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Karna KK, Choi BR, Kim CY, Kim HK, Park JK. Rubus occidentalis and Ellagic Acid Affect the Contractility of Penile Corpus Cavernosum Smooth Muscle through the Nitric Oxide-Cyclic Guanosine Monophosphate and Cyclic Adenosine 3',5'-Monophosphate Signaling Pathway. J Clin Med 2022; 11:2947. [PMID: 35629073 DOI: 10.3390/jcm11102947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/18/2022] [Accepted: 05/21/2022] [Indexed: 02/01/2023] Open
Abstract
The present study was designed to evaluate the relaxation effect of Rubus occidentalis (RO) and ellagic acid (EA) on rabbit penile corpus cavernosum smooth muscle (PCCSM). Rabbit PCCSM was treated with ROE or EA after preincubation with nitric oxide synthase (NOS), guanylate cyclase (GC), adenylyl cyclase (AC) or protein kinase A (PKA) blocker. Cyclic nucleotides in the perfusate were analyzed using radioimmunoassay (RIA). Subsequently, perfused PCCSMs were subjected to analysis to evaluate the expression level of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS). The interaction of ROE or EA with phosphodiesterase (PDE) 5 and PDE4 inhibitors, such as udenafil (UDE) and rolipram (ROL), were also evaluated. Both ROE and EA relaxed the PCCSM in a concentration-dependent manner. Coincubation of ROE or EA with NOS, GC, AC, or PKA blocker significantly decreased the ROE- and EA-induced relaxation. Pretreatment of ROE and EA significantly upregulated the cyclic guanosine monophosphate (cGMP), cyclic adenosine 3′,5′-monophosphate (cAMP), and eNOS levels in the perfused PCCSM. Furthermore, the treatment of ROE and EA markedly increased the UDE- and ROL-induced relaxation of the PCCSM. In conclusion, ROE and EA induced PCCSM relaxation by activating the nitric oxide (NO)-cGMp and cAMp signaling pathways and may have a synergistic action to improve erectile function.
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Jiang M, Zhuang Y, Zu WC, Jiao L, Richard SA, Zhang S. Overexpression of EPAC2 reduces the invasion of glioma cells via MMP-2. Oncol Lett 2019; 17:5080-5086. [PMID: 31186720 PMCID: PMC6507491 DOI: 10.3892/ol.2019.10200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/26/2019] [Indexed: 01/15/2023] Open
Abstract
Exchange proteins directly activated by cAMP (EPACs) are crucial cyclic adenosine 3′,5′-monophosphate- determined signaling pathway intercessors, which are associated with the pathogenesis of neurological disorders and numerous human diseases. To the best of our knowledge, the role of EPAC2 signaling via matrix metalloproteinase 2 (MMP-2) in the pathogenesis of glioma has not been studied. Therefore, the present study focused on the role of EPAC2 in glioma, and assessed the invasiveness of human glioma cell lines following EPAC2 overexpression. Expression levels of EPAC2 in normal brain tissues and clinical glioma specimens were detected by western blotting. An EPAC2 overexpression vector was transfected into U251 and U87 cell lines to increase the expression levels of EPAC2. Expression levels of MMP-2 were detected by western blotting, and the invasive abilities of glioma cells were detected by a Transwell assay. EPAC2 was relatively highly expressed in normal brain tissue, while EPAC2 expression was significantly decreased in clinical glioma specimens (P<0.01). In vitro transfection of EPAC2 overexpression vector significantly reduced the MMP-2 protein levels of glioma cells, and, at the same time, the invasive cell number was significantly decreased in a Transwell assay. The present study demonstrated that MMP-2 regulation via EPAC2 overexpression is a novel promising therapeutic route in malignant types of glioma.
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Affiliation(s)
- Ming Jiang
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China.,Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Yan Zhuang
- Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Wang-Cun Zu
- Department of Neurosurgery, Northern Jiangsu People's Hospital, Yangzhou University, Yangzhou, Jiangsu 225000, P.R. China
| | - Lei Jiao
- Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China
| | - Seidu A Richard
- Department of Neurosurgery, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu 212001, P.R. China.,Department of Immunology, Jiangsu University, Zhenjiang, Jiangsu 212013, P.R. China.,Department of Medicine, Princefield University, P.O. Box MA 128, Ho, Volta Region, Ghana
| | - Shiming Zhang
- Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
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Kim DU, Nam J, Cha MD, Kim SW. Inhibition of phosphodiesterase 4D decreases the malignant properties of DLD-1 colorectal cancer cells by repressing the AKT/mTOR/Myc signaling pathway. Oncol Lett 2019; 17:3589-3598. [PMID: 30867802 DOI: 10.3892/ol.2019.9996] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 12/03/2018] [Indexed: 12/31/2022] Open
Abstract
Colorectal cancer (CRC) is a complex disease involving numerous genetic abnormalities. One of the major characteristics of CRC is enhanced Wnt signaling caused by loss-of-function mutations in the adenomatous polyposis coli (APC) gene. Previously, it has been demonstrated that the majority of malignant phenotypes following APC deletion in adult murine small intestines could be rescued when Myc, a downstream target of the Wnt pathway, was deleted. This indicated that Myc is a critical regulator of CRC development following APC loss. Previous studies reported that cyclic adenosine 3',5'-monophosphate (cAMP) can influence the AKT/mammalian target of rapamycin (mTOR) survival pathway in cancer and Myc is a critical downstream molecule of AKT/mTOR signaling. Phosphodiesterase 4D (PDE4D), a member of the cAMP-specific PDE4 family, has been associated with drug resistance in CRC. However, the association between PDE4D and Myc remains unclear. To investigate the potential role of PDE4D in Myc regulation in CRC, the present study evaluated the expression levels of PDE4 subtypes in DLD-1 CRC cells. Additionally, the effects of PDE4 inhibitors on Myc expression and oncogenic properties were analyzed by western blot analysis, reverse transcription-quantitative polymerase chain reaction, colony formation and soft agar assays. It was demonstrated that cAMP/PDE4D signals serve a critical role in regulating Myc expression in DLD-1 CRC cells. Furthermore, PDE4D was identified to be a main hydrolyzer of cAMP and suppression of PDE4D using selective inhibitors of PDE4 increased intracellular cAMP levels, which resulted in a marked decrease in the oncogenic properties of DLD-1 cells, including colony formation, cell proliferation and anchorage-independent growth. Notably, the current data imply that cAMP represses Myc expression via the downregulation of AKT/mTOR signaling, which was abolished by high PDE4D activities in DLD-1 cells. Additionally, a natural polyphenol resveratrol in combination with forskolin elevated the concentration of cAMP and enhanced the expression of Myc and the malignant phenotype of DLD-1 cells, reproducing the effect of known chemical inhibitors of PDE4. In conclusion, the present study identified that cAMP/PDE4D signaling is a critical regulator of Myc expression in DLD-1 and possibly other CRC cells.
