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Tamilarasan KP, Temmel H, Das SK, Al Zoughbi W, Schauer S, Vesely PW, Hoefler G. Skeletal muscle damage and impaired regeneration due to LPL-mediated lipotoxicity. Cell Death Dis 2012; 3:e354. [PMID: 22825472 PMCID: PMC3406590 DOI: 10.1038/cddis.2012.91] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
According to the concept of lipotoxicity, ectopic accumulation of lipids in non-adipose tissue induces pathological changes. The most prominent effects are seen in fatty liver disease, lipid cardiomyopathy, non-insulin-dependent diabetes mellitus, insulin resistance and skeletal muscle myopathy. We used the MCK(m)-hLPL mouse distinguished by skeletal and cardiac muscle-specific human lipoprotein lipase (hLPL) overexpression to investigate effects of lipid overload in skeletal muscle. We were intrigued to find that ectopic lipid accumulation induced proteasomal activity, apoptosis and skeletal muscle damage. In line with these findings we observed reduced Musculus gastrocnemius and Musculus quadriceps mass in transgenic animals, accompanied by severely impaired physical endurance. We suggest that muscle loss was aggravated by impaired muscle regeneration as evidenced by reduced cross-sectional area of regenerating myofibers after cardiotoxin-induced injury in MCK(m)-hLPL mice. Similarly, an almost complete loss of myogenic potential was observed in C2C12 murine myoblasts upon overexpression of LPL. Our findings directly link lipid overload to muscle damage, impaired regeneration and loss of performance. These findings support the concept of lipotoxicity and are a further step to explain pathological effects seen in muscle of obese patients, patients with the metabolic syndrome and patients with cancer-associated cachexia.
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Affiliation(s)
- K P Tamilarasan
- Institute of Pathology, Medical University of Graz, Auenbruggerplatz 25, 8036 Graz, Austria
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Siamwala JH, Majumder S, Tamilarasan KP, Muley A, Reddy SH, Kolluru GK, Sinha S, Chatterjee S. Simulated microgravity promotes nitric oxide-supported angiogenesis via the iNOS-cGMP-PKG pathway in macrovascular endothelial cells. FEBS Lett 2010; 584:3415-23. [PMID: 20600009 DOI: 10.1016/j.febslet.2010.06.039] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 06/17/2010] [Accepted: 06/24/2010] [Indexed: 10/19/2022]
Abstract
Angiogenesis is a physiological process involving the growth of blood vessel in response to specific stimuli. The present study shows that limited microgravity treatments induce angiogenesis by activating macrovascular endothelial cells. Inhibition of nitric oxide production using pharmacological inhibitors and inducible nitric oxide synthase (iNOS) small interfering ribo nucleic acid (siRNA) abrogated microgravity induced nitric oxide production in macrovascular cells. The study further delineates that iNOS acts as a molecular switch for the heterogeneous effects of microgravity on macrovascular, endocardial and microvascular endothelial cells. Further dissection of nitric oxide downstream signaling confirms that simulated microgravity induces angiogenesis via the cyclic guanosine monophosphate (cGMP)-PKG dependent pathway.
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Affiliation(s)
- Jamila H Siamwala
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, MIT Campus, Chennai, India
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Majumder S, Rajaram M, Muley A, Reddy HS, Tamilarasan KP, Kolluru GK, Sinha S, Siamwala JH, Gupta R, Ilavarasan R, Venkataraman S, Sivakumar KC, Anishetty S, Kumar PG, Chatterjee S. Thalidomide attenuates nitric oxide-driven angiogenesis by interacting with soluble guanylyl cyclase. Br J Pharmacol 2010; 158:1720-34. [PMID: 19912234 DOI: 10.1111/j.1476-5381.2009.00446.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Nitric oxide (NO) promotes angiogenesis by activating endothelial cells. Thalidomide arrests angiogenesis by interacting with the NO pathway, but its putative targets are not known. Here, we have attempted to identify these targets. EXPERIMENTAL APPROACH Cell-based angiogenesis assays (wound healing of monolayers and tube formation in ECV304, EAhy926 and bovine arterial endothelial cells), along with ex vivo and in vivo angiogenesis assays, were used to explore interactions between thalidomide and NO. We also carried out in silico homology modelling and docking studies to elucidate possible molecular interactions of thalidomide and soluble guanylyl cyclase (sGC). KEY RESULTS Thalidomide inhibited pro-angiogenic functions in endothelial cell cultures, whereas 8-bromo-cGMP, sildenafil (a phosphodiesterase inhibitor) or a NO donor [sodium nitroprusside (SNP)] increased these functions. The inhibitory effects of thalidomide were reversed by adding 8-bromo-cGMP or sildenafil, but not by SNP. Immunoassays showed a concentration-dependent decrease of cGMP in endothelial cells with thalidomide, without affecting the expression level of sGC protein. These results suggested that thalidomide inhibited the activity of sGC. Molecular modelling and docking experiments revealed that thalidomide could interact with the catalytic domain of sGC, which would explain the inhibitory effects of thalidomide on NO-dependent angiogenesis. CONCLUSION AND IMPLICATIONS Our results showed that thalidomide interacted with sGC, suppressing cGMP levels in endothelial cells, thus exerting its anti-angiogenic effects. These results could lead to the formulation of thalidomide-based drugs to curb angiogenesis by targeting sGC.
