Mandal. K. Singh, PhD

Research Assistant Professor UPMC Montefiore Hospital - NW628 3459 Fifth Avenue Pittsburgh, PA 15213 Phone: 412-624-9046 Fax: 412-647-7875 Email: singhmk@upmc.edu Assistant: Mary Williams Assistant Email: williamsmc@upmc.edu

Bio

Dr. Singh obtained his Ph.D. in Biology from University of California, Santa Cruz with the thesis: Selective chemical modification of sites involved in assembly/attachment of bacteriophage T4. This study was published in Nature 1974;252:321-323. He has made research contributions in erythrocyte biology, lymphocytic choriomeningitis and human immunodeficiency viruses (LCMV & HIV-1) and gene expression changes in peripheral blood mononuclear cells from Multiple Sclerosis patients undergoing b–interferon therapy.

Clinical Interests

Dr. Singh works 100% in research and his main interest is in participating as a team member in the research and patient care activities of the Simmons Center.

Academic and Research Interests

Dr. Singh's current studies pertain to the role of gene expression in pulmonary diseases especially IPF.

In this study we analyzed the protein expression changes during the erythrocytic differentiation of K562 cells by two dimensional gel electrophoresis and found an elevation Heat shock protein 70 (HSP70). In this figure we show an increase expression of HSP70 in bone morrow erythroblasts by invitro translation, immunoprecipitation and western blotting.

In this study we report the in vitro selection of viral variants with decreased sensitivity to A-77003. A-77003 was a first generation inhibitor of the HIV-1 protease. We show that a single amino acid substitution (Arg to Gln or Lys) at position 8 of the protease results in a substantial decrease in the inhibitory activity of the drug on the enzyme and a comparable increase in viral resistance. These findings, when analyzed by using the three-dimensional structure of the protease-drug complex, provided a strategic guide for the future development of new HIV-1 protease inhibitors. Space-filling views of the wild-type Arg-8 and mutant Gln-8 contacts with A-77003 (yellow). Atoms of the enzyme are color coded by type: nitrogen, blue;oxygen, red; carbon, green. Arg-8 and Gln-8 side chains are on the bottom right side of the complex and form contacts with Asp-129 carboxylate (bottom left) and the position 3 pyridine (middle) groups of the enzyme and inhibitor, respectively.

Multiple sclerosis (MS) is a disabling idiopathic inflammatory disorder with evidence of immune dysfunction. Current therapies for MS include preparations of beta-interferon (beta IFN). We studied the gene expression patterns in peripheral blood mononuclear cells from relapsing-remitting MS patients undergoing weekly beta IFN-1a therapy to identify biomarkers for IFN-b responsiveness. Oligonucleotide microarrays were used for the comparative analysis of gene expression patterns from longitudinal PBMC samples taken from five patients undergoing beta IFN therapy. We selected a candidate diagnostic set of 136 genes that were differentially expressed between pretreatment and IFN-b-1a-treated MS patients. In this figure we applied this gene set to cluster the specimens according to their expression profiles, the pretreatment samples clustered in one branch, and acute and chronic samples following treatment clustered in another branch. However, the chronic samples from the single clinical non-responder clustered with the pretreatment branch, suggesting that a possible reversal of beta IFN-induced gene expression may be contributing to the poor clinical response.

Key Publications

Shen K, Krakora SM, Cunningham M, Singh M, Wang X, Hu FZ, Post JC, Ehrlich GD Medical treatment of craniosynostosis:recombinant Noggin inhibits coronal suture closure in the rat craniosynostosis model. Orthod Cranifac Res 2009; 12: 254-262.

Singh MK, Scott TF, LaFramboise WA, Hu FZ, Post CJ, Ehrlich GD. Gene expression changes in peripheral blood mononuclear cells from Multiple Sclerosis patients undergoing b–Interferon therapy. J Neurol Sci 2007; 258:52-59. PMID: 17467740

Puaux A-L, Marsac D, Prost S, Singh MK, Earl P, Moss B, LeGrand R, Riviere R, Michael M-L. Efficient priming of simian/human immunodeficiency virus (SHIV)-specific T-cell responses with DNA encoding hybrid SHIV/hepatitis B surface antigen particles . Vaccine 2004;22:3535-3545. PMID: 15315833

Ho DD, Toyoshima T, Mo H, Kempf DJ, Norbeck DW, Chen C, Wideburg NE, Burt SK, Erickson J, Singh MK. Characterization of human immunodeficiency virus type-1 variants with increased resistance to a C2-symmetric protease inhibitor. J Virology 1994;68:2016-2020. PMID: 8107264

Singh MK, Yu J. Accumulation of a heat shock-like protein during differentiation of human erythroid cell line K562. Nature 1984;309:631-633. PMID: 6587191

PubMed Link