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Balasubramaniam A, Mohangandhi V, Sambandamoorthy AK. Role of myofascial release therapy on pain and lumbar range of motion in mechanical back pain: An exploratory investigation of desk job workers. IBNOSINA JOURNAL OF MEDICINE AND BIOMEDICAL SCIENCES 2014. [DOI: 10.4103/1947-489x.210367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background: Low back pain is the most common cause of work related disability in persons aged less than 45 years. Workers who sit in front of the computer for more than 40 hours per week end up with low back pain. Bad positioning of the body parts in a single day doesn’t make poor postures, whereas adaptation of the incorrect posture for a longer duration results in weak muscles and postural problems. Abnormal posture results in pain, disability and muscle weakness. Most of the management of low back pain focuses on the rehabilitation of the pain and very few studies focus on work station corrections. Aim: This study aims to find out the effect of work station modification with Myofascial release therapy on pain and lumbar flexion range of motion in mechanical low back pain in desk job workers. Methods: Forty subjects were included using simple random sampling method, subjects were chosen following an inclusion and exclusion criteria. Group A, underwent myofascial release therapy, whereas group B underwent myofascial release therapy technique with work station modification. The outcome measures were pain and range of motion of lumbar spine, which measured using visual analogue scale and modified schober’s method. Student ‘t’ test was used to find out the difference between the groups. Results: This study showed that there was a significant difference between the group A & group B. Conclusion: The study concludes that the work station modification along with myofascial release therapy was very effective in improving range of motion, and reducing pain.
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Raj CN, Balasubramaniam A, Nadeem S. Effect of various extracts of Tabernaemontana divaricata on haloperidol induced catalepsy in rats. ACTA ACUST UNITED AC 2014. [DOI: 10.3329/icpj.v3i3.17891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Parkinsons disease (PD) is one of the neurodegenerative diseases with selective loss of dopamine neurons of the substantia nigra pars compacta. In the present study, anti-cataleptic activity of Tabernaemontana divaricata leaves extracts viz. aqueous and ethanolic at different doses (50, 100 and 150 mg/kg i.p.) were studied using haloperidol (1 mg/kg, i.p.) induced catalepsy in rats which is a useful animal model for screening drugs for Parkinsons disease. Both the extracts were found to reduce catalepsy significantly (P<0.001) as compared to the haloperidol treated rats showing greater effect at 150 mg/kg i.p. dose. Thus the present study reveals the anti-cataleptic activity of Tabernaemontana divaricata evaluating the traditional folklore medicinal use of the plant.DOI: http://dx.doi.org/10.3329/icpj.v3i3.17891 International Current Pharmaceutical Journal, February 2014, 3(3): 240-242
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Shankar M, Balasubramaniam A, Gowrishankar NL, Mahendran S. Synthesis and Biological Evaluation of New Bis-Indolyl (3-O-Benzyl-1,2-O-Isopropylidenexylopentadialdose-α-D-Glucofuranose). Pharm Chem J 2014. [DOI: 10.1007/s11094-014-1001-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Balasubramaniam A, Sukumar K, Suresh P, Puvarajan B. Molecular characterisation of membrane glycoprotein and 5b protein of nephropathogenic infectious bronchitis virus. Vet World 2013. [DOI: 10.14202/vetworld.2013.857-861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Balasubramaniam A, Gopalakrishnamurthy T, Sivaseelan S, Balasubramaniam G, Rajeswar J. Evaluation of an inactivated vaccine for nephropathogenic infectious bronchitis virus. Vet World 2013. [DOI: 10.5455/vetworld.2013.134-138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Selvaraju G, Balasubramaniam A, Rajendran D, Kannan D, Geetha M. Multiple linear regression model for forecasting Bluetongue disease outbreak in sheep of North-west agroclimatic zone of Tamil Nadu, India. Vet World 2013. [DOI: 10.5455/vetworld.2013.321-324] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Shankar M, Balasubramaniam A, Gowrishankar NL, Mahendran S. Synthesis and biological evaluation of new bis-indolyl (3-O-benzyl-1,2-O-isopropylidenexylopentadialdose-α-D-glucofuranose). Pharm Chem J 2012. [DOI: 10.1007/s11094-012-0804-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Srividya MR, Thota B, Arivazhagan A, Thennarasu K, Balasubramaniam A, Chandramouli BA, Hegde AS, Santosh V. Age-dependent prognostic effects of EGFR/p53 alterations in glioblastoma: study on a prospective cohort of 140 uniformly treated adult patients. J Clin Pathol 2011; 63:687-91. [PMID: 20702468 DOI: 10.1136/jcp.2009.074898] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To assess the prognostic influence of EGFR amplification/overexpression, p53 immunoreactivity and their age-dependent prognostic effects in a large prospective cohort of uniformly treated adult patients with newly diagnosed glioblastoma. METHODS Tumours from a uniformly treated prospective cohort of adult patients with newly diagnosed glioblastoma (n=140) were examined for EGFR amplification by fluorescence in situ hybridisation and EGFR/p53 expression by immunohistochemistry. Statistical methods were employed to assess the degree of association between EGFR amplification/overexpression and p53 immunopositivity. Survival analyses were performed by employing Cox proportional hazard models to assess the independent prognostic value of EGFR/p53 alterations and test the propensity for risk with age by assessing their interaction with patient age. RESULTS A strong positive correlation between EGFR amplification and EGFR overexpression (rho=0.5157; p<0.0001; CI 0.3783 to 0.6309) and a negative association of EGFR amplification (rho=-0.3417; p<0.0001; CI -0.4842 to -0.1816) and EGFR overexpression (rho=-0.3095; p<0.001; CI -0.4561 to -0.1465) with p53 immunopositivity was observed. Only patient age (HR: 1.029; p=0.004; CI 1.009 to 1.049) was associated with shorter survival by univariate Cox regression analysis. Multivariable Cox proportional hazards models revealed a statistically significant interaction between EGFR overexpression and age to be associated with shorter survival (HR: 1.001; p<0.0001; CI 1.000 to 1.002), thus predicting a higher hazard with increasing age. No age interaction of EGFR amplification status (HR: 1.001; p=0.642; CI 0.995 to 1.008) and p53 immunopositivity (HR: 1.000; p=0.841; CI 0.999 to 1.001) was noted in this cohort. CONCLUSIONS The prognostic value of EGFR overexpression is age-dependent, and there is a propensity for a higher hazard with increasing patient age. Identifying such groups of patients with more aggressive disease becomes mandatory, since they would benefit from intense therapeutic protocols targeting EGFR.
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Parker MS, Sah R, Balasubramaniam A, Sallee FR, Zerbe O, Parker SL. Non-specific binding and general cross-reactivity of Y receptor agonists are correlated and should importantly depend on their acidic sectors. Peptides 2011; 32:258-65. [PMID: 21126552 PMCID: PMC3025077 DOI: 10.1016/j.peptides.2010.11.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2010] [Revised: 11/12/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
Abstract
Non-specific binding of Y receptor agonists to intact CHO cells, and to CHO cell or rat brain particulates, is much greater for human neuropeptide Y (hNPY) compared to porcine peptide Y (pPYY), and especially relative to human pancreatic polypeptide (hPP). This binding of hNPY is reduced by alkali cations in preference to non-ionic chaotrope urea, while the much lower non-specific binding of pPYY is more sensitive to urea. The difference could mainly be due to the 10-16 stretch in 36-residue Y agonists (residues 8-14 in N-terminally clipped 34-peptides), located in the sector that contains all acidic residues of physiological Y agonists. Anionic pairs containing aspartate in the 10-16 zone could be principally responsible for non-specific attachments, but may also aid the receptor site binding. Two such pairs are found in hNPY, one in pPYY, and none in hPP. The hydroxyl amino acid residue at position 13 in mammalian PYY and PP molecules could lower conformational plasticity and the non-selective binding via intrachain hydrogen bonding. The acidity of this tract could also be important in agonist selectivity of the Y receptor subtypes. The differences point to an evolutionary reduction of promiscuous protein binding from NPY to PP, and should also be important for Y agonist selectivity within NPY receptor group, and correlate with partial agonism and out-of group cross-reactivity with other receptors.