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Affiliation(s)
- Syamantak Majumder
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, TN, India
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Majumder S, Tamilarasan KP, Kolluru GK, Muley A, Nair CM, Omanakuttan A, Murty KVGK, Chatterjee S. Activated pericyte attenuates endothelial functions: nitric oxide-cGMP rescues activated pericyte-associated endothelial dysfunctions. Biochem Cell Biol 2008; 85:709-20. [PMID: 18059529 DOI: 10.1139/o07-140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatic stellate cells are liver-specific pericytes and exist in close proximity with endothelial cells. The activation of liver pericytes is intrinsic to liver pathogenesis, and leads to endothelial dysfunction, including the low bioavailability of nitric oxide (NO). However, the role of nitric oxide in pericyte-endothelium cross-talk has not yet been elucidated. This work examines the cellular mechanism of action of NO in pericyte-mediated endothelial dysfunction. We used in vitro coculture and conditioned medium systems to study the effects of activated liver pericytes on endothelial function, and an egg yolk vascular bed model was used to study the effects of activated pericytes on angiogenesis. This study also demonstrates that activated pericytes attenuate the migration, proliferation, permeability, and NO production of endothelial cells. Our results demonstrate that activated pericytes restrict angiogenesis in egg yolk vascular bed models, and NO supplementation recovers 70% of the inhibition. Our results also demonstrate that supplementation with NO, sildenafil citrate (phosphodiesterase inhibitor), and 8-bromo-cGMP (cGMP analog) partially recovers activated-pericyte-mediated endothelium dysfunction. We conclude that NO-cGMP alleviates activated-pericyte-associated endothelial dysfunction, including angiogenesis, in a cGMP-dependent manner.
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Affiliation(s)
- Syamantak Majumder
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, MIT Campus, Chennai, Tamil Nadu, India
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Majumder S, Muley A, Kolluru GK, Saurabh S, Tamilarasan KP, Chandrasekhar S, Reddy HB, Purohit S, Chatterjee S. Cadmium reduces nitric oxide production by impairing phosphorylation of endothelial nitric oxide synthase. Biochem Cell Biol 2008; 86:1-10. [DOI: 10.1139/o07-146] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cadmium (Cd) perturbs vascular health and interferes with endothelial function. However, the effects of exposing endothelial cells to low doses of Cd on the production of nitric oxide (NO) are largely unknown. The objective of the present study was to evaluate these effects by using low levels of CdCl2concentrations, ranging from 10 to 1000 nmol/L. Cd perturbations in endothelial function were studied by employing wound-healing and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. The results suggest that a CdCl2concentration of 100 nmol/L maximally attenuated NO production, cellular migration, and energy metabolism in endothelial cells. An egg yolk angiogenesis model was employed to study the effect of Cd exposure on angiogenesis. The results demonstrate that NO supplementation restored Cd-attenuated angiogenesis. Immunofluorescence, Western blot, and immuno-detection studies showed that low levels of Cd inhibit NO production in endothelial cells by blocking eNOS phosphorylation, which is possibly linked to processes involving endothelial function and dysfunction, including angiogenesis.
