respectively. A full length of caveolin-1 cDNA was obtained, and inserted into the SN12C to make stable cells expressing the caveolin-1 gene (SN12C/Cav). In these cells, the status of the caveolin-1 expression was evaluated, and the cytotoxicity to doxorubicin or interferon compared to other cell lines. RESULTS: The SN12CPM7 cells were less sensitive to the doxorubicin than the SN12C cells in the cytotoxicity study. The Northern blot analysis revealed that the expression of caveolin-1 was higher in the SN12CPM7 than in the SN12C cells. The expression levels of the caveolin-1 gene in the SN12C/Cav and SN12CPM7 were very similar. The MTT assay, using transfected cell lines, revealed that the SN12C/Cav was more resistant to both the doxorubicin and interferon than the SN12C. CONCLUSIONS: In HRCCs, up-regulation of the caveolin-1 gene may be associated with the change in the biological response to anti-cancer drugs. The induction of the caveolin-1 gene expression may provide the cancer cells with some protection against the action of cytotoxic drugs.

The effect and mechanism of caveolin-1 upregulation on the proliferation of MGC803 cell line / 中国医师杂志

Objective To study the effect of caveolin-1 gene expression on the proliferation of human gastric adenocarcinoma cells,and to explore the possibility for its future usage in gene therapy.Methods The full-length caveolin-1 gene was stably transfected into the MGC803 cell line by lipofectin.The Pcl neo vector was transfected at the same time as mock control.The expression of caveolin-1 was detected by Western blot in both the caveolin-1 gene transfected MGC803 cells and the controls.The cell cycle was analyzed by flow cytometry.Results After transfected with caveolin-1,MGC803 cells significantly up-regulated the expression of caveolin 1 and extended their doubling time.The cell proliferation was inhibited and the cell cycle was arrested in the G_0/G_1 phase.Conclusion Caveolin-1 can inhibit the proliferation of MGC803 cells and induce cell cycle arrest in G_0/G_1 phase.

Effect of estrogen on the gene expression of caveolin-1 in rat vascular smooth muscle cells / 中国病理生理杂志

AIM: To assess the effect of estrogen on the gene expression of caveolin-1 in rat vascular smooth muscle cells (VSMCs). METHODS: Wistar rats were ovariectomized and subjected to subcutaneous implantation of placebo pellets (OVX+V group) or estradiol pellets (OVX+E group). 2 weeks after implantation, the expression of caveolin-1 gene in endothelium-denuded aortic tissue was examined by RT-PCR. Furthermore, Northern blotting was used to analyze the mRNA expression of caveolin-1 in cultured rat VSMCs. RESULTS: RT-PCR showed that expression of caveolin-1 gene was significantly higher in OVX+E group than that in OVX+V group. Northern blot analysis showed that the mRNA expression of caveolin-1 was higher in VSMCs pretreated with 17?-estradiol (17?-E 2) than that in VSMCs without 17?-E 2 pretreatment. CONCLUSION: Estrogen up-regulates the gene expression of caveolin-1 in the vascular wall, partially indicating the cardiovascular effect of estrogen. [

Influence of caveolin-1 on the ET-1-induced VSMC proliferation / 中国病理生理杂志

AIM: To investigate the effect of caveolin-1 on the endothelin-1 (ET-1)-induced vascular smooth muscle cells (VSMC) proliferation. METHODS: The -thymidine (TdR) incorporation, immunofluorescence assays and western blotting were used in this study. RESULTS: The ETA receptor specific antagonist BQ123 inhibited the increase in TdR incorporation in response to ET-1 on VSMC. Immunofluorescence assays showed that caveolin-1 was mostly distributed in plasmalemma of VSMC. After 24 h treatment of VSMC with ET-1, the expression of caveolin-1 in VSMC was significantly decreased. Western blotting showed that ET-1 inhibited the expression of caveolin-1 in VSMC, BQ123 reversed the effect of ET-1. CONCLUSION: Caveolin-1 was mostly distributed in plasmalemma of VSMC. ET-1 downregulated caveolin-1 expression in VSMC via ETA receptor.