PAGE 1

University of Florida | Journal of Undergraduate Research | Volume 12 Issue 3 | Summer 2011 1 Regulation of Bone Resorption by Isoforms of Osteoclast Associated I mmunoglobul in Like R eceptor Erin Talbot College of Dentistry, University of Florida Bone resorption is controlled by cells known as osteoclasts, whose growth is controlled by the osteoclast associated immunogl obulin like receptor (OSCAR) gene. The aim of this study was to identify the effects of proinflammatory cytokines TNF IL 1, and LPS on OSCAR s and OSCAR m expression in HUVEC and THP c ells Cell cultures were plated, stimulated by a proinflammatory cytokine, and lysed. The RNA collected was then purified, reverse transcribed, and quantitated using real time PCR. After 24 hour stimulati on periods OSCAR m was consistently higher in THP cells treated with IL 1 and LPS, but not in cells treated by TNF OSCAR s control copy numbers were elevated in THP cells treated by all three cytokines. HUVEC cells treated by the three cytokines ha d increased quantities of both OSCAR s and OSCAR m. This suggests that the two isoforms of OSCAR may have different biolo gic functions. INTRODUCTION Osteoclasts are cells that destroy bone and are active in people who suffer from rheumatoid arthritis and other chronic inflammatory disorders ( 1,2 ). OSCAR regulates monocyte differentiation into osteoclasts. Osteoclast associated immunoglobulin like receptor (OSCAR) gene has two groups of isoforms: soluble OSCAR (OSCAR s) and membrane bound OSCAR (OSCAR m) ( 3 ). The expression of OSCAR gene in monocytes is necessary for their differentiation into osteoclasts, which ca use bone resorption ( 3 ). Upon ligand binding, OSCAR is activated in monocytes and neutrophils leading to complex signaling cascades ( 4 ). Proinflammatory cytokines such as interleukin (IL) 1, tumor necrosis factor (TNF) lipopolysaccharide (LPS) ar e known to induce bone resorption ( 4 ). Here we examined the expression of soluble and membrane bound isoforms of OSCAR by monocytes and endothelial cells in response to simulation. METHODS Human umbilical vein endothelial cells (HUVEC) were plated and g rown in vitro THP 1, a human monocytic leukemia cell line was also maintained in culture. The cells were split and re plated the day before the experiment. Cells in three plates were stimulated for 24 hours by TNF IL 1 or LPS, and the fourth unstimulated dish served as a control group. When studying the effect of cytokines on the presence of OSCAR in THP cells, three concentrations of each cytokine were tested. The cytokine dying the HUVEC cells. In both cases the cells were lysed and total RNA was SuperScript First Strand Synthesis kit. The expression of OSCAR s and OS CAR m were then tested by using the cDNA to perform real time PCR. The primers used for PCR were specific for OSCAR s and OSCAR m, and a GAPDH primer was used as a control primer. The lowest copy number of the tested concentrations run with GAPDH was set a s the standard 1:1 ratio. The remaining tested concentrations were compared with the 1:1 ratio to obtain ratio values for those as well. These ratios were then multiplied by the original copy numbers of the OSCAR s and OSCAR m data to obtain the correct co py number. The correct copy number from all three trials was averaged and compared to the control value to obtain the % Change Compare to Control. RESULTS When THP 1 cells were stimulated by 0.1 ng/ml of TNF the expression of OSCAR m had very minimal change. The three trials resulted in 26.81%, 0.56%, and 28.24% change in copy number compared to the control copy number values, which averaged to 0.66%. H owever the cells stimulated by 1 ng/ml had an average increase of 137%, derived from percentages 2 11.94%, 78.36%, and 279.46%. When stimulated by 10 ng/ml TNF there was a 19.98%, 24.65%, and 32.35% c hange in OSCAR m expression c ompared to the control copy numbers averaging a 4% decrease in OSCAR m expression As seen in Figure 1, no obvious trend can be identified in the change in expression of OSCAR m in THP 1 cells after 24 hours of stimulation by TNF