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Affiliation(s)
- Syamantak Majumder
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Ajit Muley
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Gopi Krishna Kolluru
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Samir Saurabh
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - K. P. Tamilarasan
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Sidhharth Chandrasekhar
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Hima Bindu Reddy
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Sharad Purohit
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
| | - Suvro Chatterjee
- Vascular Biology Lab, Life Sciences, AU-KBC Research Centre, MIT Campus, Anna University, Chennai, Tamil Nadu 600044, India
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta, GA 30912, USA
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Tamilarasan KP, Kolluru GK, Rajaram M, Indhumathy M, Saranya R, Chatterjee S. Thalidomide attenuates nitric oxide mediated angiogenesis by blocking migration of endothelial cells. BMC Cell Biol 2006; 7:17. [PMID: 16584574 PMCID: PMC1456963 DOI: 10.1186/1471-2121-7-17] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Accepted: 04/04/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Thalidomide is an immunomodulatory agent, which arrests angiogenesis. The mechanism of anti-angiogenic activity of thalidomide is not fully understood. As nitric oxide is involved in angiogenesis, we speculate a cross-talk between thalidomide and nitric oxide signaling pathway to define angiogenesis. The aim of present study is to understand the mechanistic aspects of thalidomide-mediated attenuation of angiogenesis induced by nitric oxide at the cellular level. METHODS To study the cellular mechanism of thalidomide-mediated blocking of angiogenesis triggered by nitric oxide, we used two endothelial cell based models: 1) wound healing and 2) tube formation using ECV 304, an endothelial cell line. These cell-based models reflect pro-angiogenic events in vivo. We also studied the effects of thalidomide on nitric oxide mediated egg yolk angiogenesis. Thalidomide could block the formation of blood vessels both in absence and presence of nitric oxide. Thalidomide effects on migration of, and actin polymerization in, ECV 304 cells were studied at the single cell level using live cell imaging techniques and probes to detect nitric oxide. RESULTS Results demonstrate that thalidomide blocks nitric oxide-mediated angiogenesis in egg yolk model and also reduces the number of tubes formed in endothelial cell monolayers. We also observed that thalidomide arrests wound healing in presence and absence of nitric oxide in a dose-dependent fashion. Additionally, thalidomide promotes actin polymerization and antagonizes the formation of membrane extensions triggered by nitric oxide in endothelial cells. Experiments targeting single tube structure with thalidomide, followed by nitric oxide treatment, show that the tube structures are insensitive to thalidomide and nitric oxide. These observations suggest that thalidomide interferes with nitric oxide-induced migration of endothelial cells at the initial phase of angiogenesis before cells co-ordinate themselves to form organized tubes in endothelial cells and thereby inhibits angiogenesis. CONCLUSION Thalidomide exerts inhibitory effects on nitric oxide-mediated angiogenesis by altering sub-cellular actin polymerization pattern, which leads to inhibition of endothelial cell migration.
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Affiliation(s)
- KP Tamilarasan
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, India
| | | | - Megha Rajaram
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, India
| | - M Indhumathy
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, India
- Worked as summer students in June-July 2005. They are B.Tech students from the
Vivekanandhaa College of Engineering for Women, Tiruchengode, Namakkal, TN, India
| | - R Saranya
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, India
- Worked as summer students in June-July 2005. They are B.Tech students from the
Vivekanandhaa College of Engineering for Women, Tiruchengode, Namakkal, TN, India
| | - Suvro Chatterjee
- Vascular Biology Lab, AU-KBC Research Centre, Anna University, Chennai, India
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Kolluru GK, Tamilarasan KP, Geetha Priya S, Durgha NP, Chatterjee S. Cadmium induced endothelial dysfunction: consequence of defective migratory pattern of endothelial cells in association with poor nitric oxide availability under cadmium challenge. Cell Biol Int 2006; 30:427-38. [PMID: 16616865 DOI: 10.1016/j.cellbi.2006.02.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 01/08/2006] [Accepted: 02/14/2006] [Indexed: 10/24/2022]
Abstract
Recent advances in cadmium toxicity research suggest an association between cadmium and vascular diseases. However, the mechanisms of cadmium implications in vascular diseases are not yet explained. The objective of our present study is to explore the mechanism of cadmium induced endothelial dysfunction. Doses of 0, 1 and 5microM cadmium chloride were used to test the effects of cadmium on nitric oxide induced tube formation, cellular migration and subcellular actin polymerization in ECV-304 endothelial cells. An egg-yolk vascular bed model was used to study the effects of cadmium on angiogenesis. Results of the present study show that 5microM cadmium chloride effectively inhibited angiogenesis, cellular migration and tube formation. Phalloidin staining, which represents actin polymerization of endothelial cells, reveals that cadmium induces an altered F-actin pattern, which could be the prime cause for cadmium mediated inhibition of cellular migration and angiogenesis. Cadmium was also found to inhibit nitric oxide production in endothelial cells in a calcium free medium, which further hints that cadmium might impair endothelial functions by inhibiting endothelial nitric oxide synthase.
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Affiliation(s)
- Gopi Krishna Kolluru
- Vascular Biology Lab, AU-KBC Research Centre, MIT Campus, Anna University, Chennai 600 044, Tamil Nadu, India
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