- Email: [email protected]
Possible involvement of A2A adenosine receptor functions in the neuroprotective effect of caffeine against quinolinic acid-induced motor dysfunction and associated memory impairment in rats
Poster Presentations: P3
docking and binding site analysis. First a predicted 3D structure of MPC1&2 was performed using the Bax Group (NIH) PDB Utility Server to create a file extended structure from amino acid residue sequences listed on UniProt. Additionally, Protter was used to generate a 2D visualization of MPC1&2 embedded within the inner mitochondrial membrane. Pyruvate and inhibitor 3D data were downloaded from PubChem as SDF files and Babel was used to convert them to PDB format required by Autodock. The TZDs, pioglitazone and MSDC-0160 were tested as novel MPC inhibitors and compared with well-established inhibitors, UK-5099 and a-cyano-4-hydroxycinnamate. Autodock/Vina was used to screen the entire MPC1&2 molecules for potential binding sites; PyMOL was used to visualize and analyze these binding sites in 3D. Results: MPC1 and MPC2 each were predicted to have two transmembrane spanning alpha helical segments containing cysteine residues (C60&61 in MPC1 and C54 in MPC2). Both N- and C-terminals projected to the same side of the membrane, intermembrane space for MPC2 and matrix for MPC1. (Fig. 1) Pyruvate had 8 binding sites on the entire MPC1/2 complex and both TZDs and known inhibitors bound only to 7 or less, including the critical ones at the cysteine residues of MPC1/2 within the inner mitochondrial membrane. (Fig. 2). The TZDs had higher affinities comparable to the known inhibitors. (Fig. 3). Conclusions: A convergence of pyruvate, characterized inhibitor, and TZD binding sites were localized at cysteine residues of the MPC1/2 transmembrane regions, consistent with biochemical predictions made in the 1970s and 90s by A.P. Halestrap and K.A. Nalecz laboratories, respectively. Supported by Alzheimer’s Association and NIHG12-MD007591.
P3-321
POSSIBLE BEHAVIORAL, BIOCHEMICAL, AND MITOCHONDRIAL ENZYME ALTERATIONS IN THE NEUROPROTECTIVE EFFECT OF CENTELLA ASIATICA AGAINST ALUMINUM-INDUCED COGNITIVE DYSFUNCTION
Anil Kumar, Sr., Atish Prakash, Jr., Panjab University, Chandigarh, India. Contact e-mail: [email protected] Background: The present study has been designed to investigate the neuroprotective effect of Centella asiatica on chronic aluminum exposure induced mitochondrial enzyme alteration, oxidative stress and cognitive dysfunction in rat. Methods: Aluminum (100 mg/kg) was administered orally in male wistar rats. Centella asciatica (150 and 300 mg/kg, p.o.) drug treatment was given daily for a period of six weeks. Various behavioral (Morris water maze and plus maze performance tasks), biochemical (oxidative stress parameters) and cellular estimations (mitochondrial enzyme complex), aluminum concentration in the brain were assessed after six week. Results: Chronic administration of Centella asiatica (150 and 300 mg/kg) significantly improved memory performance (as evidenced from Morris water maze and elevated plus maze tests), oxidative defense (decreased lipid peroxidation, nitrite concentration, and restoration of superoxide dismutase, catalase and reduced glutathione), decreased aluminum concentration, acetylcholinestrease activity and reversal of mitochondrial enzyme activity as compared to control (aluminum) treated animals. Conclusions: Results of the study demonstrate neuroprotective potential of Centella asiatica against aluminum chloride-induced cognitive dysfunction and mitochondrial oxidative damage.