PAGE 2

ERIN TALBOT University of Florida | Journal of Undergraduate Research | Volume 12 Issue 3 | Summer 2011 2 Figure 1: 24 hours TNF Alpha compared to control Figure 1 shows that OSCAR s increased consistently in all three concentrations. The three samples stimulated by 0.1ng/ml of TNF had concentrations 215.89%, 337.38%, and 18.01% of the contro l copy number, resulting in an average of 178.42%. When stimulated by 1 ng/ml of TNF the expression of OSCAR s had an average increase of 160.36%, with three trial values of 99.82%, 46.08%, and 335.18% in comparison to their control copy numbers. The t hird group of samples was stimulated by 10 ng/ml of TNF and increased OSCAR s expression by 79.43%, 219.09%, and 228.21%, averaging 175.58%. The average expression of the three concentrations of cytokine stimulation were close in value, showing that TNF consistently increased the expression of OSCAR s in THP 1 cells after 24 hours of stimulation. However among the three trials for each given cytokine concentration, the percentage change in copy numbers varied. When testing the effects of IL 1 stimulati on on THP 1 cells both OSCAR m and OSCAR s expression was increased, as shown in Figure 2. There was an average increase in OSCAR m expression of 55.01% compared to the control value when THP 1 cell samples were stimulated with 10 pg/ml over a period of 2 4 hours. This was derived by individual trial values of 26.08%, 289.30%, and 98.18%. The THP 1 cells stimulated by 100 pg/ml resulted in expression 144.99%, 56.49%, and 477.64% of the control copy numbers, averaging a 98.76% increase in OSCAR m expressi on. Cells stimulated by 1000 pg/ml of IL 1 had OSCAR m copy numbers 20.17%, 72.20%, and 477.64% of the control copy numbers, averaging a 128.42% increase in OSCAR m expression. The lowest percentage change was seen in 10 pg/ml and the highest percentage increase was seen in 1000 pg/ml treatment, showing that an increase in concentration of IL 1 used to stimulate THP 1 cells over a 24 hour period will also increase the degree to which OSCAR m expression is increased. Figure 2: 24 hours IL 1 compared to control

