ResearchOur overall research interest is to investigate how maturation of specific hemeproteins maybe adversely affected in cardiopulomonary diseases and inflammatory myopathies. Studying the disease pathogenesis would then enable us to design strategies for therapeutic intervention. We are focusing on a vasodilatory hemeprotein,.soluble guanylate cyclase (sGC) and investigating how this heme maturation maybe affected in cardiopulmonary diseases such as pulmonary arterial hypertension (PAH) and asthma. From our basic research in hemeprotein maturation, we found thathsp90 interacted almost exclusively with heme-free apo-inducible nitric oxide synthase (apo-iNOS)/apo-sGCβ1 in cells and then drove heme-insertion into these proteins by a ATP dependent process. For hemeprotein sGC we established that sGCβ1-hsp90 interactions in cells is mutually exclusive or holds a reciprocal relationship with respect to sGC-α1β1 heterodimerization and this can be a marker of sGC activity. A strong sGC heterodimer maybe indicative of healthy sGC and a weak heterodimer with strong sGCβ1-hsp90 interaction would mimic a diseased state where sGC is heme-free and is immune to activation by its natural activator nitric oxide (NO). In our findings published few years back, we find that due to high levels of NO, lung sGC is dysfunctional in asthma and impedes bronchodilation. Interestingly we also established that low nitric oxide (NO) levels can drive heme-insertion into sGC-β1 and cause an elevated sGCα1β1 heterodimer, implying that NO levels are critical to sGC function, in healthy and diseased states. In this study the hallmarks of sGC dysfunction in asthma were similar to what we previously found, a weak sGC-α1β1 heterodimer and a strong sGCβ1-hsp90 interaction. We can now imprint this sGC dysfunction as a disease indicator in asthma.
More recently we found that hsp90 can also promote hemoglobin (Hb) and myoglobin (Mb) heme- maturation following a similar mechanism further reinforcing the concept of hsp90-client protein maturation. We can now investigate the implications of these hsp90 promoted globin heme-maturation events in diseased conditions where these globins are dysfunctional or dysregulated, in order to enable development of novel strategies for therapeutic intervention.
The proposal entitled “Nitric oxide induced soluble guanylate cyclase dysfunction or activation: Implications as disease indicators or in therapy”, was awarded NIH grants in form of a one year R56 and a succeeding RO1 (over 2 million dollars) from National heart lung blood institute to study the effects of variable nitric oxide levels on soluble guanylate cyclase function in the lungs. The above funded proposal builds on our findings (Ref. 6, under selected publications) that describe a new way of treating asthma by triggering bronchodilation by an alternative pathway in the airway (the NO-sGC-cGMP pathway), using soluble guanylate cyclase (sGC) activators that can directly activate the sGC enzyme. We propose several translational approaches to decipher molecular mechanisms which make lung sGC dysfunctional under high NO. Based on our previous studies on hemeprotein maturation (Ref. 7) we find that low levels of NO can trigger a rapid buildup of sGC-α1β1 heterodimer by inserting heme into the β1 subunit. We further propose to exploit this beneficial effect of low NO to better stabilize the human lung sGC heterodimer formation, decipher molecular mechanisms causing heme-free sGC accumulation and will explore pathways to restore sGC dysfunction in airway smooth muscle cells (ASMCs) from asthma.
C. J. Koziol-White*, A. Ghosh, S. C. Erzurum, P. Sandner, D. J. Stuehr, and R. A. Panettieri, Jr. Soluble guanylate cyclase agonists induce bronchodilation in human small airways. Am J Respir Cell Mol Biol. 62 (2020) 43-48. PMID: 31340135
A. Ghosh* and D. J. Stuehr. Hsp90 and Its Role in Heme-Maturation of Client Proteins: Implications for Human Diseases. Chapter 12 (Book: Heat Shock Proteins, Vol 19, 2019, Heat Shock Protein 90 in Human Diseases and Disorders, Springer Nature Publications).
A. Ghosh*, Y. Dai, P. Biswas and D. J. Stuehr*. Myoglobin maturation is driven by the hsp90 chaperone machinery and by soluble guanylyl cyclase. FASEB J 33 (2019), 9885-9896. PMID: 31170354
A. Ghosh*, G. Garee, E. A. Sweeny, Y. Nakamura and D. J. Stuehr.* Hsp90 chaperones hemoglobin maturation in erythroid and non-erythroid cells. Proc Natl Acad Sci U S A. 115 (2018) E1117-E1126. PMID: 29358373. Read Story (LRI News)
A. Ghosh and D. J. Stuehr. Regulation of sGC via hsp90, cellular heme, sGC agonists, and NO: New pathways and clinical perspectives. Antioxid Redox Signal. 26 (2017),182-190. PMID:26983679. Article featured in the cover of the Feb 2017 issue of the journal.
A. Ghosh,C. J. Koziol-White, A. Kewal, G. Cheng, L. Ruple, D. Groneberg, A. Friebe, S. Comhair, J. P. Stasch, R. A. Panettieri, M. A. Aronica, S. C. Erzurum and D. J. Stuehr.Soluble guanylate cyclase as an alternative target for bronchodilator therapy in asthma. Proc Natl Acad Sci U S A. 113 (2016), E2355-E2362. PMID: 27071111. Read Story (Cleveland Clinic Newsroom)
A. Ghosh, J.P. Stasch, A. Papapetropoulos and D. J. Stuehr. Nitric Oxide and Heat Shock Protein 90 Activate Soluble Guanylate Cyclase by Driving Rapid Change in Its Subunit Interactions and Heme Content. J Biol Chem. 289 (2014), 15259-15271. PMID: 24733395
Arnab Ghosh, PhD, has received a four-year, $1.6 million R01 grant from the National Heart, Lung, and Blood Institute, part of the National Institutes of Health, to study how dysfunction of the nitric oxide receptor, soluble guanylate cyclase (sGC), contributes to inflammatory asthma and may be targeted to treat the disease. This follows an earlier one-year R56 bridge award for the same proposal.
Published online January 22 in Proceedings of the National Academy of Sciences, Cleveland Clinic researchers describe for the first time how hemoglobin (Hb) forms and matures. Up until now, this process was only partially understood. Understanding how Hb is formed is critical to treating blood disorders, and research suggests may have implications for cancer treatment.