P3-322
P761 POSSIBLE INVOLVEMENT OF A2A ADENOSINE RECEPTOR FUNCTIONS IN THE NEUROPROTECTIVE EFFECT OF CAFFEINE AGAINST QUINOLINIC ACID-INDUCED MOTOR DYSFUNCTION AND ASSOCIATED MEMORY IMPAIRMENT IN RATS
Jitendriya Mishra1, Anil Kumar, Sr.2, 1Panjab University, Chandigarh, India, Chandigarh, India; 2Panjab University, Chandigarh, India. Contact e-mail: [email protected] Background: Adenosine is now considered to be the major inhibitory neurotransmitter in addition to gamma amino butyric acid (GABA). Adenosine A2A receptors antagonists as well as A1 agonists are well known for their neuroprotective effects. The present study investigated the possible involvement of A2A receptor function in protective effect of caffeine against quinolinic acid induced Huntington’s disease (HD) like motor dysfunction and associated cognitive impairment in rats. Methods: Quinolinic acid (QA) (200 nmol/2 ml saline) was administered as a single bilateral intrastriatal injection. ZM-241385 and DPMA were administered 20 min prior to QA administration. Caffeine (10, 20 and 40 mg/kg) treatment was continued for 21 days following QA administration. Motor (locomotor and grip strength) and memory performance were evaluated intermittently and striatal mitochondrial function, endogenous antioxidant profile, neurotransmitter and cytokines levels were measured on day 21. Results: Intrastriatal QA administration resulted in significant reduction in body weight, marked motor impairment, increased oxidative stress, impaired mitochondrial complex activities and decreased state 3 respiration (NAD+/FAD+ -linked), altered cytokine and neurotransmitter levels as compared to sham treated animals. However, ZM-241385 treatment (20 min prior to QA administration) displayed marked improvement, whereas DPMA treatment caused further damage in QA treated animals. Further, caffeine treatment for 21 days significantly attenuated these behavioral, biochemical and cellular alterations as compared to control (QA 200 nmol) group displaying ZM241358 like effect. Unlike DPMA treatment, chronic treatment of caffeine to ZM-241385 treated animals significantly attenuated the QA induced behavioral, neurochemical and cellular alterations as compared to their effects per se. Conclusions: The study highlights about the possible involvement of A2A receptor antagonism in the neuroprotective effect of caffeine against QA induced motor dysfunction and associated complications in rats.
docking and binding site analysis. First a predicted 3D structure of MPC1&2 was performed using the Bax Group (NIH) PDB Utility Server to create a file extended structure from amino acid residue sequences listed on UniProt. Additionally, Protter was used to generate a 2D visualization of MPC1&2 embedded within the inner mitochondrial membrane. Pyruvate and inhibitor 3D data were downloaded from PubChem as SDF files and Babel was used to convert them to PDB format required by Autodock. The TZDs, pioglitazone and MSDC-0160 were tested as novel MPC inhibitors and compared with well-established inhibitors, UK-5099 and a-cyano-4-hydroxycinnamate. Autodock/Vina was used to screen the entire MPC1&2 molecules for potential binding sites; PyMOL was used to visualize and analyze these binding sites in 3D. Results: MPC1 and MPC2 each were predicted to have two transmembrane spanning alpha helical segments containing cysteine residues (C60&61 in MPC1 and C54 in MPC2). Both N- and C-terminals projected to the same side of the membrane, intermembrane space for MPC2 and matrix for MPC1. (Fig. 1) Pyruvate had 8 binding sites on the entire MPC1/2 complex and both TZDs and known inhibitors bound only to 7 or less, including the critical ones at the cysteine residues of MPC1/2 within the inner mitochondrial membrane. (Fig. 2). The TZDs had higher affinities comparable to the known inhibitors. (Fig. 3). Conclusions: A convergence of pyruvate, characterized inhibitor, and TZD binding sites were localized at cysteine residues of the MPC1/2 transmembrane regions, consistent with biochemical predictions made in the 1970s and 90s by A.P. Halestrap and K.A. Nalecz laboratories, respectively. Supported by Alzheimer’s Association and NIHG12-MD007591.