PAGE 3

REGULATION OF BONE R ESORPTI ON BY I SOFORMS OF OSCAR University of Florida | Journal of Undergraduate Research | Volume 12 Issue 3 | Summer 2011 3 Stimulation of THP 1 cells for 24 hours by 10 pg/ml of IL 1 had a 84.43%, 19.79%, and 1029.69% change in OSCAR s expression when compared to the control copy numbers, averaging an increase of 308.49%. Treatment with 100 pg/ml of IL 1 caused 135.43%, 51.9 5%, and 42.96% changes in copy number, averaging a 48.14% increase in OSCAR s expression. The third group of THP 1 cell samples stimulated for 24 hours by 1000 pg/ml IL 1 increased OSCAR s expression by 60.71%, 21.38%, and 57.43%, averaging a 8.22% incre ase. Although treatment with all three concentrations of cytokines increased, the expression of OSCAR m percentages differ s greatly Figure 2 shows that stimulation by 10 pg/ml of IL 1 has a greater impact on increasing OSCAR m expression after 24 hours than stimulation by 100 pg/ml or 1000 pg/ml of IL 1. THP 1 cells were then stimulated for 24 hours with LPS. When treated with 1 ng/ml of LPS there was 275.46%, 8855.77%, and 5712.19% increases in OSCAR m expression, averaging 4947.81% more OSCAR m t han the control copy number. Stimulation with 10 ng/ml for 24 hours led to 131.46%, 5366.76%, and 1577.75% increases, averaging a OSCAR m copy number 2358.66% higher than the control copy number. The greatest increase in OSCAR m was observed when THP 1 cel ls were stimulated with 100 ng/ml of LPS. The copy number of OSCAR m increased 5915.77%, 48138.04%, and 55309.80%, averaging a 36454.54% increase in OSCAR m expression. This data in Figure 3 shows that OSCAR m expression in THP 1 cells is much more sensiti ve to treatment by LPS for 24 hours than to treatment with TNF 1. Figure 3 : 24 hours LPS compared to control Stimulation of THP 1 cells for 24 hours with LPS increased the expression of OSCAR s as well. When treated with 1 ng/ml of LPS the expression of OSCAR s was 1196.12%, 1474.06%, and 2010.10% higher than the control copy number, averaging a 1560.09% increase. Treatment with 10 ng/ml of LPS resulted in 983.91%, 118 1.20%, and 1151.07% increases in OSCAR s expression, averaging a 1105.39% increase in copy number when compared to the control copy number. The greatest change in OSCAR s expression was observed when THP 1 cells were stimulated with 100 ng/ml of LPS. This led to 16359.58%, 13690.94%, and 11006.06% increases in OSCAR s copy number, averaging an increase of 13685.53%. This data showed that THP 1 cells are more sensitive to treatment by LPS for 24 hours than they are to treatment with TNF 1 when mea suring OSCAR s copy number. The same tests were run with HUVEC in 24 hour periods. These results are displayed in Figure 4. When OSCAR m expression increased 294.01%, 37.29%, and 78.42%, averaging 136.57%. Stimulation with 1 1 resulted in 35.93%, 38.61%, and 2128.41% averaging 708.58% increase in OSCAR m expression. The third group of 50.98%, 11.64%, and 88.24% changes in OSCAR m expression, averaging 50.29%. Results s how that HUVEC response to IL 1 increased the expression of OSCAR m the most in comparison to stimulation by TNF

PAGE 4

ERIN TALBOT University of Florida | Journal of Undergraduate Research | Volume 12 Issue 3 | Summer 2011 4 Figure 4: 24 hours HUVEC compared to control The last group tested the effects of the three cytokines on HUVEC OSCAR of TNF for 24 hours caused a 65.59%, 524.88%, and 213.29% increase compared to the control copy number, averaging 267.92%. The second set of samples was 1 and had a 31.12%, 1762.06%, and 2836.48% increase in OSCAR s expression, averaging 1543.22%. The HUVEC stimulated 395.02% in OSCAR s express ion compared to the control copy numbers, averaging a change of 396.23%. The same trend holds true for OSCAR s expression in HUVEC as OSCAR m. Of the three cytokines, IL 1 had the greatest impact on OSCAR s expression after 24 hours of stimulation. CONCLUSION Within the limits of this preliminary study, it can be concluded that THP 1 and HUVEC cells show differential expression of soluble and membrane bound isoforms of OSCAR in response to stimulation by proinflammatory cytokines. This also leads us to believe that OSCAR s and OSCAR m may thus have different biological functions. Given the large standard deviation, we will be repeating these experiments to establish reproducibility Further studies may give insight as to the effect TNF 1, an d LPS have on the two isoforms of OSCAR. Those findings would be useful in developing treatment for cases in which excess bone resorption causes disease, such as rheumatoid arthritis or periodontal disease. REFERENCES 1. Kaplan, C, Finnegan, A. Osteoclasts, pro inflammatory cytokines, RANK L and bone remodeling in rheumatoid arthritis [Abstract]. Front Biosci 2003 ; 8 : d1018 29 2. Herman, S, M ller, RB Kr n ke, G, Zwerina, J, Redlich, K, Hueber, AJ, et al Induction of osteoclast associated receptor, a key osteoclast costimulation molecule, in rheumatoid arthritis. Arthritis Rheum 2008; 58 : 3041 3050 3. National Center for Biotechnology Information OSCAR osteoclast associated, immunoglobulin like receptor [homo sapiens]. http://www.ncbi.nlm.nih.gov/ gene/126014 4. Dinarello, CA Proinflammatory cytokines. CHEST 2000 ; 118 : 503 508