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Bogdahn U, Hau P, Stockhammer G, Venkataramana NK, Mahapatra AK, Suri A, Balasubramaniam A, Nair S, Oliushine V, Parfenov V, Poverennova I, Zaaroor M, Jachimczak P, Ludwig S, Schmaus S, Heinrichs H, Schlingensiepen KH. Targeted therapy for high-grade glioma with the TGF-β2 inhibitor trabedersen: results of a randomized and controlled phase IIb study. Neuro Oncol 2010; 13:132-42. [PMID: 20980335 PMCID: PMC3018908 DOI: 10.1093/neuonc/noq142] [Citation(s) in RCA: 293] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This randomized, open-label, active-controlled, dose-finding phase IIb study evaluated the efficacy and safety of trabedersen (AP 12009) administered intratumorally by convection-enhanced delivery compared with standard chemotherapy in patients with recurrent/refractory high-grade glioma. One hundred and forty-five patients with central reference histopathology of recurrent/refractory glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA) were randomly assigned to receive trabedersen at doses of 10 or 80 µM or standard chemotherapy (temozolomide or procarbazine/lomustine/vincristine). Primary endpoint was 6-month tumor control rate, and secondary endpoints included response at further timepoints, survival, and safety. Six-month tumor control rates were not significantly different in the entire study population (AA and GBM). Prespecified AA subgroup analysis showed a significant benefit regarding the 14-month tumor control rate for 10 µM trabedersen vs chemotherapy (p= .0032). The 2-year survival rate had a trend for superiority for 10 µM trabedersen vs chemotherapy (p = .10). Median survival for 10 µM trabedersen was 39.1 months compared with 35.2 months for 80 µM trabedersen and 21.7 months for chemotherapy (not significant). In GBM patients, response and survival results were comparable among the 3 arms. Exploratory analysis on GBM patients aged ≤55 years with Karnofsky performance status >80% at baseline indicated a 3-fold survival at 2 and 3 years for 10 µM trabedersen vs chemotherapy. The frequency of patients with related or possibly drug-related adverse events was higher with standard chemotherapy (64%) than with 80 µM trabedersen (43%) and 10 µM trabedersen (27%). Superior efficacy and safety for 10 µM trabedersen over 80 µM trabedersen and chemotherapy and positive risk–benefit assessment suggest it as the optimal dose for further clinical development in high-grade glioma.
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Parker MS, Sah R, Balasubramaniam A, Sallee FR, Sweatman T, Park EA, Parker SL. Dimers of the neuropeptide Y (NPY) Y2 receptor show asymmetry in agonist affinity and association with G proteins. J Recept Signal Transduct Res 2009; 28:437-51. [PMID: 18946765 DOI: 10.1080/10799890802447423] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In conditions precluding activation of G proteins, the binding of agonists to dimers of the neuropeptide Y (NPY) Y2 receptor shows two components of similar size, but differing in affinity. The dimers of all NPY receptors are solubilized as approximately 180-kDa complexes containing one G protein alpha beta gamma trimer. These heteropentamers are stable to excess agonists, chelators, and alkylators. However, dispersion in the weak surfactant cholate releases approximately 300-kDa complexes. These findings indicate that both protomers in the Y2 dimer are associated with G protein heterotrimers, but the extent of interaction depends on affinity for the agonist peptide. The G protein in contact with the first-liganded, higher-affinity protomer should have a stronger interaction with the receptor and a larger probability of activation.