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Affiliation(s)
- Dong Uk Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Jehyun Nam
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Matthew D Cha
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Sang-Woo Kim
- Department of Biological Sciences, Pusan National University, Busan 46241, Republic of Korea
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Tai Z, Lin Y, He Y, Huang J, Guo J, Yang L, Zhang G, Wang F. Luteolin sensitizes the antiproliferative effect of interferon α/β by activation of Janus kinase/signal transducer and activator of transcription pathway signaling through protein kinase A-mediated inhibition of protein tyrosine phosphatase SHP-2 in cancer cells. Cell Signal 2013; 26:619-28. [PMID: 24333668 DOI: 10.1016/j.cellsig.2013.11.039] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/07/2013] [Accepted: 11/26/2013] [Indexed: 01/08/2023]
Abstract
New negative regulators of interferon (IFN) signaling, preferably with tissue specificity, are needed to develop therapeutic means to enhance the efficacy of type I IFNs (IFN-α/β) and reduce their side effects. We conducted cell-based screening for IFN signaling enhancer and discovered that luteolin, a natural flavonoid, sensitized the antiproliferative effect of IFN-α in hepatoma HepG2 cells and cervical carcinoma HeLa cells. Luteolin promoted IFN-β-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway activation by enhancing the phosphorylation of Jak1, Tyk2, and STAT1/2, thereby promoting STAT1 accumulation in the nucleus and endogenous IFN-α-regulated gene expression. Of interest, inhibition of phosphodiesterase (PDE) abolished the effect of IFN-β and luteolin on STAT1 phosphorylation. Luteolin also increased the cAMP-degrading activity of PDE bound with type I interferon receptor 2 (IFNAR2) and decreased the intracellular cAMP level, indicating that luteolin may act on the JAK/STAT pathway via PDE. Protein kinase A (PKA) was found to negatively regulate IFN-β-induced JAK/STAT signaling, and its inhibitory effect was counteracted by luteolin. Pull-down and immunoprecipitation assays revealed that type II PKA interacted with IFNAR2 via the receptor for activated C-kinase 1 (RACK-1), and such interaction was inhibited by luteolin. Src homology domain 2 containing tyrosine phosphatase-2 (SHP-2) was further found to mediate the inhibitory effect of PKA on the JAK/STAT pathway. These data suggest that PKA/PDE-mediated cAMP signaling, integrated by RACK-1 to IFNAR2, may negatively regulate IFN signaling through SHP-2. Inhibition of this signaling may provide a new way to sensitize the efficacy of IFN-α/β.
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Affiliation(s)
- Zhengfu Tai
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Yuan Lin
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Key Laboratory of Bio-resources and Eco-environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, China
| | - Yujiao He
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Junmei Huang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Jiajia Guo
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Lijuan Yang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Guolin Zhang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.
| | - Fei Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China.
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Abstract
OBJECTIVES This study examined the effect of cilostazol, a potent phosphodiesterase inhibitor, on the progression of neuropathies associated with streptozotocin-induced diabetes mellitus in Sprague-Dawley rats. METHODS Eight weeks after streptozotocin treatment, a pelleted diet containing 0.03% cilostazol (15 mg/kg body weight) was given for four weeks. Body weight, blood glucose level, motor nerve conduction velocity (MNCV), myelinated fiber density and size distribution of sciatic nerves were compared between age-matched normal rats (Group 1), control diabetic rats (Group 2) and cilostazol-treated diabetic rats (Group 3). RESULTS Body weight was significantly reduced and blood glucose level was significantly increased in diabetic rats (Group 2 and 3) compared to normal rats. MNCV and cAMP content of sciatic nerves were significantly reduced in diabetic rats 12 weeks after streptozotocin treatment. Myelinated fiber size and density were also significantly reduced, and thickening of the capillary walls and duplication of the basement membranes of the endoneural vessels were observed in the diabetic rats. Whereas both body weight and blood glucose level of Group 3 did not differ significantly from those of Group 2, cilostazol treatment significantly increased MNCV and cAMP content of sciatic nerves in Group 3 but not to the levels observed in Group 1. MNCV positively correlated with cAMP content of sciatic nerves (r = 0.86; p < 0.001). Cilostazol treatment not only restored myelinated fiber density and size distribution but reversed some of the vascular abnormalities. CONCLUSION These findings suggest that a reduced cAMP content in motor nerves may be involved in the development of diabetic neuropathy, and that cilostazol may prevent the progression of diabetic neuropathy by restoring functional impairment and morphological changes of peripheral nerves.
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Affiliation(s)
- K S Suh
- Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea
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