Summer Focus on Medical Research : Regulation of Bone Resorption by Isoforms of Osteoclast Associated Immunoglobulin-Lik...
ALL VOLUMES CITATION THUMBNAILS PDF VIEWER PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00091523/00601
 Material Information
Title: Summer Focus on Medical Research : Regulation of Bone Resorption by Isoforms of Osteoclast Associated Immunoglobulin-Like Receptor
Series Title: Journal of Undergraduate Research
Physical Description: Serial
Language: English
Creator: Talbot, Erin
Publisher: University of Florida
Place of Publication: Gainesville, Fla.
Publication Date: 2011
 Subjects
Genre: serial   ( sobekcm )
 Notes
Abstract: Bone resorption is controlled by cells known as osteoclasts, whose growth is controlled by the osteoclast associated immunoglobulin-like receptor (OSCAR) gene. The aim of this study was to identify the effects of proinflammatory cytokines TNF-α, IL-1, and LPS on OSCAR-s and OSCAR-m expression in HUVEC and THP cells. Cell cultures were plated, stimulated by a proinflammatory cytokine, and lysed. The RNA collected was then purified, reverse transcribed, and quantitated using real-time PCR. After 24-hour stimulation periods, OSCAR-m was consistently higher in THP cells treated with IL-1 and LPS, but not in cells treated by TNF- α. OSCAR-s control copy numbers were elevated in THP cells treated by all three cytokines. HUVEC cells treated by the three cytokines had increased quantities of both OSCAR-s and OSCAR-m. This suggests that the two isoforms of OSCAR may have different biologic functions.
 Record Information
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: sobekcm - UF00091523_00601
System ID: UF00091523:00601

Downloads

This item has the following downloads:

( PDF )


Full Text



Regulation of Bone Resorption by Isoforms of Osteoclast

Associated Immunoglobulin-Like Receptor

Erin Talbot

College of Dentistry, University of Florida

Bone resorption is controlled by cells known as osteoclasts, whose growth is controlled by the osteoclast associated immunoglobulin-
like receptor (OSCAR) gene. The aim of this study was to identify the effects of proinflammatory cytokines TNF-a, IL-1, and LPS on
OSCAR-s and OSCAR-m expression in HUVEC and THP cells. Cell cultures were plated, stimulated by a proinflammatory cytokine,
and lysed. The RNA collected was then purified, reverse transcribed, and quantitated using real-time PCR. After 24-hour stimulation
periods, OSCAR-m was consistently higher in THP cells treated with IL-1 and LPS, but not in cells treated by TNF- a. OSCAR-s
control copy numbers were elevated in THP cells treated by all three cytokines. HUVEC cells treated by the three cytokines had
increased quantities of both OSCAR-s and OSCAR-m. This suggests that the two isoforms of OSCAR may have different biologic
functions.


INTRODUCTION

Osteoclasts are cells that destroy bone and are active in
people who suffer from rheumatoid arthritis and other
chronic inflammatory disorders (1,2). OSCAR regulates
monocyte differentiation into osteoclasts. Osteoclast
associated immunoglobulin-like receptor (OSCAR) gene
has two groups of isoforms: soluble OSCAR (OSCAR-s)
and membrane bound OSCAR (OSCAR-m) (3). The
expression of OSCAR gene in monocytes is necessary for
their differentiation into osteoclasts, which cause bone
resorption (3). Upon ligand binding, OSCAR is activated in
monocytes and neutrophils, leading to complex signaling
cascades (4). Proinflammatory cytokines, such as
interleukin (IL)-1, tumor necrosis factor (TNF)-a, and
lipopolysaccharide (LPS), are known to induce bone
resorption (4). Here, we examined the expression of
soluble and membrane-bound isoforms of OSCAR by
monocytes and endothelial cells in response to simulation.

