Biochemistry & Pharmacology: Open Access
Open Access
ISSN: 2167-0501
+44-20-4587-4809
ISSN: 2167-0501
+44-20-4587-4809
Berardo C, Di Pasqua LG, Siciliano V, Nicoletti F, Plinio R, Vairetti M and Ferrigno A
University of Pavia, Italy
IRCCS Neuromed, Italy
Sapienza University, Italy
Scientific Tracks Abstracts: Biochem Pharmacol (Los Angel)
The Negative Allosteric Modulator (NAM) 2-methyl-6-(phenylethynyl) pyridine (MPEP) of metabotropic Glutamate
Receptor subtype 5 (mGluR5) improves viability of isolated anoxic hepatocytes1. It is known that during ischemia/
reperfusion (I/R) injury, Kupffer cells activation occurs, causing an increase in TNF-�?± production. Moreover, TNF-�?± positively
correlates with iNOS expression through NF-�?ºB2,3 and because of the presence of TNF Response Element on iNOS gene4,5.The
aims of this study were: to investigate the protection mediated by other NAMs (MTEP and Fenoabam) against anoxic damage
in isolated hepatocytes and to investigate the liver functionality in two ex vivo models of I/R. Male Wistar rat hepatocytes
were exposed to 90 minutes anoxia at 37�?°C with: MPEP and 3-((2-methyl-4-thiazolyl ethynyl pyridine (MTEP) at 3-30�?¼M,
Fenobam at 1-10-50-100�?¼M. Hepatocytes viability was evaluated by trypan blue exclusion and LDH release. Wildtype and
mGluR5 knockout livers from Balb-c mice were isolated, subjected to cold or normothermic I/R and treated with MPEP
0.3�?¼M; transaminases release, BAX and Bcl-2, iNOS, eNOS and TNF-�?± protein expression were evaluated in cold I/R samples,
while LDH, AST, TNF-�?± release were evaluated in normothermic samples. MPEP 30�?¼M, MTEP 3�?¼M and Fenobam 50�?¼M
improved significantly anoxic isolated hepatocytes viability respect to anoxic controls. MPEP addition during I/R significantly
reduced LDH, transaminases and TNF-alpha respect to ischemic controls in both cold and normothermic I/R, with a trend
similar to mGluR5 knockout samples. Furthermore, MPEP reduced TNF-�?± levels, causing selectively iNOS expression decrease
without affecting eNOS expression. Our results demonstrated that MPEP, MTEP and Fenobam protect rat hepatocytes against
ischemic injury. Furthermore, MPEP is able to reduce susceptibility of liver grafts to the preservation injury in two ex vivo
models, in which the pharmacological blockade of mGluR5, interrupting the excitotoxic cascade, reduces the inflammation
mediator TNF-�?±.
Recent Publications
1. Storto et. 2000. Selective blockade of mGlu5 metabotropic glutamate receptors protects rat hepatocytes against hypoxic damage.
Hepatology.
2. Nandi et al. 2010. TNF-�?± modulates iNOS expression in an experimental rat model of indomethacin-induced jejunoileitis.
Molecular and Cellular Biochemistry, 336(1��?2), pp.17��?24
3. Fonseca et al. 2003. TNF-�?± mediates the induction of nitric oxide synthase in macrophages but not in neutrophils in experimental
cutaneous leishmaniasis. European Journal of Immunology, 33(8), pp.2297��?2306
4. Muntan�?© et al. 2000. TNF-alpha dependent production of inducible nitric oxide is involved in PGE(1) protection against acute
liver injury. Gut, 47(4), pp.553��?62
5. Medeiros et al. 2007. Connecting TNF- �?± Signaling Pathways to iNOS Expression in a Mouse Model of Alzheimerâ�?�?s Disease:
Relevance for the Behavioral and Synaptic Deficits Induced by Amyloid Protein. Journal of Neuroscience, 27(20), pp.5394��?5404.
Clarissa Berardo, Doctorate in Biomedical Sciences, curriculum Pharmacology. Master Degree in Molecular Biology and Genetics. She has her expertise in mouse and rat liver isolation to study preservation techniques for organ transplantation (Cold Storage and Machine Perfusion), hepatocytes isolation from mouse and rat, primary and tumoral (HepG2 and Huh7.5) cell culture, use of genetic (Zucker) and nutritional (Methionine and Choline Deficient Diet) animal models to study hepatic diseases, such as NAFLD, NASH and ischemia/reperfusion injury. Knowledge of principal techniques performed in biomedical laboratory: western blot analysis, RT-PCR, histological techniques, biochemical and enzymatic assays.