Osteoarthritis (OA) is the most common musculoskeletal disorder characterized by cartilage degradation and joint inflammation. Currently the only effective treatment is surgical joint replacement. MicroRNAs (miRNA) are a class of non-coding RNAs regulating gene expression by sequence specific inhibition of target mRNA translation. Specific miRNAs has been shown to exhibit altered pattern of expression in RA synovium and in other rheumatic diseases but their role in OA pathogenesis is yet to be defined. In our preliminary studies we analyzed the global expression of miRNAs in human chondrocytes stimulated with IL-12 and discovered that miRNA mir-27b (mir-27b), with no known function, was downregulated several fold. In silico analysis identified a number of possible target mRNAs including the matrix metalloproteinase-13 (MMP-13) mRNA. We have previously shown that a standardized pomegranate extract (PE) exert cartilage and chondroprotective effects by inhibiting the expression of MMP-13 in human cartilage explants in vitro and the development of inflammatory arthritis in a mouse model in vivo. Of relevance to the studies proposed in this application is our finding that downregulation of mir-27b by IL-12 was blocked by PE. Our basic hypothesis is that "PE suppresses the IL-12-induced cartilage catabolic effects in OA by inhibiting the downregulation of mir-27b and other selected microRNAs that target MMP-13 mRNA in human chondrocytes". A corollary of this hypothesis is that "bioactive constituents of PE exert their cartilage/ chondroprotective effects by modulating the expression of specific miRNAs that negatively regulate the expression of MMP-13 in vivo". We propose the following specific aims:
Specific Aim - 1: We will identify other miRNAs that target MMP-13 mRNA in human chondrocytes and are differentially modulated by IL-12. Using a larger number of patient samples we will confirm the effect of IL-12 on the expression of mir-27b and other miRNAs identified above and determine whether PE prevents their modulation by IL-12 in human OA chondrocytes in vitro.
Specific Aim -2: To determine the impact of altered expression of mir-27b and of other miRNAs identified above on the expression MMP-13 in human OA chondrocytes stimulated with IL-12 in vitro.
Specific Aim -3: In a mouse model of OA we will develop the miRNA expression profile in the joints during disease induction and progression. We will also examine the effect of PE consumption on the expression of miR-27b and other miRNAs that target MMP-13 in mouse OA joints and correlate their expression profile with the disease progression. Knowledge gained from these studies may provide insight into developing novel and cost effective therapeutic approaches for the treatment/ prevention of OA.

Public Health Relevance

Osteoarthritis (OA) is characterized by high levels of IL-12, excessive production of ROS and articular cartilage degeneration in the affected joints. However, its etiology and precise pathogenetic mechanisms remain unclear. MicroRNAs (miRNA) are a class of non-coding RNAs regulating gene expression by sequence-specific inhibition of target mRNA translation. Specific miRNAs have been shown to exhibit an altered pattern of expression in RA synovium and in other diseases. Currently there is limited information available on the expression of miRNAs in human chondrocytes but their role in OA is yet to be defined. In addition there is no information on the effects of dietary polyphenols on miRNA expression in any cell type. By studying the regulation of miRNA expression by bioavailable dietary constituents, our findings are likely to open the door for the development of novel therapeutic strategies for the treatment of OA and other diseases.

Agency
National Institute of Health (NIH)
Institute
National Center for Complementary & Alternative Medicine (NCCAM)
Type
Research Project (R01)
Project #
5R01AT005520-03
Application #
8289337
Study Section
Special Emphasis Panel (ZRG1-MOSS-C (04))
Program Officer
Williamson, John S
Project Start
2010-08-01
Project End
2013-03-31
Budget Start
2012-08-01
Budget End
2013-03-31
Support Year
3
Fiscal Year
2012
Total Cost
$30,885
Indirect Cost
$11,213
Name
Case Western Reserve University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
077758407
City
Cleveland
State
OH
Country
United States
Zip Code
44106
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Haseeb, Abdul; Makki, Mohammad Shahidul; Haqqi, Tariq M (2014) Modulation of ten-eleven translocation 1 (TET1), Isocitrate Dehydrogenase (IDH) expression, ?-Ketoglutarate (?-KG), and DNA hydroxymethylation levels by interleukin-1? in primary human chondrocytes. J Biol Chem 289:6877-85
Haseeb, Abdul; Chen, Dongxing; Haqqi, Tariq M (2013) Delphinidin inhibits IL-1*-induced activation of NF-*B by modulating the phosphorylation of IRAK-1(Ser376) in human articular chondrocytes. Rheumatology (Oxford) 52:998-1008
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Akhtar, Nahid; Haqqi, Tariq M (2012) MicroRNA-199a* regulates the expression of cyclooxygenase-2 in human chondrocytes. Ann Rheum Dis 71:1073-80
Akhtar, Nahid; Miller, Mark Js; Haqqi, Tariq M (2011) Effect of a Herbal-Leucine mix on the IL-1*-induced cartilage degradation and inflammatory gene expression in human chondrocytes. BMC Complement Altern Med 11:66
Akhtar, Nahid; Haqqi, Tariq M (2011) Epigallocatechin-3-gallate suppresses the global interleukin-1beta-induced inflammatory response in human chondrocytes. Arthritis Res Ther 13:R93
Rasheed, Zafar; Akhtar, Nahid; Haqqi, Tariq M (2011) Advanced glycation end products induce the expression of interleukin-6 and interleukin-8 by receptor for advanced glycation end product-mediated activation of mitogen-activated protein kinases and nuclear factor-*B in human osteoarthritis chondrocytes. Rheumatology (Oxford) 50:838-51