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Bogdahn U, Schneider T, Oliushine V, Parfenov V, Mahapatra AK, Balasubramaniam A, Venkataramana N, Stockhammer G, Heinrichs H, Schlingensiepen K. Randomized, active-controlled phase IIb study with trabedersen (AP 12009) in recurrent or refractory high-grade glioma patients: Basis for phase III endpoints. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.2037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
2037 Background: High-grade gliomas (HGG) strongly overexpress TGF-beta 2. Trabedersen (AP 12009), a TGF-beta 2-specific inhibitor, was successfully tested in 3 Phase I/II studies in recurrent or refractory HGG. Methods: The Phase IIb study AP 12009-G004 was an open-label, randomized, active-controlled dose-finding study. Main objectives: to compare response rate, survival, and safety of 2 doses of trabedersen (10 μM or 80 μM) vs. standard chemotherapy (TMZ or PCV). 145 patients with recurrent or refractory HGG (AA WHO grade III or GBM WHO grade IV) were randomized and 134 patients (AA = 39; GBM = 95) received study medication. Trabedersen was given intratumorally by convection-enhanced delivery. Results: AA and GBM patients in both trabedersen groups had long-lasting tumor responses (currently up to 4 years). AA: (10 μM trabedersen vs. control): significantly better overall response rate was noted at 14 months (CR+PR; p=0.034*) and lower tumor progression rates at 6, 12 and 14 months; difference at 14 months was statistically significant (p=0.003*). 2-year survival rate was 2-fold higher (p=0.088**). Tumor progression rate at 14 months and 2-year survival rate correlated with a median overall survival benefit of 17.4 months. GBM: 10 μM trabedersen was as efficacious as standard chemotherapy in all patients. It was clearly superior regarding 2-year survival in the pre-specified subgroup of patients younger than 55 years and the subgroup with a KPS > 80. The superior long-term survival of trabedersen-treated AA and GBM patients was the basis for extending the follow-up period of this Phase IIb study. Conclusions: Based on Phase IIb results, the pivotal Phase III study SAPPHIRE in recurrent or refractory AA patients has started. Primary efficacy endpoint is 2-year survival rate; secondary endpoints are progression rate at 14 months, time to death, quality of life, safety and tolerability. A separate study in GBM is being planned. [Table: see text] [Table: see text]
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Parker MS, Sah R, Park EA, Sweatman T, Balasubramaniam A, Sallee FR, Parker SL. Oligomerization of the heptahelical G protein coupling receptors: a case for association using transmembrane helices. Mini Rev Med Chem 2009; 9:329-39. [PMID: 19275726 DOI: 10.2174/1389557510909030329] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The heptahelical G protein coupling receptors oligomerize extensively via transmembrane domains, in association with heterotrimeric G proteins. This provides higher affinity for agonists, conformational stability necessary for signal transduction, and protection from intracellular proteinases. The oligomerization is relevant to organismic pathophysiology and could be targeted by natural or modified agonists.
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Parker SL, Parker MS, Estes AM, Wong YY, Sah R, Sweatman T, Park EA, Balasubramaniam A, Sallee FR. The neuropeptide Y (NPY) Y2 receptors are largely dimeric in the kidney, but monomeric in the forebrain. J Recept Signal Transduct Res 2008; 28:245-63. [PMID: 18569526 DOI: 10.1080/10799890802084341] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The neuropeptide Y(NPY) Y2 receptors are detected largely as dimers in the clonal expressions in CHO cells and in particulates from rabbit kidney cortex. However, in two areas of the forebrain (rat or rabbit piriform cortex and hypothalamus), these receptors are found mainly as monomers. Evidence is presented that this difference relates to large levels of G proteins containing the Gi alpha -subunit in the forebrain areas. The predominant monomeric status of these Y2 receptors should also be physiologically linked to large synaptic inputs of the agonist NPY. The rabbit kidney and the human CHO cell-expressed Y2 dimers are converted by agonists to monomers in vitro at a similar rate in the presence of divalent cations.
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Estes A, Wong Y, Parker M, Sallee F, Balasubramaniam A, Parker S. Neuropeptide Y (NPY) Y2 receptors of rabbit kidney cortex are largely dimeric. ACTA ACUST UNITED AC 2008; 150:88-94. [DOI: 10.1016/j.regpep.2008.06.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 04/28/2008] [Accepted: 06/01/2008] [Indexed: 10/22/2022]
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Copeland R, Balasubramaniam A, Tiwari V, Zhang F, Bridges A, Linhardt RJ, Shukla D, Liu J. Using a 3-O-sulfated heparin octasaccharide to inhibit the entry of herpes simplex virus type 1. Biochemistry 2008; 47:5774-83. [PMID: 18457417 PMCID: PMC2504729 DOI: 10.1021/bi800205t] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Heparan sulfate (HS) is a highly sulfated polysaccharide and is present in large quantities on the cell surface and in the extracellular matrix. Herpes simplex virus type 1 (HSV-1) utilizes a specialized cell surface HS, known as 3-O-sulfated HS, as an entry receptor to establish infection. Here, we exploit an approach to inhibiting HSV-1 infection by using a 3-O-sulfated octasaccharide, mimicking the active domain of the entry receptor. The 3-O-sulfated octasaccharide was synthesized by incubating a heparin octasaccharide (3-OH octasaccharide) with HS 3-O-sulfotransferase isoform 3. The resultant 3-O-sulfated octasaccharide has a structure of Delta UA2S-GlcNS6S-IdoUA2S-GlcNS6S-IdoUA2S-GlcNS3S6S-IdoUA2S-GlcNS6S (where Delta UA is 4-deoxy-alpha-L-threo-hex-4-enopyranosyluronic acid, GlcN is D-glucosamine, and IdoUA is L-iduronic acid). Results from cell-based assays revealed that the 3-O-sulfated octasaccharide has stronger activity in blocking HSV-1 infection than that of the 3-OH octasaccharide, suggesting that the inhibition of HSV-1 infection requires a unique sulfation moiety. Our results suggest the feasibility of inhibiting HSV-1 infection by blocking viral entry with a specific oligosaccharide.