METHODS

Human umbilical vein endothelial cells (HUVEC) were
plated and grown in vitro. THP-1, a human monocytic
leukemia cell line, was also maintained in culture. The
cells were split and re-plated the day before the
experiment. Cells in three plates were stimulated for 24
hours by TNF-a, IL-1, or LPS, and the fourth unstimulated
dish served as a control group. When studying the effect of
cytokines on the presence of OSCAR in THP cells, three
concentrations of each cytokine were tested. The cytokine
concentrations were controlled at 1 gg/ml when studying
the HUVEC cells.


In both cases, the cells were lysed, and total RNA was
purified using Qiagen's RNeasy assay kit. The RNA was
then reverse transcribed to cDNA with Invitrogen's
SuperScript First-Strand Synthesis kit. The expression of
OSCAR-s and OSCAR-m were then tested by using the
cDNA to perform real-time PCR. The primers used for
PCR were specific for OSCAR-s and OSCAR-m, and a
GAPDH primer was used as a control primer.
The lowest copy number of the tested concentrations run
with GAPDH was set as the standard 1:1 ratio. The
remaining tested concentrations were compared with the
1:1 ratio to obtain ratio values for those as well. These
ratios were then multiplied by the original copy numbers of
the OSCAR-s and OSCAR-m data to obtain the correct
copy number. The correct copy number from all three trials
was averaged and compared to the control value to obtain
the % Change Compare to Control.

RESULTS

When THP-1 cells were stimulated by 0.1 ng/ml of
TNF-a, the expression of OSCAR-m had very minimal
change. The three trials resulted in -26.81%, 0.56%, and
28.24% change in copy number compared to the control
copy number values, which averaged to 0.66%. However,
the cells stimulated by 1 ng/ml had an average increase of
137%, derived from percentages 211.94%, -78.36%, and
279.46%. When stimulated by 10 ng/ml TNF-a, there was
a -19.98%, -24.65%, and 32.35% change in OSCAR-m
expression compared to the control copy numbers,
averaging a 4% decrease in OSCAR-m expression. As seen
in Figure 1, no obvious trend can be identified in the
change in expression of OSCAR-m in THP-1 cells after 24
hours of stimulation by TNF-a.


University of Florida I Journal of Undergraduate Research I Volume 12, Issue 3 I Summer 2011
1





ERIN TALBOT


400%

300%

200%


100% +


0%

-100%

-200%


mm -^T


0 1 ng/ml


1 ng/ml


Figure 1: 24 hours TNF-Alpha compared to control


Figure 1 shows that OSCAR-s increased consistently in
all three concentrations. The three samples stimulated by
0. Ing/ml of TNF-a had concentrations 215.89%, 337.38%,
and -18.01% of the control copy number, resulting in an
average of 178.42%. When stimulated by 1 ng/ml of TNF-
a, the expression of OSCAR-s had an average increase of
160.36%, with three trial values of 99.82%, 46.08%, and
335.18% in comparison to their control copy numbers. The
third group of samples was stimulated by 10 ng/ml of TNF-
a and increased OSCAR-s expression by 79.43%,
219.09%, and 228.21%, averaging 175.58%. The average
expression of the three concentrations of cytokine
stimulation were close in value, showing that TNF-a
consistently increased the expression of OSCAR-s in THP-
1 cells after 24 hours of stimulation. However, among the
three trials for each given cytokine concentration, the
percentage change in copy numbers varied.
When testing the effects of IL-1 stimulation on THP-1
cells, both OSCAR-m and OSCAR-s expression was


1000%

800%

600%

400%

200%

0%

-200%


increased, as shown in Figure 2. There was an average
increase in OSCAR-m expression of 55.01% compared to
the control value when THP-1 cell samples were stimulated
with 10 pg/ml over a period of 24 hours. This was derived
by individual trial values of -26.08%, 289.30%, and -
98.18%. The THP-1 cells stimulated by 100 pg/ml resulted
in expression 144.99%, -56.49%, and 477.64% of the
control copy numbers, averaging a 98.76% increase in
OSCAR-m expression. Cells stimulated by 1000 pg/ml of
IL-1 had OSCAR-m copy numbers -20.17%, -72.20%, and
477.64% of the control copy numbers, averaging a
128.42% increase in OSCAR-m expression. The lowest
percentage change was seen in 10 pg/ml and the highest
percentage increase was seen in 1000 pg/ml treatment,
showing that an increase in concentration of IL-1 used to
stimulate THP-1 cells over a 24-hour period will also
increase the degree to which OSCAR-m expression is
increased.