P3-321
POSSIBLE BEHAVIORAL, BIOCHEMICAL, AND MITOCHONDRIAL ENZYME ALTERATIONS IN THE NEUROPROTECTIVE EFFECT OF CENTELLA ASIATICA AGAINST ALUMINUM-INDUCED COGNITIVE DYSFUNCTION
Anil Kumar, Sr., Atish Prakash, Jr., Panjab University, Chandigarh, India. Contact e-mail: [email protected] Background: The present study has been designed to investigate the neuroprotective effect of Centella asiatica on chronic aluminum exposure induced mitochondrial enzyme alteration, oxidative stress and cognitive dysfunction in rat. Methods: Aluminum (100 mg/kg) was administered orally in male wistar rats. Centella asciatica (150 and 300 mg/kg, p.o.) drug treatment was given daily for a period of six weeks. Various behavioral (Morris water maze and plus maze performance tasks), biochemical (oxidative stress parameters) and cellular estimations (mitochondrial enzyme complex), aluminum concentration in the brain were assessed after six week. Results: Chronic administration of Centella asiatica (150 and 300 mg/kg) significantly improved memory performance (as evidenced from Morris water maze and elevated plus maze tests), oxidative defense (decreased lipid peroxidation, nitrite concentration, and restoration of superoxide dismutase, catalase and reduced glutathione), decreased aluminum concentration, acetylcholinestrease activity and reversal of mitochondrial enzyme activity as compared to control (aluminum) treated animals. Conclusions: Results of the study demonstrate neuroprotective potential of Centella asiatica against aluminum chloride-induced cognitive dysfunction and mitochondrial oxidative damage.
P3-322
P761 POSSIBLE INVOLVEMENT OF A2A ADENOSINE RECEPTOR FUNCTIONS IN THE NEUROPROTECTIVE EFFECT OF CAFFEINE AGAINST QUINOLINIC ACID-INDUCED MOTOR DYSFUNCTION AND ASSOCIATED MEMORY IMPAIRMENT IN RATS
Jitendriya Mishra1, Anil Kumar, Sr.2, 1Panjab University, Chandigarh, India, Chandigarh, India; 2Panjab University, Chandigarh, India. Contact e-mail: [email protected] Background: Adenosine is now considered to be the major inhibitory neurotransmitter in addition to gamma amino butyric acid (GABA). Adenosine A2A receptors antagonists as well as A1 agonists are well known for their neuroprotective effects. The present study investigated the possible involvement of A2A receptor function in protective effect of caffeine against quinolinic acid induced Huntington’s disease (HD) like motor dysfunction and associated cognitive impairment in rats. Methods: Quinolinic acid (QA) (200 nmol/2 ml saline) was administered as a single bilateral intrastriatal injection. ZM-241385 and DPMA were administered 20 min prior to QA administration. Caffeine (10, 20 and 40 mg/kg) treatment was continued for 21 days following QA administration. Motor (locomotor and grip strength) and memory performance were evaluated intermittently and striatal mitochondrial function, endogenous antioxidant profile, neurotransmitter and cytokines levels were measured on day 21. Results: Intrastriatal QA administration resulted in significant reduction in body weight, marked motor impairment, increased oxidative stress, impaired mitochondrial complex activities and decreased state 3 respiration (NAD+/FAD+ -linked), altered cytokine and neurotransmitter levels as compared to sham treated animals. However, ZM-241385 treatment (20 min prior to QA administration) displayed marked improvement, whereas DPMA treatment caused further damage in QA treated animals. Further, caffeine treatment for 21 days significantly attenuated these behavioral, biochemical and cellular alterations as compared to control (QA 200 nmol) group displaying ZM241358 like effect. Unlike DPMA treatment, chronic treatment of caffeine to ZM-241385 treated animals significantly attenuated the QA induced behavioral, neurochemical and cellular alterations as compared to their effects per se. Conclusions: The study highlights about the possible involvement of A2A receptor antagonism in the neuroprotective effect of caffeine against QA induced motor dysfunction and associated complications in rats.