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Manivannan R, Dhanaraj SA, Rao YUB, Balasubramaniam A, Gowrishankar NL, Jawahar N, Jubie S. In vivo Evaluation of Single Dose Tetanus Toxoid Vaccine Formulation with Chitosan Microspheres. Indian J Pharm Sci 2008; 70:11-5. [PMID: 20390074 PMCID: PMC2852047 DOI: 10.4103/0250-474x.40325] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 09/10/2007] [Accepted: 01/06/2008] [Indexed: 11/25/2022] Open
Abstract
Chitosan adsorbed microspheres containing tetanus toxoid were prepared in the size range of 10 mum to 75 mum, by emulsion-cross linking technique at different speeds of agitation. The amount of tetanus toxoid incorporated into chitosan microspheres were estimated by limes flocculation test and in vivo evaluation of tetanus toxoid adsorbed chitosan microspheres were determined by toxin neutralization method using albino mice. The results of in vivo release for the batches of 10 mum and 25 mum correlates with the results of in vitro in which both the batches passes the limit of IP standard (4 Lf) where as, for the batches of 50 mum and 75 mum, the in vitro release of tetanus toxoid was 2 Lf. But our in vivo studies for the batches of 50 mum and 75 mum fail to pass the limit stated in IP. The release of tetanus toxoid from the chitosan microspheres was found to be sustained for the period of 6 months.
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Abstract
We briefly survey the current knowledge and concepts regarding structure and function of the neuropeptide Y Y2 receptor and its agonists, especially as related to pharmacology of the receptor and its roles in pathological processes. Specific structural features are considered that could be responsible for the known compartmentalization and participation of the receptor in cell and tissue organization. This is further discussed in relation to changes of levels of the Y2 receptor in pathological conditions (especially in epilepsy and drug abuse), to endocytosis and recycling, and to participation in wound healing, retinopathy and angiogenesis. Properties of the receptor and of Y2 agonists are considered and reviewed in connection to the negative regulation of transmitter release, feeding, mood and social behavior. The possible involvement of the Y2 receptor in diabetes, carcinogenesis and bone formation is also reviewed.
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Parker SL, Parker MS, Sallee FR, Balasubramaniam A. Oligomerization of neuropeptide Y (NPY) Y2 receptors in CHO cells depends on functional pertussis toxin-sensitive G-proteins. ACTA ACUST UNITED AC 2007; 144:72-81. [PMID: 17651824 PMCID: PMC4387131 DOI: 10.1016/j.regpep.2007.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 05/27/2007] [Accepted: 06/14/2007] [Indexed: 10/23/2022]
Abstract
Human neuropeptide Y Y2 receptors expressed in CHO cells are largely oligomeric, and upon solubilization are recovered by density gradient centrifugation as approximately 180 kDa complexes of receptor dimers and G-protein heterotrimers. A large fraction of the receptors is inactivated in the presence of pertussis toxin, in parallel with inactivation of Gi alpha subunits (with half-periods of about 4 h for both). This is accompanied by a very long-lasting loss of receptor dimers and of masked surface Y2 sites (an apparent receptor reserve pre-coupled mainly to Gi alpha subunit-containing G-proteins). However, surface Y2 receptors accessible to large peptide agonists are much less sensitive to the toxin. All surface Y2 receptors are rapidly blocked by Y2 antagonist BIIE0246, with a significant loss of the dimers, but with little change of basal Gi activity. However, both dimers and Y2 receptor compartmentalization are restored within 24 h after removal of the antagonist. In CHO cells, the maintenance and organization of Y2 receptors appear to critically depend on functional pertussis toxin-sensitive G-proteins.