* OSCm 24 hr% Change Compared to
Control
* OSCs 24 hr % Change Compared to
Control


Figure 2: 24 hours IL-1 compared to control

University of Florida I Journal of Undergraduate Research I Volume 12, Issue 3 I Summer 2011
2


* OSCm 24 hr % Change Compared to
Control
* OSCs 24 hr % Change Compared to
Control


10 pg/ml 100pg/ml 1000


1 ng/ml





REGULATION OF BONE RESORPTION BY ISOFORMS OF OSCAR


Stimulation of THP-1 cells for 24 hours by 10 pg/ml of
IL-1 had a -84.43%, -19.79%, and 1029.69% change in
OSCAR-s expression when compared to the control copy
numbers, averaging an increase of 308.49%. Treatment
with 100 pg/ml of IL-1 caused 135.43%, 51.95%, and -
42.96% changes in copy number, averaging a 48.14%
increase in OSCAR-s expression. The third group of THP-
1 cell samples stimulated for 24 hours by 1000 pg/ml IL-1
increased OSCAR-s expression by 60.71%, 21.38%, and -
57.43%, averaging a 8.22% increase. Although treatment
with all three concentrations of cytokines increased, the
expression of OSCAR-m percentages differs greatly.
Figure 2 shows that stimulation by 10 pg/ml of IL-1 has a
greater impact on increasing OSCAR-m expression after
24 hours than stimulation by 100 pg/ml or 1000 pg/ml of
IL-1.


70000%
60000%
50000%
40000%
30000%
20000%
10000%
0%


THP-1 cells were then stimulated for 24 hours with LPS.
When treated with 1 ng/ml of LPS, there was 275.46%,
8855.77%, and 5712.19% increases in OSCAR-m
expression, averaging 4947.81% more OSCAR-m than the
control copy number. Stimulation with 10 ng/ml for 24
hours led to 131.46%, 5366.76%, and 1577.75% increases,
averaging a OSCAR-m copy number 2358.66% higher
than the control copy number. The greatest increase in
OSCAR-m was observed when THP-1 cells were
stimulated with 100 ng/ml of LPS. The copy number of
OSCAR-m increased 5915.77%, 48138.04%, and
55309.80%, averaging a 36454.54% increase in OSCAR-m
expression. This data in Figure 3 shows that OSCAR-m
expression in THP-1 cells is much more sensitive to
treatment by LPS for 24 hours than to treatment with TNF-
a or IL-1.








S OSCm 24 hr % Change Compared to
Control


* OSCs 24 hr % Change Compared to
Control


1 ng/ml


10 ng/ml


100 ng/ml


Figure 3: 24 hours LPS compared to control


Stimulation of THP-1 cells for 24 hours with LPS
increased the expression of OSCAR-s as well. When
treated with 1 ng/ml of LPS, the expression of OSCAR-s
was 1196.12%, 1474.06%, and 2010.10% higher than the
control copy number, averaging a 1560.09% increase.
Treatment with 10 ng/ml of LPS resulted in 983.91%,
1181.20%, and 1151.07% increases in OSCAR-s
expression, averaging a 1105.39% increase in copy number
when compared to the control copy number. The greatest
change in OSCAR-s expression was observed when THP-1
cells were stimulated with 100 ng/ml of LPS. This led to
16359.58%, 13690.94%, and 11006.06% increases in
OSCAR-s copy number, averaging an increase of
13685.53%. This data showed that THP-1 cells are more
sensitive to treatment by LPS for 24 hours than they are to