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Parker SL, Parker MS, Sah R, Balasubramaniam A, Sallee FR. Self-regulation of agonist activity at the Y receptors. Peptides 2007; 28:203-13. [PMID: 17194507 DOI: 10.1016/j.peptides.2006.07.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 07/29/2006] [Indexed: 11/20/2022]
Abstract
Neuropeptide Y (NPY) is one of the most abundant neuropeptides, and is likely to be present at nanomolar levels over extended periods in the synaptic space of many forebrain areas. This might be linked to an evolved generalized toning activity through a number of other peptide receptors that use C-terminally amidated agonists (with LHRH and orexin receptors and GIR as examples). However, the Y1 and Y2 receptors (which constitute the bulk of Y receptors active in the neural matrix) possess subnanomolar affinities that, at saturating NPY levels, could produce excessive signaling, as well as receptor losses via repeated endocytosis. The related Y4 receptor shows an even higher agonist affinity, and faces the same problem in visceral and neural locations accessible to pancreatic polypeptide (PP). An examination of agonist peptide interaction with Y receptors shows that Y1 and Y4 receptors in particular (as located on either the intact cells, or on particulates derived from various cell types) develop a blockade dependent on ligand concentration, with the blocking ranks of [NPY]>>[peptide YY] (PYY) for the Y1, and [human PP]>>>[PYY-related Y4 agonist] for the Y4 receptor. This blockade is also echoed in a concentration-related reduction in biological activity of primary agonists (NPY and PP), resembling a partial agonism, and is influenced especially by the allosteric interactivity of agonists. With the Y2 receptor, the blocking by agonists is less pronounced, but the signaling by NPY-related peptides is apparently less than with PYY-related agonists. The extended occupancy and self-attenuation of primary agonist activity at Y receptors could represent an evolutionary solution contributing to a balancing of metabolic signaling, agonist clearance and receptor conservation.
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Jois SDS, Nagarajarao LM, Prabhakaran M, Balasubramaniam A. Modeling of neuropeptide receptors Y1, Y4, Y5, and docking studies with neuropeptide antagonist. J Biomol Struct Dyn 2006; 23:497-508. [PMID: 16494499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Neuropeptide Y (NPY), receptors belong to the G-protein coupled receptor superfamily. NPY mediates several physiological responses, such as blood pressure, food intake, sedation. These actions of NPY are mediated by six receptor subtypes denoted as Y1-Y5 and y6. Modeling of receptor subtypes and binding site identification is an important step in developing new therapeutic agents. We have attempted to model the three NPY receptor types, Y1, Y4, and Y5 using homology modeling and threading methods. The models are consistent with previously reported experimental evidence. To understand the interaction and selectivity of NPY analogues with different neuropeptide receptors, docking studies of two neuropeptide analogues (BVD10 and BVD15) with receptors Y1 and Y4 were carried out. Results of the docking studies indicated that the interaction of ligands BVD10 and BVD15 with Y1 and Y4 receptors are different. These results were evaluated for selectivity of peptide analogues BVD10 and BVD15 towards the receptors.
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Parker MS, Sah R, Sheriff S, Balasubramaniam A, Parker SL. Internalization of cloned pancreatic polypeptide receptors is accelerated by all types of Y4 agonists. ACTA ACUST UNITED AC 2005; 132:91-101. [PMID: 16213038 DOI: 10.1016/j.regpep.2005.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 09/08/2005] [Indexed: 11/18/2022]
Abstract
Internalization of cloned rat or human Y4 receptors expressed in Chinese hamster ovary (CHO) cells increased with concentration of all types of Y4 agonists, including human and rat pancreatic polypeptides, the Y1 receptor group co-agonists possessing C-terminal TRPRY.NH2 pentapeptide, and a C-terminally amidated dimeric nonapeptide related to neuropeptide Y, GR231118. These peptides also inhibited forskolin-stimulated adenylyl cyclase activity in Y4 receptor-expressing cells, and stimulated the binding of 35S-labeled GTP-gamma-S to pertussis toxin-sensitive G-proteins in particulates from these cells. Peptide VD-11 (differing from GR231118 only by C-terminal oxymethylation) acted as a competitive antagonist in all of the above processes. Agonist-induced stimulation of the Y4 receptor internalization persisted in the presence of allosteric inhibitors of hPP binding, N5-substituted amilorides, which also were relatively little active in G-protein stimulation and cyclase inhibition by Y4 agonists. Acceleration of Y4 receptor internalization by agonists apparently is related to relaxation of allosteric constraints to ligand attachment and sequestration of the receptor-ligand complex.
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Balasubramaniam A, Voulvoulis N. The appropriateness of Multicriteria Analysis in environmental decision-making problems. ENVIRONMENTAL TECHNOLOGY 2005; 26:951-62. [PMID: 16196404 DOI: 10.1080/09593332608618484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Environmental decision-making occurs in numerous environmental sectors and covers a diverse range of problems. Of the various decision tools available not all of them may be appropriate for any single decision problem, and any particular decision-aid may not be applicable in all decision problems. This article reviews applications of MCA, and considers the appropriateness of Multicriteria Analysis (MCA) in environmental decision-making problems. Due to natural and decision environments being multidimensional, environmental decision-making is characterized by complexity. Consequently MCA has commonly been used in this area. In Environmental Impact Assessment (EIA) the multiple dimensions of the impacts evaluated have been easily represented in MCA as multiple criteria. Waste management and water resource planning problems involving public participation have been facilitated by MCA, through the structuring and articulation of the public's values. MCA has also been applied in water quality problems, allowing the incorporation of incommensurable criteria into evaluations. The appropriateness of MCA for environmental decision problems can be viewed in the context of a typical decision-making process, making it easier to identify the contribution MCA can make at various decision-making stages. MCA can be particularly appropriate when the decision-making context is characterized by multiple objectives and multiple criteria, incommensurable criteria, mixed data and the need for ease of use, and the analysis context is characterized by multiple participants.
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Jois SDS, Nagarajarao LM, Prabhakaran M, Balasubramaniam A. Modeling of Neuropeptide Receptors Y1, Y4, Y5, and Docking Studies with Neuropeptide Antagonist Analogues: Implications for Selectivity. J Biomol Struct Dyn 2004; 22:497-508. [DOI: 10.1080/07391102.2004.10506987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Shahab M, Balasubramaniam A, Sahu A, Plant TM. Central nervous system receptors involved in mediating the inhibitory action of neuropeptide Y on luteinizing hormone secretion in the male rhesus monkey (Macaca mulatta). J Neuroendocrinol 2003; 15:965-70. [PMID: 12969241 DOI: 10.1046/j.1365-2826.2003.01085.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An earlier finding that gonadotropin-releasing hormone (GnRH) secretion may be triggered prematurely in the juvenile male monkey by central administration of 1229U91, a Y1 receptor antagonist, contributed to our current hypothesis that neuropeptide Y (NPY) is a major component of the brake that holds pulsatile GnRH release in check during prepubertal development in primates. However, 1229U91 is also a Y4 receptor agonist, and the present study was conducted to further examine the role of the Y1 receptor in mediating the putative inhibitory action of NPY on GnRH release. Agonadal juvenile and postpubertal male monkeys were implanted with i.v. and i.c.v. cannulae to gain continuous access to the venous and cerebroventricular circulations without sedation. Luteinizing hormone (LH) secretion was measured to provide an indirect index of GnRH release. The specific Y1 antagonists, VD-11 (476 microg; n = 4) and isopropyl 3-chloro-5-[1-((6-[2-(5-ethyl-4-methyl-1,3-thiazol-2-yl)ethyl]-4-morpholin-4-ylpyridin-2-yl)amino)ethyl]phenylcarbamate (Compound A, 300 microg; n = 4), did not mimic the stimulatory action of 1229U91 on GnRH secretion in the juvenile male monkey. Additionally, neither NPY (200 microg; n = 2), a general Y receptor agonist, nor rPP (100 microg; n = 4), a Y4 agonist, mimicked the action of 1229U91 in stimulating GnRH release. Moreover, previous exposure of the hypothalamus of juvenile monkeys (n = 5) to NPY (660 microg) failed to block 1229U91-induced (200 microg) GnRH release. However, the action of NPY (364 microg) in inhibiting GnRH release postpubertally was attenuated by 1229U91 (300 microg). We conclude that, although the action of exogenous NPY to suppress GnRH release from the postpubertal hypothalamus appears to be mediated, at least in part, by the Y1 receptor, the existence of a Y1 receptor pathway inhibitory to GnRH release in the prepubertal hypothalamus remains to be substantiated.
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