treatment with TNF-a or IL-1 when measuring OSCAR-s
copy number.
The same tests were run with HUVEC in 24-hour
periods. These results are displayed in Figure 4. When
treated with 1 gg/ml of TNF, OSCAR-m expression
increased 294.01%, 37.29%, and 78.42%, averaging
136.57%. Stimulation with 1 gg/ml IL-1 resulted in
35.93%, -38.61%, and 2128.41%, averaging 708.58%
increase in OSCAR-m expression. The third group of
HUVEC stimulated by 1 gg/ml LPS resulted in -50.98%, -
11.64%, and -88.24% changes in OSCAR-m expression,
averaging -50.29%. Results show that HUVEC response to
IL-1 increased the expression of OSCAR-m the most in
comparison to stimulation by TNF-a or LPS.


University of Florida I Journal of Undergraduate Research I Volume 12, Issue 3 I Summer 2011
3





ERIN TALBOT


3500%

3000%-

2500%

2000%

1500%

1000%-

500%-

0%-
TNF IL-1
-500%e 4: 2 h H c t



Figure 4: 24 hours HUVEC compared to control


The last group tested the effects of the three cytokines on
HUVEC OSCAR-s expression. Stimulation with 1 gg/ml
of TNF for 24 hours caused a 65.59%, 524.88%, and
213.29% increase compared to the control copy number,
averaging 267.92%. The second set of samples was
stimulated by 1 gg/ml of IL-1 and had a 31.12%,
1762.06%, and 2836.48% increase in OSCAR-s
expression, averaging 1543.22%. The HUVEC stimulated
by 1 gg/ml LPS showed a change of 22.90%, 770.78%, and
395.02% in OSCAR-s expression compared to the control
copy numbers, averaging a change of 396.23%. The same
trend holds true for OSCAR-s expression in HUVEC as
OSCAR-m. Of the three cytokines, IL-1 had the greatest
impact on OSCAR-s expression after 24 hours of
stimulation.



REFERENCES


1. Kaplan, C, Finnegan, A.. Osteoclasts, pro inflammatory cytokines, RANK-L
and bone remodeling in rheumatoid arthritis [Abstract]. Front Bioscz 2003;8:
d1018-29.


* OSCm 24 hr % Change Compared to
Control
* OSCs 24 hr % Change Compared to
Control


CONCLUSION

Within the limits of this preliminary study, it can be
concluded that THP-1 and HUVEC cells show differential
expression of soluble and membrane bound isoforms of
OSCAR in response to stimulation by proinflammatory
cytokines. This also leads us to believe that OSCAR-s and
OSCAR-m may thus have different biological functions.
Given the large standard deviation, we will be repeating
these experiments to establish reproducibility. Further
studies may give insight as to the effect TNF-a, IL-1, and
LPS have on the two isoforms of OSCAR. Those findings
would be useful in developing treatment for cases in which
excess bone resorption causes disease, such as rheumatoid
arthritis or periodontal disease.




3. National Center for Biotechnology Information. OSCAR osteoclast associated,
immunoglobulin-like receptor [homo sapiens]. http://www.ncbi.nlm.nih.gov/
gene/126014.
4. Dinarello, CA. Proinflammatory cytokines. CHEST 2000;118: 503-508.


2. Herman, S, Miiller, RB, Kr6nke, G, Zwerina, J, Redlich, K, Hueber, AJ, et al.
Induction of osteoclast-associated receptor, a key osteoclast costimulation
molecule, in rheumatoid arthritis. Arthritis Rheum 2008;58: 3041-3050.















University of Florida I Journal of Undergraduate Research I Volume 12, Issue 3 I Summer 2011
4




University of Florida Home Page
© 2004 - 2011 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated May 24, 2011 - Version 3.0.2 - mvs